How Important Is Postoperative Pain After Cardiac Surgery?

Nociception Control of Bilateral Single-Shot Erector Spinae Plane Block Compared to No Block in Open Heart Surgery-A Post Hoc Analysis of the NESP Randomized Controlled Clinical Trial

Background and Objectives: The erector spinae plane block (ESPB) is an analgesic adjunct demonstrated to reduce intraoperative opioid consumption within a Nociception Level (NOL) index-directed anesthetic protocol. We aimed to examine the ESPB effect on the quality of intraoperative nociception control evaluated with the NOL index. Materials and Methods: This is a post hoc analysis of the NESP (Nociception Level Index-Directed Erector Spinae Plane Block in Open Heart Surgery) randomized controlled trial. Eighty-five adult patients undergoing on-pump cardiac surgery were allocated to group 1 (Control, n = 43) and group 2 (ESPB, n = 42). Both groups received general anesthesia. Preoperatively, group 2 received bilateral single-shot ESPB (1.5 mg/kg/side 0.5% ropivacaine mixed with dexamethasone 8 mg/20 mL). Until cardiopulmonary bypass (CPB) was initiated, fentanyl administration was individualized using the NOL index. The NOL index was compared at five time points: pre-incision (T1), post-incision (T2), pre-sternotomy (T3), post-sternotomy (T4), and pre-CPB (T5). On a scale from 0 (no nociception) to 100 (extreme nociception), a NOL index > 25 was considered an inadequate response to noxious stimuli. Results: The average NOL index across the five time points in group 2 to group 1 was 12.78 ± 0.8 vs. 24.18 ± 0.79 (p < 0.001). The NOL index was significantly lower in the ESPB-to-Control group at T2 (12.95 ± 1.49 vs. 35.97 ± 1.47), T3 (13.28 ± 1.49 vs. 24.44 ± 1.47), and T4 (15.52 ± 1.49 vs. 34.39 ± 1.47) (p < 0.001) but not at T1 and T5. Compared to controls, significantly fewer ESPB patients reached a NOL index > 25 at T2 (4.7% vs. 79%), T3 (0% vs. 37.2%), and T4 (7.1% vs. 79%) (p < 0.001). Conclusions: The addition of bilateral single-shot ESPB to general anesthesia during cardiac surgery improved the quality of intraoperative nociception control according to a NOL index-based evaluation.

Intrathecal Morphine for Analgesia in Minimally Invasive Cardiac Surgery: A Randomized, Placebo-controlled, Double-blinded Clinical Trial

BACKGROUND

Intrathecal morphine decreases postoperative pain in standard cardiac surgery. Its safety and effectiveness have not been adequately evaluated in minimally invasive cardiac surgery. The authors hypothesized that intrathecal morphine would decrease postoperative morphine consumption after minimally invasive cardiac surgery.

METHODS

In this randomized, placebo-controlled, double-blinded clinical trial, patients undergoing robotic totally endoscopic coronary artery bypass received either intrathecal morphine (5 mcg/kg) or intrathecal saline before surgery. The primary outcome was postoperative morphine equivalent consumption in the first 24 h after surgery; secondary outcomes included pain scores, side effects, and patient satisfaction. Pain was assessed via visual analog scale at 1, 2, 6, 12, 24, and 48 h after intensive care unit arrival. Opioid-related side effects (nausea/vomiting, pruritus, urinary retention, respiratory depression) were assessed daily. Patient satisfaction was evaluated with the Revised American Pain Society Outcome Questionnaire.

RESULTS

Seventy-nine patients were randomized to receive intrathecal morphine (n = 37) or intrathecal placebo (n = 42), with 70 analyzed (morphine 33, placebo 37). Intrathecal morphine patients required significantly less median (25th to 75th percentile) morphine equivalents compared to placebo during first postoperative 24 h (28 [16 to 46] mg vs. 59 [41 to 79] mg; difference, -28 [95% CI, -40 to -18]; P < 0.001) and second postoperative 24 h (0 [0 to 2] mg vs. 5 [0 to 6] mg; difference, -3.3 [95% CI, -5 to 0]; P < 0.001), exhibited significantly lower visual analog scale pain scores at rest and cough at all postoperative timepoints (overall treatment effect, -4.1 [95% CI, -4.9 to -3.3] and -4.7 [95% CI, -5.5 to -3.9], respectively; P < 0.001), and percent time in severe pain (10 [0 to 40] vs. 40 [20 to 70]; P = 0.003) during the postoperative period. Mild nausea was more common in the intrathecal morphine group (36% vs. 8%; P = 0.004).

CONCLUSIONS

When given before induction of anesthesia for totally endoscopic coronary artery bypass, intrathecal morphine decreases use of postoperative opioids and produces significant postoperative analgesia for 48 h.

EDITOR’S PERSPECTIVE

Ultrasound-guided Modified Parasternal Intercostal Nerve Block: Role of Preemptive Analgesic Adjunct for Mitigating Poststernotomy Pain

Background and Aim

To assess the quality and effectiveness of postoperative pain relief after fast-tracking tracheal extubation in cardiac surgery intensive care unit, effected by a single-shot modified parasternal intercostal nerve block compared with routine in-hospital analgesic protocol, when administered before sternotomy.

Design

A prospective, randomized, double-blinded interventional study.

Setting

Single-center tertiary teaching hospital.

Participants

Ninety adult patients undergoing elective coronary artery bypass grafting surgery under cardiopulmonary bypass.

