1. Patient Selection
<ol>
	<li>Consider inclusion of patients with the following tonsil-related diseases: recurrent tonsillitis; dysphagia caused by large tonsils; tonsil stones; obstructive sleep apnea related to tonsils.</li>
	<li>Include only adult patients.</li>
	<li>Check for allergies, specifically to local anesthetics.</li>
	<li>Assess the gag-reflex intensity using the GSI (Table 1). For adequate CO2LT treatment, full visualization of the tonsils is required and patients need to be able to hold their breath for at least 15 s at a time.</li>
	<li>In patients with a GSI &#62; 2 consider the following exercise to decrease the gag-reflex intensity.
	<ol>
		<li>Inform the patient that the gag-reflex can be (partially) faded-out by training.</li>
		<li>Explain to the patient that the exercise will be uncomfortable in the first few days to weeks.</li>
		<li>Advise the patient to use their toothbrush to gently touch / brush their tongue base and tonsils each time they brush their teeth (preferably twice a day). Instruct the patient to increase pressure when performing this procedure each sequential day.</li>
	</ol>
	</li>
	<li>Exclude the following patients: with Friedman grade IV (kissing) tonsils; with undertreated coagulation disorders; using any form of anticoagulants; with an active tonsil infection / peritonsillar abscess; women who are pregnant; those who are uncooperative during tonsil examination.</li>
</ol>
2. Informed Consent and Pre-operative Instruction Visit
<ol>
	<li>Obtain written informed consent including the following.
	<ol>
		<li>Explain the intervention to the patient as follows: &#34;The tonsil(s) will be partially evaporated using a laser beam. Local anesthesia will be used to numb the tissue and therefore you will be fully awake and mentally present during treatment. No pain is expected during treatment and low to moderate pain may occur in the first days after treatment. Treatment will take approximately 10-15 min per tonsil. If no complications occur, admission to the floor after treatment is not necessary and you will be able to leave the hospital in 30 min to an hour after treatment, accompanied by a friend or relative that is able to drive you.&#34;</li>
		<li>Explain alternative treatment options (where applicable: expectant management, conventional tonsillectomy or antibiotics).</li>
		<li>Explain possible complications of the CO2LT including: per- and post-operative bleeding, infection, incomplete resolution of tonsil disease; need for a second tonsillotomy or a tonsillectomy, pain, allergic reaction to anesthetic, temporary change of taste, (temporary) damage to surrounding structures.</li>
	</ol>
	</li>
	<li>Instruct the patient not to eat any heavy meals on the day of treatment.</li>
	<li>Instruct the patient to take 1,000 mg acetaminophen (paracetamol) 30 min before treatment if acetaminophen is not contraindicated in that specific patient (including, but not limited to active liver disease and liver failure).</li>
	<li>Ask patients with a troublesome gag-reflex during examination to reduce the gag-reflex by rubbing their tongue base and tonsils with their toothbrush at least twice a day for 1 min, preferably for at least 2 weeks.</li>
</ol>
3. Preparation of Patient and Equipment
<ol>
	<li>Attach the laser pen to the CO&#173;2-laser machine.</li>
	<li>Make sure that the correct settings are chosen (Figure 1) such as (i) continuous laser beam, (ii) 15-30 W intensity depending on the size of the tonsil; generally, start at 18 W and increase the power up to 30 W depending on the size of the tonsils and patient&#39;s cooperation, (iii) shape-size of 2-4 mm depending on the size of the (remainder of the) tonsil, (iv) shape: round.</li>
	<li>Make sure that the surgeon, the surgical technologist, and the patient are wearing laser safety glasses.</li>
	<li>Make sure that the surgeon and the surgical technologist are wearing appropriate protective surgical masks.</li>
	<li>Confirm that the headlight for the surgeon is working.</li>
	<li>Confirm that a pulse oximeter for patient monitoring is present.</li>
	<li>Confirm that wooden tongue depressors are within reach. 
	CAUTION: Do not use metal depressors, since they can reflect the laser beam.</li>
</ol>
4. Time-out Procedure
<ol>
	<li>Ask the patient for their name and date of birth.</li>
	<li>Ask the patient for the intervention that will take place.</li>
	<li>Ask the patient for the side of treatment.</li>
	<li>Ask the patient for any allergies, specifically for local anesthetics and medications.</li>
	<li>Check with the surgical technologist if all equipment is present.</li>
	<li>Check if the laser-indication light of the operating room is switched on and all windows are covered for laser safety.</li>
</ol>
5. Patient Instructions Before Surgery
<ol>
	<li>Ask the patient to inhale deeply, followed by breathing out slowly during treatment.</li>
	<li>Explain to the patient that he/she is in control and can signal at any time, which will lead to a pause of the laser-treatment.</li>
	<li>Instruct the patient to use his/her hand to signal if they wish to pause treatment by tapping the surgeon&#8217;s leg.</li>
	<li>Instruct the patient not to swallow any liquids during treatment to prevent aspiration and laryngospasms. Provide a kidney basin to the patient to spit any liquids into when necessary.</li>
	<li>Reassure the patient not to panic if they experience a feeling as if their airway is blocked, as this is due to local anesthesia of the pharynx region. Remind the patient again that the treatment can be paused at any moment.</li>
</ol>
6. Positioning the Patient and Inspection of the Tonsils
<ol>
	<li>Place the pulse oximeter on the patient&#39;s index finger and confirm that it is functioning correctly.</li>
	<li>Position the patient in an upright position using the chair / table controls.</li>
	<li>Set the height of the chair / table so that the surgeon can stand straight comfortably while performing the laser treatment.</li>
	<li>Ask the patient to make any adjustments to the seating to ensure comfortable and safe positioning.</li>
	<li>Inspect both tonsils and exclude active inflammation.</li>
	<li>Assess the gag-reflex using the GSI and judge the feasibility of the laser treatment. For adequate CO2LT treatment, the surgeon should be able to fully visualize the tonsils and patients need to be able to hold their breath for at least 15 s.</li>
</ol>
7. Anesthesia of the Tonsil
<ol>
	<li>Tell the patient that the tonsils will be anesthetized one at a time.</li>
	<li>In case of a significant gag-reflex (GSI grade 2-3) use xylocaine-spray or superficial anesthesia of the tongue-base and pharynx to reduce the gag-reflex.</li>
	<li>Take an ampule with local anesthetic and inject ~0.2 mL slowly into the upper pole, ~0.2 mL into the mid-pole and 0.2 mL into the lower-pole of the tonsil. 
	NOTE: Optionally, the tonsil-pillars can be infiltrated as well. This is recommended when the tonsils are hidden behind the pillars or to decrease the gag-reflex.</li>
	<li>Instruct the patient not to swallow any local anesthetic, but to spit it out.</li>
	<li>Reassure the patient that any feeling of throat tightness is due to the anesthetic; not due to any actual obstruction.</li>
</ol>
8. Laser-treatment of the Tonsil
<ol>
	<li>Ask the patient to breathe in deeply and exhale slowly.</li>
	<li>Have the surgical technologist hold the smoke suction close to the opening of the mouth, without blocking the surgeon&#39;s view.</li>
	<li>Use two wooden tongue blades to depress the tongue / tongue-base and expose the tonsil.</li>
	<li>During the patient&#8217;s exhalation, laser the lymphatic tissue of the lobules in a sweeping motion.</li>
	<li>Stop when the patient taps your (the surgeon&#39;s) leg.</li>
	<li>Let the patient catch his/her breath again and repeat steps 8.1&#8211;8.4 until complete cryptolysis is accomplished.</li>
	<li>If necessary, inject extra local anesthetic (with or without epinephrine).</li>
</ol>
9. Tips for Laser Treatment
<ol>
	<li>In case of peroperative hemorrhage: laser the spot that is bleeding &#34;out of focus&#34;. This will lead to burning of the lymphatic tissue with crust formation with a similar effect as coagulation (opposed to evaporation when using the laser &#39;in focus&#39;). Alternatively, use a (bipolar) coagulation device to stop the bleeding.</li>
	<li>Use the wooden tongue blades to press against the anterior tonsillar pillar to expose the tonsil further.</li>
	<li>Use the wooden tongue blades to press against the upper part of the tonsil pillars to expose the upper lobule of the tonsil.</li>
	<li>Use the wooden tongue blades to scoop up the lower tonsil lobule and expose it for laser treatment (one can leave them scooped up on the tongue blades).</li>
</ol>
10. Instructions After Treatment
<ol>
	<li>Give the patient a popsicle for a minimum of 30 min of postoperative observation.</li>
	<li>Instruct the patient not to drink or eat anything else for 2 h until the local anesthetic has worn off to prevent aspiration.</li>
	<li>Instruct the patient not to drink / eat hot (temperature) or spicy drinks/food or food with hard crusts for a week to prevent postoperative bleeding.</li>
	<li>Tell the patient to take pain medication only if necessary. 
	NOTE: We advise a maximum of 1,000 mg acetaminophen (paracetamol) 4 times a day, if necessary.</li>
	<li>Tell the patient to refrain from strenuous physical exercise for a week.</li>
	<li>Advise the patient to go to the nearest emergency department in case a postoperative bleeding occurs. Advise the patient to contact the ENT department in case of a postoperative infection (e.g., fever).</li>
</ol>

