Opioid-Based Anesthesia and Analgesia for Adult Cardiac Surgery: History and Narrative Review of the Literature

Malewicz N, Ebel M, K. Zahn P, H. Meyer-Frießem C. Pupillometric Monitoring of Nociception in Cardiac Anesthesia

BACKGROUND

High-dose opioids are conventionally used for cardiac anesthesia, but without monitoring of nociception. In non-cardiac surgical procedures the intra - operative dose of opioids can be individualized and reduced with pupillometric monitoring of the pupillary pain index (PPI; scale 1-9). A randomized controlled trial was carried out to explore whether pupillometry can be used for nociception monitoring in cardiac anesthesia and whether it leads to opioid reduction.

METHODS

A sample of 57 cardiac surgery patients receiving continuously administered sufentanil (initial dosage 0.7 μg*kg-¹*h-¹) was divided into a PPI group (sufentanil reduction if PPI<3 up to a minimum of 0.15 μg*kg-¹*h-¹, n=32) and a control group (standard anesthesia; n = 25). The primary outcome was the time from the end of anesthesia to extubation. The secondary outcomes were total intraoperative dose of sufentanil/noradrenaline, postoperative pain intensity (numeric rating scale [NRS] 0-10) and intraoperative awareness. German Clinical Trials Registry no. DRKS 00012329.

RESULTS

The primary outcome, extubation time, did not differ between the two groups (1.14 h, 95% confidence interval [-0.99; 3.27], p = 0.592). Compared with the control patients (68% male, age 70 ± 10.4 years, PPI 1.1 ± 0.2), the mean sufentanil infusion rate in the PPI patients (81% male, age 68 ± 10.3 years, PPI 1.1 ± 0.2) decreased by 81.8% (-0.68 μg*kg-¹*h-¹ [-0,7; -0.67], p<0.001) to the predetermined minimum level, without intraoperative awareness. Moreover, the noradrenaline dose was reduced by 56% (1235.51 μg [321.91; 2149.12], p = 0.005) and the postoperative pain intensity by 45% (2.11 NRS [0.93; 3.3] after 24 h, p = 0.003).

CONCLUSION

Pupillometry is appropriate for nociception monitoring in cardiac anesthesia. Thereby a considerable reduction of intraoperative opioids as well as increased intraoperative hemodynamic stability was achieved and postoperative opioid-induced hyperalgesia was prevented. The consistently low PPI scores, indicating adequate analgesia, suggest that further reduction of opioid doses is feasible.

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.

Cardioprotective Effect of Anesthetics: Translating Science to Practice

Cardiovascular diseases are the number one cause of mortality in the world, particularly among the aging population. Major adverse cardiac events are also a major contributor to perioperative complications, affecting 2.6% of noncardiac surgeries and up to 18% of cardiac surgeries. Cardioprotective effects of volatile anesthetics and certain intravenous anesthetics have been well-documented in preclinical studies; however, their clinical application has yielded conflicting results in terms of their efficacy. Therefore, better understanding of the underlying mechanisms and developing effective ways to translate these insights into clinical practice remain significant challenges and unmet needs in the area. Several recent reviews have focused on mechanistic dissection of anesthetic-mediated cardioprotection. The present review focuses on recent clinical trials investigating the cardioprotective effects of anesthetics in the past five years. In addition to highlighting the main outcomes of these trials, the authors provide their perspectives about the current gap in the field and potential directions for future investigations.

Sublingual Sufentanil Tablet System Versus Continuous Morphine Infusion for Postoperative Analgesia in Cardiac Surgery Patients

OBJECTIVE(S)

To assess the effectiveness and side effects of a patient-controlled sublingual sufentanil tablet system for postoperative analgesia after cardiac surgery and to compare it to a nurse-controlled continuous morphine infusion.

DESIGN

Prospective, open-label, randomized controlled trial.

SETTING

Single university academic center.

PARTICIPANTS

Adult patients undergoing cardiac surgery, which included a sternotomy.

INTERVENTIONS

Sublingual sufentanil tablet system versus nurse-controlled continuous morphine infusion.

