Bicarbonate Therapy for Critically Ill Patients with Metabolic Acidosis: A Systematic Review

Effect of isotonic sodium bicarbonate infusion on perioperative acid-base status among patients undergoing emergency laparotomy for perforation peritonitis (ISABEL trial): a randomized controlled trial

PURPOSE

Perioperative metabolic acidosis negatively affects patient outcomes. Perioperative fluid therapy has a clinically significant effect on acid-base balance. This study was conducted to evaluate the effects of isotonic sodium bicarbonate infusion (ISB) versus balanced crystalloid solution (BCS) on perioperative acid-base balance, in terms of postoperative base excess, among patients undergoing emergency laparotomy for perforation peritonitis.

METHODS

This prospective, randomized, single-center, double-blinded study was conducted in a tertiary hospital from October 2021 to November 2022. A total of 90 patients undergoing emergency laparotomy for perforation peritonitis were randomly assigned to receive either isotonic sodium bicarbonate (ISB) or Ringer's Lactate as a balanced crystalloid solution (BCS) for perioperative maintenance fluid therapy. The primary outcome was to compare the base excess (BE) at the end of surgery. The secondary outcomes were to compare the postoperative clinical outcomes, including the requirement of vasopressors, duration of mechanical ventilation, HDU/ICU stay, the incidence of AKI within seven days, the incidence of re-exploration, and in-hospital mortality. Additionally, pH, PaCO2, HCO3, BE, and lactates intraoperatively and up to 24 h postoperatively were also compared.

RESULTS

The median base excess (BE) values at the end of surgery were significantly better in the ISB group - 4.80 [- 6.80, - 4.10] as compared to the BCS group - 7.30 [- 8.50, - 6.30]. The ISB group had a lower incidence of postoperative AKI (9% ISB versus 24% BCS) and requirement of vasopressors (18% ISB versus 44% BCS). However, there was no major difference between the incidence of re-exploration, length of ICU/HDU stay, and in-hospital mortality.

CONCLUSION

Infusing isotonic sodium bicarbonate (ISB) for intraoperative maintenance fluid therapy in patients undergoing emergency laparotomy for perforation peritonitis significantly improves perioperative acid-base balance with better postoperative clinical outcomes compared to a balanced crystalloid solution (BCS).

Acute and sub-acute toxicity study of aqueous and methanol root extract of Tetracera alnifolia in male albino rats

The aim of this study was to assess the acute and sub-acute toxicity of aqueous and methanol extracts of the root of Tetracera alnifolia as well as the effects on some biochemical parameters in albino rats as many plants used in traditional medicine lack scientific and clinical evidence to support a better understanding of their safety and efficacy. Phytochemical screening and proximate analysis of the pulverised root of Tetracera alnifolia was carried out using previously reported protocol. Sub-acute toxicity study of each extract was done for 28 days followed by organs function tests and histopathology studies of the liver, kidney and heart. Evaluation of lipid profile and oxidative stress marker to ascertain the effect of each extract on lipid peroxidation and their antioxidant property was done after administration of 200 mg/Kg body weight of each extract for a period of thirty-five days. Acute toxicity study of each extract gave oral LD50 (rat) of greater than 5000 mg/kg body weight with no signs of toxicity. Sub-acute toxicity study showed both extracts were non-toxic to the liver, kidney, heart and blood at doses between 200 and 3000 mg/Kg body weight assessed by the respective organ function tests, hematological parameters, and histopathology study. However, higher doses seem toxic to the liver particularly at 5000 mg/kg B. W due to increase in plasma AST, ALT and ALP activities accompanied with reduced protein and albumin concentrations. Effects of each extracts at 200 mg/Kg body weight on some biochemical parameters revealed no significant difference in lipid profile parameters and no lipid peroxidation. Each extract may possess antioxidant property due to increase in catalase activity. The result from this research may help validate the safety of the oral use of this plant in traditional medicine.

ISCCM Position Statement on the Management of Severe Malaria in Intensive Care Unit

Malaria is a worldwide health concern, but a great majority of cases occur in tropical countries like India. With almost 95% of Indian population living in malaria endemic regions, India contributes to most of the global malaria cases and deaths, outside of African countries. Despite significant advances towards malaria control and eradication, mortality associated with severe malaria remains particularly high. Changing epidemiology, vulnerable patient population, overlapping symptomatology, and limited availability of parenteral preparations of artemisinin derivatives pose significant challenges in management of severe malaria. Further, the dearth of large-scale randomized trials from the developing countries makes it difficult to establish evidence-based guidelines pertaining to their situation. Thus, this position paper aims to provide guidance to critical care physicians across the country on managing patients with severe malaria in intensive care units (ICUs).

HOW TO CITE THIS ARTICLE

Hegde A, Chhallani AK, Gupta B, Kadapatti K, Karnad D, Maheshwarappa HM, et al. ISCCM Position Statement on the Management of Severe Malaria in Intensive Care Unit. Indian J Crit Care Med 2024;28(S2):S59-S66.

