Better Monitoring Reduces Post-op Respiratory Complications

Sending patients with obstructive sleep apnea (OSA) who are undergoing endoscopic sinus surgery (ESS) to the ICU for intensive monitoring during the first postoperative night improves respiratory complication–related outcomes, a new study has found.

Patients with OSA have a higher incidence of postoperative respiratory complications, according to researchers from Jikei University, in Tokyo. Certain procedures, such as ESS, may nix the use of post-op continuous positive airway pressure for sleep apnea, according to the researchers. They implemented a policy at their hospital, in 2011, that required all patients with documented or suspected OSA to be admitted to the ICU for monitoring following ESS.

In the study, first author Yuki Kuwabara, MD, and colleagues retrospectively reviewed ICU data for 152 OSA patients who underwent ESS from 2011 to 2015 to determine the efficacy of this policy. They found that 17.8% of these patients experienced post-op respiratory complications, which were defined as a SpO2 reduction of more than 3% from baseline or an apnea episode lasting longer than 20 seconds. Patients were treated with supplemental oxygen therapy via face mask or were awakened; both methods were used for some cases. No patients required further airway interventions, the researchers reported at the 2016 annual meeting of the American Society of Anesthesiologists (abstract A3065). They also found that these patients experienced a full recovery with minimal interventions when these complications were treated promptly.

Respiratory Compromise Outside the Operating Room

Some experts agree that better monitoring is vital to reduce the incidence of respiratory complications, and studies like this one draw attention to the growing problem of respiratory compromise in the anesthesia field.

The incidence and awareness of respiratory compromise have increased significantly in recent years, and are seen particularly outside the operating room anesthesia setting, according to Jeffery S. Vender, MD, clinical professor of anesthesiology at the University of Chicago Pritzker School of Medicine.

“Respiratory compromise is any situation where there is an increased risk of decompensation that can lead to either respiratory failure and/or death,” he said. “It can be considered a spectrum from the stable, healthy patient to the patient in acute distress on a ventilator in the ICU in respiratory failure. It’s the progression across this spectrum that we are trying to reduce through earlier recognition and prevention.”

Dr. Vender said the rate of affected non–operating room ambulatory patients has increased dramatically over the past decade. Multiple studies have shown a higher incidence of respiratory complications outside the operating room, and have suggested that better monitoring can help to prevent a higher death rate (Curr Opin Anaesthesiol 2009;22:502-508), according to Dr. Vender.

He said pulse oximetry has been the gold-standard monitoring tool and is an excellent tool for detecting hypoventilation, but its effectiveness is limited in patients receiving oxygen therapy.

“The use of oxygen suppresses our ability to identify hypoventilation earlier because … you maintain your oxygen saturation reading while your [carbon dioxide] may be going up, and it remains unidentified to a later point,” he said. “If you’re going to use oxygen and you have high-risk situations—e.g., those patients who are obese, those patients who are opioid-naive … or those patients who are going to get deep levels of sedation—better monitoring could provide earlier recognition and thereby potentially reduce the incidence of respiratory complications and/or death.”

Dr. Vender suggested that the use of capnography might be more effective in reducing this incidence of respiratory complications and can be applicable to multiple populations (e.g., patients receiving gastrointestinal endoscopy and patient-controlled analgesia). A recent study has suggested that the addition of capnography monitoring during procedural sedation for gastrointestinal endoscopy can help improve patient safety and cost savings (Endosc Int Open 2016;4:E340-E351). He noted that organizations such as the American Society of Anesthesiologists and the Association of Anaesthetists of Great Britain & Ireland have released statements recommending the use of capnography for monitoring respiratory complications.

“Today, it is estimated that over 13 million people in the United States receive patient-controlled analgesia, with an incidence of respiratory depression between 0.16% and 5%. This means the potential incidence is somewhere between 20,000 and 600,000 patients who could incur respiratory depression in the postoperative state,” he said. “If patients receiving narcotics are on oxygen, we potentially delay the ability to detect hypoventilation, which is what’s being induced by the narcotics, which leads to the respiratory depression and the potential respiratory failure.”