Obstructive sleep apnea (OSA) is a common respiratory disease accompanied by a pause in spontaneous breathing during sleep. OSA episodes can happen multiple times while sleeping, lowering sleep quality and making the person exhausted during the day. It has been identified as a separate risk factor for various clinical disorders, including hypertension, stroke, depression, diabetes, workplace or motor vehicle accidents, and significant loss of productivity. As obesity increases in the young and aging population, the prevalence of OSA also increases gradually.
Only 10 to 20 % of these individuals are preoperatively diagnosed with OSA and treated. The remaining 80 to 90 % of patients remain undiagnosed; hence, they are not managed. Because of the lack of preoperative diagnosis, these untreated individuals may be at a greater risk of morbidity and death. The anesthetic management of OSA patients in ambulatory settings may be difficult. OSA patients have restricted airways and are more sensitive to anesthetic medications. They may also have underlying clinical symptoms that must be addressed before their scheduled operation. Individuals at high risk of OSA had a greater chance of difficult intubation and required medication to manage hemodynamics. The benefits of ambulatory surgery include patient convenience and a high level of patient satisfaction.
Does Obesity Alone Predispose Obstructive Sleep Apnea?
Besides obesity, advanced age, male predominance, smoking, excessive alcohol intake, craniofacial deformities, favorable family history, and genetic predisposition are risk factors for OSA. Alcohol use has been demonstrated to increase the frequency of airway blockage, lengthen the duration of apneas, suppress arousals, and enhance the severity of hypoxemia. A cephalometric analysis (the analysis of dental and skeletal relationships found in the human skull) study of the Apnea-Hypopnea Index (AHI) found retrognathia ( the lower jaw is in an abnormal position in relation to the upper jaw) of the mandible and an inferiorly positioned hyoid bone contributed to a higher degree of sleep-disordered breathing.
What Is The Diagnosis and Screening of Obstructive Sleep Apnea?
Snoring is a key symptom of OSA and is nearly 100 % sensitive in confirming the diagnosis. However, it has limited specificity and positive predictive value when used alone. Despite the fact that polysomnography (PSG) is the best technique for diagnosing OSA, it is not feasible to perform PSG on all patients since it is costly, time taking, and needs experienced people. The Wisconsin and Berlin questionnaires were reported to have the highest sensitivity and specificity in predicting the presence of mild OSA. The STOP-Bang and Berlin questionnaires were reported to have the greatest sensitivity and specificity in predicting moderate or severe OSA. The STOP and STOP-Bang questionnaires have always been found to have the highest methodological validity, reasonable accuracy, and user-friendliness.
STOP questionnaire consists of the following questions:
STOP-Bang scoring model consists of the following questions
When PSG is not available, one can use a nocturnal oximeter to make a diagnosis of OSA. Though numerous screening techniques are available for the prediction of OSA, combining the STOP-Bang questionnaire and the nocturnal oximeter may provide the greater sensitivity needed for OSA diagnosis.
What Is the Perioperative Care of OSA Patients in an Ambulatory Anesthetic Setting?
A scoring system is developed to evaluate if an OSA patient is at greater perioperative risk of complications and to decide on ambulatory surgery suitability. It is determined based on the disease severity, the invasiveness of the surgery, the anesthesia used, and postoperative opioids demand. OSA scores of below three are the candidates for ambulatory surgery.
Ambulatory surgery should not be performed on patients with a significantly higher risk of perioperative complications. Mild OSA patients who undergo simple or minor surgical procedures under local, regional, or general anesthesia and are intended to have a low postoperative opioid requirement may be candidates for ambulatory surgery.
On the other hand, patients receiving airway or upper abdominal laparoscopic surgery should not undergo ambulatory surgery. Patients with mild-to-moderate OSA and optimized comorbidities could be capable of undergoing ambulatory surgery safely. Patients with severe OSA who do not have optimized comorbidities are not perfect candidates for ambulatory surgery. Sedatives, anesthetics, and analgesics can worsen pharyngeal obstruction in an already dysfunctional airway and complicate general anesthesia administration in OSA patients. Outpatient surgical settings must be prepared to handle any issues that may arise while anesthetizing OSA patients. In emergency conditions, an inpatient admission facility should be readily available.
What Is the Outcome of Obstructive Sleep Apnea Patients Undergoing Ambulatory Surgery?
Several studies found that patients with OSA have an excellent safety record when undergoing ambulatory surgery. Careful selection of OSA patients, use of short-acting anesthetic agents, and increased perioperative attention will reduce adverse cardiopulmonary events in outpatient anesthetic settings.
What Is the Treatment for Patients with Obstructive Sleep Apnea?
Obstructive sleep apnea treatments solve nighttime breathing disruptions, improve sleep quality, and reduce other health complications. Positive airway pressure (PAP) therapy is the primary treatment for OSA. PAP therapy uses pressurized air pumped through a bedside machine and into the nose or mouth to keep the airway open while sleeping. Deliver PAP therapy through continuous positive airway pressure (CPAP), bi-level positive airway pressure (BiPAP or BPAP), or auto-titrating positive airway pressure (AT-PAP) (APAP).
CPAP: The machine delivers air at a constant and predetermined pressure during inspiration and expiration; it can use a release to reduce the pressure at the start of each exhaled breath. CPAP is the most common type of PAP device for people with OSA.
BiPAP: The machines deliver air at predetermined pressures between inspiration and expiration.
APAP: APAP differs from other PAP devices in that the air pressure changes in response to signals from the body, such as airflow and snoring. APAP can also be called auto-adjusting CPAP or auto-PAP.
Behavioral changes are also crucial for managing obstructive sleep apnea along with treatment; changes in position, reducing weight, limiting alcohol consumption, and using other sedative medications.
Anesthesiologists may face difficulties while treating OSA patients. Patients with obstructive sleep apnea can undergo ambulatory surgery safely. The careful selection of OSA patients, short-acting anesthetic agents, and increased perioperative attentiveness reduce adverse cardiopulmonary incidents in ambulatory anesthetic settings. Necessary facilities for inpatient admission of OSA patients should be available. Ambulatory surgical patients with severe OSA who require postoperative narcotics may not be safe.