<ol>
	<li>Koskenkorva, T., Koivunen, P., Alho, O. -. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predictive+Factors+for+Medical+Consultation+for+Sore+Throat+in+Adults+with+Recurrent+Pharyngotonsillitis.">Predictive Factors for Medical Consultation for Sore Throat in Adults with Recurrent Pharyngotonsillitis.</a> International Journal of Otolaryngology. 2016, 6095689 (2016).</li><li>Cullen, K. A., Hall, M. J., Golosinskiy, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ambulatory+surgery+in+the+United+States,+2006.">Ambulatory surgery in the United States, 2006.</a> National Health Statistics Reports. (11), 1-25 (2009).</li><li>Bhattacharyya, N., Kepnes, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Revisits+and+postoperative+hemorrhage+after+adult+tonsillectomy.">Revisits and postoperative hemorrhage after adult tonsillectomy.</a> The Laryngoscope. 124 (7), 1554-1556 (2014).</li><li>Salonen, A., Kokki, H., Nuutinen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recovery+After+Tonsillectomy+in+Adults:+A+Three-Week+Follow-up+Study.">Recovery After Tonsillectomy in Adults: A Three-Week Follow-up Study.</a> The Laryngoscope. 112 (1), 94-98 (2002).</li><li>Younis, R. T., Lazar, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=History+and+current+practice+of+tonsillectomy.">History and current practice of tonsillectomy.</a> The Laryngoscope. 112 (8), 3-5 (2002).</li><li>Koempel, J. A., Solares, C. A., Koltai, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+evolution+of+tonsil+surgery+and+rethinking+the+surgical+approach+to+obstructive+sleep-disordered+breathing+in+children.">The evolution of tonsil surgery and rethinking the surgical approach to obstructive sleep-disordered breathing in children.</a> The Journal of Laryngology and Otology. 120 (12), 993-1000 (2006).</li><li>Koltai, P. J., Solares, C. A., Mascha, E. J., Xu, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracapsular+partial+tonsillectomy+for+tonsillar+hypertrophy+in+children.">Intracapsular partial tonsillectomy for tonsillar hypertrophy in children.</a> The Laryngoscope. 112 (8), 17-19 (2002).</li><li>Arya, A., Donne, A. J., Nigam, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Double-blind+randomized+controlled+study+of+coblation+tonsillotomy+versus+coblation+tonsillectomy+on+postoperative+pain.">Double-blind randomized controlled study of coblation tonsillotomy versus coblation tonsillectomy on postoperative pain.</a> Clinical Otolaryngology and Allied Sciences. 28 (6), 503-506 (2003).</li><li>Isaacson, G., Szeremeta, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pediatric+tonsillectomy+with+bipolar+electrosurgical+scissors.">Pediatric tonsillectomy with bipolar electrosurgical scissors.</a> American Journal of Otolaryngology. 19 (5), 291-295 (1998).</li><li>D'Eredit&#224;, R., Marsh, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contact+diode+laser+tonsillectomy+in+children.">Contact diode laser tonsillectomy in children.</a> Otolaryngology--Head and Neck Surgery: Official Journal of American Academy of Otolaryngology-Head and Neck Surgery. 131 (5), 732-735 (2004).</li><li>Hegazy, H. M., Albirmawy, O. A., Kaka, A. H., Behiry, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pilot+comparison+between+potassium+titanyl+phosphate+laser+and+bipolar+radiofrequency+in+paediatric+tonsillectomy.">Pilot comparison between potassium titanyl phosphate laser and bipolar radiofrequency in paediatric tonsillectomy.</a> The Journal of Laryngology and Otology. 122 (4), 369-373 (2008).</li><li>Lourijsen, E. S., Wong Chung, J. E. R. E., Koopman, J. P., Blom, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Post-operative+morbidity+and+1-year+outcomes+in+CO2-laser+tonsillotomy+versus+dissection+tonsillectomy.">Post-operative morbidity and 1-year outcomes in CO2-laser tonsillotomy versus dissection tonsillectomy.</a> Acta Oto-Laryngologica. 136 (10), 983-990 (2016).</li><li>Hultcrantz, E., Ericsson, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pediatric+tonsillotomy+with+the+radiofrequency+technique:+less+morbidity+and+pain.">Pediatric tonsillotomy with the radiofrequency technique: less morbidity and pain.</a> The Laryngoscope. 114 (5), 871-877 (2004).</li><li>Dickinson, C. M., Fiske, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+gagging+problems+in+dentistry:+I.+Aetiology+and+classification.">A review of gagging problems in dentistry: I. Aetiology and classification.</a> Dental Update. 32 (1), 26-32 (2005).</li><li>Krespi, Y. P., Ling, E. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser-assisted+serial+tonsillectomy.">Laser-assisted serial tonsillectomy.</a> The Journal of otolaryngology. 23 (5), 325-327 (1994).</li><li>Unkel, C., Lehnerdt, G., Schmitz, K. J., Jahnke, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser-tonsillotomy+for+treatment+of+obstructive+tonsillar+hyperplasia+in+early+childhood:+a+retrospective+review.">Laser-tonsillotomy for treatment of obstructive tonsillar hyperplasia in early childhood: a retrospective review.</a> International Journal of Pediatric Otorhinolaryngology. 69 (12), 1615-1620 (2005).</li><li>Papaspyrou, G., Linxweiler, M., Kn&#246;bber, D., Schick, B., Al Kadah, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+CO2+tonsillotomy+versus+argon+plasma+coagulation+(APC)+tonsillotomy:+A+retrospective+study+with+10-year+follow-up.">Laser CO2 tonsillotomy versus argon plasma coagulation (APC) tonsillotomy: A retrospective study with 10-year follow-up.