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Fasting before prilocaine Biers' block

Three Part Question

In [patients with uncomplicated colles' fracture] is [fasting before prilocaine Biers' block] necessary for [the prevention of life threatening complications]?

Clinical Scenario

A 75 year old man presents to the emergency department with a wrist injury. X-ray reveals a Colles' fracture with dorsal angulation requiring manipulation. The patient has had lunch one hour before presentation. Your colleague tells you that you should manipulate the fracture before your shift ends in a hours time, but a passing anaesthetist says that you should wait at least 5 hours (6 hours after food) before you do anything. The departmental manager points out that this means the patient should be admitted since they will "breach" the target time of 4 hours if you wait. If they are admitted the next available trauma list is in 36 hours. You wonder whether the patient should be fasted for 4-6 hours or if it is safe to reduce this fracture under Bier's block without any period of fasting.

Search Strategy

Medline 1966-week 3 March 2005 using the OVID interface
Embase 1980-week 13 2005 using the OVID interface
Cochrane Library Issue 1 2005
Medline:[(biers adj OR exp nerve block/ OR exp anesthesia, local/ OR exp anesthesia, conduction/)] AND [(exp fasting/ OR] Limit to Human and English. 40 papers found
Embase: [biers adj OR exp nerve block/ OR exp regional anesthesia/ OR exp intravenous anesthesia/] AND [ exp dietary restriction/ OR exp food deprivation/ OR] Limit to Human and English. 28 papers
Cochrane :"biers block" [all fields] OR Colles' Fracture (Mesh) AND Fasting (Mesh) 32 articles

Search Outcome

50 papers found overall of which 47 were irrelevant to the study question. All the references of the relevant papers were searched and 2 more papers were found. 4 papers are included below:

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Bartholomew K and Sloan JP,
Patients with colles' fracture reduced under Biers' block anaesthesiaQuestionnaire survey to 106 emergency departmentsSerious complicationsNo serious or fatal complications
Lowen R and Taylor J,
Patients with colles' fracture reduced under Biers' blockQuestionnaire survey to 120 emergency departments. 97% response rateComplicationsConvulsions - 2
Kendall JM et al,
Patients with colles' reduced under Biers' blockPostal survey to 150 emergency departments. 58% responseComplicationsNo significant adverse effectPoor response
O'Sullivan I et al,
Patients with colles' fracture who were treated under Biers' blockQuestionnaire survey to 282 emergency departments.77% responseComplications in fasted and unfasted patientsNo difference


The evidence found does not address`the question directly and is limited to the postal surveys. All studies showed that major complications are extremely rare in both groups and, where the question was addressed, there is no evidence of increased rate of complications in patients who were not fasted.

Clinical Bottom Line

The limited evidence available suggests there is no need to fast patients prior to Biers' block. Further research is required.


  1. Bartholomew K, Sloan JP. Prilocaine for Biers' block; how safe is safe? Arch Emerg Med 1990;7:189-95.
  2. Lowen R, Taylor J. Biers' block - the experience of Australian emergency departments. Med J Aus 1994;160:108-11.
  3. Kendall JM, Allen PE, Mccabe SE. A tide of change in the management of an old fracture. J Acc Emerg Med 1995;12:187-8.
  4. O'Sullivan I, Brooks S, Maryosh J. Is fasting necessary before prilocaine Biers' block? J Acc Emerg Med 1996;13:105-7.