Respiratory complications following tonsillectomy/UPPP: is step-down monitoring necessary?

Abstract

We conducted a study to determine if the risk of airway compromise following tonsillectomy with uvulopalatopharyngoplasty justifies the added cost and inconvenience of step-down monitoring in an intensive care unit. We performed a retrospective chart review of 130 patients with obstructive sleep apnea who had undergone isolated tonsillectomy with uvulopalatopharyngoplasty at our tertiary care center. The average length of stay in the step-down unit was 18 hours. We found that only eight of these patients (6.2%) had a postoperative desaturation level of less than 90%, including three of 12 patients (25%) who had comorbid conditions. No patient had an adverse respiratory event. We conclude that step-down monitoring in an intensive care unit is not necessary, although caution should be exercised in monitoring patients with comorbidities because they appear to be more prone to desaturation. A complete lack of adverse respiratory events has not been reported in previous studies.

Introduction

Obstructive sleep apnea (OSA) affects approximately 4% of men and 2% of women in the United States. (1-4) OSA can lead to serious medical conditions such as cardiac and pulmonary hypertension, arrhythmias, and seizures. Surgical treatment options are plentiful; they include tonsillectomy with uvulopalatopharyngoplasty (tonsillectomy/UPPP), genioglossus advancement, hyoid suspension, palatal advancement or stiffening, and tracheostomy.

The postoperative management of tonsillectomy/UPPP patients has evolved as this procedure is being performed with greater frequency. Early reports of postoperative complications encouraged us to monitor our patients in an intensive care setting to watch for any exacerbation of preoperative apnea that could lead to fatal arrhythmias or postoperative swelling that could lead to adverse respiratory events. (5,6) Because our institution has anecdotally reported postoperative complications only in rare cases, we sought to determine if airway complications in patients who underwent isolated tonsillectomy/UPPP were significant enough to warrant the added expense and inconvenience of step-down monitoring in the intensive care unit.

Patients and methods

We retrospectively reviewed the charts of 130 patients with OSA who had undergone tonsillectomy/UPPP between Jan. 1, 1995, and Dec. 31, 1998, at the Naval Medical Center in Portsmouth, Va. Postoperatively, each patient had been kept for overnight observation with face-tent oxygen supplementation in our step-down intensive care unit. Continuous pulse oximetry and cardiac monitoring were performed. We excluded from our study patients who had undergone UPPP without tonsillectomy and those who had undergone tonsillectomy/UPPP simultaneously with another procedure, such as genioglossus advancement, septoplasty, or hyoid suspension.

We noted each patient's preoperative respiratory disturbance index (RDI), lowest desaturation level (based on a screening sleep study), severity of sleep apnea, and relevant medical conditions. We used these parameters to determine if they had any correlation to each patient's lowest postoperative oxygen saturation level and length of hospital stay.

Results

Our patient population of 128 men and two women ranged in age from 20 to 77 years (mean: 36). Their preoperative RDIs ranged from 7 to 87 (mean: 39.7), and the lowest preoperative desaturation levels on sleep study ranged from 42 to 95% (mean: 76%). Twelve patients had one or more comorbid conditions; 10 had hypertension, eight had reactive airway disease, and two had coronary artery disease. In these 12 patients, the preoperative RDIs ranged from 16 to 69 (mean: 41.0) and the lowest desaturation levels ranged from 63 to 87% (mean: 73%).

The average length of stay in the step-down unit was 18 hours. Postoperatively, only eight of the 130 patients (6.2%) had desaturation levels less than 90%, including three of 12 (25%) who had comorbidities. Three patients (2.3%) required preventive nasopharyngeal airway placement, apparently because the surgeon had been concerned that soft-palate swelling might present an airway problem. No patient experienced an adverse respiratory event, a finding that has heretofore not been reported in previous studies. We found no correlation between the severity of sleep apnea on preoperative sleep study and postoperative desaturation.

Discussion

Postoperative management of tonsillectomy/UPPP patients has traditionally included observation in a step-down intensive care unit. Overnight monitoring became standard following reports that such surgery might lead to serious complications, including airway compromise, cardiac arrhythmias, and postobstructive pulmonary edema. (5,6)

In one of the first comprehensive studies, Fairbanks surveyed 72 residency programs in the United States to gather anecdotal data oil complications following surgery for OSA over a 9-year period. (5) Responses indicated there had been 16 fatalities, seven near-fatalities, and 17 cases of airway loss. No data were available on the preoperative health, severity of OSA, or the extent of surgery in these patients.

In 1989, Esclamado et al studied 135 patients who had undergone various types of surgery for OSA.7 They found that complications occurred in 18 patients (13%); 14 of these complications (78%) were airway-related. All 18 complications, however, had occurred either during preoperative intubation or immediately following extubation; none had occurred during the postoperative recovery period.

