2017-18 HSC Section 3 Green Book

Research Original Investigation

Complications After Obstructive Sleep Apnea Upper Airway Surgery

P atients with obstructive sleep apnea (OSA) have an in- creased risk of postoperative complications. 1-4 Guide- lines from the American Society of Anesthesiologists recommend that, for patients with OSA, the operative risk de- pends on the severity of the underlying OSA and the invasive- ness of the surgical procedure. 5,6 These guidelines, which are based primarily on expert opinion, rated airway surgery as the type of surgerywith thehighest riskof potential operative com- plications. Although it may be intuitive to suggest that pa- tientswithmore severeOSAare at higher riskof operative com- plications, the literature supporting this claim is conflicting. Several studies 7-9 found significant correlation between op- erative complications and apnea severity, whereas others 10-12 found the opposite. Surgical procedures for OSA often involve multiple, con- current surgery at different sites of the upper airway. 13,14 How- ever, most of the data of operative complications in patients undergoing upper airway surgery for OSAmainly focused on a single-siteoperation,suchasuvulopalatopharyngoplasty(UPPP) or tonsillectomy. 7,9-12 To our knowledge, only a limited num- ber of previous studies 8,10 have attempted to stratify the risks of complications from concurrent, multilevel surgery for OSA diagnosed by strict criteria and yielded differing results. The aim of this retrospective study was to investigate the nature of the associations between the severity of OSA and the number and anatomical sites of upper airway operations with operative complications. The primary hypothesis was that, in patients undergoing upper airway surgery for OSA, the sever- ity of OSA would be associated with a higher rate of operative complications. The secondaryhypothesiswas that the sites and number of operations performed would influence the rate of operative complications. Methods Data were collected by systematic review of patient medical records supplementedby 1-to-1 personal interviewwith the pa- tients. Inclusion criteria were OSA diagnosis by polysomnog- raphy (apnea-hypopnea index [AHI], >5), age older than 18 years, and single or combination surgery on the upper airway as treatment of OSA with the patient under general anesthe- sia at a tertiary care hospital in Malaysia between October 1, 2008, and October 1, 2015. The study was performed at Hos- pital Tg Ampuan Afzan, Kuantan, Pahang, and the Interna- tional IslamicUniversityMalaysia. Onlydata frompatientswho gavewritten informed consent for the use of theirmedical rec- ords for research purposes were included in the study. All data were deidentified. Exclusion criteria were patients with syn- dromes associated with craniofacial abnormalities, oxygen- dependent cardiopulmonary patients, and patientswith a his- tory of congenital cardiac disease or cardiac surgery. The study obtained ethical clearance from the ethical committee board of International Islamic University Malaysia and approval by the clinical research committee of Hospital Tg AmpuanAfzan, Kuantan, Malaysia. The diagnosis of OSAwas confirmed preoperatively using a 22-channel SapphireCrystal polysomnogram(CleveMed Inc).

All polysomnography was performed as a technologist- attendedovernight study at a single center. The technical speci- fications, scoring of polysomnographic data, and diagnosis of OSA were made according to the American Academy of Sleep Medicine (AASM) guidelines. 15,16 Procedure, Instrumentation, and Monitoring In the studypatients, upper airwayoperations to treatOSAwere single or combination surgery on the nasal, palatopharyngeal, and tongue base area. The classifications of the types of sur- gery used in the study are as follows. Nasal surgery included septoplasty, turbinoplasty, nasal polypectomy, and turbinate reduction surgery. Palatopharyngeal surgery included UPPP, uvulopalatal flap procedure, modified cautery-assisted pala- tal stiffeningoperation, laser-assisteduvulopalatoplasty, radio- frequency stiffening of the soft palate, tonsillectomy, adenoid- ectomy, and lateral pharyngoplasty. Tongue base surgery was radiofrequency or coblator tongue base reduction surgery. The patients with OSA in our hospital usually had a routine trial of continuous positive airwaypressure (CPAP) treatment after the diagnosis by polysomnography. Indications for surgery in our patientsweredefinite anatomical upper airwayobstructionand failed or intolerable CPAP treatment, following the AASM guideline. 15 Potential candidates were identified from the operating theater electronic database. Verbal informed consent was ob- tained by telephone conversation, and the patients were ar- ranged for an interview session, after which written consent was obtained. Datawere collectedmainly throughmedical rec- ord review, complemented by the patients’ self-reporting dur- ing the interview session. The data extracted included pa- tient characteristic information; comorbidmedical condition; preoperative, intraoperative, and postoperative surgical and anesthetic variables; preoperative polysomnographic re- sults; and operative complications. The complications were pulmonary, cardiovascular, or surgery related. Pulmonary com- plications were defined as clinically important and clearly documented in the records, such as aspiration, atelectasis, sus- pected or definite respiratory infections, airway intervention by means of CPAP or bilevel positive airway pressure (BiPAP) in thosewho never used it preoperatively, pulmonary edema, postoperative tracheal reintubation or tracheostomy, oxygen Key Points Question In upper airway surgery for obstructive sleep apnea (OSA), would the severity of OSA or multilevel surgery be associated with a higher rate of short-term operative complications? Findings In a cohort study of 95 adults, the rate of complications was 51%. No significant association was found between OSA severity based on the apnea-hypopnea index and the number of concurrent operations with complications. Meaning In patients with OSA undergoing upper airway surgery, the severity of OSA as assessed by the apnea-hypopnea index and concurrent multilevel surgery performed were not associated with a higher rate of operative complications.

JAMA Otolaryngology–Head & Neck Surgery March 2017 Volume 143, Number 3 (Reprinted)

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