Efficacy of programmed intermittent bolus epidural analgesia in thoracic surgery: a randomized controlled trial

Background

Continuous epidural infusion (CEI) has some disadvantages, such as increased local anesthetic consumption and limited area of anesthetic distribution. Programmed intermittent bolus (PIB) is a technique of epidural anesthesia in which boluses of local anesthetic are automatically injected into the epidural space. The usefulness of PIB in thoracic surgery remains unclear. In this study, we aimed to compare the efficacies of PIB epidural analgesia and CEI in patients undergoing thoracic surgery.

Methods

This randomized prospective study was approved by the Institutional Review Board. The study included 42 patients, who were divided into CEI (n = 21) and PIB groups (n = 21). In the CEI group, patients received continuous infusion of the local anesthetic at a rate of 5.1 mL/90 min. In the PIB group, a pump delivered the local anesthetic at a dose of 5.1 mL every 90 min. The primary endpoints were the frequency of patient-controlled analgesia (PCA) and the total dose of local anesthetic until 36 h following surgery. Student’s t-test, the chi-square test, and the Mann–Whitney U test were used for statistical analyses.

Results

The mean number of PCA administrations and total amount of local anesthetic were not significantly different between the two groups up to 24 h following surgery. However, the mean number of PCA administrations and total amount of local anesthetic at 24–36 h after surgery were significantly lower in the PIB group than in the CEI group (median [lower–upper quartiles]: 0 [0–2.5] vs. 2 [0.5–5], P = 0.018 and 41 [41–48.5] vs. 47 [43–56], P = 0.035, respectively). Hypotension was significantly more frequent in the PIB group than in the CEI group at 0–12 h and 12–24 h (3.3% vs. 0.5%, P = 0.018 and 7.9% vs. 0%, P = 0.017, respectively).

Conclusion

PIB can reduce local anesthetic consumption in thoracic surgery. However, it might result in adverse events, such as hypotension.

Trial registration

This randomized prospective study was approved by the Institutional Review Board (IRB No. 15-9-06) of the Fukuoka University Hospital, Fukuoka, Japan, and was registered in the clinical trials database UMIN (ID 000019904) on 24 November 2015. Written informed consent was obtained from all patients.

Development of genotyping method for functionally relevant variants of cytochromes P450 in cynomolgus macaques

In cynomolgus macaques (Macaca fascicularis), widely used in drug metabolism studies, CYP2C9, CYP2C76, CYP2D6, CYP3A4, and CYP3A5, important drug-metabolizing enzymes, are abundantly expressed in liver and metabolize cytochrome P450 substrates. CYP2C9 (c.334A>C), CYP2C76 (c.449TG>A), CYP2D6 (c.891A>G), CYP3A4 (IVS3 + 1G>del), and CYP3A5 (c.625A>T) substantially influence metabolic activity of enzymes, and thus are important variants in drug metabolism studies. In this study, a real-time PCR method was developed for genotyping these variants. The validity of the methods was verified by genotyping two wild type, two heterozygous, and two homozygous DNAs and was used to genotype 41 cynomolgus macaques (from Cambodia, Indonesia, the Philippines, or Vietnam) for the five variants, along with another important variant CYP2C19 (c.308C>T). The CYP2C9 and CYP2C19 variants were found only in Cambodian and Vietnamese animals, while the CYP2C76 and CYP2D6 variants were found only in Indonesian and Philippine animals. The CYP3A4 and CYP3A5 variants were not found in any of the animals analyzed. Mauritian animals, genotyped using next-generation sequencing data for comparison, possessed the CYP2C19 and CYP2D6 variants, but not the other variants. These results indicated differences in prevalence of these important variants among animal groups. Therefore, the genotyping tool developed is useful for drug metabolism studies using cynomolgus macaques.

Scalloped tongue is associated with nocturnal intermittent hypoxia among community-dwelling Japanese: the Toon Health Study

Scalloped tongue is considered as a possible clinical finding of obstructive sleep apnoea (OSA). There are few evidence of the association between scalloped tongue and OSA. To examine the association between scalloped tongue and nocturnal intermittent hypoxia (NIH), a surrogate marker of OSA, among a general Japanese population. Study participants were 398 men and 732 women aged 30-79 years who participated in the Toon Health Study from 2011 to 2014. Scalloped tongue was classified into three categories: none, mild and moderate-to-severe. Moderate-to-severe NIH was defined as the 3% oxygen desaturation index of ≥15 events/h during sleep for one night with pulse oximetry. The multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for moderate-to-severe NIH were calculated according to scalloped tongue categories using a logistic regression model. There were 69 (6·1%) moderate-to-severe NIH cases in this population. The multivariable-adjusted ORs (95% CIs) of moderate-to-severe NIH were 1·59 (0·85-2·95) for mild and 2·39 (1·10-5·17) for the moderate-to-severe scalloped tongue group compared with the group without scalloped tongues. When stratified by overweight status (BMI <25 or ≥25 kg m^-2 ), the respective ORs (95% CIs) were 2·83 (1·06-7·55) and 4·74 (1·28-17·49) among overweight individuals, and 0·94 (0·40-2·70) and 1·52 (0·57-4·05) among non-overweight individuals. Scalloped tongue was associated with higher prevalence of moderate-to-severe NIH among the general Japanese population and this association was more evident in overweight individuals.

Impact of lesion characteristics on the prediction of optimal poststent fractional flow reserve

BACKGROUND

Poststent fractional flow reserve (FFR) is a useful indicator of optimal percutaneous coronary intervention, and higher poststent FFR is associated with favorable long-term clinical outcome. However, little is known about the factors influencing poststent FFR. The purpose of this study was to determine the impact of lesion characteristics on poststent FFR.

METHODS

For patients who had scheduled stent implantation for stable angina, FFR measurements at maximum hyperemia were performed before and after coronary stent implantation. As one of lesion characteristics, the FFR pressure drop pattern was evaluated and classified as either an abrupt or a gradual pattern according to the pullback curve of FFR.

RESULTS

A total of 205 lesions with physiological significant stenosis were evaluated. Fractional flow reserve value increased from 0.67±0.10 to 0.87±0.07 after stent implantation. Optimal poststent FFR was achieved in 75 lesions (36.6%). Logistic regression analysis demonstrated that optimal poststent FFR was positively correlated with an abrupt pressure drop pattern (hazard ratio [HR] 2.11, 95% CI 1.06-4.15, P=.03) and prestent FFR (HR 1.04, 95% CI 1.03-2.04, P=.03; per 0.1 increase), and negatively correlated with lesion localization to the left anterior descending artery (HR 0.18, 95% CI 0.09-0.36, P<.0001). The c statistic for predicting optimal poststent FFR was 0.763 (95% CI 0.702-0.819).

CONCLUSION

Abrupt pressure drop patterns, prestent FFR, and lesion localization to the left anterior descending artery were independent predictors of optimal poststent FFR.