Do routine paracetamol levels need to be taken in all patients presenting with overdose ?
Date First Published:
April 25, 2007
Last Updated:
August 11, 2009
Report by:
T Leckie, Consultant in Emergency Medicine (Royal Oldham Hospital, Oldham, UK, )
Search checked by:
Kerstin Hogg, Royal Oldham Hospital, Oldham, UK,
Three-Part Question:
In [alert cooperative adults who present following overdose] do [paracetamol levels] detect [unsuspected paracetamol overdoses requiring treatment]?
Clinical Scenario:
A 22 year old woman attends the accident and emergency department immediately following a deliberate injestion of 8 ibuprofen tablets. You have no reason to doubt her story of impulsive overdose taken with suicidal intent. You wonder whether her management should include 4 hour paracetamol levels.
Search Strategy:
Medline 1950 to April Week 3 2009 via OVID interphase:
Search Details:
({[overdose.mp or exp overdose or deliberate self harm.mp. or exp self-injurious behaviour] AND [paracetamol.mp or acetaminophen.mp or exp acetaminophen] limit to "diagnosis(sensitivity)"} OR {[overdose.mp or exp overdose or deliberate self harm.mp. or exp self-injurious behaviour] AND [paracetamol.mp or acetaminophen.mp or exp acetaminophen] limit to "clinical prediction guides (sensitivity)"}) limit to adult and human and English language.
Outcome:
A total of 185 papers was found, three were relevant to the question and a further five were found from paper references.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Paracetamol and salicylate testing: routinely required for all overdose patients? Graham, CA; Irons, AJ; Munro PT. 2006, Scotland | Consious overdose patients attending ED with a clear time of ingestion (not staggered) | Prospective Observational study of 134 patients | 63/134 History +ve | 40/63 (63%) detected, 15/63 (23.8%) treated | Small sample |
| 71/134 History -ve | 0/71 detected | ||||
| Measuring plasma paracetamol concentrations in all patients with drug overdoses; development of a clinical decision rule and clinicians willingness to use it. Harington, K; Hartley, J; Clancy, M. 2002, England | All adult suspected overdose patients attending the ED attending between Feb and May 2000 | 307 consecutive patients | 152/307 History +ve | 8 no levels, 99/152 (65%) detected, 4/152 (2.6%) needed antidote | 6/13 GCS <15, 10/13 significant alcohol injestion other 3 frequent ovedose or multiple drugs in overdose |
| 155/307 History -ve | 13 no levels, 13/155 (8.4%) detected, 0/155 (0%) needed antidote | ||||
| Measuring plasma paracetamol concentrations in all patients with drug overdose or altered consiousness: does it change outcome? Dargan PI; Ladhani S; Jones AL. 2001, England | All adult patients attending the ED over a 12 month period who had paracetamol levels measured | Retrospective audit of 411 patients (115 after collapse and 296 after OD) | 122/411 history +ve non staggered <24 hrs | 94/122 (77%) detected, 16/122 (13%) treated | Small Numbers |
| 136/411 history -ve | 0/136 (0%) detected | ||||
| 115/411 Collapse low GCS | 4/115 (3.5%) detected, 4/115 (3.5%) treated | ||||
| Acetaminophen and Salicylate serum levels in patients with suicidal ingestion or altered mental status. Sporer KA; Khayam-Bashi H. 1996, USA | All adult patients with altered mental state or overdose who had levels taken. | Retrospective chart audit of all patients with blood levels over 20 months 1992-3. 1820 patients | 177/1820 history +ve | 120/177 (68%) detected | 2 patients had taken "everything" 3 with low GCS and suspected overdose |
| 1643/1820 history -ve | 55/1643 (3.3%) detected, 5/1643 (0.3%) levels >20mcg/ml(>50mcg/ml), 0/1643 (0%) treated | ||||
| Value of rapid screening for acetaminophen in all patients with intentional drug overdose. Ashbourne J; Olsen K; Khayam-Bashi H. 1989, USA | Adults presenting with suspected or confirmed intentional overdose | 486 prospectively identified patients February to July 1986 (101 other eligible patients missed) | 114/486 history +ve | 43/114 (38%) detected | 1 treated patient didn't speak English and the paracetamol history had not been obtained initiallly. No clear reason for other 6 but treatment not required. Small study |
| 372/486 history -ve | 7/372 (1.9%) detected, 1/372 (0.27%) required treatment | ||||
| Utility of acetaminophen screening in unsuspected suicidal ingestions. Lucanie R; Chianf WK; Reilly R. 2002, USA | All non-paracetamol overdoses reported to a regional poison control centre over 6 months. | Retrospective study of 320/471 patients (151 missing levels) | History -ve | 23/320 (7.2%) detected >10mcg/ml, 12/320 (3.8) treated | No information on the patients treated. |
| The clinical value of screening for paracetamol in patients with acute poisoning. Chan TY; Chan AY; Ho CS; Critchley JA. 1995, Hong Kong | Chinese patients presenting with overdose to the general medical wards between January 1992 and June 1993. | Retrospective study of 294 overdose patients | 86/294 History +ve | 8/86 (9.3%) treated | Small study |
| 208/294 History -ve | 4/208 (1.9%) detected, 0/208 (0%) treated | ||||
| Drug screening of patients who deliberately harm themselves admitted to the emergency department. Skelton H, Dann LM, Ong RT, et al. 1998, Australia | 200 Patients selected at random from ED, with a provisional diagnosis of deliberate self-harm | Prospective cohort | Number of patients testing positive for paracetamol | 48/200 (24%) | No breakdown of results giving overall number of history +ve and –ve patients<br><br>No breakdown of results for number of history –ve patients with paracetamol levels >100 mg/l |
| Number of patients testing positive for paracetamol with -ve history | 7/48 (14.6%) | ||||
| Overall % with >100 mg/l plasma concentration | 13/48 (27%) |
Author Commentary:
Most papers in this BET show no patients with an uncomplicated negative history who required antidote. In the paper from the regional poison centre in New York it was difficult to extract individual details of cases. I suspect that their patient population does not represent the alert cooperative patient in the three-part question.
Bottom Line:
Paracetamol levels in history-negative patients have a low yield. However, the test is cheap and readily available and treating significant overdoses is lifesaving.
References:
- Graham, CA; Irons, AJ; Munro PT.. Paracetamol and salicylate testing: routinely required for all overdose patients?
- Harington, K; Hartley, J; Clancy, M.. Measuring plasma paracetamol concentrations in all patients with drug overdoses; development of a clinical decision rule and clinicians willingness to use it.
- Dargan PI; Ladhani S; Jones AL.. Measuring plasma paracetamol concentrations in all patients with drug overdose or altered consiousness: does it change outcome?
- Sporer KA; Khayam-Bashi H.. Acetaminophen and Salicylate serum levels in patients with suicidal ingestion or altered mental status.
- Ashbourne J; Olsen K; Khayam-Bashi H.. Value of rapid screening for acetaminophen in all patients with intentional drug overdose.
- Lucanie R; Chianf WK; Reilly R.. Utility of acetaminophen screening in unsuspected suicidal ingestions.
- Chan TY; Chan AY; Ho CS; Critchley JA.. The clinical value of screening for paracetamol in patients with acute poisoning.
- Skelton H, Dann LM, Ong RT, et al.. Drug screening of patients who deliberately harm themselves admitted to the emergency department.