Cerebral microbleeds in the poisoned patient: An observational magnetic resonance imaging study

Critical illness-associated cerebral microbleeds of poorly understood pathophysiology have been observed on magnetic resonance imaging (MRI) in severely hypoxaemic patients similarly to high-altitude cerebral oedema patients. The prevalence and circumstances of occurrence of such cerebral microbleeds in the severely poisoned patients are unknown. We retrospectively reviewed all cerebral MRIs performed in the poisoned patients with atypical neurological presentation or outcome admitted to our intensive care unit in 2014-2021. Three out of 64 patients (4.7%) investigated with cerebral MRI among the 2986 severely poisoned patients presented cerebral microbleeds. Microbleeds were localized in the white cerebral matter mainly in the corpus callosum. Ingested toxicants included dichlorvos, methadone and tramadol. Patients were found comatose with possibly prolonged severe hypoxaemia requiring prompt tracheal intubation and mechanical ventilation. They presented delayed arousal and dysexecutive syndrome leading to sequelae. Microbleeds on MRI can occur in the critically ill poisoned patients and seems to be a multifactorial phenomenon. A direct relationship with the toxicant seems improbable. Physicians should be aware of such a non-specific complication accounting for sequelae.

Factors associated with prolonged intensive care stay among self-poisoned patients

CONTEXT

Since recovery or death is generally observed within a few days after intensive care unit (ICU) admission of self-poisoned patients in the developed countries, reasons for the prolonged ICU stay are of interest as they have been poorly investigated. We aimed to identify the characteristics, risk factors, outcome, and predictors of death in self-poisoned patients requiring prolonged ICU management.

METHODS

We conducted an eight-year single-center cohort study including all self-poisoned patients who stayed at least seven days in the ICU. Patients admitted with drug adverse events and chronic overdoses were excluded. Using multivariate analyses, we investigated risk factors for prolonged ICU stay in comparison with a group of similar size of self-poisoned patients with <7day-ICU stay and studied risk factors for death.

RESULTS

Among 2,963 poisoned patients admitted in the ICU during the study period, the number who stayed beyond seven days was small (398/2,963, 13.1%), including 239 self-poisoned patients (125 F/114M; age, 51 years [38-65] (median [25th-75th percentiles]); SAPSII, 56 [43-69]). Involved toxicants included psychotropic drugs (59%), cardiotoxicants (31%), opioids (15%) and street drugs (13%). When compared with patients who stayed <7days in the ICU, acute kidney injury (odds ratio (OR), 3.15; 95% confidence interval (1.36-7.39); p = .008), multiorgan failure (OR, 8.06 (3.43-19.9); p < .001), aspiration pneumonia (OR, 8.48 (4.28-17.3); p < .001), and delayed awakening related to the persistent toxicant effects, hypoxic encephalopathy and/or oversedation (OR, 8.64 (2.58-40.7); p = .002) were independently associated with prolonged ICU stay. In-hospital mortality rate was 9%. Cardiac arrest occurring in the prehospital setting and during the first hours of ICU management (OR, 27.31 (8.99-158.76); p < .001) and delayed awakening (OR, 14.94 (6.27-117.44); p < .001) were independently associated with increased risk of death, whereas exposure to psychotropic drugs (OR, 0.08 (0.02-0.36); p = .002) was independently associated with reduced risk of death.

CONCLUSION

Self-poisoned patients with prolonged ICU stay of ≥7days are characterized by concerning high rates of morbidities and poisoning-attributed complications. Acute kidney injury, multiorgan failure, aspiration pneumonia, and delayed awakening are associated with ICU stay prolongation. Cardiac arrest occurrence and delayed awakening are predictive of death. Further studies should focus on the role of early goal-directed therapy and patient-targeted sedation in reducing ICU length of stay among self-poisoned patients.