Independent risk factors for a complicated hospital course in intensive care unit overdose patients

Abstract

Aim: The purpose of the present study was to identify risk factors associated with a complicated hospital course in overdose patients admitted to the intensive care unit.

Methods: A total of 335 overdose patients were retrospectively studied in the surgical and medical intensive care unit of an academic tertiary hospital. Factors possibly associated with a complicated hospital course were evaluated. Complicated hospital course was defined as the occurrence of pneumonia, rhabdomyolysis, decubitus ulcer, nerve palsy, prolonged intubation, prolonged hospitalization, or death.

Results: Of the 335 overdose patients, 93 (27.8%) had a complicated hospital course. Complicated hospital course was found to be associated with a high number of ingested pills (median, 135 [interquartile range, 78-240] versus 84 [53-134] tablets, P < 0.0001), low Glasgow Coma Scale score on admission (7 [3-11] versus 13 [8-15], P < 0.0001), and a high serum lactate level on admission (1.8 [1.0-3.0] versus 1.4 [0.9-2.0] mg/dL, P < 0.01) on univariate analysis of these factors in patients with and without a complicated hospital course. The independent risk factors for a complicated hospital course identified on multivariate analysis were a high number of ingested pills (≥100 tablets), low admission Glasgow Coma Scale score (<9), and high serum lactate on admission (≥2.0 mg/dL). The probability of a complicated hospital course for patients with 0, 1, 2, or all 3 independent risk factors were 7%, 22%, 40%, and 81%, respectively.

Conclusion: The total number of ingested pills, admission Glasgow Coma Scale score, and serum lactate level on admission are predictive of a complicated hospital course in overdose patients admitted to the intensive care unit.

Keywords: Complications; drug overdose; lactate; toxicology/poisoning; triage.

Figure 1

Main types of drug ingested by overdose patients admitted to the intensive care unit of Kyorin University Hospital, Tokyo, Japan from January 2010 to December 2012 (n = 335). The drug with the largest quantity of ingested pills was shown in each case. NSAID, non‐steroidal anti‐inflammatory drugs; SSRI, selective serotonin reuptake inhibitors; SNRI, serotonin and norepinephrine reuptake inhibitors.

Figure 2

Sensitivity and specificity curves with corresponding optimal cut‐off values for the three independent factors associated with a complicated hospital course in overdose patients admitted to the intensive care unit of Kyorin University Hospital, Tokyo, Japan from January 2010 to December 2012 (n = 335). GCS, Glasgow Coma Scale.