Investigations

Depending on the urgency of your findings, a number of investigations may be of use. Be wary of your pre and post-test probabilities associated with certain findings, and when discussing with specialties, if you find resistance, early discussion with a ED senior will help you advocate for your patient, and where necessary, review differentials.

Urine dip – looking for nitrites and leukocytes (leukocyte esterase) in the presence of a bacteria. Other findings such as blood, glucose and specific gravity will indicate other systemic issues such as kidney injury, diabetes mellitus and dehydration.

Venous blood gas – will flag up acidaemia and abnormalities associated with illness and infection. Most blood gas machines will provide a result for lactate and glucose which will be of importance particularly in patients with infectious aetiologies.

FBC and CRP– may show signs of infection / inflammation, but can have a delayed response in early illness. When raised, may be more sensitive than specific.

U&Es – useful for assessment of renal function, and benchmarking against previous values.

LFTs and Amylase – useful for screening for other causes of abdominal pain

Blood cultures – should be delivered as part of the ‘Sepsis 6’ interventions for those patients with suspicion of sepsis

Wound/Skin/Urethral swabs – of use in some differentials, but be wary of ensuring some means of follow up for the results.

Ultrasound – remember that when testicular torsion is the most likely diagnosis, then the only investigation of choice is surgical exploration. 

Where ultrasound can be of benefit would include trauma, to look at blood supply through colour Doppler, as well as evaluating size of haematoma and evidence of testicular injury. Refer to local guidelines as to who organises ultrasound and over what time frame, as it is likely to vary with time of day and site.

Learning Bite

When getting intravenous access, take relevant bloods at the same time to cover the differentials discussed unless it’s a clear cut diagnosis, in which case, do the minimum and necessary for time-critical diagnoses like torsion and gangrene.