Reducing Pain on Chest Tube Removal

Abstract & Commentary

By David J. Pierson, MD, Editor, Professor, Pulmonary and Critical Care Medicine, Harborview Medical Center, University of Washington, Seattle, is Editor for Critical Care Alert.

Synopsis: In this study in non-intubated post-cardiac surgery patients, a single 0.5 μg/kg intravenous bolus of remifentanil greatly reduced the pain associated with chest drain removal compared to placebo, without the respiratory depression observed with a dose of 1.0 μg/kg.

Source: Casey E, et al. Bolus remifentanil for chest drain removal in ICU. Intensive Care Med 2010 Mar 18; Epub ahead of print.

Casey and colleagues compared the effects on pain, level of consciousness, and vital signs of 2 different doses of remifentanil and placebo for removal of chest drains after cardiac surgery in 60 patients. The patients (mean age, 64 years; 77% men) had undergone coronary artery bypass grafting (40 patients) or valve surgery (20 patients), had been extubated, were hemodynamically stable, and were undergoing routine chest tube removal in the ICU or high-dependency unit on the 2nd or 3rd postoperative day. In double-blind fashion, they were randomized to receive a single dose of intravenous remifentanil (either 1.0 or 0.5 μg/kg) or saline placebo over 1 minute, and then all chest drains (3 in 38 patients, 2 in 22 patients) were removed simultaneously 2 minutes later. All patients had been receiving routine analgesia with morphine, diclofenac, and acetaminophen, with the last doses 2-5 hours (mean, 4 hours) prior to tube removal. Just prior to study drug infusion, again at the time of tube removal, and at 2-minute intervals for the next 10 minutes, the patients indicated their level of pain via a 10-cm visual analog scale, with 0 being "no pain" and 10 "severe pain."

There were no differences in the patients' level of sedation by Ramsay sedation score in the 3 study groups. Patients receiving placebo rated the pain on chest drain removal as 5 (range, 3-6), as compared to those receiving remifentanil 0.5 μg/kg (1; range 0-2) and 1.0 μg/kg (0; range 0-2); P = 0.001. Heart rate was significantly reduced following the higher remifentanil dose but was not different between 0.5 μg/kg and placebo. Both remifentanil doses significantly reduced blood pressure and respiratory rate, but not to clinically worrisome levels. The higher dose was followed by a significant decrease in saturation by pulse oximetry (mean, 94% vs 97% with placebo; P = 0.049), but there was no change with the 0.5 μg/kg dose. However, two patients became apneic and unresponsive following the 1.0 μg/kg dose, and required several minutes of bag-mask ventilation. No clinically important adverse effects were observed with the lower remifentanil dose. The authors conclude that a remifentanil bolus of 0.5 μg/kg is safe and effective for chest drain removal after heart surgery in the ICU.

Commentary

Many patients who have had cardiac surgery say that removal of the chest drains was the single most painful, distressing part of the experience. This study demonstrates that a single, moderate intravenous dose of the potent synthetic μ-opioid receptor agonist remifentanil substantially reduces this pain, and safely so within the limits of the study's size (20 patients in each group). However, the authors demonstrated that the larger 1.0 μg/kg dose was sufficient to cause apnea in 10% of the patients who received it, and although it was not observed following the 0.5 μg/kg dose (which was basically just as effective in preventing pain), the possibility of this adverse effect occurring cannot be excluded. The authors included only patients in an intensive care environment, and rightly caution against extending this therapy into less intensively staffed areas of the hospital.