overnight sleep study in such cases. At the very least, administer the
STOP-Bang test developed by Toronto Western Hospital
(stopbang.ca) before surgery.
No matter what the results of pre-op diagnoses are, anesthesia
providers should always be prepared for things to take a negative
turn, especially with obese patients, says Dr. Sinha. Because obese
patients have lower oxygen reserves and their utilization is faster,
anesthesia is riskier than usual.
"The single biggest cause of aspiration in the operating room is pre-
mature attempts at laryngoscopy before the patient is anesthetized,"
notes Dr. Sinha. "It is not the inability of the provider to intubate the
patient that causes the problem. It is the inability of the provider to
ventilate the patient that causes the problem."
Dr. Sinha adds that whenever possible, avoid sedation with obese
patients because of the OSA-related risks, and instead use regional
anesthetics or opioid-free drugs that provide analgesia without respi-
ratory depression. The lack of sedation also helps the patient ambu-
late better post-op, which in turn helps avoid blood clots, UTIs, consti-
pation and other problems that can result from being sedentary.
9. Positioning
Be careful about positioning the patient in the OR. The supine position
is particularly dangerous for obese patients, as it leads to a greater
decrease in functional residual capacity (FRC), total respiratory sys-
tem and pulmonary compliance, and a larger ventilation/perfusion mis-
match than in a normal weight patient, writes Jay B. Brodsky, MD, a
founding member of the International Society for the Peri-operative
Care of the Obese Patient (ISPCOP), in "Positioning the Morbidly
Obese Patient for Surgery" (osmag.net/qqN2NF).
Never let spontaneously breathing, extremely obese patients lie
9 8 • O U T PA T I E N T S U R G E R Y M A G A Z I N E • F E B R U A R Y 2 0 1 9
