Poisoning in an intensive care unit: 8 years experience Dr Grace SM Lam Department of Intensive Care Toxicology Meeting 7 August 2009

introduction Poisoning Knowledge of local poisoning pattern A significant cause of morbidity & mortality worldwide, and a common cause of ICU admission. A heterogeneous subject that poses a challenge for clinicians. Knowledge of local poisoning pattern Guide focus of poisoning prevention; Guide clinical research & professional training; Improve management of patients with poisoning.

Aims of study To describe: Pattern of poisoning Clinical characteristics Outcomes Of patients admitted to the ICU for poisoning

methods The study included patients: Admitted to PYNEH ICU From 1 January 2000 – 31 May 2008 For poisoning, defined as exposure to: An agent capable of producing a deleterious response in an individual; or A drug at a dosage exceeding that normally used for human in the prophylaxis, diagnosis or therapy of disease Significant head injury after intoxication & fire victims were excluded

results 7796 Total ICU admissions during the study period 279 admissions identified using the inclusion criteria 265 further analyzed (3.4% total ICU admission) 14 excluded: 10 chronic alcoholics /drug addicts with significant HI 4 fire victims with CO poisoning

Demographic & clinical characteristics All patients (N=265) CO poisoning (N=40) TCA poisoning (N=46) Age (years; median, IQR) 38 (30-49) 36 (30-42) 35 (29-46) Female 144 (54.3%) 17 (42.5%) 30 (65.2%) Charlson’s Comorbidity score ≥1 219 (82.6%) 46 (17.4%) 39 (97.5%) 1 (2.5%) 38 (82.6%) 8 (17.4%) Presence of psychiatric illness Depression Schizophrenia and related disorder 127 (47.9%) 75 (59.1%) 15 (11.8%) 14 (35%) 5 (35.7%) 1 (7.1%) 37 (80.4%) 27 (73.0%) 2 (5.4%) Previous suicidal attempt 87 (32.8%) 15 (37.5%) 20 (43.5%) Intent Suicide Recreation Accident Homicide 225 (84.9%) 33 (12.5%) 5 (1.9%) 2 (0.8%) 40 (100%) 46 (100%) Time to AED presentation (hours; median, IQR) (N=169) 2 (1-5) (N=21) 5 (1-8.5) (N=39) 2 (1-4) Physiological parameters on presentation (median, IQR) Glasgow coma scale Mean arterial pressure (mmHg) 9 (4-14) 88 (78-100) 8 (5-11) 86 (78-99) 10 (6-14) 91 (84-99) Initial blood results (median, IQR) Creatine Kinase (mmol/L) COHb (%) 129 (66-390) --- 368 (80-1711) 28.4 (13.2-38.8) 87 (48-197) APACHE II score (median, IQR) 15 (9-19.5) 17 (11-21) 15 (9-19)

Pattern of poisoning Miscellaneous Theophylline Bricanyl durule Agent Number (%) Sedatives Benzodiazepines Zopidem & Zopiclone Phenobarbital Others 67 (25.3%) 31 (11.7%) 4 (1.5%) 11 (4.1%) Alcohol 61 (23.0%) Antidepressant TCA SSRI Lithium 46 (17.4%) 13 (4.9%) 2 (0.8%) 9 (3.4%) Carbon monoxide 40 (15.1%) Antipsychotics 29 (10.9%) Drugs of abuse CNS depressants CNS stimulants 18 (6.8%) 10 (3.8%) Analgesics Paracetamol Dologesic Salicylate NSAIDS 5 (1.9%) 6 (2.3%) 3 (1.1%) Anti-histamines Household products Dettol 8 (3.0%) Anti-hypertensives Beta-blockers CCB Organophosphate Tetramine Miscellaneous 35 (13.2%) Unknown Miscellaneous Theophylline Bricanyl durule Anti-epileptic agents Hypoglycemic agents Artane Allopurinol Warfarin Commercial slimming agent Thinner

Mortality 8 (3%) did not survive to hospital discharge 5 (1.9%) died in ICU Age (years) Sex Agent(s) used Treatments Survival from presentation (Days) Cause of death 61 M Thinner, Paracetamol Ventilation, Vasopressor, CVVH 1 Multi-organ failure 39 Carbon monoxide CPR, Ventilation, Vasopressor Hypoxic encephalopathy, Brainstem death 26 F Dothiepin, Paracetamol CPR, Ventilation, MDAC 2 Cardiac arrest on arrival 29 Amphetamine, Tripolidine, Alcohol Ventilation, 3 Cerebral oedema 53 Lithium, Chlorpromazine, Alcohol Ventilation, Vasopressor, Gastric lavage, MDAC, CVVH 5 33 Amphetamine, Ketamine Ventilation, Tracheostomy 75 Nosocomial pneumonia 65 Dothiepin, Metformin, Glibenclamide MDAC 170 46 Phenobarbital Ventilation 1877 Nosocomial sepsis

