The effect of oral pregabalin on the minimum alveolar concentration of isoflurane in cats

OBJECTIVE

To investigate the effect of three different doses of oral pregabalin on minimum alveolar concentration of isoflurane (MACISO) in cats.

STUDY DESIGN

Prospective, randomized, placebo-controlled, blinded, crossover trial.

ANIMALS

A group of eight healthy adult cats aged 24-48 months.

METHODS

Cats were randomly assigned to three oral doses of pregabalin (low dose: 2.5 mg kg-1, medium dose: 5 mg kg-1, high dose: 10 mg kg-1) or placebo 2 hours before MACISO determination, with the multiple treatments administered with a minimum 7 day washout period. Anesthesia was induced and maintained with isoflurane in oxygen until endotracheal intubation was achieved, and maintained with isoflurane with volume-controlled ventilation. MACISO was determined in triplicate using the bracketing technique and tail clamp method 120 minutes after pregabalin or placebo administration. Physiologic variables (including heart rate and blood pressure) recorded during MACISO determination were averaged and compared between the pregabalin and placebo treatments. One-way analysis of variance and the Friedman test were used to assess the difference for normally and non-normally distributed data, respectively. The Tukey test was used as a post hoc analysis. Values of p < 0.05 were considered significant.

RESULTS

The MACISO with the medium- and high-dose pregabalin treatments were 1.33 ± 0.21% and 1.23 ± 0.17%, respectively. These were significantly lower than MACISO after placebo treatment (1.62 ± 0.13%; p = 0.014, p < 0.001, respectively), representing a decrease of 18 ± 9% and 24 ± 6%. The mean plasma pregabalin concentration was negatively correlated with MACISO values. Physiologic variables did not differ significantly between treatments.

CONCLUSIONS AND CLINICAL RELEVANCE

Doses of 5 or 10 mg kg-1 pregabalin, administered orally 2 hours before determining MACISO, had a significant isoflurane-sparing effect in cats.

The Effect of Pregabalin on the Minimum Alveolar Concentration of Sevoflurane: A Randomized, Placebo-Controlled, Double-Blind Clinical Trial

Background

Pregabalin is commonly used perioperatively to reduce post-operative pain and opioid consumption and to prevent the development of chronic pain. It has been shown to reduce anesthetic consumption in balanced anesthesia, but studies investigating its effect on the minimum alveolar concentration (MAC) of volatile anesthetics are lacking. The aim of this study was to investigate the effect of two different doses of pregabalin on the MAC of sevoflurane.

Methods

In a randomized, double-blinded, placebo controlled clinical study, 75 patients were assigned to receive placebo, 300 mg pregabalin, or 150 mg pregabalin, as a capsule 1 h before anesthesia induction with sevoflurane only. After equilibration, the response to skin incision (movement vs. non-movement) was monitored. The MAC was assessed using an up- and down-titration method.

Results

The MAC of sevoflurane was estimated as 2.16% (95% CI, 2.07–2.32%) in the placebo group, 1.44% (95% CI, 1.26–1.70%) in the 300 mg pregabalin group, and 1.81% (95% CI, 1.49–2.13%) in the 150 mg pregabalin group. We therefore report a 33% reduction in the MAC of sevoflurane in the 300 mg pregabalin group as compared to placebo. The MAC of the 150 mg pregabalin group was reduced by 16% as compared to placebo but was not statistically significant.

Conclusions

The administration of 300 mg pregabalin reduced the MAC of sevoflurane by 33%, while the administration of 150 mg pregabalin did not significantly reduce the MAC of sevoflurane. Pregabalin use led to a small reduction in post-operative pain levels but increased side effects in a dose-dependent manner.

Optimizing Robotic Hysterectomy for the Patient Who Is Morbidly Obese with a Surgical Safety Pathway

STUDY OBJECTIVE

Obesity is a growing worldwide epidemic, and patients classified as obese undergoing gynecologic robotic surgery are at increased risk for surgical complications. This study aimed to evaluate the feasibility and outcomes of a surgical safety protocol known as the High BMI [Body Mass Index] Pathway (HBP) for patients with BMI ≥40 kg/m² undergoing planned robotic hysterectomy. Our primary outcome was the rate of all-cause perioperative complications in patients undergoing surgery with the use of the HBP.

DESIGN

A retrospective cohort study.

SETTING

An academic teaching hospital.

PATIENTS

A total of 138 patients classified as morbidly obese (BMI ≥40 kg/m²) undergoing robotic hysterectomy.

INTERVENTIONS

The HBP was developed by a multidisciplinary team and was instituted on January 1, 2016, as a quality improvement project. Patients classified as morbidly obese undergoing robotic hysterectomy after this date were compared with consecutive historical controls.

MEASUREMENTS AND MAIN RESULTS

Seventy-two patients underwent robotic hysterectomies on the HBP and were compared with 66 controls. There were no differences in age, BMI, blood loss, number of comorbidities, or cancer diagnosis. Since the implementation of the HBP, there has been a decrease in anesthesia time (-57.0 minutes; p = .001) and total operating room time (-47.0 min; p = .020), as well as lower estimated blood loss (median 150 mL [interquartile range 100-200] vs 200 mL [interquartile range 100-300]; p = .002) and reduction in overnight hospital admissions (33.3% vs 63.6%; p <.001). In the HBP group, there were fewer all-cause complications (19.4% vs 37.9%; p = .023) and infectious complications (8.3% vs 33.3%; p = .001), and there was no increase in the readmission rates (p = .400). In multivariable analysis, the HBP reduced all-cause complications (odds ratio 0.353; p = .010) after controlling for the covariate (total time in the operating room).

CONCLUSION

The HBP is a feasible method of optimizing the outcome for patients classified as morbidly obese undergoing major gynecologic surgery. Initiation of the HBP can lead to decreased anesthesia and operating times, all-cause complications, and overnight hospital admissions without increasing readmission rates.

Pregabalin does not decrease acute pain or postoperative nausea and vomiting after hysterectomy: a meta-analysis

OBJECTIVE

Hysterectomy is associated with severe postoperative pain. The relative efficacy of pregabalin compared with other treatments for post-hysterectomy pain is unclear.

METHODS

We searched the PubMed, Cochrane Library, and Web of Science databases for studies that compared the use of pregabalin and placebo for reducing pain in patients undergoing hysterectomy.

RESULTS

This meta-analysis showed that pregabalin had limited pain-relieving effects at 2, 6, 24, and 48 hours after hysterectomy compared with placebo. Pregabalin significantly reduced postoperative nausea and vomiting. However, there was no significant difference in postoperative sedation or visual disturbances between patients treated with pregabalin and placebo.

CONCLUSIONS

Pregabalin is not clinically superior to placebo in terms of reducing pain intensity and morphine consumption in patients undergoing hysterectomy. However, the limitations of this meta-analysis mean that more high-quality randomized controlled trials are necessary to verify our pooled results.