MEASUREMENTS AND MAIN RESULTS

A total of 483 cardiac surgery patients were screened for eligibility, of whom 64 patients completed the study. No statistically significant differences were found for baseline characteristics between both groups. All mean numeric rating scale (NRS) pain scores from after extubation until intensive care unit discharge were ≤3 in both groups. The cumulative mean NRS pain score from 24 hours after extubation (primary outcome) (t = hours after extubation) was significantly different in favor of the morphine group: (t = 0-24) (0.8 [0.7] v 1.3 [0.8]; p = 0.006). Later cumulative mean pain scores were also in favor of the morphine group: (t = 24-48) (0.2 [0.3] v 0.6 [0.5]; p = 0.001) and (t = 48-63) (0.0 [0.0] v 0.1 [0.2]; p = 0.013). The cumulative opioid dose (in milligrams intravenous morphine equivalents) was significantly higher in the morphine group compared with the sublingual sufentanil group (241.94 [218.73] v 39.84 [21.96]; p = 0.0001). No differences were found for the incidences of postoperative nausea and vomiting, sedation, hypoventilation, bradycardia, or hypotension between both groups (secondary outcomes).

CONCLUSIONS

Despite resulting in statistically significantly higher pain scores, a patient-controlled sublingual sufentanil tablet system offers adequate analgesia after cardiac surgery and reduces opioid consumption when compared with continuous morphine infusion.

The Impact of Anesthetic Regimen on Outcomes in Adult Cardiac Surgery: A Narrative Review

Despite improvements in surgical techniques and perioperative care, cardiac surgery still is burdened by relatively high mortality and frequent major postoperative complications, including myocardial dysfunction, pulmonary complications, neurologic injury, and acute kidney injury. Although the surgeon's skills and volume and patient- and procedure-related risk factors play a major role in the success of cardiac surgery, there is growing evidence that also optimizing perioperative care may improve outcomes significantly. The present review focuses on the aspects of perioperative care that are strictly related to the anesthesia regimen, with special reference to volatile anesthetics and neuraxial anesthesia, whose effect on outcome in adult cardiac surgery has been investigated extensively.

Remifentanil and sevoflurane based anesthesia combined with bilateral erector spinae plane block in patients undergoing off-pump coronary artery bypass graft surgery

Introduction

Working on the institutional Enhanced Recovery After Surgery (ERAS Cardio) protocol for off-pump coronary artery bypass graft surgery (OP-CABG) we have noticed that patients treated according to the modified anesthesia protocol had not only significantly shorter time of respiratory support and intensive care unit stay but also lower postoperative troponin T concentration than patients who had standard fentanyl/sevoflurane-based anesthesia.

Aim

To compare the perioperative course of patients undergoing OP-CABG surgery and receiving standard fentanyl/sevoflurane anesthesia and those anesthetized according to the institutional ERAS Cardio protocol with remifentanil, sevoflurane, and bilateral extensor spinae plane (ESP) block.

Material and methods

Design: a prospective, open-label, observational study performed in a tertiary health center. Participants: 30 consecutive patients undergoing off-pump coronary bypass graft surgery. Interventions: 15 patients had standard anesthesia with etomidate, fentanyl, and rocuronium for induction and fentanyl/sevoflurane for maintenance (standard group); 15 others had bilateral single shot ESP block, then etomidate, remifentanil and rocuronium for induction, and remifentanil/sevoflurane for maintenance of anesthesia.

Results

Median time to extubation was 7.6 (5.5–12.5) h and 1.7 (1–3.25) h in “standard care” and ERAS groups, respectively (p = 0.00002). Length of stay in the intensive care unit was also shorter for patients in the ERAS group 20.5 (18–24) vs. 48 (42–48) h (p = 0.00001). Troponin concentration increased to a lesser extent in patients from the ERAS group: an increase of 151.8 (71.9–174.3) ng/ml vs. 253.8 (126.6–373.1) ng/ml, p = 0.008.

