[Ventilation in acute respiratory distress. Lung-protective strategies]

[Acute pancreatitis in intensive care medicine : Which risk score is useful?]

INTRODUCTION

Acute pancreatitis is a disease with an increasing incidence in the Western countries associated with a high mortality depending on severity of disease. Etiology is often biliary or due to alcoholism. Incidence of etiology varies between regions depending on risk-factor prevalence. Several risk scores are available to estimate mortality. The aim of the study is to identify the risk factors most relevant for patients being treated for severe acute pancreatitis in an ICU of a tertiary medical center.

PATIENTS AND METHODS

The retrospective cohort study included 91 patients (61.2% men, mean age 52 years) with severe acute pancreatitis who were treated between 2002 and 2013 at the medical ICU of a tertiary medical center. Risk factors were identified using COX regression analysis and associations were assessed with the χ² test.

RESULTS

Pulmonary failure necessitating ventilator support, renal failure requiring renal replacement therapy, need for vasopressor therapy, positive blood cultures, and bleeding complications were identified as risk factors for high mortality in severe acute pancreatitis. Low calcium and high lactate levels are independent risk factors for mortality.

CONCLUSION

Critically ill patients with severe pancreatitis have high mortality rates that can be estimated using risk scores. Weighting of risk factors may differ depending on region and severity of disease. For patients included in our study, the Ranson Criteria and the APACHE II Score may be most applicable.

Effects of different tidal volume ventilation on paraquat-induced acute lung injury in piglets

Background

The aim of this study was to explore the effects of different tidal volume (V_T) ventilation on paraquat-induced acute lung injury or acute respiratory distress syndrome (ALI/ARDS) in piglets.

Material/Methods

We developed ALI/ARDS models in piglets by intraperitoneal injection of paraquat (PQ). The piglets were randomly divided into three groups: small V_T group (V_T=6 ml/kg, n=6), middle V_T group (V_T=10 ml/kg, n=6), and large V_T group (V_T=15 ml/kg, n=6), with the positive end-expiratory pressure (PEEP) set as 10 cmH₂O. The hemodynamics were monitored by pulse-indicated continuous cardiac output (PiCCO) and the airway pressure changes and blood gas analysis indexes were recorded at different time points. The pathological changes were observed by lung puncture.

Results

The piglets showed ALI/ARDS in 4.5±0.8 hours after PQ intraperitoneal injection. PH, PaO₂ and oxygenation indexes in the three groups all decreased after modeling success compared with baseline, and PaCO₂ increased significantly. PH in the small VT group decreased most obviously after ventilation for 6 hours. PaO₂ and oxygenation indexes in the small VT group showed the most obvious increase after ventilation for 2 hours and were much higher than the other two groups after ventilation for 6 hours. PaCO₂ increased gradually after mechanical ventilation and the small VT group showed most obvious increase. The ELWI increased obviously after ventilation for 2 hours and then the small VT group clearly decreased. PIP and plateau pressure (Pplat) in the small VT group decreased gradually and in the middle and large VT group they increased after ventilation. The lung histopathology showed that the large VT group had the most severe damage and the small VT group had only minimal damage.

Conclusions

Small tidal volume ventilation combined with PEEP could alleviate the acute lung injury induced by paraquat and improve oxygenation.