Determinants of Lactic Acidosis in Acute Cyanide Poisonings:

Acute kidney injury in patients with burns

Burn injury is associated with a high risk of acute kidney injury (AKI) with a prevalence of AKI among patients with burns of 9-50%. Despite an improvement in burn injury survival in the past decade, AKI in patients with burns is associated with an extremely poor short-term and long-term prognosis, with a mortality of >80% among those with severe AKI. Factors that contribute to the development of AKI in patients with burns include haemodynamic alterations, burn-induced systemic inflammation and apoptosis, haemolysis, rhabdomyolysis, smoke inhalation injury, drug nephrotoxicity and sepsis. Early and late AKI after burn injury differ in their aetiologies and outcomes. Sepsis is the main driver of late AKI in patients with burns and late AKI has been associated with higher mortality than early AKI. Prevention of early AKI involves correction of hypovolaemia and avoidance of nephrotoxic drugs (for example, hydroxocobalamin), whereas prevention of late AKI involves prevention and early recognition of sepsis as well as avoidance of nephrotoxins. Treatment of AKI in patients with burns remains supportive, including prevention of fluid overload, treatment of electrolyte disturbance and use of kidney replacement therapy when indicated.

Development of a prehospital lactic acidosis score for early-mortality. A prospective, multicenter, ambulance-based, cohort study

BACKGROUND

Lactic acidosis is a clinical status related to clinical worsening. Actually, higher levels of lactate is a well-established trigger of emergency situations. The aim of this work is to build-up a prehospital early warning score to predict 2-day mortality and intensive care unit (ICU) admission, constructed with other components of the lactic acidosis besides the lactate.

METHODS

Prospective, multicenter, observational, derivation-validation cohort study of adults evacuated by ambulance and admitted to emergency department with acute diseases, between January 1st, 2020 and December 31st, 2021. Including six advanced life support, thirty-eight basic life support units, referring to four hospitals (Spain). The primary and secondary outcome of the study were 2-day all-cause mortality and ICU-admission. The prehospital lactic acidosis (PLA) score was derived from the analysis of prehospital blood parameters associated with the outcome using a logistic regression. The calibration, clinical utility, and discrimination of PLA were determined and compared to the performance of each component of the score alone.

RESULTS

A total of 3334 patients were enrolled. The final PLA score included: lactate, pCO2, and pH. For 2-day mortality, the PLA showed an AUC of 0.941 (95%CI: 0.914-0.967), a better performance in calibration, and a higher net benefit as compared to the other score components alone. For the ICU admission, the PLA only showed a better performance for AUC: 0.75 (95%CI: 0.706-0.794).

CONCLUSIONS

Our results showed that PLA predicts 2-day mortality better than other lactic acidosis components alone. Including PLA score in prehospital setting could improve emergency services decision-making.

A comprehensive review of treatments for hydrogen sulfide poisoning: past, present, and future

Hydrogen sulfide (H₂S) poisoning remains a significant source of occupational fatalities and is the second most common cause of toxic gas-induced deaths. It is a rapidly metabolized systemic toxicant targeting the mitochondria, among other organelles. Intoxication is mostly acute, but chronic or in-between exposure scenarios also occur. Some genetic defects in H₂S metabolism lead to lethal chronic H₂S poisoning. In acute exposures, the neural, respiratory, and cardiovascular systems are the primary target organs resulting in respiratory distress, convulsions, hypotension, and cardiac irregularities. Some survivors of acute poisoning develop long-term sequelae, particularly in the central nervous system. Currently, treatment for H₂S poisoning is primarily supportive care as there are no FDA-approved drugs. Besides hyperbaric oxygen treatment, drugs in current use for the management of H₂S poisoning are controversial. Novel potential drugs are under pre-clinical research development, most of which target binding the H₂S. However, there is an acute need to discover new drugs to prevent and treat H₂S poisoning, including reducing mortality and morbidity, preventing sequalae from acute exposures, and for treating cumulative pathology from chronic exposures. In this paper, we perform a comprehensive review of H₂S poisoning including perspectives on past, present, and future.

Severe lactic acidosis from acute cyanide poisoning after intentional amygdalin ingestion in a teenager

Cyanide poisoning via the oral route is a remarkably rare entity in the United States. Though acute toxicity from this poison may present with classic signs and symptoms (smell of bitter almonds on breath and cherry-red skin), these signs are frequently not clinically observed in the intoxicated patient, making it low on the routine differential diagnosis leading to both diagnostic and therapeutic challenges for the bedside clinician. This is a case of a 17-yearold male with a history of depression who presented to the Emergency Room (ER) with altered mental status, abdominal pain, and emesis. A severely elevated and worrisome lactic acidosis triggered the ER’s septic shock bundle and algorithm, but further investigation ultimately led to the unifying diagnosis of intentional cyanide poisoning.