Conclusions

Remifentanil/sevoflurane anesthesia combined with bilateral ESP block shortens mechanical ventilation time and ICU stay, and decreases postoperative troponin-T concentration in patients undergoing off-pump coronary bypass graft surgery.

Prolonged Perioperative Use of Pregabalin and Ketamine to Prevent Persistent Pain after Cardiac Surgery

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Persistent postsurgical pain is common and affects quality of life. The hypothesis was that use of pregabalin and ketamine would prevent persistent pain after cardiac surgery.

Methods

This randomized, double-blind, placebo-controlled trial was undertaken at two cardiac surgery centers in the United Kingdom. Adults without chronic pain and undergoing any elective cardiac surgery patients via sternotomy were randomly assigned to receive either usual care, pregabalin (150 mg preoperatively and twice daily for 14 postoperative days) alone, or pregabalin in combination with a 48-h postoperative infusion of intravenous ketamine at 0.1 mg · kg−1 · h−1. The primary endpoints were prevalence of clinically significant pain at 3 and 6 months after surgery, defined as a pain score on the numeric rating scale of 4 or higher (out of 10) after a functional assessment of three maximal coughs. The secondary outcomes included acute pain, opioid use, and safety measures, as well as long-term neuropathic pain, analgesic requirement, and quality of life.

Results

In total, 150 patients were randomized, with 17 withdrawals from treatment and 2 losses to follow-up but with data analyzed for all participants on an intention-to-treat basis. The prevalence of pain was lower at 3 postoperative months for pregabalin alone (6% [3 of 50]) and in combination with ketamine (2% [1 of 50]) compared to the control group (34% [17 of 50]; odds ratio = 0.126 [0.022 to 0.5], P = 0.0008; and 0.041 [0.0009 to 0.28], P &lt; 0.0001, respectively) and at 6 months for pregabalin alone (6% [3 of 50]) and in combination with ketamine 0% (0 of 5) compared to the control group (28% [14 of 50]; odds ratio = 0.167 [0.029 to 0.7], P = 0.006; and 0.000 [0 to 0.24], P &lt; 0.0001). Diplopia was more common in both active arms.

Conclusions

Preoperative administration of 150 mg of pregabalin and postoperative continuation twice daily for 14 days significantly lowered the prevalence of persistent pain after cardiac surgery.

Erector spinae-plane block as an analgesic alternative in patients undergoing mitral and/or tricuspid valve repair through a right mini-thoracotomy - an observational cohort study

Introduction

One of the main challenges in cardiac surgery is effective postoperative analgesia. Erector spinae-plane block (ESP block) is a novel regional technique, introduced by Forero in 2016 for neuropathic chest pain, then used successfully for mastectomy.

Aim

To establish the efficacy of the ESP block in patients undergoing mitral and/or tricuspid valve repair through a right mini-thoracotomy.

Material and methods

It is a prospective observational cohort study performed in a tertiary health center. In the treatment group, a single-shot ESP block was performed before anesthetic induction. General anesthesia was induced with etomidate, remifentanil, and rocuronium, and continued with sevoflurane and remifentanil. Remifentanil infusion was continued for 2 h post-operatively, then stopped, and the patient’s trachea was extubated. Patient-controlled analgesia was started with oxycodone immediately. Total oxycodone consumption and pain severity on the visual analog scale during the first 24 h were analyzed. In the control group, no regional block was performed. Instead of remifentanil, fentanyl was used. Patients were extubated on the second day. Pain was treated with morphine, administered according to nurses’ discretion. Pain intensity was evaluated on the numerical rating scale.

Results

Nineteen patients were evaluated in the ESP and 25 in the control group. Mechanical ventilation time was shorter in the ESP group (0.6 (0.4–1.1) h) than in the control one (10 (8–17) h, p = 0.00001). Moreover, patients in the ESP group spent fewer days in the intensive care unit (1 (1–1) vs. (2 (2–2), p = 0.0001).

Conclusions

The ESP block seems to be safe and efficient for pain control in patients undergoing right mini-thoracotomy for mitral and/or tricuspid valve repair.