An Adult Non-Obese Male, a Case of Obstructive Sleep Apnoea Posted For Tonsillectomy and Septoplasty – Challenges Faced

Obstructive sleep apnoea is a common problem and affects both men and women, and people across all ages. Obstructive sleep apnoea (OSA) is a sleep disorder that is characterised by frequent disruption of breathing during sleep.

It has been shown that OSA is more prevalent among males who are obese and specifically those who have large necks. The enlarged neck will then lead to constricted upper airways in the mouth, throat, and the nose. OSA in children can be as a result of enlarged adenoids and tonsils. The problem of enlarged adenoids and tonsils can also affect adults who are not obese even though it is very rare.

Obstructive sleep apnoea presents problems especially during surgery in the administration of anaesthesia. Challenges are seen in situations such as mask ventilation, accelerated arterial desaturation, laryngoscopy, intubation, in the choice of analegsia, and in postoperative respiratory obstruction.

In a case that was the basis of the study, a male thirty years of age with a history of obstructive sleep apnoea was recruited for tonsillectomy and septoplasty under general anaesthesia. The patient had a history of severe snoring, recurrent attacks of rhinitis over a period of one year, daytime somnolence, episodes of airway obstruction, probable hypopnoea during sleep.

For purposes of the study, the patient was evaluated through polysomnography. The results of the polysomnograph were the minimum SpO2 values of 51% that would last for as many as 10 seconds, and another seven episodes of SpO2 less than 88%. The total snoring episodes were numbered at 205 and mean duration of snoring episodes was six seconds. The average minimum oxygen saturation was 83.9%, the maximum heart rate was 141 beats per minute with an average of 96 beats per minute and the desaturation index was 81.1. The AHI (Apnoea hypopnoea index) was significantly high at 80.0/hour. The patient also had enlarged tonsils and a deviated nasal septum on the left.

OSA has been identified as major factor behind mortality and morbidity in the developed world. The high risk for peri-operative complications in OSA patients has been a source of great concern to the medical profession. The American Society of Anaesthesiologists (ASA) has gone ahead and recommended that patients get screened for OSA and the risk of peri-operative complications. The STOP-BANG model has been the screening tool used to assess the risk in OSA patients. OSA patients are considered to be high risk if they have three or more of the STOP-BANG criteria. Hence if OSA is severe, the patient can be put under CPAP (Continuous positive airway pressure) or BiPAP (Bi-level positive airway pressure) to optimize peri-operative recovery. Secondly, OSA patients with a potential for upper airway obstruction or apnoea may be exquisitely sensitive to all central nervous system depressant drugs even in minimal doses. Propofol may be used for induction of anaesthesia with its fast onset, short duration and good relaxation. It will eliminate the high risk and poor perioperative outcome.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3968665/

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