</a> International Journal of Pediatric Otorhinolaryngology. 92, 56-60 (2017).</li><li>Linder, A., Markstr&#246;m, A., Hultcrantz, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+the+carbon+dioxide+laser+for+tonsillotomy+in+children.">Using the carbon dioxide laser for tonsillotomy in children.</a> International Journal of Pediatric Otorhinolaryngology. 50 (1), 31-36 (1999).</li><li>Baharudin, A., Shahid, H., Rhendra, M. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+tonsillotomy+in+children+with+tonsillar+hyperplasia.">Laser tonsillotomy in children with tonsillar hyperplasia.</a> The Medical journal of Malaysia. 61 (3), 377-379 (2006).</li><li>Linder, A., Markstr&#246;m, A., Hultcrantz, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+the+carbon+dioxide+laser+for+tonsillotomy+in+children.">Using the carbon dioxide laser for tonsillotomy in children.</a> International Journal of Pediatric Otorhinolaryngology. 50 (1), 31-36 (1999).</li><li>Magdy, E. A., Elwany, S., El-Daly, A. S., Abdel-Hadi, M., Morshedy, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coblation+tonsillectomy:+a+prospective,+double-blind,+randomised,+clinical+and+histopathological+comparison+with+dissection-ligation,+monopolar+electrocautery+and+laser+tonsillectomies.">Coblation tonsillectomy: a prospective, double-blind, randomised, clinical and histopathological comparison with dissection-ligation, monopolar electrocautery and laser tonsillectomies.</a> J Laryngol Otol. , (2008).</li><li>Densert, O., Desai, H., Eliasson, A., Frederiksen, L., Andersson, D., Olaison, J., Widmark, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Olaison+Tonsillotomy+in+Children+with+Tonsillar+Hypertrophy.">Olaison Tonsillotomy in Children with Tonsillar Hypertrophy.</a> Acta Oto-Laryngologica. 121 (7), 854-858 (2001).</li><li>Krespi, Y. P., Kizhner, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+tonsil+cryptolysis:+In-office+500+cases+review.">Laser tonsil cryptolysis: In-office 500 cases review.</a> American Journal of Otolaryngology. 34 (5), 420-424 (2013).</li><li>Stelter, K., de la Chaux, R., Patscheider, M., Olzowy, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Double-blind,+randomised,+controlled+study+of+post-operative+pain+in+children+undergoing+radiofrequency+tonsillotomy+versus+laser+tonsillotomy.">Double-blind, randomised, controlled study of post-operative pain in children undergoing radiofrequency tonsillotomy versus laser tonsillotomy.</a> The Journal of Laryngology &amp; Otology. 124 (8), 880-885 (2010).</li><li>Hultcrantz, E., Linder, A., Markstr&#246;m, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tonsillectomy+or+tonsillotomy?--A+randomized+study+comparing+postoperative+pain+and+long-term+effects.">Tonsillectomy or tonsillotomy?--A randomized study comparing postoperative pain and long-term effects.</a> International Journal of Pediatric Otorhinolaryngology. 51 (3), 171-176 (1999).</li><li>Wong Chung, J. E. R. E., van Benthem, P. P. G., Blom, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tonsillotomy+versus+tonsillectomy+in+adults+suffering+from+tonsil-related+afflictions:+a+systematic+review.">Tonsillotomy versus tonsillectomy in adults suffering from tonsil-related afflictions: a systematic review.</a> Acta Oto-Laryngologica. 138 (5), 492-501 (2018).</li><li>Windfuhr, J. P., Savva, K., Dahm, J. D., Werner, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tonsillotomy:+facts+and+fiction.">Tonsillotomy: facts and fiction.</a> European archives of oto-rhino-laryngology: official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS): affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. 272 (4), 949-969 (2015).</li><li>Schoem, S. R., Watkins, G. L., Kuhn, J. J., Alburger, J. F., Kim, K. Z., Thompson, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+Early+Postoperative+Pain+With+Bupivacaine+in+Adult+Local+Tonsillectomy.">Control of Early Postoperative Pain With Bupivacaine in Adult Local Tonsillectomy.</a> Archives of Otolaryngology-Head &amp; Neck Surgery. 119 (3), 292-293 (1993).</li><li>Bredenkamp, J. K., Abemayor, E., Wackym, P. A., Ward, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tonsillectomy+under+local+anesthesia:+A+safe+and+effective+alternative.">Tonsillectomy under local anesthesia: A safe and effective alternative.</a> American Journal of Otolaryngology. 11 (1), 18-22 (1990).</li><li>Pekkarinen, H., K&#228;rj&#228;, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Results+of+long-term+ECG+monitoring+in+patients+submitting+to+tonsillectomy+under+local+anaesthesia.">Results of long-term ECG monitoring in patients submitting to tonsillectomy under local anaesthesia.</a> The Journal of Laryngology and Otology. 96 (8), 725-730 (1982).</li><li>Chung, J. H., Lee, Y. C., Shin, S. Y., Eun, Y. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+for+recurrence+of+peritonsillar+abscess.">Risk factors for recurrence of peritonsillar abscess.</a> The Journal of Laryngology and Otology. 128 (12), 1084-1088 (2014).</li><li>Kronenberg, J., Wolf, M., Leventon, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peritonsillar+abscess:+recurrence+rate+and+the+indication+for+tonsillectomy.">Peritonsillar abscess: recurrence rate and the indication for tonsillectomy.</a> American Journal of Otolaryngology. 8 (2), 82-84 (1987).</li></ol>

