Anesthetic considerations in robotic mitral valve surgery

Thoracic Interfascial Plane Blocks and Outcomes After Minithoracotomy for Valve Surgery

Introduction. Thoracic interfascial plane blocks are increasingly used for pain management after minimally invasive thoracotomy for valve repair and replacement procedures. We hypothesized that the addition of these blocks to the intercostal nerve block injected by the surgeon would further reduce pain scores and opioid utilization. Methods. In this retrospective cohort study, 400 consecutive patients who underwent minimally invasive thoracotomy for mitral or aortic valve replacement and were extubated within 2 hours of surgery were enrolled. The maximum pain score and opioid utilization on the day of surgery and other outcome variables were compared between patients who received interfascial plane blocks and those who did not. Results.193 (48%) received at least one interfascial plane block while 207 (52%) received no interfascial plane block. Patients who received a thoracic interfascial plane block had a maximum VAS score on the day of surgery (mean 7.4 ± 2.5) after the block was administered which was significantly lower than patients in the control group who did not receive the block (mean 7.9 ± 2.2) (P = .02). Opioid consumption in the interfascial plane block group on the day of surgery was not significantly different from the control group. Conclusion. Compared to intercostal blocks alone, the addition of thoracic interfascial plane blocks was associated with a modest reduction in maximum VAS score on the day of surgery. However, no difference in opioid consumption was noted. Patients who received interfascial plane blocks also had decreased blood transfusion requirements and a shorter hospital length of stay.

Regional anesthesia techniques for cardiac surgery: where are we?

PURPOSE OF REVIEW

Inadequate pain relief after cardiac surgery results in decreased patient experience and satisfaction, increased opioid consumption with its associated adverse consequences, and reduced efficiency metrics. To mitigate this, regional analgesic techniques are an increasingly important part of the perioperative cardiac anesthesia care plan. The purpose of this review is to compare current regional anesthesia techniques, and the relative evidence supporting their efficacy and safety in cardiac surgery.

RECENT FINDINGS

Numerous novel plane blocks have been developed in recent years, with evidence of improved pain control after cardiac surgery.

SUMMARY

The current data supports the use of a variety of different regional anesthesia techniques to reduce acute pain after cardiac surgery. However, future randomized trials are needed to quantify and compare the efficacy and safety of different regional techniques for pain control after cardiac surgery.

Unilateral Pulmonary Edema After Robotically Assisted Mitral Valve Repair Requiring Veno-Venous Extracorporeal Membrane Oxygenation

Unilateral pulmonary edema (UPE) is an uncommon yet potentially life-threatening complication of minimally invasive cardiac surgery (MICS). Most frequently described after robotically assisted mitral valve (MV) repair, it is characterized by right lung edema, hypoxemia, hypercapnia, pulmonary hypertension, and hemodynamic instability beginning minutes-to-hours after separation from cardiopulmonary bypass (CPB). The authors describe a severe case with refractory hypoxemia requiring veno-venous (VV) extracorporeal membrane oxygenation (ECMO) after robotically assisted MV repair.

Postoperative Nausea and Vomiting and Pain After Robotic-Assisted Mitral Valve Repair

OBJECTIVE

To determine the rate and clinical factors associated with postoperative nausea and vomiting (PONV) and severe pain after robotic-assisted mitral valve repair.

DESIGN

Retrospective chart review.

SETTING

Major quaternary academic medical center.

PARTICIPANTS

Adult patients undergoing robotic-assisted mitral valve repair from May 5, 2018 through September 13, 2019.

INTERVENTIONS

Participant electronic medical records were abstracted for clinical characteristics, PONV within the first 72 postoperative hours, episodes of severe pain (defined as pain score ≥7 using an 11-point numerical pain rating scale), and opioid use within the first 24 postoperative hours. Multivariate analyses were performed.

MEASUREMENTS AND MAIN RESULTS

Of 124 participants, PONV was noted in 83 (67%; 95% confidence interval [CI] 58%-75%) patients and severe pain in 96 (77%, 95% CI 69%-84%) patients. The median (interquartile range) time to PONV was 6.1 (3.7-14.7) hours. After adjusting for age, sex, and duration of surgery, pre-incisional use of methadone was associated with reduced risk for severe pain (odds ratio 0.40 [95% CI 0.16-0.99]; p = 0.048) and a lower 24-postoperative hour opioid requirement (estimate -29.0 mg intravenous morphine equivalents [95% CI -46.7 to -11.3]; p = 0.006). However, methadone was not associated with a reduction of the cumulative opioid dose (intraoperative and 24-hour postoperative opioid dose; p = 0.248). Both severe pain and PONV were associated with longer hospital stay.

CONCLUSION

PONV and severe pain are common after robotic-assisted mitral valve repair. Peri-incisional methadone is associated with a modest decrease in the severe pain rate but without a reduction in opioid dose or hospital stay.

