Optimal Blood Sampling Site for Point of Care Lactate Assessment

Following a hip fracture, surgical treatment is advocated to improve pain and mobility. Most patients are elderly and a majority of them are frail. Current best practice tariff and National Institute for health and care excellence guidelines recommends that all those patients who undergo an operation should be performed within 36 hours from the time of injury to optimise recovery and function. The patients need to be medically optimised to undergo a major operation to have their hip fracture fixed. The adequacy of resuscitation is monitored by several clinical and biochemical markers. One of the important markers of resuscitation is serum lactate levels. This is used routinely in polytrauma patients. (Moran and Forward, 2012) The initial interest in lactate in hip fracture patients was based on the philosophy that a hip fracture in a frail elderly patient may be equivalent to a polytrauma in a young fit patient. Subsequently, high serum lactate levels on admission in hip fracture patients have been shown to be associated with higher mortality1. However, at present, this is not routinely monitored in hip fracture patients. Measurement of serum lactate levels presents logistics difficulties, as the blood sample has to be taken to an analyser and analysed within 20 minutes. Hence the investigators want to use a point of care electronic hand held device - the Lactate Pro 2. The investigators have already tested this device against the laboratory analysers and it has been proven to be accurate. However in preliminary testing the investigators found a significant difference between fingertip and earlobe samples in volunteers. The volunteers do not represent our population of interest, which are hip fracture patients. The investigators aim is to determine which sample site; earlobe or fingertip, for Lactate Pro 2 testing best matches venous forearm samples upon which the association of higher mortality with high lactate was based.

Any risk to the patients participating in this study would be very small. The inclusion criteria to participate in this research study is a patient who has had a recent hip fracture awaiting surgery with a Mental Test score of 7/10 or above and is able to consent.

Inclusion criteria

• Male or Female, aged 18 years or above.
• Diagnosed with an acute hip fracture.
• Have a mental test score of 7/10 or greater on assessment during admission.
• Participant is willing to consent to the study.

Exclusion criteria

• The participant will not enter the study if

• There are Injuries other than isolated hip fracture
• Age <18 years
• They are not willing to consent for the study
• They have a mental test score less than 7/10 at the time of admission.