Open access publication of this manuscript was supported by Lumenis.

This paper describes the steps to perform a CO2LT. To our knowledge, this is the first article to describe this intervention in such detail. Outpatient CO2LT under local anesthesia is a novel surgical method and therefore the presented procedural details have mostly been developed through hands-on experience of the authors.
As for any surgical intervention, pre-operative patient selection is important. For CO2LT, a relatively calm and cooperative patient without a procedure-restricting gag-reflex is desirable. Therefore, an adequate assessment of limitations due to patient anxiety pertaining to the procedure and gag-reflex are of great importance to reach consistent treatment effects. Furthermore, we advise not to perform CO2LT on patients with grade IV (Friedman grading), or &#8220;kissing-tonsils&#8221; because of the risks of damaging surrounding tissues with the laser-beam.
In our experience, leaving the tonsil capsule intact and limiting the tissue damage reduces post-operative pain, recovery time and post-operative morbidity compared to tonsillectomy under general anesthesia. This is in agreement with current literature16,17,18,19,20,21,22,23,24,25,26. Despite the potential incomplete resolution of tonsil disease with CO2LT, many patients prefer CO2LT over tonsillectomy when informed of their options. This preference has been consistently reported prospectively (pre-surgery) and retrospectively (at follow-up)12. We therefore believe that CO2LT fills a gap in treatment options for tonsil-related disease, both from the doctors&#39;&#160;and the patients&#39;&#160;perspective. Current ongoing studies should provide further insight into the value of CO2LT in adults with tonsil diseases13.
There is a wide variety of techniques and devices available to perform a tonsillotomy, each with its own potential pros and cons. Utilized surgical devices besides the CO2-laser include microdebriders, coblators, surgical scissors, radiofrequency ablation probes, interstitial thermal therapy instruments and diode lasers. There is no conclusive evidence favoring any one instrument over another for tonsillotomy in adults27. Microdebriders, coblators and CO2-lasers are among the most frequently used instruments for tonsillotomy28. Reports on effectiveness, pain and postoperative complications vary, but current evidence suggests equal efficacy of tonsillotomy compared to tonsillectomy with less postoperative pain and complications27,28, independent of the method of tonsillotomy.
Even though tonsil-surgery under local anesthesia has been described since decades, it is not performed often in current practice16,29,30,31. Many otolaryngologists are uncomfortable with the idea of tonsil surgery under local anesthesia. This may partly be due to a lack of experience with this specific form of tonsil surgery as well as due to concerns over the airway and bleeding control30.
CO2LT has some clear logistical advantages. First, using only local anesthetics obviates the need for an anesthesia team. Second, the operation can be performed in the outpatient setting and there is no need for an operation room. Third, the surgical instruments used with CO2LT are non-disposable and only the laser pen needs to be sterilized after use. Sterilization of the laser pen is a simple procedure for any central sterile services department. These factors all lead to cost-reduction. On the other hand, the use of a laser requires a specialized intervention room meeting the local laser safety standards.
We currently exclude patients with a history of peritonsillar abscess because of the intrinsic risk in those patients of recurrent peritonsillar abscess (14%)32. The risk of recurrence is zero in patients after tonsillectomy33. In tonsillotomy, residual tissue may lead to a recurrence of an abscess. We also advise to exclude patients on anticoagulants or with bleeding disorders from treatment with CO2LT. Even though our experience is that bleeding sites can easily be managed with the CO2-laser, or if necessary, with bipolar coagulation. The fact that the patient is conscious and not intubated might complicate per-operative treatment of more profound bleeding due to decreased coagulation. If necessary, the patient can be brought under full anesthesia and the bleeding site can be stopped with diathermy or ligation, similar to postoperative bleeding after tonsillectomy. In our &#62;1,000 patient experience, such an event has never occurred. We estimate the need to use bipolar coagulation under local anesthesia to be around 2% of cases.
Furthermore, as of yet we have never had to stop a CO2LT case early due to an uncooperative patient. Incidentally a strong gag-reflex has led to suboptimal laser-treatment of the lower part of the tonsil. In those cases, sending the patient home with our gag-reflex training scheme led to successful treatment of the remaining tonsil tissue during a subsequent CO2LT procedure. It is important to note that these numbers and procedural characteristics are based on personal experience of the authors at a single center and should be evaluated in further studies.