Transversus Thoracis Muscle Plane Block

The transversus thoracis muscle plane block (TTP) block is a newly developed regional anesthesia technique which provides analgesia to the anterior chest wall. Since its introduction, this technique has been utilized for a wide range of surgical procedures as well as nonsurgical indications. Current evidence suggests that the TTP block provides effective analgesia for breast and cardiac surgeries, cardiac device implantation, pericardiocentesis, and acute and chronic pain management. To date, no major complications have been reported. Currently there is an urgent need to standardize the nomenclature of this technique to facilitate accurate communication amongst care providers, researchers, and authors. In this review, we describe the TTP block technique, review the indications and available evidence in clinical practice, and discuss alternative blocks and future prospects.

Minimal volume ventilation during robotically assisted mitral valve surgery

INTRODUCTION

A minimal volume ventilation method for robotically assisted mitral valve surgery is described in this study. In an attempt to reduce postoperative pulmonary dysfunction, 40 of 174 patients undergoing robotically assisted mitral valve surgery were ventilated with a small tidal volume during cardiopulmonary bypass.

METHODS

After propensity score matching, 31 patients with minimal volume ventilation were compared with 54 patients with no ventilation. Total ventilation time, PaO₂/FiO₂ ratio, arterial lactate concentration, and the rate of unilateral pulmonary edema in the matched minimal ventilation and standard treatment groups were evaluated.

RESULTS

Patients in the minimal ventilation group had shorter ventilation times, 12.0 (interquartile range: 9.9-15.0) versus 14.0 (interquartile range: 12.0-16.3) hours (p = 0.036), and lower postoperative arterial lactate levels, 0.99 (interquartile range: 0.81-1.39) versus 1.28 (interquartile range: 0.99-1.86) mmol/L (p = 0.01), in comparison to patients in the standard treatment group. There was no difference in postoperative PaO₂/FiO₂ ratio levels or in the rate of unilateral pulmonary edema between the groups.

CONCLUSION

Minimal ventilation appeared beneficial in terms of total ventilation time and blood lactatemia, while there was no improvement in arterial blood gas measurements or in the rate of unilateral pulmonary edema. The lower postoperative arterial lactate levels may suggest improved lung perfusion among patients in the minimal volume ventilation group. The differences in the ventilation times were in fact small, and further studies are required to confirm the possible advantages of the minimal volume ventilation method in robotically assisted cardiac surgery.

Myocardial Protection in Minimally Invasive Mitral Valve Surgery: Retrograde Cardioplegia Alone Using Endovascular Coronary Sinus Catheter Compared With Combined Antegrade and Retrograde Cardioplegia

OBJECTIVE

To compare myocardial protection with retrograde cardioplegia alone with antegrade and retrograde cardioplegia in minimally invasive mitral valve surgery (MIMS).

DESIGN

Retrospective study.

SETTING

Tertiary care university hospital.

PARTICIPANTS

The authors studied 97 MIMS patients using retrograde cardioplegia alone and 118 MIMS patients using antegrade and retrograde cardioplegia.

INTERVENTIONS

The data from patients admitted for MIMS using retrograde cardioplegia (MIMS retro) between 2009 to 2012 were compared with the data from patients undergoing MIMS with antegrade and retrograde cardioplegia (MIMS ante-retro) between 2006 and 2010 (control group). Cardioplegia in the MIMS retro group was delivered solely through an endovascular coronary sinus (CS) catheter positioned under echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia was used in the MIMS ante-retro group. Data regarding myocardial infarction (MI; creatine kinase Mb, troponin T, electrocardiogram), myocardial function, and hemodynamic stability were collected for comparison.

MEASUREMENTS AND MAIN RESULTS

Adequate cardioplegia administration (CS pressure >30 mmHg and asystole) was attained in 74.2% of the patients with retrograde cardioplegia alone. In 23.7% of the patients, the addition of an antegrade cardioplegia was necessary. No difference was observed in the incidence of MI (0 MIMS retro v 1 for MIMS ante-retro, p = 0.3623), difficult separation from cardiopulmonary bypass, and postoperative malignant arrhythmia. No difference was found for maximal creatine kinase Mb (39.1 [28.0-49.1] v 37.9 [28.6-50.9]; p = 0.8299) and for maximal troponin T levels (0.39 [0.27-0.70] v 0.47 [0.32-0.79]; p = 0.1231) for MIMS retro and MIMS ante-retro, respectively. However, lactate levels in the MIMS retro group were significantly lower than in the MIMS ante-retro group (2.1 [1.4-3.05] v 2.4 [1.8-3.3], respectively; p = 0.0453). No difference was observed in duration of intensive care unit stay and death. MIMS retro patients had a shorter hospital stay (7.0 [6.0-8.0] v 8.0 [7.0-9.0] days; p = 0.0003).

CONCLUSION

Retrograde cardioplegia administration alone provided comparable myocardial protection to antegrade and retrograde cardioplegia during MIMS, but was not sufficient to achieve asystole in one-fifth of patients.

Anaesthetic issues in robotic-assisted minimally invasive surgery

Over the past decade there has been an exponential increase in the number of robotic-assisted surgical procedures performed in Australia and internationally. Despite this growth, there are no level I or II studies examining the anaesthetic implications of these procedures. Available observational studies provide insight into the significant challenges for the anaesthetist. Most anaesthetic considerations overlap with those of non-robotic surgery. However, issues with limited patient access and extremes of positioning resulting in physiological disturbances and risk of injury are consistently demonstrated concerns specific to robotic-assisted procedures.