Effects of perioperative hypothermia and reactive oxygen species in the healing of colonic anastomosis in rats

Temperature Changes During Electrophysiology Ablation in Veterans and 1-Year Success Rates: A Retrospective Pilot Analysis

OBJECTIVES

The authors hypothesized that body core temperature during cardiac arrhythmia procedures in the electrophysiology laboratory declines, and examined the association of changes with the patient or procedural factors. They hypothesized that a greater degree of change negatively affects 1-year ablation success.

DESIGN

Retrospective observational study.

SETTING

Veteran's Administration Boston Healthcare System.

PARTICIPANTS

Consecutive records of veterans undergoing ablation procedures under general anesthesia.

INTERVENTIONS

Retrospective data collection and analysis from the electronic medical record.

MEASUREMENTS AND MAIN RESULTS

Patient and procedural characteristics were collected from the electronic medical record. Core temperature data included baseline (BT) (following entry to the care process on the day of the procedure), the start (ST) and end of the procedure temperatures (ET), and their differences. The 1-year ablation success was assessed as described elsewhere in the literature. The authors used the paired t-test, linear, and logistic regression for hypothesis testing. Among 107 veterans, core temperatures were significantly lower between BT and ST, BT and ET, and ST and ET (p < 0.001 for all). One-year ablation success was 74.8% (n = 80). In multivariate logistic regression adjusted for age, body mass index and BTs showed a greater degree of change from BT to ET, and the ST-to-ET temperature was significantly associated with lower odds of success (odds ratios of 0.57 and 0.42, respectively; p < 0.05 for both).

CONCLUSIONS

Core temperature declines during ablation. Greater temperature decline during general anesthesia was associated with lower 1-year ablation success rates.

Detrimental effect of intraoperative hypothermia on pancreatic fistula after pancreaticoduodenectomy: A single-centre retrospective study

BACKGROUND

Although perioperative hypothermia was found to be associated with gastrointestinal anastomotic leakage in preclinical studies, its association with postoperative pancreatic fistula (POPF) following pancreaticoduodenectomy was never evaluated. We investigated the association between intraoperative hypothermia and clinically relevant (CR)-POPF following pancreaticoduodenectomy.

METHODS

We retrospectively reviewed 2163 consecutive patients who underwent pancreaticoduodenectomy during 2007-2019. Based on intraoperative time-weighted average core temperature, patients were grouped into normothermia (36.0-37.5°C), mild hypothermia (35.0-<36.0°C), and severe hypothermia (<35°C). We conducted multivariable logistic regression analysis for CR-POPF, a propensity score analysis using inverse probability of treatment weighting (IPTW) to adjust the baseline differences between the three groups, followed by multivariable logistic regression with IPTW for CR-POPF.

RESULTS

Among the 2008 patients analysed, 1118 (55.7%) and 120 (6.0%) had mild and severe hypothermia, respectively, and 14.2% overall incidence of CR-POPF. Severe intraoperative hypothermia was significantly associated with CR-POPF before and after IPTW (before: odds ratio [OR] 1.79, 95% confidence interval [CI]: 1.03-3.09, P = .038; after: OR 2.48, 95% CI: 1.28-4.81, P = .007); however, mild hypothermia had no significant associations.

CONCLUSION

Severe intraoperative hypothermia is significantly associated with the occurrence of CR-POPF following pancreaticoduodenectomy, suggesting that hypothermia is deleterious on pancreaticojejunal anastomotic healing.

Effect of ulinastatin combined with mild therapeutic hypothermia on intestinal barrier dysfunction following cardiopulmonary resuscitation in rats

The aim of the present study was to investigate the effect of ulinastatin (UTI) alone or combined with mild therapeutic hypothermia (MTH) on intestinal barrier dysfunction following cardiopulmonary resuscitation (CPR) in rats. A total of 25 adult male Sprague-Dawley rats were randomly organized into five groups: Sham; control; UTI; MTH; and the combined group. The latter four groups were induced with the asphyxiated cardiac arrest rat model and treated with different interventions. After 6 h of treatment, the intestinal tissues of the rats were examined by electron microscopy, and the levels of intestinal malondialdehyde (MDA) and superoxide dismutase (SOD) were determined. The results of the present study indicated that the target temperature had successfully been attained in MTH and the combined group, and the other three groups of rats all survived at a normal temperature. In the rats treated with UTI or MTH, the epithelial cells exhibited pathological changes in their tight junctions and epithelial cell surface microvilli compared with the sham group. In the rats treated with a combination of UTI and MTH, whilst the epithelial cells exhibited a few slight changes, including mitochondrial edema, they were largely similar to the normal epithelial cells. However, there were significant differences in the levels of MDA and SOD between the different treatment groups. UTI combined with MTH may serve a protective role by suppressing oxidative stress in the small intestinal mucosa following CPR in rats compared with either UTI or MTH treatment alone.

DHA reduces oxidative stress following hypoxia-ischemia in newborn piglets: a study of lipid peroxidation products in urine and plasma

BACKGROUND

Lipid peroxidation mediated by reactive oxygen species is a major contributor to oxidative stress. Docosahexaenoic acid (DHA) has anti-oxidant and neuroprotective properties. Our objective was to assess how oxidative stress measured by lipid peroxidation was modified by DHA in a newborn piglet model of hypoxia-ischemia (HI).

METHODS

Fifty-five piglets were randomized to (i) hypoxia, (ii) DHA, (iii) hypothermia, (iv) hypothermia+DHA or (v) sham. All groups but sham were subjected to hypoxia by breathing 8% O2. DHA was administered 210 min after end of hypoxia and the piglets were euthanized 9.5 h after end of hypoxia. Urine and blood were harvested at these two time points and analyzed for F4-neuroprostanes, F2-isoprostanes, neurofuranes and isofuranes using UPLC-MS/MS.

RESULTS

F4-neuroprostanes in urine were significantly reduced (P=0.006) in groups receiving DHA. Hypoxia (median, IQR 1652 nM, 610-4557) vs. DHA (440 nM, 367-738, P=0.016) and hypothermia (median, IQR 1338 nM, 744-3085) vs. hypothermia+DHA (356 nM, 264-1180, P=0.006). The isoprostane compound 8-iso-PGF2α was significantly lower (P=0.011) in the DHA group compared to the hypoxia group. No significant differences were found between the groups in blood.

CONCLUSION

DHA significantly reduces oxidative stress by measures of lipid peroxidation following HI in both normothermic and hypothermic piglets.