Complications Complication All (N=265) CO (N=40) TCA (N=46) Rhabdomyolysis Acute renal failure Adverse cardiac events Shock Seizure Aspiration pneumonia Delayed neurological sequelae 28 (10.6%) 10 (3.7%) 15 (5.7%) 21 (7.9%) 23 (8.7%) 31 (11.7%) --- 10 (25.0%) 1 (2.5%) 2 (5.0%) 8 (20.0%) 3 (7.5%) 4 (8.7%) 1 (2.2%) 3 (6.5%) 5 (10.9%) 7 (15.2%)

Duration of mechanical ventilation 67.9% intubated and mechanically ventilated 65.3% with GCS ≤8 on presentation Median = 1 day Independent predictors of a duration of mechanical ventilation > 1 day: Odds ratio (95% Confidence interval) P value Rhabdomyolysis Aspiration pneumonia APACHE II ≥25 5.20 (1.29 – 20.99) 4.43 (1.53 – 12.83) 3.54 (1.24 – 10.07) 0.021 0.006 0.018

ICU Length of stay Median = 1 day Independent predictors of an ICU LOS >1 day: Odds ratio (95% CI) P value Rhabdomyolysis Aspiration pneumonia Shock Age >65 years APACHE II score ≥25 Alcohol intoxication 12.18 (3.07 – 4.88) 9.25 (2.70 – 31.73) 6.19 (1.33 – 28.88) 4.95 (1.52 – 16.13) 3.69 (1.19 – 11.46) 0.22 (0.07 – 0.66) <0.001 0.020 0.008 0.024 0.007

Acute HOSPITAL length of stay Median = 3 days Independent predictors of an acute hospital LOS >3 days: Odds ratio (95% CI) P value Age >65 years Aspiration pneumonia Presence of comorbidity Alcohol intoxication 6.64 (1.40 – 31.44) 5.34 (1.39 – 20.50) 4 (1.67 – 9.57) 0.36 (0.18 – 0.75) 0.017 0.015 0.002 0.006

result CO poisoning: HBO performed in 2 (5%) patients No factor was identified as independent predictors of neurological or cardiac complications Including initial COHb level

result TCA poisoning No factor was identified as independent predictors of neurological or cardiac complications Complications No. (%) QRS duration QTC duration RaVR R/SaVR <0.1s ≥0.1s <0.44s ≥0.44s <3mm ≥3mm <0.7 ≥0.7 Cardiac sequelae Absent Present P value 26 (96.3) 13 (81.3) 1 (3.7) 3 (18.8) 0.137 18 (100) 21 (84) 0 (0) 4 (16) 0.127 25 (86.2) 14 (100) 4 (13.8) 0 0.286 30 (88.2) 9 (100) 4 (11.8) 0 0.564 Seizure 26 (96.3) 12 (75) 1 (3.7) 4 (25) 0.056 17 (94.4) 21 (84) 1 (5.6) 4 (16) 0.380 26 (89.7) 12 (85.7) 3 (10.3) 2 (14.3) 1.00 30 (88.2) 8 (88.9) 4 (11.8) 1 (11.1) Combined 25 (92.6) 11 (68.8) 2 (7.4) 5 (31.3) 0.820 17 (94.4) 19 (76) 1 (5.6) 6 (24) 0.209 24 (82.8) 12 (85.7) 5 (17.2) 2 (14.3) 28 (82.4) 8 (88.9) 6 (17.6) 1 (11.1)

limitations Retrospective study ICU admission was not standardized Missing data e.g. time of intoxication ICU admission was not standardized Heterogeneous study population & uncommon adverse outcomes limited the validity of statistical analyses Long-term outcome was not systematically studied Single-center study

conclusions The 4 commonest poisons encountered in our ICU from 2000 to 2008 were BDZ, alcohol, TCA, and CO Mortality was comparable to international data Timely management with emphasis on prevention of aspiration pneumonia may reduce adverse outcomes It is hoped that outcomes of these patients can be further improved in the future through: Collaboration with local advisory bodies (HKPIC) Raising clinicians’ awareness Continued efforts on clinical trials