Comparison of lumbar and thoracic epidural narcotics for postoperative analgesia in patients undergoing abdominal aortic aneurysm repair

Postoperative day one: a high risk period for respiratory events

BACKGROUND

In 2001, the Joint Commission on Accreditation of Healthcare Organizations released Pain Management Standards that has led to an increased focus on pain control. Since then the Institute for Safe Medication Practices has noted that overaggressive pain management has led to increases in oversedation and fatal respiratory depression. One of our previous studies found that postoperative patients may be reaching dangerously high levels of sedation as a result of pain management. Our hypothesis is that postoperative patients who have a respiratory event caused by analgesic use are more likely to have that event in the first postoperative day.

METHODS

We performed a retrospective case-control analysis identifying 62 postoperative patients who had a respiratory event. A respiratory event was defined as respiratory depression caused by narcotic use in the postoperative period that was reversed by naloxone. Sixty-two postoperative patients with no such event were chosen randomly and frequency matched based on surgical procedure and diagnosis-related group. Risk factors for an event were identified.

RESULTS

Of the cases, 77.4% had a respiratory event in the first 24 hours postoperatively. Significant risk factors for an event were as follows: 65 years of age or older, having chronic obstructive pulmonary disease, having 1 or more comorbidities, and being placed on hydromorphone.

CONCLUSIONS

The first 24 hours after surgery represents a high-risk period for a respiratory event as a result of narcotic use. The realization of this risk can lead to the implementation of standards to increase patient safety in the first postoperative day.

Comparison of Lumbar Epidural Tramadol and Lumbar Epidural Morphine for Pain Relief After Thoracotomy: A Repeated-Dose Study

OBJECTIVE

The purpose of this study was to compare lumbar epidural morphine and lumbar epidural tramadol with respect to onset and duration of analgesia, analgesic efficacy, and drug-related side effects after muscle-sparing thoracotomy.

DESIGN

Prospective, randomized, double-blind, clinical study.

SETTING

Single university hospital.

PARTICIPANTS

Forty patients who underwent elective muscle-sparing thoracotomy.

INTERVENTIONS

Before anesthesia induction, an epidural catheter was placed in the L2-3 or L3-4 interspace using the loss-of-resistance technique. On arrival at the intensive care unit, patients were randomized to receive doses of either 100 mg of tramadol (group T) or 4 mg of morphine (group M) via the lumbar epidural catheter. Each dose was diluted in 10 mL of normal saline. On awakening from anesthesia, if the patient's pain score on a 0- to 100-mm visual analog scale was above 40 mm, the initial epidural drug dose was administered. The initial injection in each case was taken as time 0. Subsequent pain scores above 40 mm were considered indications for epidural dosing; each patient was allowed 2 doses in the first 12 hours postoperatively and 2 more in the second 12 hours.

MEASUREMENTS AND MAIN RESULTS

The groups' analgesia onset times were similar, but duration of analgesia was significantly shorter in group T than in group M (p < 0.01). There were no differences between the groups with respect to pain scores at rest or during coughing at any of the time points investigated. Sedation scores were lower in group T than in group M at 1, 2, 3, 4, and 8 hours (p value range, 0.0001-0.05). Compared with group T, group M showed significantly greater drops in arterial oxygen tension from baseline at 3, 4, 8, and 12 hours (p value range, 0.0001-0.05). The group means for arterial carbon dioxide tension and respiratory rate were similar at all time points investigated.

CONCLUSION

The study revealed that the quality of analgesia achieved with repeated doses of lumbar epidural tramadol after muscle-sparing thoracotomy is comparable to that achieved with repeated doses of lumbar epidural morphine. Compared with morphine, lumbar epidural tramadol results in less sedation and a less-pronounced decrease in oxygenation.