Hyperchloremic Acidosis: Pathophysiology and Clinical Impact

Effect of Pre-Hospital Intravenous Fluids on Initial Metabolic Acid-Base Status in Trauma Patients: A Retrospective Cohort Study

Despite its known harmful effects, normal saline is still commonly used in the treatment of hypovolemia in polytrauma patients. Given the lack of pre-hospital research on this topic, the current study aims to assess the current practice of fluid administration during the pre-hospital phase of care and its effects on initial metabolic acid-base status in trauma patients. We extracted and completed data from patients recorded in the Lausanne University Hospital (CHUV) trauma registry between 2008 and 2019. Patients were selected according to their age, the availability of a blood gas analysis after arrival at the emergency room, data availability in the trauma registry, and the modality of arrival in the ED. The dominantly administered pre-hospital fluid was normal saline. No association between the type of fluid administered during the pre-hospital phase and the presence of hyperchloremic acidosis in the ED was observed.

Systematic review and meta-analysis of fluid therapy protocols in acute pancreatitis: type, rate and route

BACKGROUND

Adequate fluid resuscitation is paramount in the management of acute pancreatitis (AP). The aim of this study is to assess benefits and harms of fluid therapy protocols in patients with AP.

METHODS

MEDLINE, Embase, Science Citation Index and clinical trial registries were searched for randomised clinical trials published before May 2020, assessing types of fluids, routes and rates of administration.

RESULTS

A total 15 trials (1073 participants) were included. Age ranged from 38 to 73 years; follow-up period ranged from 0.5 to 6 months. Ringer lactate (RL) showed a reduced number of severe adverse events (SAE) when compared to normal saline (NS) (OR 0.48; 95%CI 0.29-0.81, p = 0.006); additionally, NS showed reduced SAE (RR 0.38; 95%IC 0.27-0.54, p < 0.001) and organ failure (RR 0.30; 95%CI 0.21-0.44, p < 0.001) in comparison with hydroxyethyl starch (HES). High fluid rate fluid infusion showed increased mortality (OR 2.88; 95%CI 1.41-5.88, p = 0.004), increased number of SAE (RR 1.42; 95%CI 1.04-1.93, p = 0.030) and higher incidence of sepsis (RR 2.80; 95%CI 1.51-5.19, p = 0.001) compared to moderate fluid rate infusion.

CONCLUSIONS

In patients with AP, RL should be preferred over NS and HES should not be recommended. Based on low-certainty evidence, moderate-rate fluid infusion should be preferred over high-rate infusion.

A retrospective analysis of the haemodynamic and metabolic effects of fluid resuscitation in Vietnamese adults with severe falciparum malaria

Background

Optimising the fluid resuscitation of patients with severe malaria is a simple and potentially cost-effective intervention. Current WHO guidelines recommend central venous pressure (CVP) guided, crystalloid based, resuscitation in adults.

Methods

Prospectively collected haemodynamic data from intervention trials in Vietnamese adults with severe malaria were analysed retrospectively to assess the responses to fluid resuscitation.

Results

43 patients were studied of whom 24 received a fluid load. The fluid load resulted in an increase in cardiac index (mean increase: 0.75 L/min/m² (95% Confidence interval (CI): 0.41 to 1.1)), but no significant change in acid-base status post resuscitation (mean increase base deficit 0.6 mmol/L (95% CI: −0.1 to 1.3). The CVP and PAoP (pulmonary artery occlusion pressure) were highly inter-correlated (r_s = 0.7, p<0.0001), but neither were correlated with acid-base status (arterial pH, serum bicarbonate, base deficit) or respiratory status (PaO₂/FiO₂ ratio). There was no correlation between the oxygen delivery (DO₂) and base deficit at the 63 time-points where they were assessed simultaneously (r_s = −0.09, p = 0.46).

Conclusions

In adults with severe falciparum malaria there was no observed improvement in patient outcomes or acid-base status with fluid loading. Neither CVP nor PAoP correlated with markers of end-organ perfusion or respiratory status, suggesting these measures are poor predictors of their fluid resuscitation needs.