Recurrent tonsil disease is a common health problem resulting in frequent visits to outpatient clinics, antimicrobial treatments, and missed work days1. Tonsillectomy2 is currently the most used surgical intervention for tonsil-related complaints in adults. During a tonsillectomy, the patient is brought under general anesthesia and the entire tonsil, including the tonsil capsule, is removed followed by diathermy coagulation of any bleeding sites. This intervention is rather invasive and associated with significant post-operative morbidity and a long, typically painful, recovery period3,4. An alternative to tonsillectomy is tonsillotomy, which is the partial intra-capsular removal of the tonsil tissue.
Both tonsillectomy and tonsillotomy have been performed for millennia 5,6. The first descriptions of subtotal tonsil removal date back to 1 BC6. Since that time many techniques for tonsil removal have been developed including the use of scalpels, microdebriders7, coblators8, electrosurgical scissors9, diode-lasers10, radiofrequency probes11 and CO2-lasers12.
CO2-lasertonsillotomy under local anesthesia (CO2LT) for the treatment of tonsil-related complaints is a fairly novel surgical treatment, which is gaining popularity as an alternative for the classic tonsillectomy. Recent studies have shown a shorter and less painful recovery period, but similar overall patient-satisfaction with CO2LT treatment when compared to conventional tonsillectomy12,13. During a CO2LT the tonsil is locally anesthetized and only the lobules of lymphatic tonsillar tissue are removed. The tonsillar capsule, through which blood vessels, nerves and lymphatic vessels pass, is left intact. Leaving the tonsillar-capsule intact likely leads to a reduced rate of post-operative bleeding, reduced post-operative pain, and a shorter recovery time14.
A potential problem with leaving the tonsillar capsule intact can be the incomplete resolution of the tonsil-related complaints, resulting in the need for a secondary CO2LT in a subset of patients12. Furthermore, to be eligible for CO2LT treatment patients must be able to remain calm during treatment and their gag reflex intensity should not limit treatment possibilities. The gag reflex is a physiological reflex to protect the airway15, which can only be partly blunted by local anesthesia in the mouth and pharynx; a particularly strong gag reflex can compromise the safe performance of a CO2LT. To assess the severity of the reflex the Gagging Severity Index (GSI) can be used15. The GSI is an index ranging from 1 (very mild) to 5 (very severe) [Table 1] and was originally developed in dentistry to classify the intensity of the gagging reflex and its consequences for dental treatments. In any patient with a GSI grade 3 or more the gagging reflex should first be reduced to increase the odds that the CO2LT procedure will be successful. We advise patients to try to fade out their gag-reflex by &#34;brushing&#34;&#160;their tongue-base and tonsils each time they brush their teeth. We have found this exercise to be capable of reducing the gag reflex intensity in most patients by 1-2 GSI points.&#160;

<table border="0" cellpadding="0" cellspacing="0" style="width:853px;" width="853">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:425px;">Carpule syringe and local anesthetic (eg xyloca&#239;ne:adrenaline 1:80.000)</td>
			<td style="width:143px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td style="width:167px;">n/a</td>
		</tr>
		<tr height="44">
			<td height="44" style="height:44px;">CO2 Laser system</td>
			<td style="width:143px;">Lumenis</td>
			<td style="width:119px;">AcuPulse DUO CO2 laser</td>
			<td>F125&#160; CO2 Laser System</td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:425px;">Coagulation device&#160;</td>
			<td style="width:143px;">Erbe</td>
			<td style="width:119px;">Erbe ICC 80 Surgical Generator With Footswitch</td>
			<td>n/a</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:425px;">Laser safety goggles</td>
			<td style="width:143px;">Lumenis</td>
			<td style="width:119px;">Laservision goggles AX0000068&#160;</td>
			<td>n/a</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:425px;">Operating chair</td>
			<td style="width:143px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>With possibilities for the patient to sit upright (eg opthalmic chair or dental chair)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Operating room which meets the local laser-safety standards</td>
			<td style="width:143px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>n/a</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:425px;">Suction device</td>
			<td style="width:143px;">TBH</td>
			<td style="width:119px;">TBH LN 100 or 2000</td>
			<td>Air suction and filtration device</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:425px;">Surgical masks</td>
			<td style="width:143px;">3M</td>
			<td style="width:119px;">3M 7502 mask with 2138 P3 filters</td>
			<td>n/a</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:425px;">wooden tongue depressor</td>
			<td style="width:143px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>Do not use metal tongue depressors</td>
		</tr>
	</tbody>
</table>

co2-lasertonsillotomy under local anesthesia in adults

Tonsil-related complaints are very common among the adult population. Tonsillectomy under general anesthesia is currently the most performed surgical treatment in adults for such complaints. Unfortunately, tonsillectomy is an invasive treatment associated with a high complication rate and a long recovery time. Complications and a long recovery time are mostly related to removing the vascular and densely innervated capsule of the tonsils. Recently, CO2-lasertonsillotomy under local anesthesia has been demonstrated to be a viable alternative treatment for tonsil-related disease with a significantly shorter and less painful recovery period. The milder side-effect profile of CO2-lasertonsillotomy is likely related to leaving the tonsil capsule intact. The aim of the current report is to present a concise protocol detailing the execution of CO2-lasertonsillotomy under local anesthesia. This intervention has been performed successfully in our hospital in more than 1,000 patients and has been found to be safe and to be associated with a steep learning curve.

