Endotracheal Intubation in the Pharmaceutical-Poisoned Patient: a Narrative Review of the Literature

Zinc Phosphide Poisoning: From A to Z

Zinc phosphide is a rodenticide that is used in agricultural, urban and industrial environments in México. After ingestion, it reacts with hydrochloric acid, hydrolyzing into phosphine. It causes cellular hypoxia via mitochondrial toxicity, resulting in multiple organ dysfunction and death. There is no antidote or specific treatment for zinc phosphide toxicity. We present the case of a 45-year-old female who ingested zinc phosphide with suicidal intent. On arrival at the emergency department, she had multisystemic disorders. Supportive care, decontamination and antidotal therapy were initiated. Subsequently, she evolved to clinical improvement with a resolution of the biochemical abnormalities of tissue hypoperfusion. She was discharged on day 7 without complications. In this review, we provide updated therapeutic options and discuss their specific pathophysiological basis.

Development and validation of a novel poisoning agitation-sedation score for predicting the need for endotracheal intubation and mechanical ventilation in acutely poisoned patients with disturbed consciousness

BACKGROUND

Accurate assessment of disturbed consciousness level (DCL) is crucial for predicting acutely poisoned patients' outcomes.

AIM

Development of a novel Poisoning Agitation-Sedation Score (PASS) to predict the need for endotracheal intubation (ETI) and mechanical ventilation (MV) in acutely poisoned patients with DCL. Validation of the proposed score on a new set of acutely poisoned patients with DCL.

METHODS

This study was conducted on 187 acutely poisoned patients with DCL admitted to hospital from June 2020 to November 2021 (Derivation cohort). Patients' demographics, toxicological data, neurological examination, calculation of the Glasgow Coma Scale (GCS), Full Outline of Unresponsiveness (FOUR) score, Richmond Agitation-Sedation Scale (RASS), and outcomes were gathered for developing a new score. The proposed score was externally validated on 100 acutely poisoned patients with DCL (Validation cohort).

RESULTS

The PASS assessing sedation consists of FOUR (reflexes and respiration) and GCS (motor) and provides a significantly excellent predictive power (AUC = 0.975) at a cutoff ≤9 with 100% sensitivity and 92.11% specificity for predicting the need for ETI and MV in sedated patients. Additionally, adding RASS (agitation) to the previous model exhibits significantly good predictive power (AUC = 0.893), 90.32% sensitivity, and 73.68% specificity at a cutoff ≤14 for predicting the need for ETI and MV in disturbed consciousness patients with agitation.

CONCLUSION

The proposed PASS could be an excellent, valid and feasible tool to predict the need for ETI and MV in acutely poisoned disturbed consciousness patients with or without agitation.

Risk of peri-intubation adverse events during emergency department intubation of overdose patients: a national emergency airway registry (near) analysis

BACKGROUND

More than 20,000 emergency department (ED) patients undergo intubation for overdose each year. While the characteristics of patients intubated for overdose and poisoning are well described, little is known about the intubation outcomes of overdose patients in the ED.

OBJECTIVES

We quantify the frequency of peri-intubation adverse events for patients intubated in the ED for overdose, and determine whether first attempt success without adverse events differs between patients intubated for overdose and patients intubated for other reasons.

METHODS

We analyzed data from the National Emergency Airway Registry (NEAR), a prospective multicenter registry of ED intubations collected from an international network of 22 academic and community hospitals. We included patients 14 years and older whose first attempt was oral intubation, with data entered into NEAR between 1 January 2016 and 31 December 2018. The primary outcome was successful intubation on the first attempt. We used multivariable logistic regression to determine whether indication was independently associated with successful intubation on the first attempt after adjusting for age, gender, obesity, initial impression of difficult airway, presence of difficult airway characteristics, and use of video laryngoscopy. Secondary outcomes included successful intubation on the first attempt without adverse events, the occurrence of rescue surgical airways, and the occurrence of adverse events. Adverse events included hypoxemia, hypotension, peri-intubation cardiac arrest, bradycardia, mechanical injury to oral or airway structures, vomiting, tachydysrhythmia, esophageal intubation, laryngospasm, and pneumothorax.

