The prognostic value of elevated neutrophil–lymphocyte ratio for cardiac surgery-associated acute kidney injury: A systematic review and meta-analysis

Background

Patients undergoing cardiac surgery are at significant risk of developing postoperative acute kidney injury (AKI). Neutrophil–lymphocyte ratio (NLR) is a widely available inflammatory biomarker which may be of prognostic value in this setting.

Methods

We conducted a systematic review and meta-analysis of studies reporting associations between perioperative NLR with postoperative AKI. We searched Medline, Embase and the Cochrane Library, without language restriction, from inception to May 2022 for relevant studies. We meta-analysed the reported odds ratios (ORs) with 95% confidence intervals (CIs) for both elevated preoperative and postoperative NLR with risk of postoperative AKI and need for renal replacement therapy (RRT). We conducted a meta-regression to explore inter-study statistical heterogeneity.

Results

Twelve studies involving 10,724 participants undergoing cardiac surgery were included, with eight studies being deemed at high risk of bias using PROBAST modelling. We found statistically significant associations between elevated preoperative NLR and postoperative AKI (OR 1.45, 95% CI 1.18–1.77), as well as postoperative need for RRT (OR 2.37, 95% CI 1.50–3.72). Postoperative NLR measurements were not of prognostic significance.

Conclusions

Elevated preoperative NLR is a reliable inflammatory biomarker for predicting AKI following cardiac surgery.     

Remote photobiomodulation: an emerging strategy for neuroprotection

<正>Photobiomodulation (PBM)-the irradiation of cells or tissues with low-intensity red to near-infrared light-is emerging as an effective means of enhancing cell and tissue resilience and repair. As reviewed elsewhere (Gordon et al., 2019), the intracellular effects of     

Insurance-mandated preoperative dietary counseling does not improve outcome and increases dropout rates in patients considering gastric bypass surgery for morbid obesity

BACKGROUND: Preoperative dietary counseling (PDC) before bariatric surgery is mandated by a growing number of insurance payers. Their claim is that PDC improves outcomes and postoperative compliance. We compared outcomes of GBP patients undergoing a mandatory 13 weeks of PDC (n = 72) to a contemporaneous group of patients with no such requirement (no-PDC; n = 252) who underwent operation between January 2000 and December 2002. METHODS: The PDC and no-PDC groups were characterized by similar male:female ratios (1:4 vs 1:4.6), mean age (42 years), mean body weight (324 lb vs 309 lb), and mean body mass index (BMI) (52 kg/m2 vs 50 kg/m2). The PDC group had a higher incidence of obstructive sleep apnea compared with the no-PDC group (41% vs 28%; P < .04) but otherwise the two groups had similar incidences of obesity-related comorbidities. The presurgery dropout rate was 50% higher in the PDC group than in the no-PDC group (28% vs 19%; P < .05). RESULTS: At 1 year follow-up, the no-PDC patients had a statistically greater percentage excess weight loss (67% vs 60%; P < .0001), lower BMI (32 vs 35; P < .015), and lower body weight (197 vs 218; P < .01). Resolution of major comorbidities, complication rates, 30-day postoperative mortality, and postoperative compliance with follow-up were similar in the two groups. CONCLUSIONS: The data demonstrate that insurance-mandated PDC is an obstacle to patient access for surgical treatment of severe obesity and has no impact on weight loss outcome or postsurgical compliance. PDC should be abandoned by the insurance industry.     

Additive Effects of Sevoflurane and Propofol on γ-Aminobutyric Acid Receptor Function

Background: Previous studies have shown that propofol and sevoflurane enhance the function of [gamma]-aminobutyric acid type A (GABAA) receptors. However, it is not known whether these two drugs modulate the same molecular pathways. In addition, little is known about receptor function in the presence of both propofol and sevoflurane. The aim of this study was to better understand the interactions of propofol and sevoflurane with the GABAA receptor.