In a previously published prospective study in 107 patients with one year follow-up, postoperative questionnaires were used to assess recovery rate and recurrence of tonsil-related symptoms for CO2LT compared to conventional tonsillectomy12. Forty-six patients underwent conventional tonsillectomy under general anesthesia and 61 patients underwent CO2LT. In total, 72.5% of patients in the CO2LT group were cured from their tonsil-related symptoms. Three patients (7.5%) in the CO2LT group required revision surgery for recurring tonsil complaints. In the tonsillectomy group, 97.2% of patients were cured after initial treatment. The overall satisfaction rate was similar in both treatment groups, but the mean pain intensity scores two weeks post-operatively were 5.4 (out of 10, range 0-9) after tonsillotomy and 7.7 (out of 10, range 2-10) after tonsillectomy leading to longer (9.9 vs. 5.4) use and use of stronger pain medication (NSAIDs / opioids versus acetaminophen) after tonsillectomy. Days to full recovery and number of post-operative bleeding events were both significantly higher in the tonsillectomy group (Figure 2).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/59702/59702fig1.jpg" /> 
Figure 1: Photo of laser settings. Standard laser settings for CO2LT on the laser system used. <a href="https://www.jove.com/files/ftp_upload/59702/59702fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/59702/59702fig2a.jpg" /> 
Figure 2: Patient reported recovery after tonsillotomy and tonsillectomy. Cumulative percentage of patients that reported complete recovery postoperatively after tonsillotomy (TO) and tonsillectomy (TE). Data were previously published by Lourijssen et al.12. <a href="https://www.jove.com/files/ftp_upload/59702/59702fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Dickinson and Fiske</td>
			<td rowspan="2">Definition and characteristics of grade of reflex</td>
		</tr>
		<tr>
			<td>Gagging Severity Index grades</td>
		</tr>
		<tr>
			<td>Grade I</td>
			<td>Very mild, occasional and controlled by the patient.</td>
		</tr>
		<tr>
			<td rowspan="2">Grade 2</td>
			<td>Moderate, control is required by the patient</td>
		</tr>
		<tr>
			<td>with reassurance from the dental team.</td>
		</tr>
		<tr>
			<td>Grade 3</td>
			<td>Moderate, consistent and limits treatment options.</td>
		</tr>
		<tr>
			<td>Grade 4</td>
			<td>Severe and treatment is impossible.</td>
		</tr>
		<tr>
			<td rowspan="2">Grade 5</td>
			<td>Very severe, affecting patient behavior</td>
		</tr>
		<tr>
			<td>and dental attendance and making treatment impossible.</td>
		</tr>
	</tbody>
</table>
Table 1: Gagging Severity Index (GSI) score15.

Watch this Scientific Journal Video about CO2-Lasertonsillotomy Under Local Anesthesia in Adults at JoVE.com

CO2-Lasertonsillotomy Under Local Anesthesia in Adults

CO2-lasertonsillotomy under local anesthesia is an interesting alternative treatment method for tonsillectomy under general anesthesia for tonsil-related complaints in adults. This report presents a step-by-step protocol detailing the execution of CO2-lasertonsillotomy under local anesthesia.

CO2-Lasertonsillotomy Under Local Anesthesia in Adults

Tonsil-related complaints are very common among the adult population. Tonsillectomy under general anesthesia is currently the most performed surgical ...

co2-lasertonsillotomy-under-local-anesthesia-in-adults

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23.8K Views.  HagaZiekenhuis. CO2-lasertonsillotomy under local anesthesia is an interesting alternative treatment method for tonsillectomy under general anesthesia for tonsil-related complaints in adults. This report presents a step-by-step protocol detailing the execution of CO2-lasertonsillotomy under local anesthesia.

Video: CO2-Lasertonsillotomy Under Local Anesthesia in Adults

A Novel Rescue Technique for Difficult Intubation and Difficult Ventilation

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which works especially well with poor mask fit.
Can not intubate, can not ventilate" (CICV) is a potentially life threatening situation. In this video we present a simulation of the technique we used in a case of CICV where oxygenation and ventilation were maintained by inserting an endotracheal tube (ETT) nasally down to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.
A 13 year old patient was taken to the operating room for incision and drainage of a neck abcess and direct laryngobronchoscopy. After preoxygenation, anesthesia was induced intravenously. Mask ventilation was found to be extremely difficult because of the swelling of the soft tissue. The face mask could not fit properly on the face due to significant facial swelling as well. A direct laryngoscopy was attempted with no visualization of the larynx. Oxygen saturation was difficult to maintain, with saturations falling to 80%. In order to oxygenate and ventilate the patient, an endotracheal tube was then inserted nasally after nasal spray with nasal decongestant and lubricant. The tube was pushed gently and blindly into the hypopharynx. The mouth and nose of the patient were sealed by hand and positive pressure ventilation was possible with 100% O2 with good oxygen saturation during that period of time. Once the patient was stable and well sedated, a rigid bronchoscope was introduced by the otolaryngologist showing extensive subglottic and epiglottic edema, and a mass effect from the abscess, contributing to the airway compromise. The airway was secured with an ETT tube by the otolaryngologist.This video will show a simulation of the technique on a patient undergoing general anesthesia for dental restorations.

We describe a technique to maintain oxygenation and ventilation using an endotracheal tube inserted nasally to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which ...

Guidelines for Elective Pediatric Fiberoptic Intubation

Fiberoptic intubation in pediatric patients is often required especially in difficult airways of syndromic patients i.e. Pierre Robin Syndrome. Small babies will desaturate very quickly if ventilation is interrupted mainly to high metabolic rate. We describe guidelines to perform a safe fiberoptic intubation while maintaining spontaneous breathing throughout the procedure. Steps requiring the use of propofol pump, fentanyl, glycopyrrolate, red rubber catheter, metal insuflation hook, afrin, lubricant and lidocaine spray are shown.

We describe guidelines to perform a safe and efficient elective fiberoptic intubation in pediatric patients while maintaining spontaneous ventilation.

Fiberoptic intubation in pediatric patients is often required especially in difficult airways of syndromic patients i.e. Pierre Robin Syndrome. Small ...

Collecting And Measuring Wound Exudate Biochemical Mediators In Surgical Wounds

We describe a methodology by which we are able to collect and measure biochemical inflammatory and nociceptive mediators at the surgical wound site. Collecting site-specific biochemical markers is important to understand the relationship between levels in serum and surgical wound, determine any associations between mediator release, pain, analgesic use and other outcomes of interest, and evaluate the effect of systemic and peripheral drug administration on surgical wound biochemistry. This methodology has been applied to healthy women undergoing elective cesarean delivery with spinal anesthesia. We have measured wound exudate and serum mediators at the same time intervals as patient's pain scores and analgesics consumption for up to 48 hours post-cesarean delivery. Using this methodology we have been able to detect various biochemical mediators including nerve growth factor (NGF), prostaglandin E2 (PG-E2) substance P, IL-1&#x03B2;, IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, TNF&alpha;, INF&#x03B3;, G-CSF, GM-CSF, MCP-1 and MIP-1&#x03B2;. Studies applying this human surgical wound bioassay have found no correlations between wound and serum cytokine concentrations or their time-release profile (J Pain. 2008; 9(7):650-7).1 We also documented the utility of the technique to identify drug-mediated changes in wound cytokine content (Anesth Analg 2010; 111:1452-9).2

This article provides a detailed and visual description of a methodology for collecting and measuring biochemical inflammatory and nociceptive mediators at the surgical wound site following cesarean delivery. This human bioassay has been used to determine correlations between wound and serum cytokine concentrations and drug-mediated changes in wound cytokines, chemokines and neuropetides.