RESULTS

We analyzed 17,984 patients, including 1,983 (11%) intubated for overdose, and 16,001 (89%) intubated for other indications. Patients intubated for overdose were younger (median age 38 vs 55 years), were less frequently obese (26% vs 34%), and fewer had difficult airway characteristics (38% vs 53%). Overdose patients were more likely to have preoxygenation performed (45% vs 35%), more likely to have apenic oxygenation (39% vs 31%), and more likely to have bougie used (33% vs 17%). First attempt success was 90.5% in patients intubated for overdose and 87.5% in patients intubated for other reasons (absolute difference 3.0%; 95% CI: -1.3 to 7.3). First attempt success without adverse events was higher in overdose patients (85.0%) compared to other patients (78.7%) (absolute difference, 6.3%; 95% CI 1.0 to 11.7%). Overdose patients experienced significantly less hypotension (1.5% vs 4.1%), and tended to have fewer adverse events overall. Multivariable model results were consistent with the unadjusted results including no difference in first pass success (adjusted odd ratio 1.02 [95% CI 0.86-1.23]). There was a higher first pass success without complication in patients intubated for overdose (adjusted odds ratio 1.23; 95% CI 1.07 to1.43).

CONCLUSION

For patients in whom the primary indication for intubation is overdose there is an increased chance of first attempt success without adverse event.

Relationship between tracheal intubation and the drugs used by patients with drug overdose due to self-harm

Background

Tracheal intubation may be performed in patients with drug overdose due to self-harm; however, the details of the causative drug are unknown. The purpose of this study was to clarify the relationship between drugs or its blood levels of patients with drug overdose and the need for tracheal intubation based on the actual measurement results.

Methods

From October 2018 to March 2020, 132 patients with drug overdose due to self-harm who were transported to the emergency department (ED) were studied. Patient drugs were measured using gas chromatography–mass spectrometry (GC-MS) and were analyzed on the basis of the GC/MS Forensic Toxicological Database. Logistic analysis was performed by combining patient information and GC-MS information.

Results

The Glasgow Coma Scale (GCS) and Japan Coma Scale (JCS) efficiently predicted tracheal intubation in patients with drug overdose during transport triage; GCS (cut-off value: 12, area under the curve (AUC): 0.81, 95% confidence interval (CI): 0.71–0.88, sensitivity: 0.85, specificity: 0.71, P < 0.05) and JCS (cut-off value: 3, AUC: 0.74, 95% CI: 0.60–0.84, sensitivity: 0.60, specificity: 0.84, P < 0.05). The drugs detected in all patients with drug overdose in order were benzodiazepine receptor agonists (BZs; 43.9%), anticonvulsants (38.6%), antipsychotics (25.0%), and antidepressants (9.8%). In univariate logistic analysis, antipsychotics (odds ratio (OR) 2.46, 95% CI 1.19–5.20, P < 0.05), anticonvulsants (OR 2.71, 95% CI 1.26–5.98, P < 0.05), and anticonvulsants above alert blood levels (OR 27.8, 95% CI 2.92–264.1, P < 0.05) were significantly associated with tracheal intubation in patients with drug overdose, but not BZs and antidepressants. Also, in multivariate logistic analysis, antipsychotics (OR 2.27, 95% CI 1.07–4.83, P < 0.05), anticonvulsants (OR 2.50, 95% CI 1.14–5.64, P < 0.05) and in multivariate logistic analysis of blood levels, anticonvulsants above the alert blood levels (OR 24.9, 95% CI 2.56–241.6, P < 0.05) were significantly associated with tracheal intubation in patients with drug overdose respectively.

Conclusions

Logistic analysis revealed that the use of anticonvulsants and antipsychotics were significantly associated with an increased OR in the tracheal intubation of patients with drug overdose due to self-harm.