Materials and Methods

Patients were randomized into two groups. Patients in the parasternal intercostal block group (PIB) (n = 45) received ultrasound-guided modified parasternal intercostal nerve block with 0.5% levobupivacaine after anesthesia induction at 2^nd-6^th intercostal space along postinduction using standardized anesthesia drugs with routine postoperative hospital analgesic protocol with intravenous morphine. Patients in the group following routine hospital analgesia protocol (HAP) (n = 45) served as controls, with standardized anesthesia drugs and routine hospital postoperative analgesic protocol with intravenous morphine. The primary study outcome aimed to evaluate pain at rest and when doing deep breathing exercises with spirometry, coughing expectorations using a 11-point numerical rating scale.

Results

The postoperative pain score at rest and during breathing exercises was compared between the two groups at different time durations (15 min after extubation and every 4^th hourly for 24 h). Patients in the PIB group had significantly lower pain scores and better quality of analgesia during the entire study period at rest and during breathing exercise (P < 0.0001). Furthermore, the side effect profile and need of rescue analgesics were better in the PIB group than the HAP group at different time intervals.

Conclusion

PIB is safe for presternotomy administration and provided significant quality of pain relief postoperatively, as seen after tracheal extubation for a period of 24 h, on rest as well as with deep breathing, coughing, and chest physiotherapy exercises when compared to intravenous morphine alone after sternotomy. This study further emphasizes the role of preemptive analgesia in mitigating postoperative sternotomy pain and it's role as a plausible safe analgesic adjunct facilitating fast tracking with sternotomies on systemic heparinization.

The impact of fluoroscopic confirmation of thoracic imaging on accuracy of thoracic epidural catheter placement on postoperative pain control

Background

Thoracic epidural analgesia (TEA) provides superior postoperative pain control compared to parenteral opioids after major thoracic and abdominal surgeries. However, some studies with respect to benefits of continuous TEA have shown mixed results. The purpose of this study was to determine the rate of successful TEA catheter insertion into the epidural space using contrast fluoroscopy and the impact of placement location on postoperative analgesia and opioid use.

Patients and methods

After Advocate health care institutional review board approval, we conducted a prospective, open-label, single intervention study on patients undergoing thoracic or upper abdominal surgery. A thoracic paramedian epidural approach and a loss of resistance to saline technique were used to place an epidural catheter above the T11 level and fluoroscopic images with injected contrast were taken to locate the catheter tip in the epidural space.

Results

Twenty-five subjects were included in the study, of which 3 catheters (12%) were not identified as being in the epidural space. We found an average difference of 1.5 vertebral levels between clinical and radiological assessments of catheter tips. Thirteen catheters (52%) were more than 1 vertebral level away from the clinically assessed level. No significant difference was found in the pain scores at 1, 24, and 48 hours after surgery between patients with correct versus incorrect catheter placement. Less opioids were used in the correct catheter placement group at 24 hours (256 morphine milligram equivalent [MME] vs 201 MME) and at 48 hours after surgery (250 MME vs 173 MME), but it was not statistically significant (p=0.149 and p=0.068, respectively).

Conclusion

Improvement in assuring success in the technique for TEA catheter placement following major thoracic or upper abdominal surgery exists, for which contrast-enhanced fluoroscopy might be a promising solution.

[Perioperative gabapentin and pregabalin in cardiac surgery: a systematic review and meta-analysis]

OBJECTIVES

Sternotomy for cardiac surgeries causes significant postoperative pain and when not properly managed may cause significant morbidity. As neuropathic pain is a significant component here, gabapentin and pregabalin may be effective in these patients and may reduce postoperative opioid consumption. The purpose of this systematic review was to find out efficacy of gabapentin and pregabalin in acute postoperative pain after cardiac surgery.

METHODS

Published prospective human randomized clinical trials, which compared preoperative and/or postoperative gabapentin/pregabalin with placebo or no treatment for postoperative pain management after cardiac surgery has been included in this review.

RESULTS

Four RCTs each for gabapentin and pregabalin have been included in this systematic review. Three gabapentin and two pregabalin studies reported decrease in opioid consumption in cardiac surgical patients while one gabapentin and two pregabalin studies did not. Three RCTs each for gabapentin and pregabalin reported lower pain scores both during activity and rest. The drugs are not associated with any significant complications.

CONCLUSION

Despite lower pain scores in the postoperative period, there is insufficient evidence to recommend routine use of gabapentin and pregabalin to reduce opioid consumption in the cardiac surgical patients.

Effect of Gabapentin on Pain after Cardiac Surgery: A Randomised, Double-Blind, Placebo-Controlled Trial

This study evaluated whether perioperative administration of gabapentin in cardiac surgery patients could reduce postoperative opioid consumption, postoperative sleep or perceived quality of recovery. This randomised controlled trial assigned 60 patients undergoing cardiac surgery to receive 1200 mg of gabapentin or placebo two hours preoperatively, and then 600 mg of gabapentin or placebo twice a day for the next two postoperative days. Postoperative opioid use was measured by the amount of fentanyl used in the first 48 hours postoperatively. Pain at rest and with movement at 12, 24, 48 and 72 hours after surgery, sleep scores on postoperative days two and three and patient-perceived quality of recovery were also assessed. Fentanyl use, visual analog pain scores, sleep scores, adjunctive pain medication use and number of anti-emetics given were not significantly different between the gabapentin and placebo groups. The incidence of side-effects was similar between the gabapentin and placebo groups, and no difference was found between groups in relation to quality of recovery. These findings indicate that preoperative use of gabapentin followed by postoperative dosing for two days did not significantly affect the postoperative pain, sleep, opioid consumption or patient-perceived quality of recovery for patients undergoing cardiac surgery.