Efficacy of Remifentanil in Patients Undergoing Cardiac Surgery: A Systematic Review and Network Meta-Analysis

Remifentanil, characterized by its ultra-short action duration and nonorgan-dependent metabolism, is applied in postcardiac surgery settings worldwide. While previous studies have compared its efficacy with that of other opioids, it has never been compared to a single specific opioid. Here, we evaluated whether remifentanil shortens mechanical ventilation (MV) times in patients after cardiac surgery. We identified randomized controlled trials that compared various opioids in adults (≥18 years) admitted to the intensive care unit after cardiac surgery. The primary outcome was the duration of MV, expressed as the mean difference (MD) in minutes, with a 95% confidence interval (CI). A 60-min reduction was considered significant based on prior research. Data were sourced from MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE, the World Health Organization International Clinical Trials Platforms Search Portal, and ClinicalTrials.gov, and a frequentist network meta-analysis was conducted. The eight identified studies indicate no differences in the duration of MV between remifentanil and fentanyl (MD 0.09 min; 95%CI -36.89-37.08), morphine (MD -19 min; 95%CI -55.86-16.21), or sufentanil (MD -2.44 min; 95%CI -67.52-62.55). Our study revealed that remifentanil did not reduce MV times in patients after cardiac surgery. The study protocol was registered with the Open Science Forum (https://osf.io/) (DOI 10.17605/OSF.IO/YAHW2).

Postoperative Pulmonary Complications and Perioperative Strategies: A Systematic Review

The occurrence of postoperative pulmonary complications (PPCs) is frequently observed and has been linked to elevated levels of morbidity and mortality, which have adverse effects on both clinical and financial outcomes in healthcare settings. This systematic review aims to present the evidence that supports our comprehension of PPCs and emphasize the circumstances that necessitate the use of postoperative noninvasive ventilation (PNIV) or re-intubation with postoperative mechanical ventilation (POMV). A search was conducted on the National Library of Medicine's Pubmed database and Cochrane Library until November 29, 2020, to find published reports of randomized control trials (RCTs) that assessed postoperative pulmonary complications. Data related to the prevalence of PPCs and the use of PNIV, POMV, and length of hospital stay were extracted from all the studies. For the analysis, a total of 13 studies involving 6,609 patients were included, and out of these, four RCTs reported statistically significant results. The use of protective lung ventilation (PLV) with low tidal volume and positive end-expiratory pressure (PEEP) during intraoperative ventilation, along with pressure-controlled (PCV) ventilation, as well as the postoperative ventilation strategy of continuous positive airway pressure (CPAP) combined with standard oxygen therapy were the only techniques that demonstrated a clear reduction in the incidence of PPCs. Furthermore, the use of PLV with low tidal volume and PEEP and intraoperative mechanical ventilation with a vital capacity maneuver followed by 10 cm H2O of PEEP were found to decrease the requirement for postoperative noninvasive ventilation. CPAP with standard oxygen therapy was the only intervention that reduced the need for reintubation. Various ventilation strategies are available for both intraoperative and postoperative periods with the goal of decreasing the need for postoperative noninvasive ventilation (PNIV) or re-intubation with postoperative mechanical ventilation (POMV).

Evaluation of the Effects of an Extubation Protocol With Neostigmine on Duration of Mechanical Ventilation After Cardiac Surgery

OBJECTIVES

Residual neuromuscular blockade is associated with increased postoperative pulmonary complications. This study aimed to evaluate the effect of an extubation protocol incorporating neuromuscular blockade reversal (NMBR) by train-of-four monitoring on "fast-track" cardiac surgery outcomes.

DESIGN

A retrospective cohort study.

SETTING

At a university hospital.

PARTICIPANTS

Out of 1,843 cardiac surgery patients, from February 2, 2015, to March 31, 2017, 957 (52%) underwent cardiac surgery on or after February 29, 2016.

INTERVENTIONS

An extubation protocol, comprised of weaning from mechanical ventilation and NMBR guidelines, was implemented on February 29, 2016.