Management of severe thermal burns in the acute phase in adults and children

OBJECTIVES

To provide recommendations to facilitate the management of severe thermal burns during the acute phase in adults and children.

DESIGN

A committee of 20 experts was asked to produce recommendations in six fields of burn management, namely, (1) assessment, admission to specialised burns centres, and telemedicine; (2) haemodynamic management; (3) airway management and smoke inhalation; (4) anaesthesia and analgesia; (5) burn wound treatments; and (6) other treatments. At the start of the recommendation-formulation process, a formal conflict-of-interest policy was developed and enforced throughout the process. The entire process was conducted independently of any industry funding. The experts drew up a list of questions that were formulated according to the PICO model (Population, Intervention, Comparison, and Outcomes). Two bibliography experts per field analysed the literature published from January 2000 onwards using predefined keywords according to PRISMA recommendations. The quality of data from the selected literature was assessed using GRADE® methodology. Due to the current paucity of sufficiently powered studies regarding hard outcomes (i.e. mortality), the recommendations are based on expert opinion.

RESULTS

The SFAR guidelines panel generated 24 statements regarding the management of acute burn injuries in adults and children. After two scoring rounds and one amendment, strong agreement was reached for all recommendations.

CONCLUSION

Substantial agreement was reached among a large cohort of experts regarding numerous strong recommendations to optimise the management of acute burn injuries in adults and children.

Association between hydroxocobalamin administration and acute kidney injury after smoke inhalation: a multicenter retrospective study

Background

The use of hydroxocobalamin has long been advocated for treating suspected cyanide poisoning after smoke inhalation. Intravenous hydroxocobalamin has however been shown to cause oxalate nephropathy in a single-center study. The impact of hydroxocobalamin on the risk of acute kidney injury (AKI) and survival after smoke inhalation in a multicenter setting remains unexplored.

Methods

We conducted a multicenter retrospective study in 21 intensive care units (ICUs) in France. We included patients admitted to an ICU for smoke inhalation between January 2011 and December 2017. We excluded patients discharged at home alive within 24 h of admission. We assessed the risk of AKI (primary endpoint), severe AKI, major adverse kidney (MAKE) events, and survival (secondary endpoints) after administration of hydroxocobalamin using logistic regression models.

Results

Among 854 patients screened, 739 patients were included. Three hundred six and 386 (55.2%) patients received hydroxocobalamin. Mortality in ICU was 32.9% (n = 243). Two hundred eighty-eight (39%) patients developed AKI, including 186 (25.2%) who developed severe AKI during the first week. Patients who received hydroxocobalamin were more severe and had higher mortality (38.1% vs 27.2%, p = 0.0022). The adjusted odds ratio (95% confidence interval) of AKI after intravenous hydroxocobalamin was 1.597 (1.055, 2.419) and 1.772 (1.137, 2.762) for severe AKI; intravenous hydroxocobalamin was not associated with survival or MAKE with an adjusted odds ratio (95% confidence interval) of 1.114 (0.691, 1.797) and 0.784 (0.456, 1.349) respectively.

Conclusion

Hydroxocobalamin was associated with an increased risk of AKI and severe AKI but was not associated with survival after smoke inhalation.

Trial registration

ClinicalTrials.gov, NCT03558646

Cyanide and lactate levels in patients during chronic oral amygdalin intake followed by intravenous amygdalin administration

The natural compound amygdalin has gained high popularity among tumor patients as a complementary or alternative treatment option. However, due to metabolization of amygdalin to cyanide (HCN) following oral consumption, there could be a high risk of lactic acidosis caused by cyanide intoxication. The present retrospective study was undertaken to evaluate cyanide blood and lactate plasma levels of tumor patients (n = 55) before and after intravenous (i.v.) amygdalin infusion. All patients had also continuously ingested amygdalin tablets (3 x 500 mg/day), excepting on the days of i.v. administration. Each patient received one to five intravenous amygdalin treatments. The time period between each i.v. application ranged between 4-6 days. The initial i.v. dose was 6 mg (n = 28), 9 mg (n = 1), 15 mg (n = 1) or 18 mg (n = 25). The mean cyanide blood level before i.v. amygdalin administration was 34.74 μg/L, which increased significantly to a mean value of 66.20 μg/L after i. v. amygdalin application. In contrast, lactate decreased significantly from 1266 μmol/L pre-infusion to 868 μmol/L post-infusion. Increasing i.v. amygdalin by 1 mg was also associated with a significant increase in the cyanide level, while the lactate blood level significantly decreased. This is the first study evaluating cyanide levels under conditions employed by amygdalin administrators, i.e. after chronic oral amygdalin intake and then again after a closely subsequent intravenous amygdalin administration. Since lactate decreased, whilst cyanide increased, it is concluded that elevation of cyanide does not induce metabolic acidosis in terms of an increased lactate level.