We describe a methodology by which we are able to collect and measure biochemical inflammatory and nociceptive mediators at the surgical wound site. ...

Collecting Saliva and Measuring Salivary Cortisol and Alpha-amylase in Frail Community Residing Older Adults via Family Caregivers

Salivary measures have emerged in bio-behavioral research that are easy-to-collect, minimally invasive, and relatively inexpensive biologic markers of stress. This article we present the steps for collection and analysis of two salivary assays in research with frail, community residing older adults-salivary cortisol and salivary alpha amylase. The field of salivary bioscience is rapidly advancing and the purpose of this presentation is to provide an update on the developments for investigators interested in integrating these measures into research on aging. Strategies are presented for instructing family caregivers in collecting saliva in the home, and for conducting laboratory analyses of salivary analytes that have demonstrated feasibility, high compliance, and yield quality specimens. The protocol for sample collection includes: (1) consistent use of collection materials; (2) standardized methods that promote adherence and minimize subject burden; and (3) procedures for controlling certain confounding agents. We also provide strategies for laboratory analyses include: (1) saliva handling and processing; (2) salivary cortisol and salivary alpha amylase assay procedures; and (3) analytic considerations.

We demonstrate: (1) procedures for collection of salivary samples in cognitive impaired older adults by family caregivers in the home setting, (2) procedures for measuring stress activity via salivary cortisol and alpha amylase, and (3) representative profiles. Protocols that allow researchers to study stress-linked processes advance our understanding of biological sensitivity and susceptibility.

Salivary measures have emerged in bio-behavioral research  that are easy-to-collect, minimally invasive, and relatively inexpensive  biologic markers of ...

Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and neurological patients1-4, but also in healthy older adults5,6. The quantitative gait analysis described in this protocol is performed with a recently-introduced photoelectric system (see&#160;Materials table) which has the potential to be used in the clinic because it is portable, easy to set up (no subject preparation is required before a test), and does not require maintenance and sensor calibration. The photoelectric system consists of series of high-density floor-based photoelectric cells with light-emitting and light-receiving diodes that are placed parallel to each other to create a corridor, and are oriented perpendicular to the line of progression7. The system simply detects interruptions in light signal, for instance due to the presence of feet within the recording area. Temporal gait parameters and 1D spatial coordinates of consecutive steps are subsequently calculated to provide common gait parameters such as step length, single limb support and walking velocity8, whose validity against a criterion instrument has recently been demonstrated7,9. The measurement procedures are very straightforward; a single patient can be tested in less than 5 min&#160;and a comprehensive report can be generated in less than 1&#160;min.

This protocol is used to evaluate spatial and temporal gait variables of neurological/orthopedic patients and older persons by means of a recently-introduced floor-based photocell system.

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and ...

Novel Methods for Intranasal Administration Under Inhalation Anesthesia to Evaluate Nose-to-Brain Drug Delivery

Intranasal administration has been reported to be a potential pathway for nose-to-brain delivery of therapeutic agents that circumvents the blood-brain barrier. However, there have been few reports regarding not only the quantitative analysis but also optimal administration conditions and dosing regimens for investigations of nose-to-brain delivery. The limited progress in research on nose-to-brain pathway mechanisms using rodents represents a significant impediment in terms of designing nose-to-brain delivery systems for candidate drugs.
To gain some headway in this regard, we developed and evaluated two novel methods of stable intranasal administration under inhalation anesthesia for experimental animals. We also describe a method for the evaluation of drug distribution levels in the brain via the nose-to-brain pathway using radio-labeled [14C]-inulin (molecular weight: 5,000) as a model substrate of water-soluble macromolecules.
Initially, we developed a pipette-based intranasal administration protocol using temporarily openable masks, which enabled us to perform reliable administration to animals under stable anesthesia. Using this system, [14C]-inulin could be delivered to the brain with little experimental error.
We subsequently developed an intranasal administration protocol entailing reverse cannulation from the airway side through the esophagus, which was developed to minimize the effects of mucociliary clearance (MC). This technique led to significantly higher levels of [14C]-inulin, which was quantitatively detected in the olfactory bulb, cerebrum, and medulla oblongata, than the pipette method. This appears to be because retention of the drug solution in the nasal cavity was substantially increased by active administration using a syringe pump in a direction opposite to the MC into the nasal cavity.
In conclusion, the two methods of intranasal administration developed in this study can be expected to be extremely useful techniques for evaluating pharmacokinetics in rodents. The reverse cannulation method, in particular, could be useful for evaluating the full potential of nose-to-brain delivery of drug candidates.

Here, we describe two novel methods of stable intranasal administration under inhalation anesthesia with minimal physical stress for experimental animals. We also describe a method for quantitative evaluation of drug distribution levels in the brain via the nose-to-brain pathway using radiolabeled [14C]-inulin as a model substrate of water-soluble macromolecules.

Intranasal administration has been reported to be a potential pathway for nose-to-brain delivery of therapeutic agents that circumvents the blood-brain ...

Multi-Modal Home Sleep Monitoring in Older Adults

The gold standard for sleep monitoring is attended in-lab polysomnography; however, this method may be cost-prohibitive and inconvenient for patients and research participants. Home sleep testing has gained momentum in the field of sleep medicine due to its convenience and lower cost, as well as being more naturalistic. The accuracy and quality of home sleep testing, however, may be variable because studies are not monitored by sleep technologists. There has been some success in improving the accuracy of home sleep studies by having trained sleep technicians assist participants inside their homes with putting on the devices, but this can be intrusive and time-consuming for those involved. In this protocol, participants undergo at-home sleep monitoring with multiple devices: 1) a single-channel EEG device; 2) a home sleep test for sleep-disordered breathing and periodic limb movements; 3) actigraphy; and 4) sleep logs. A major challenge of this study is obtaining high-quality sleep monitoring data on the first attempt in order to minimize participant burden. This protocol describes the implementation of educational manuals with step-by-step instructions and photos. The goal is to improve the quality of home sleep testing.