Metabolic Acidosis in Children: A Literature Review

Metabolic acidosis is characterised by a primary decrease in the serum bicarbonate concentration, a secondary decrease in the arterial partial pressure of CO­2, and a reduction in blood pH. Metabolic acidosis, acute or chronic, may have deleterious effects on cellular function and cause increased morbidity and mortality. A systematic review of the available literature was performed to identify data on the prevalence, manifestations, cause, outcomes, and treatment of metabolic acidosis in children. Online databases (Ovid Medline, Embase, and PubMed), commercial search engines (including Google), and chapters on metabolic acidosis in the standard textbooks of paediatrics and medicine were reviewed. Systematic approach to acute metabolic acidosis starts with proper history taking and examination. This is followed by assessment of acid-base parameters, including pH, partial pressure of CO2, and bicarbonate concentration in arterial blood. Blood gas is needed to differentiate primary metabolic acidosis from compensated respiratory alkalosis. Once the diagnosis of a metabolic acidosis has been confirmed, serum electrolyte values are used to determine the serum anion gap. The various causes of increased and normal anion gap metabolic acidosis have been discussed in the article. The main aim of treatment in metabolic acidosis is to reverse the primary pathophysiology. In acute metabolic acidosis, sodium bicarbonate therapy is not beneficial due to potential complications and is reserved for specific situations. Base therapy is used in chronic metabolic acidosis where it ameliorates many of its untoward effects. Other modalities of treatment of metabolic acidosis include peritoneal or haemodialysis and tris-hydroxymethyl aminomethane.

Assessment of acute kidney injury risk using a machine-learning guided generalized structural equation model: a cohort study

Background

Acute kidney injury is common in the surgical intensive care unit (ICU). It is associated with poor patient outcomes and high healthcare resource usage. This study’s primary objective is to help identify which ICU patients are at high risk for acute kidney injury. Its secondary objective is to examine the effect of acute kidney injury on a patient’s prognosis during and after the ICU admission.

Methods

A retrospective cohort of patients admitted to a Singaporean surgical ICU between 2015 to 2017 was collated. Patients undergoing chronic dialysis were excluded. The outcomes were occurrence of ICU acute kidney injury, hospital mortality and one-year mortality. Predictors were identified using decision tree algorithms. Confirmatory analysis was performed using a generalized structural equation model.

Results

A total of 201/940 (21.4%) patients suffered acute kidney injury in the ICU. Low ICU haemoglobin levels, low ICU bicarbonate levels, ICU sepsis, low pre-ICU estimated glomerular filtration rate (eGFR) and congestive heart failure was associated with the occurrence of ICU acute kidney injury. Acute kidney injury, together with old age (> 70 years), and low pre-ICU eGFR, was associated with hospital mortality, and one-year mortality. ICU haemoglobin level was discretized into 3 risk categories for acute kidney injury: high risk (haemoglobin ≤9.7 g/dL), moderate risk (haemoglobin between 9.8–12 g/dL), and low risk (haemoglobin > 12 g/dL).

Conclusion

The occurrence of acute kidney injury is common in the surgical ICU. It is associated with a higher risk for hospital and one-year mortality. These results, in particular the identified haemoglobin thresholds, are relevant for stratifying a patient’s acute kidney injury risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02238-9.

Antidotal Sodium Bicarbonate Therapy: Delayed QTc Prolongation and Cardiovascular Events

BACKGROUND

Sodium bicarbonate therapy (SBT) is currently indicated for the management of a variety of acute drug poisonings. However, SBT effects on serum potassium concentrations may lead to delayed QTc prolongation (DQTP), and subsequent risk of adverse cardiovascular events (ACVE), including death. Emergency department (ED)-based studies evaluating associations between SBT and ACVE are limited; thus, we aimed to investigate the association between antidotal SBT, ECG changes, and ACVE.

METHODS

This was a secondary data analysis of a consecutive cohort of ED patients with acute drug overdose over 3 years. Demographic and clinical data as well as SBT bolus dosage and infusion duration were collected, and outcomes were compared with an unmatched consecutive cohort of patients with potential indications for SBT but who did not receive SBT. The primary outcome was the occurrence of ACVE, and secondary outcomes were delayed QTc (Bazett) prolongation (DQTP), and death. Propensity score and multivariable adjusted analyses were conducted to evaluate associations between adverse outcomes and SBT administration. Planned subgroup analysis was performed for salicylates, wide QRS (> 100 ms), and acidosis (pH < 7.2).

RESULTS

Out of 2365 patients screened, 369 patients had potential indications for SBT, of whom 31 (8.4%) actually received SBT. In adjusted analyses, SBT was found to be a significant predictor of ACVE (aOR 9.35, CI 3.6-24.1), DQTP (aOR 126.7, CI 9.8-1646.2), and death (aOR 11.9, CI 2.4-58.9). Using a propensity score model, SBT administration was associated with ACVE (OR 5.07, CI 1.8-14.0). Associations between SBT and ACVE were maintained in subgroup analyses of specific indications for sodium channel blockade (OR 21.03, CI 7.16-61.77) and metabolic acidosis (OR: 6.42, 95% CI: 1.20, 34.19).

CONCLUSION

In ED patients with acute drug overdose and potential indications for SBT, administration of SBT as part of routine clinical care was an independent, dose-dependent, predictor of ACVE, DQTP, and death. This study was not designed to determine whether the SBT or acute overdose itself was causative of ACVE; however, these data suggest that poisoned patients receiving antidotal SBT require close cardiovascular monitoring.