In 1998, Mickelson and Hakim reviewed 347 cases of OSA surgery and found 14 complications (4.0%), including five (1.4%) airway-related complications. (8) Seven of the 14 complications (50%) had occurred in patients who had undergone simultaneous OSA and nasal surgery; only one patient had undergone a tonsillectomy/UPPP alone. Only two of the 14 complications occurred on the surgical ward; the remainder occurred during the immediate perioperative period.

Our institution's patient population is for the most part made up of healthy young servicemen who work and live in close quarters. Snoring and sleep apnea become readily apparent and are socially disruptive in a ship's berthing area. We tend to perform more OSA surgeries than do our civilian counterparts. Despite the initial concerns about postoperative airway complications expressed by others, we casually observed that patients at our institution were not experiencing adverse events, and we began to question the need for step-down monitoring. Thus, we conducted this study to determine if airway complications following isolated tonsillectomy/UPPP were significant enough to warrant the added expense and inconvenience of step-down monitoring in an intensive care unit. The results of our formal review support our earlier skepticism.

Of the 130 patient charts we reviewed, we found no case of an adverse respiratory event. If a risk category were to be arbitrarily defined as an oxygen saturation level of less than 90%, then only eight (6.2%) of our patients were at risk. Their preoperative OSA severity, as determined by sleep study, was not significantly different from the OSA severity of the entire study population. Likewise, the preoperative mean RDI and mean lowest desaturation level in our "at-risk" group (41.0 and 73%, respectively) were comparable to the mean RDI and desaturation level in the entire study group (39.7 and 76%, respectively). It is interesting that there was a much higher incidence of postoperative desaturation of less than 90% in the 12 patients with comorbid medical conditions than there was in the rest of the study population, although we draw no conclusions from this.

Four specific criticisms can be made of our study. First, our study was retrospective, which implies a selection bias. However, our inclusion and exclusion criteria were strictly adhered to, and the diverse range of preoperative OSA severity in our patients is evidence that this was a representative sample. Second, our sample size was small. Nevertheless, our study population still comprised the largest series of patients ever monitored in a step-down unit following isolated tonsillectomy/UPPP. Third, all of our patients were given postoperative oxygen supplementation, which might have prevented significant desaturation. Our aim, however, was to determine if monitoring needs to be conducted in a step-down unit. Oxygen supplementation can be administered in a regular ward just as easily. Finally, our study population was made up primarily of quite healthy men in their 30s.

Despite these limitations, we conclude that patients who undergo tonsillectomy/UPPP alone do not require the added expense and inconvenience of step-down monitoring in an intensive care unit. Caution should be exercised in patients with comorbidities because they appear to be more prone to desaturation. Postoperative care should still include supplemental oxygenation and saturation monitoring to prevent adverse respiratory events.

Acknowledgment

We appreciate the excellent research skills and assistance of Lt. Cdr. Dimitry B. Goufman, MD, who participated in the preparation of this study.

References

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(2.) He J, Kryger MH, Zorick FJ, et al. Mortality and apnea index in obstructive sleep apnea. Experience in 385 male patients, Chest 1988;94:9-14.

(3.) Hla KM, Young TB, Bidwell T, et al. Sleep apnea and hypertension. A population-based study. Ann Intern Med 1994;120: 382-8.

(4.) Strollo PJ, Jr., Rogers RM, Obstructive sleep apnea, N Engl J Med 1996;334:99-104.

(5.) Fairbanks DN. Uvulopalatopharyngoplasty complications and avoidance strategies. Otolaryngol Head Neck Surg 1990:102: 239-45.

(6.) Olsen KD. A report from the Committee on Sleep Disorders. Washington, D.C. Bulletin of the American Academy of Otolaryngology--Head and Neck Surgery 1987;3:9.

(7.) Esclamado RM, Glenn MG, McCulloch TM, Cummings CW. Perioperative complications and risk factors in the surgical treatment of obstructive sleep apnea syndrome. Laryngoscope 1989; 99:1125-9.

(8.) Mickelson SA, Hakim I. Is postoperative intensive care monitoring necessary after uvulopalatopharyngoplasty? Otolaryngol Head Neck Surg 1998;119:352-6,

From the Department of Otolaryngology--Head and Neck Surgery, Naval Medical Center, Portsmouth, Va.

Reprint requests: Peter C. Bondy, MD, Department of Otolaryngology--Head and Neck Surgery, Naval Medical Center, 27 Effingham St., Portsmouth, VA 23708. Phone: [phone]; fax: [phone]; e-mail: [e-mail]

Originally presented at the annual meeting of the Virginia Society of Otolaryngology--Head and Neck Surgery; May 9, 1999; Reston, Va.

The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or the United States government.