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Three Part Question

In [Tricyclic antidepressant overdose] how long [must a clinically stable patient be monitored] before they can be [safely discharged]

Clinical Scenario

A 29 year old woman presents to the emergency department with tricyclic antidepressant overdose. She remains alert and shows no sign of major toxicity. You wonder how long this patient must be monitored before she can be safely discharged

Search Strategy

MEDLINE 1966-June Week 4 2005 OVID Interface
EMBASE 1980 to 2005 Week 27 OVID Interface
Medline:[{exp ANTIDEPRESSIVE AGENTS, TRICYCLIC OR tricyclic.mp. OR amitriptyline.mp. OR exp AMITRIPTYLINE OR desipramine.mp. OR exp DESIPRAMINE OR clomipramine.mp. OR exp CLOMIPRAMINE OR doxepin.mp. OR exp DOXEPIN OR dothiepin.mp. OR exp DOTHIEPIN OR imipramine.mp. OR exp IMIPRAMINE OR lofepramine.mp. OR exp LOFEPRAMINE OR nortriptyline.mp. OR exp NORTRIPTYLINE OR trimipramine.mp. OR exp TRIMIPRAMINE} AND {overdose.mp. OR exp OVERDOSE OR exp POISONING} AND {monitoring.mp. OR exp MONITORING, PHYSIOLOGIC OR exp PATIENT ADMISSION OR admission.mp. OR exp Hospitalization OR admit.mp} LIMIT to English language AND Humans]
Embase: [{exp ANTIDEPRESSIVE AGENTS, TRICYCLIC OR tricyclic.mp. OR amitriptyline.mp. OR exp AMITRIPTYLINE OR desipramine.mp. OR exp DESIPRAMINE OR clomipramine.mp. OR exp CLOMIPRAMINE OR doxepin.mp. OR exp DOXEPIN OR dothiepin.mp. OR exp DOTHIEPIN OR imipramine.mp. OR exp IMIPRAMINE OR lofepramine.mp. OR exp LOFEPRAMINE OR nortriptyline.mp. OR exp NORTRIPTYLINE OR trimipramine.mp. OR exp TRIMIPRAMINE} AND {overdose.mp. OR exp OVERDOSE OR exp POISONING} AND {monitoring.mp. OR exp MONITORING, PHYSIOLOGIC OR exp PATIENT ADMISSION OR admission.mp. OR exp Hospitalization OR admit.mp} LIMIT to English language AND Humans]

Search Outcome

Medline: 135 studies found of which 5 were relevant to the 3 part question
Embase: 339 studies found of which 2 additional papers were found

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Tokarski GF. Young MJ 1988 USA	Reviewed 45 TCA overdose patients from 1982-1985 and applied algorithm	Retrospective Cohort Study	Patient discharged using Algorithm (No major signs toxicity/QRS<0.10 in 6hrs)	20 patient would have been discharged since no signs of major toxicity or QRS was <0.10s within 6 hours of admission. None of these patients developed any complications	small sample retrospective study hence vital data from notes may be missing
Banahan B, Schelkun P 1990 USA	Reviewed 33 patients with an admission diagnosis of TCA overdose between January 1985-December 1988. Applied algorithm by Tokarski and Young (see below)	Retrospective Cohort Study	Patients discharged under Algorithm (by Tokarski et al. See above)	11 patients did not show signs of Major toxicity or QRS>0.10s within 6 hours. Using the Algorithm these patient could been discharged. None developed any complications	small sample retrospective study, hence data may be missing
Hulten et al june 1992 Sweden	67 TCA overdose Patients	Cohort study	Development of Complications	All patients who developed complications did so within 6 hours of admission	Lack of raw data no sample size estimation performed
Pentel P, Sioris L 1981 USA	Patients with TCA overdose All underwent Gastric emptying	Retrospective Cohort Study	Development of Complication	All patients who developed complications did so within 1 hour of hospitalisation. No patients developed arryhthmias after being alert and having a normal ECG for 1 hour.	Does not mention the exact number of patients in the study Vital data may be missing from notes due to retrospective study.
Emerman C et al 1987 USA	92 patients with TCA overdose admission from 1975-85	Retrospective Cohort Study	Development of complications (26/37 patients had documentation)	19/26 developed complications within 30 mins. 7/26 developed complications between 30-120 mins.	Data may be missing due to retrospective study
Greenland P and Howe TA 1981 USA	62 patients with TCA overdose	Retrospective Cohort Study	Cardiac arrhythmias	No cardiac arrhythmias occurred after the first 24 hrs in any patient free of such complication earlier	Lack of raw data important details may be missing in retrospective study
Goldberg et al 1985 USa	75 patients with TCA overdose	Retrospective Cohort Study	Cardiac complications	No new complications after 24 hrs	Data may be missing due to retrospective study No actual data on times of complications following overdose

Comment(s)

Banahan B et al showed in their retrospective study that discharging stable patients with QRS duration< 0.10 seconds for 6 hours could have saved $14,000. Incidence of late arryhthmias have been reported, however these patients were not absent of clinical signs and in some patients certain clinical procedures were not performed

Clinical Bottom Line

Stable patients with tricyclic antidepressant overdose who show no sign of toxicity and no significant ECG abnormalities (ie QRS<0.10s) for 6 hours can safely be discharged.

References

1. Tokarski GF. Young MJ Criteria for admitting patients with tricyclic antidepressant overdose Journal of Emergency Medicine 6(2):121-4, 1988 Mar-Apr
2. Banahan B, Schelkun P antidepressant overdose: conservative management in the community hospital with cost saving implications The journal of emergency medicine vol 8, pp 451-454, 1990
3. Hulten BA. Adams R. Askenasi R. Dallos V. Dawling S. Volans G A Predicting severity of tricyclic antidepressant overdose Journal of Toxicology-Clinical Toxicology 30(2):161-70, 1992
4. Pentel Paul, Sioris Leo Incidence of Late arrythmias following tricyclic antidepressant overdose Clinical Toxicology 1981; 18(5) 543-548
5. Emerman C, Connors AF, Burma GM Level of consciousness as a predictpr of the complications following tricyclic overdose Annals of emergency medicine 1987; 16(3) 326-330
6. Greenland P, Howe TA cardiac monitoring in tricyclic antidepressant overdose heart&Lung 1981; 10(5): 856-9
7. Goldberg RJ, Capone RJ, Hunt JD Cardiac Complications following tricyclic antidepressant overdose JAMA 1985; 254 (13) 1772-5