PERIOPERATIVE MANAGEMENT OF OBSTRUCTIVE SLEEP APNEIC PATIENTS

Abstract

Obstructive sleep apnea is defined as the cessation of respiration for at least 10 seconds in the presence of continued respiratory effort. In serious severe cases, apnea periods are repeated from 30 to 100 times per hour in the night sleep.The consequences of episodic apnea by the patient is, no further gas exchange between the lungs and atmosphere, but O2 reserve is limited to the air within the residual volume of the lungs and the air content in the blood. There is progressive drop in arterial oxygen tension (PaO2). The apneic related hypoxia causes a marked rise in systemic and pulmonary arterial blood pressure. Corpulmonal and serious cardiac arrhythmias often result if left untreated. Arousal is due to hypoxia and accumulation of C02. The clinical picture of these patients is as follows: Snoring, apnea, arousal cycles which result in interrupted restless sleep pattern, day time sleepiness, drowsiness, headache,Cardiopulmonary effects as cardiac arrhythmias, bradycardia, hypertension andcorpulmonale.

The investigations necessary forOSA patients include ; Polysomnography, which is done while the patient is sleeping overnight in a sleep laboratory equipped with an EEG (for stages of sleep), ECG (for cardiac arrhythmias), gas analysis (for hypoxemia and CO2retention) and recording chest movement (for periods of apnea) to determine the severity of the case. X-ray including CT scan to show the narrowed oro and hypopharyngealairway; and cephalometry to evaluate the size of the mandible. Management of OSA patients is through : - Behavioral approach including ;avoidance of precipitating substances, weight loss and increasing sleep time. - Medical approach including ;pharmacological,oxygen therapy, CPAPor oral appliance. - Surgical treatment as; Tracheostomy, palatal surgery,pediatric tonsillectomy and adenoidectomy, nasal surgery or midline glossectomy. Anesthetic Management of OSA patients ;general