Vasoplegic endothelial dysfunction in orthotopic liver transplantation

Postoperative vasoplegia in lung transplantation: incidence and relation to outcome

BACKGROUND

The incidence and clinical importance of vasoplegia after lung transplantation remains poorly studied. We describe the incidence of vasoplegia and its association with complications after lung transplantation.

METHODS

Perioperative data of 279 lung transplant recipients operated on from 2015 to 2020 were retrospectively analysed.

RESULTS

Vasoplegia occurred in 41.6% of patients after lung transplantation (mild, 31.0%; moderate, 55.2%; severe, 13.8%). Compared with non-vasoplegic patients, vasoplegic patients had a higher incidence of any acute kidney injury, defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria (78.5% vs 65%, P=0.015), renal replacement therapy (47.4% vs 24.5%, P<0.001), and delayed chest closure (18.4% vs 9.2%, P=0.025); were ventilated longer (70 [32-368] vs 34 [19-105] h, P<0.001); and stayed longer in the ICU (12.9 [5-30] vs 6.8 [3-20] days, P<0.001). Mortality at 30 days and 1 yr was higher in patients with vasoplegia (11.2% vs 5.5% and 20.7% vs 11.7%, P=0.039, respectively). Severe vasoplegia represented a predictor of longer-term mortality (hazard ratio=1.65, P=0.008). Underlying infectious disease, increased BMI, higher preoperative pulmonary artery systolic pressure and bilirubin levels, lower glomerular filtration rate, and increased fresh frozen plasma transfusion were predictors of vasoplegia severity. Neutrophilia, leucocytosis, and increased C-reactive protein were associated with vasoplegia, but release of the neutrophil activation markers myeloperoxidase and heparin-binding protein was similar between groups.

CONCLUSIONS

Influenced by preoperative status as well as procedural factors and inflammatory response, vasoplegia is a common and critical condition after lung transplantation with worse short-term outcomes and long-term survival.

Effect of methylene blue on hemodynamic response in the early phase of septic shock: A case series

RATIONALE

Methylene blue (MB) has been used to increase blood pressure in septic shock, acting on the activity of guanylate cyclase and nitric oxide synthase.

PATIENCE CONCERNS

The aim of this study is to demonstrate the benefit of MB in early phase of septic shock.Diagnoses: We report 6 cases of patients with septic shock with up to 72 hours of evolution.

INTERVENTIONS

We used MB after fluid replacement, use of norepinephrine and vasopressin. Patients received a loading dose of MB and maintenance for 48 hours.

OUTCOMES

All patients presented a reduction in the dose of vasopressors and lactate levels soon after the administration of the loading dose of MB, an effect that was maintained with the maintenance dose for 48 hours. Interleukin 6 and interleukin 8 were elevated at the beginning of the septic condition, with a progressive and marked reduction after the beginning of MB infusion, demonstrating a role of MB in reducing the inflammatory activity.

LESSONS

This case series suggests that MB used early in the treatment of septic shock may be useful in reducing vasopressor dose and lactate levels. Further studies are still required to further validate these findings.

Effect of Hepatic Preconditioning with the Use of Methylene Blue on the Liver of Wistar Rats Submitted to Ischemia and Reperfusion

BACKGROUND

The liver may be injured in situations where it is submitted to ischemia, such as partial hepatectomy and liver transplantation. In all cases, ischemia is followed by reperfusion and, although it is essential for the reestablishment of tissue function, reperfusion may cause greater damage than ischemia, an injury characterized as ischemia-reperfusion (I/R) damage. The aim of this work was to analyze the effect of ischemic preconditioning with the use of methylene blue (MB; 15 mg/kg) 5 or 15 minutes before I/R (IRMB5' and IRMB15', respectively) on the hepatic injury occurring after I/R.

METHODS

Twenty-eight male Wistar rats were used, and liver samples submitted to partial ischemia (IR) or not (NI) were obtained from the same animal. The samples were divided into 7 groups. Data were analyzed statistically by means of the nonparametric Mann-Whitney test and Wilcoxon Matched test, with the level of significance set at 5% (P < .05).

RESULTS

The rate of oxygen consumption by state 3 mitochondria was inhibited in all ischemic groups compared with the sham group (SH vs IR: P = .0052; SH vs IRMB5': P = .0006; SH vs IRMB15': P = .0048), which did not occur in the nonischemic contralateral portion of the same liver (SH vs NI: P = .7652; SH vs NIMB5': P = .059; SH vs NIMB15': P = .3153). The inhibition of the rate of oxygen consumption by state 3 mitochondria was maintained in the presence of MB (IR vs IRMB5': P = .4563; IR vs IRMB15': P = .9021). The respiratory control ratio was reduced in all ischemic groups compared with the sham group, owing to the inhibition of oxygen consumption in state 3 (SH vs IR: P = .0151; SH vs IRMB5': P = .005; SH vs IRMB15': P = .0007).

CONCLUSIONS

Methylene blue had no effect on the mitochondrial respiratory parameters studied, but was able to reduce lipid peroxidation, preventing the production of reactive oxygen species (SH vs IRMB15': P = .0210).