Methods: Wild-type [alpha]1, [beta]2, [gamma]2s GABAA receptor subunit complementary DNAs were transfected into human embryonic kidney cells grown on glass coverslips using a calcium phosphate transfection method. After transfection (36-72 h), cells were whole cell patch clamped and exposed to combinations of the following: 0.3-1,000 [mu]m [gamma]-aminobutyric acid (GABA), 0-10 [mu]m propofol, and 0-1,650 [mu]m sevoflurane. Chemicals were delivered to the cells using two 10-channel infusion pumps and a rapid solution exchanger.

Results: Both propofol and sevoflurane alone enhanced the amplitude of GABAA receptor responses to submaximal concentrations of GABA in a dose-dependent manner. The enhancement was underpinned by an increase in the apparent affinity of the receptor for GABA. Coapplication of both anesthetics further enhanced the apparent affinity of the receptor for GABA.     

Influence of pH on the binding of scopolamine and N-methylscopolamine to muscarinic receptors in the corpus striatum and heart of rats

The influence of pH on the binding of scopolamine and [3H]N-methylscopolamine to muscarinic receptors in the heart and corpus striatum was investigated. The specific binding of [3H]N-methylscopolamine in the heart and corpus striatum was relatively insensitive to pH over the range of 6 through 10 but decreased markedly below pH 6.0. This reduction in binding was attributed to a reversible decrease in the observed affinity without an effect on the binding capacity. The data are consistent with the postulate that [3H]N-methylscopolamine competes with hydrogen ions for an acidic group on the muscarinic receptor that has a pKA of approximately 5.5 in both the heart and corpus striatum. When measured by competitive inhibition of the binding of [3H]N-methylscopolamine, the affinity of scopolamine decreased relative to that of [3H]N-methylscopolamine as the pH increased from 6 to 10, confirming that it is primarily the protonated form of scopolamine that binds with muscarinic receptors.     

Evaluation of amphotericin B-cyclosporine interaction in the rat

Although a significant interaction between cyclosporine and amphotericin-B (AmpB) has been observed clinically, these findings have not been duplicated in animal studies. A total of 64 male albino rats were used in single- and multiple-dose experiments with AmpB and CsA in the absence or presence of systemic Candida infection. No significant differences in glomerular filtration rate were found in rats given single i.v. doses of AmpB 1 mg/kg compared with AmpB and CsA. Furthermore, rats given i.p. AmpB 1 mg/kg and CsA 10 mg/kg daily for 10 days showed no significant differences in GFR compared with animals given CsA alone. Morphology and CsA whole-blood pharmacokinetics were not different between groups administered single-dose CsA, AmpB, or the combination; similarities also existed with multiple-dose studies. In an attempt to mimic the clinical setting, 2 groups of rats were administered i.p. CsA 10 mg/kg/day for 10 days followed by inoculation of Candida albicans. After 48 hr, a single i.v. dose of AmpB 1.0 mg/kg was associated with a 33% decline in GFR compared with those given sterile water (P less than 0.05). Systemic clearance of CsA was markedly reduced in candidiasis rats administered AmpB compared with controls given sterile water. A significant reduction in renal Candida colony-forming units was found in rats given CsA and AmpB compared with those administered CsA alone. These data suggest that the presence of systemic Candida highlights the interaction of CsA and AmpB in the rat model.     

Studies on the protein-binding of drugs with continuous ultrafiltration. 8. In vitro quantification of the interactions of phenprocoumon, warfarin and methylsulfinyl warfarin with phenylbutazone on human serum albumin

Determination of the Protein Binding of Drugs by Continuous Ultrafiltration VIII: In vitro Quantification of the Interaction between Phenprocoumon, Warfarin or Methylsulfinylwarfarin (MSW) and Phenylbutazon at Human Serum Albumin. Interactions of the title anticoagulants in concentrations of 2.5 to 15 μmol/L with phenylbutazon up to concentrations of 0.6 mmol/L were determined. Concentrations of the unbound anticoagulant were raised up to 310% for phenprocoumon and 378% for warfarin. For MSW only an elevation up to 33% was observed. This was nearly constant for phenylbutazon concentrations of 0.2 to 0.6 mmol/L. MSW is therefore recommended for a safer handling of the antithrombotic therapy with oral anticoagulants.