Apnea and bradypnea in patients receiving epidural bupivacaine-morphine for postoperative pain relief as assessed by a new monitoring method.

STUDY OBJECTIVE

To evaluate postoperative breathing patterns with a new monitoring device in patients given bupivacaine-morphine epidural analgesia.

DESIGN

Open explorative study.

SETTING

Inpatient anesthesia in a university hospital setting.

PATIENTS

15 ASA physical status I and II patients aged 28 to 87 years and scheduled for major abdominal surgery.

INTERVENTIONS

All patients underwent abdominal surgery with epidural anesthesia combined with general anesthesia. Postoperatively, they continued with epidural analgesia consisting of bupivacaine and morphine. On the first postoperative night, the breathing pattern was studied with a new noninvasive monitoring device measuring respiratory frequency and apnea. Arterial blood gas analysis was performed in case of apnea or low respiratory frequency.

MEASUREMENTS AND MAIN RESULTS

A total of 84 alarm events were registered in 11 patients. Twenty-one percent (18/84) of the alarms were associated with arterial carbon dioxide tension (PaCO2) levels greater than 48.8 mmHg. Three of the four patients with PaCO2 levels greater than 48.8 mmHg were older than 80 years of age.

CONCLUSION

The tested noninvasive monitoring device may detect abnormal respiratory breathing patterns in patients at risk for respiratory depression during epidural analgesia with bupivacaine-morphine.