MEASUREMENTS AND MAIN RESULTS

The associations of baseline characteristics with the postoperative duration of mechanical ventilation (primary outcome) and respiratory and/or adverse complications (secondary outcomes) were evaluated using regression and interrupted- time series models. The implementation of an extubation protocol was associated with an 18% decrease in the duration of mechanical ventilation (incident rate ratio [IRR] 0.82, 95% CI 0.72-0.94; p < 0.01), statistically insignificant 26% increase in patients extubated ≤6 hours (odds ratio [OR] 1.26, 95% CI 0.97-1.65; p = 0.09), and 13% shorter intensive care unit length of stay (LOS) (IRR 0.87, 95% CI 0.79-0.97; p < 0.01). Patients undergoing isolated coronary artery bypass graft or isolated valve procedures, on or after February 29, 2016, had decreased extubation times (IRR 0.82, p < 0.01 and IRR 0.80, p = 0.02). The protocol did not have a statistically significant association with hospital LOS (IRR 0.98, p = 0.57) or readmission (OR 1.22, p = 0.33), and differences in the occurrence of pulmonary complications and adverse outcomes between the pre- and postprotocol groups were clinically insignificant.

CONCLUSIONS

The application of an extubation protocol incorporating NMBR based on neuromuscular monitoring was associated with a decrease in postoperative duration of mechanical ventilation and facilitated more patients meeting the early extubation benchmark without an increased risk of respiratory complications or adverse outcomes.

The role of mechanical ventilation in primary graft dysfunction in the postoperative lung transplant recipient: A single center study and literature review

Background

Primary graft dysfunction (PGD) is still a major complication in patients undergoing lung transplantation (LTx). Much is unknown about the effect of postoperative mechanical ventilation on outcomes, with debate on the best approach to ventilation.

Aim/Purpose

The goal of this study was to generate hypotheses on the association between postoperative mechanical ventilation settings and allograft size matching in PGD development.

Method

This is a retrospective study of LTx patients between September 2011 and September 2018 (n = 116). PGD was assessed according to the International Society of Heart and Lung Transplantation (ISHLT) criteria. Data were collected from medical records, including chest x‐ray assessments, blood gas analysis, mechanical ventilator parameters and spirometry.

Results

Positive end‐expiratory pressures (PEEP) of 5 cm H₂O were correlated with lower rates of grade 3 PGD. Graft size was important as tidal volumes calculated according to the recipient yielded greater rates of PGD when low volumes were used, a correlation that was lost when donor metrics were used.

Conclusion

Our results highlight a need for greater investigation of the role donor characteristics play in determining post‐operative ventilation of a lung transplant recipient. The mechanical ventilation settings on postoperative LTx recipients may have an implication for the development of acute graft dysfunction. Severe PGD was associated with the use of a PEEP higher than 5 and lower tidal volumes and oversized lungs were associated with lower long‐term mortality. Lack of association between ventilatory settings and survival may point to the importance of other variables than ventilation in the development of PGD.

Evaluation of Neuromuscular Blockade Reversal on Postoperative Mechanical Ventilation Time in a Cardiovascular Surgery Population

OBJECTIVE

To report on postoperative outcomes related to the administration of neostigmine for reversal of nondepolarizing neuromuscular blocking agents in cardiovascular surgery patients, with a specific focus on the duration of postoperative mechanical ventilation as the primary endpoint.

DESIGN

A retrospective cohort study design was followed to achieve the study objectives.

SETTING

This was a single-center, chart review study conducted at a large academic medical center of adult patients post-cardiovascular surgery.

PARTICIPANTS

Patients were included if they had received a bolus dose of perioperative nondepolarizing neuromuscular blocking agent and underwent one of the targeted cardiovascular surgeries.

INTERVENTIONS

Final analysis comprised of 175 patients, 95 of whom received neostigmine and 80 who did not receive neostigmine.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the duration of postoperative mechanical ventilation. When controlling for all covariates, neostigmine use was associated with a 0.34-hour reduction (∼20.4 min) in duration of mechanical ventilation (parameter estimate: 0.66, 95% confidence interval 0.49-0.89; p = 0.0071). More patients who received neostigmine met the early extubation benchmark of less than 6 hours (55 v 34 patients; p = 0.04). Finally, neostigmine use was not found to be associated with increased risk of respiratory complications or postoperative nausea and/or vomiting.

CONCLUSIONS

The use of neostigmine was found to have a protective effect on the duration of postoperative mechanical ventilation without increasing the risk of adverse complications.

Low-dose spinal anesthesia for urgent laparotomy in severe myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease with an incidence of 2-10/100,000 cases per year, characterized by muscle weakness secondary to destruction of postsynaptic acetylcholine receptors. In these patients, important perioperative issues remain unresolved, namely, optimal administration of cholinesterase inhibitors, risks of regional anesthesia, and prediction of need of postoperative mechanical ventilation. We describe the use of a low-dose spinal anesthesia in a patient with MG who was submitted for emergence exploratory laparotomy. The utilization of low-dose spinal anesthesia allowed us to perform surgery with no adverse respiratory or cardiovascular events in this patient.