Here, we present a protocol to improve the quality of data from home sleep testing by providing a method to enhance instructions through a structured participant visit. This protocol includes the implementation of a step-by-step educational manual with photos to ensure proper placement of equipment.

The gold standard for sleep monitoring is attended in-lab polysomnography; however, this method may be cost-prohibitive and inconvenient for patients and ...

Electroretinogram Recording for Infants and Children under Anesthesia to Achieve Optimal Dark Adaptation and International Standards

Electroretinogram (ERG) is the only clinical objective test available to assess retinal function. Full-field ERG (ffERG) measures the panretinal rod and cone photoreceptor function as well as inner retinal function and is an important measure in the diagnosis and management of inherited retinal diseases as well as inflammatory, toxic, and nutritional retinopathies. Adhering to international standards and maintaining retinal dark adaptation are critical to acquire valid and reliable dark-adapted (scotopic) and light-adapted (photopic) ffERG responses. Performing ffERG in infants and children is challenging and often requires general anesthesia in the operating room. However, maintaining retinal dark adaptation in the operating room is becoming increasingly difficult given the numerous light sources from anesthesiology monitoring systems and other equipment. A practical and widely applicable method for ffERG testing is described in the operating room that optimizes retinal dark adaptation. The method reduces operating room time by dark-adapting the patient before general anesthesiology is instituted. The operating room is modified for dark adaptation and any remaining light source in the darkened operating room is minimized with the use of a modified portable foldable darkroom that encloses the patient&#8217;s head and the ERG examiner during ffERG scotopic recordings. The simple method adheres to ffERG international standards and provides valid reliable scotopic and photopic ffERG recordings that are critical to assess objective retinal function in this young age group where subjective assessment of visual function such as visual acuity and visual fields are not possible. Furthermore, the ffERG is the gold standard clinical test in detecting early onset inherited retinal diseases including Leber congenital amaurosis where approved gene therapy has become available. In sedated conditions, very low amplitude ffERG signals can be detected due to minimal orbicularis muscle activity interference, which is particularly relevant in patients after gene therapy to detect improved amplitude responses.

Adhering to international standards and maintaining retinal dark adaptation are critical to acquire valid full-field electroretinogram responses in the diagnosis and management of inherited retinal diseases. A practical protocol using a portable darkroom is provided to obtain full-field&#160;electroretinogram for infants and children under sedation or general anesthesia in the operating room setting.

Electroretinogram (ERG) is the only clinical objective test available to assess retinal function. Full-field ERG (ffERG) measures the panretinal rod and ...

Short-Duration Hypothermia Induction in Rats using Models for Studies examining Clinical Relevance and Mechanisms

Therapeutic hypothermia (TH) is a powerful neuroprotective strategy that has provided robust evidence for neuroprotection in pre-clinical studies of neurological disorders. Despite strong pre-clinical evidence, TH has not shown efficacy in clinical trials of most neurological disorders. The only successful trials employing therapeutic hypothermia were related to cardiac arrest in adults and hypoxic ischemic injury in neonates. Further investigations into the parameters of its use, and study design comparisons between pre-clinical and clinical studies, are warranted. This article demonstrates two methods of short-duration hypothermia induction. The first method allows for rapid hypothermia induction in rats using ethanol spray and fans. This method works by cooling the skin, which has been less commonly used in clinical trials and may have different physiological effects. Cooling is much more rapid with this technique than is achievable in human patients due to differences in surface area to volume ratio. Along with this, a second method is also presented, which allows for a clinically achievable cooling rate for short-duration hypothermia. This method is easy to implement, reproducible and does not require active skin cooling.

This article describes two methods of whole-body short-duration hypothermia induction in rats. The first, rapid induction method, employs active cooling using fans and ethanol spray for a rapid decrease in temperature. The second method is a gradual cooling method. This is achieved using the combination of isoflurane anesthesia and the reduction of temperature settings on the homeothermic heat mat. This results in a gradual decrease in core body temperature without the use of any external cooling devices.&#160;

Therapeutic hypothermia (TH) is a powerful neuroprotective strategy that has provided robust evidence for neuroprotection in pre-clinical studies of ...

Knee Arthrocentesis in Adults

Arthrocentesis of the knee is a procedure in which a needle is inserted into the knee joint, and synovial fluid is aspirated. An arthrocentesis can be diagnostic or therapeutic. Synovial fluid may be removed for testing to determine the nature of the knee effusion. If septic arthritis is suspected, urgent arthrocentesis before initiation of antibiotic treatment is indicated. Moreover, arthrocentesis can also aid in diagnosing crystal-induced arthritis such as gout or pseudogout, or non-inflammatory arthritis such as osteoarthritis. Identifying the cause of the knee effusion can guide treatment. Furthermore, removing fluid from a knee can reduce intraarticular pressure to decrease pain and improve range of motion. There is no absolute contraindication to performing this procedure, but in selecting the needle entry site, an area of skin that is infected should be avoided. Therefore, caution should be exercised when a patient presents with suspected cellulitis over the knee joint to avoid the potential risk of causing iatrogenic septic arthritis. A knee that has undergone arthroplasty should be assessed for arthrocentesis by an orthopedic surgeon. Arthrocentesis of the knee is typically performed with the patient supine. The site for needle insertion is marked, and then the skin is disinfected. After a local anesthetic is administered, a needle is inserted along the pathway that was anesthetized. Synovial fluid is aspirated, and then the needle is withdrawn. Pressure is applied until any bleeding stops. The synovial fluid can be analyzed for infection and inflammation but cannot directly confirm a diagnosis of internal derangement or autoimmune causes of arthritis. In addition to the history and physical examination, laboratory findings and imaging can clarify the etiology of a knee effusion.

Here the protocol describes arthrocentesis of the knee, a procedure in which a needle is inserted into the knee joint, and synovial fluid is aspirated. Synovial fluid may be removed for testing to determine the nature of the knee effusion. Arthrocentesis of the knee is typically performed with the patient supine.

Arthrocentesis of the knee is a procedure in which a needle is inserted into the knee joint, and synovial fluid is aspirated. An arthrocentesis can be ...