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Three Part Question

In [adult patients who are at risk of vomiting and who are immobilised after trauma] is [prophylactic use of antiemetics] effective at reducing [episodes of vomiting]?

Clinical Scenario

A 53-year-old unrestrained driver who has been involved in a head-on collision arrives at the emergency department. He is immobilised on a spinal board and is wearing a semirigid cervical collar. As he has had opiate analgesia and might have had a head injury you are worried about the risk of vomiting (and subsequent aspiration of gastric contents). A junior member of the team asks whether antiemetic agents could be used prophylactically in all trauma patients, in order to limit the risk of vomiting. Interested in the result you set them the task of researching current literature and returning later in the week with the answer.

Search Strategy

Embase and Medline were searched using the Ovid interface from 1974 to 31 March 2014 and 1946 to 1 April 2014, respectively. ((Adult/) AND (trauma.mp or multiple trauma.mp or exp multiple trauma/ OR exp thorax blunt trauma/ OR exp thorax injury/ Or trauma*.mp or blunt trauma/ OR multiple trauma/ OR abdominal blunt trauma/ OR crush trauma/ OR penetrating trauma/)) AND (metoclopramide.mp OR exp metoclopramide/ OR ondansetron.mp OR exp ondansetron/ OR prochlorperazine.mp OR exp prochlorperazine OR antiemetic.mp OR exp antiemetic agent/ OR anti-emetic.mp OR anti-nausea.mp) AND ((exp primary prevention/ OR prevention.mp. OR exp prevention/ OR prevent*.mp. OR exp prophylaxis/ OR prophyla*.mp. OR prehospital.mp.)) AND (exp nausea/ OR exp vomiting/ OR vomit*.mp. OR nausea.mp.)).
The Cochrane Library issue 5 of 12 May 2014

MeSH descriptor: [Multiple Trauma] explode all trees AND MeSH descriptor: [Antiemetics] explode all trees.

Search Outcome

One hundred and thirty-seven papers were retrieved, of which two closely dealt with the clinical question

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Easton et al 2012 Australia	196 patients fulfilling the criteria for trauma team activation, prehospital metoclopramide or ondansetron	Prospective observational cohort	OR vomiting after antiemetic use	0.19 (CI 0.04 to 0.87, p = 0.03)	Small cohort. Short follow-up period. Although patients were approached on three different occasions, subjective recall of the degree of nausea, the following day, was also used. Accuracy of recall of nausea is questionable. Wide range of ISS (injury severity score (1–15). Patients with more severe trauma requiring urgent intervention were unable to be approached and were excluded
Page et al 1996 USA	193 trauma patients undergoing abdominal CT scans with oral contrast	Retrospective cohort study	OR (adj) metoclopramide and vomiting	0.08 (CI 0.01 to 0.66)	Small cohort and small intervention group. Retrospective design with lack of control over confounding variable. Study considers vomiting only 90 min after contrast given and does not consider preceding vomiting episodes or previous antiemetic use. Those in the metoclopramide group had higher alcohol serum levels, tended to be younger and less seriously injured. Results include a combination of pilot study

Comment(s)

There is a lack of evidence for the incidence of aspiration in immobilised trauma patients. However, a theoretical risk still exists, with a static supine position increasing the likelihood of reflux and pulmonary aspiration (Morris et al, 2004). Aspiration generates significant morbidity in critical care departments. The risk is further increased in trauma patients owing to prophylactic spinal immobilisation, compromised airway protection and delayed gastric emptying (Page et al, 1996; Morris et al 2004). Within the above studies the incidence of nausea and vomiting was found to be around 8%. Common problems include the unavoidable subjective assessment of nausea, retrospective designs of existing studies and small cohorts. The studies also failed to consider any adverse events or side effects due to the use of antiemetics. To examine this subject in more detail, research needs to focus on providing a higher level of evidence through the use of large, prospective randomised controlled trials.

Clinical Bottom Line

Prophylactic use of antiemetic agents in trauma patients may reduce the likelihood of vomiting some 5–12-fold.

Level of Evidence

Level 3 - Small numbers of small studies or great heterogeneity or very different population.

References

1. Easton R, Bendinelli C, Sisak K et al. Prehospital nausea and vomiting after trauma: Prevalence, risk factors, and development of a predictive scoring system J Trauma Acute Care Surg 2012;72:1249–54.
2. Page B, Dallara J Metoclopramide in Trauma CT Scanning: Preventing Emesis of Oral Radiographic Contract Am J Emerg Med 1996;14:373–6.
3. Morris CG, McCoy W, Lavery GG. Spinal immobilisation for unconscious patients with multiple injuries. BMJ 2004;329:773.