to the editor: We would like to commend the authors of the article entitled “Treating Obstructive Sleep Apnea Improves Essential Hypertension and Quality of Life.”1 However, as health care providers in the perioperative arena, we would like to stress the importance of obstructive sleep apnea (OSA) screening and treatment from a perioperative perspective.
Recognizing and appropriately managing patients with OSA in the perioperative period is critical to avoid fatal and near fatal respiratory complications. It is recognized that central depressant drugs (general anesthetics, sedatives/hypnotics, and opiates) cause pharyngeal muscle collapse and may impair the normal ventilatory response to hypoxia and hypercapnia, resulting in prolonged apneas in the patient with OSA.2 One study3 demonstrated a 39 percent respiratory complication rate among patients with OSA who were undergoing hip or knee replacement, compared with 18 percent of patients in the control group. Serious respiratory complications occurred in 24 percent of patients with OSA, compared with 9 percent of patients in the control group.
The article1 states that 80 to 90 percent of patients with OSA are undiagnosed and, thus, family physicians, anesthesiologists, and surgeons should screen for symptoms of OSA in the perioperative evaluation. Physicians should make a presumptive diagnosis and treat patients as though they have OSA during the perioperative period if they are an obese adult with a body mass index (BMI) greater than 29 kg per m2, have a history of snoring, or have a history of apnea.2 The physical examination often reveals the anatomy of a difficult airway. Upper airway obstruction and respiratory depression can occur from minimal doses of preoperative anxiolytics and opioids.4 Premedications should be given cautiously with proper monitoring and with resuscitation equipment readily available.
Patients with OSA are frequently difficult to mask, ventilate, and intubate, and they may require a fiberoptic intubation while they are awake. These patients should be fully awake before extubation; thus, a prolonged time may be needed to safely extubate. When technically possible and appropriate, regional anesthesia (spinal, epidural, peripheral nerve block with local anesthetics) accompanied by minimal sedation is preferable to a general anesthetic and it is helpful for multiple physicians to prepare the patient for this approach.
Postoperative analgesia using continuous epidurals, spinals, or peripheral nerve block with local anesthetics, coupled with intravenous or oral nonsteroidal anti-inflammatory drugs, are desirable to prevent respiratory depression. When a general anesthetic is used, and the postoperative analgesia involves intravenous or neuroaxial opioids, then monitoring in an intensive care unit/step-down setting is recommended. Unfortunately, deaths related to epidural and intravenous opioids have been reported up to three days after surgery.5
In summary, recognition of OSA by the health care team is vital for improving quality of life and providing optimal intraoperative care. Postoperatively, continuous pulse oximetry monitoring in an intensive care unit/step-down setting will likely prevent respiratory complications in the surgical patient with OSA.