- Traditional ATLS teaching was that a digital rectal exam (DRE) is mandatory in trauma patients: “a finger or tube in every orifice”. This is no longer the case.
- The 8th edition of ATLS recommends that ‘DRE be performed selectively before inserting an indwelling urinary catheter’
- DRE rarely changes the management of trauma patients (0 to 4% of cases)
- The DRE is not a useful screening test in trauma patients (detects <1 in 4 significant injuries)
RATIONALE FOR DRE IN TRAUMA
- rectal hemorrhage
- rectal mucosal injury or wall defects
- loss of anal tone suggesting spinal cord injury
- palpable pelvic fractures or hematoma
- a high riding prostate suggestive of posterior urethral disruption
- tenderness from ruptured viscus or intraperitoneal hemorrhage
NEGATIVES OF PERFORMING A DRE IN TRAUMA
- physical discomfort
- emotional distress
- risk of verbal and/ or physical violence from an agitated patient
- possible infection risk — e.g. contamination of local wounds; risk of transmission of infection to the clinician (likely to be extremely low)
- injury — potential for worsening of the patient’s injuries (e.g. unstable pelvic fracture, rectal defects); and also risk of injury to the clinician (e.g. foreign bodies, bone fragments)
- the occurrence of false positive and false negative DRE findings
DRE FINDINGS ARE OFTEN UNRELIABLE
Shlamovitz et al (2007) found high rates of falsely negative DREs:
- 63% for decreased anal sphincter tone
- 94% for the presence of gross rectal blood
- 67% for disruption of the rectal wall integrity
- 100% for palpation of bony fragments
- 80% for abnormal position of the prostate
Reasons why DREs are unreliable include:
- DREs are often performed by junior staff
— either because it is considered a menial task, or so that the junior staff ‘gain more experience’.
- positive findings on DRE are rare… anyone ever felt a ‘high riding’ prostate?… (i.e. before the diagnosis of posterior urethral disruption was confirmed by some other means…)
- examination may be limited by tenderness and poor cooperation
- a ‘high riding prostate’ may be concealed by hematoma formation from a coexistent pelvic fracture or vessel injury
- the findings on DRE have poor inter-observer agreement
— this is well document for the assessment of prostate size and the detection of rectal tumours… even when performed by ‘experts’ such as urologists and proctologists.
Esposito et al (2005) found that 6% of DREs in trauma patients had findings that were later shown to be false (either positive or negative) when other investigations or follow up over time was performed.
EFFECTS OF FALSE FINDINGS ON DRE
False negative DREs may lead to
- injuries being missed, resulting in increased morbidity and/ or mortality
- delays in performing necessary investigations and/ or interventions
False positive DREs may lead to:
- unnecessary investigations (cost, time, radiation, contrast exposure, decreasing access for other patients, etc)
- unnecessary interventions (the possibilities include prolonged time in a c-spine collar, unnecessary fasting, being cut open for no reason, etc)
- prolonged observation (possible increase in hospital length of stay)
POSTERIOR URETHRAL INJURY
Abnormal prostate position is near useless for detecting posterior urethral injury
- 60% of the time there there were no clinical signs prior to urinary catheter insertion
Possible clinical signs and their sensitivities
- blood at the urethral meatus (20% sensitivity)
- gross haematuria prior to catheter insertion (17% sensitivity)
- abnormal prostate position (20% sensitivity)
- scrotal or perineal ecchymosis
- inability to void
- Consider posterior urethral disruption if a pelvic fracture is present (95% are associated with fractures)
- Suspect posterior urethral disruption if there is haematuria on IDC insertion or if the IDC doesn’t pass easily.
- Perform a retrograde urethrogram to confirm posterior urethral disruption (ATLS suggests doing this before IDC insertion if posterior urethral injury is suspected — this is probably unnecessary as longs as IDC insertion is gentle).
SPINAL CORD INJURY
Normal anal tone does NOT exclude spinal cord injury
- Shlamovitz et al (2007) found DRE was only 37% sensitive with a negative likelihood ratio (LR) of 0.66
- Guldner et al (2006) had similar findings, with a negative LR of 0.5.
A positive DRE finding of decreased anal tone is more useful (but other features — such as paralysis) may indicate the presence of a spinal cord injury
- Shlamovitz et al (2007): positive LR = 8.5
- Guldner et al (2006): postive LR = 6.8
Other practice points
- Assessing rectal tone is of little use if the patient has been given neuromuscular blockers following intubation. Tone may also be reduced in the unconscious patient, as a result of post-intubation sedation or traumatic brain injury for instance.
- In the patient with neurological deficits, assessment for sacral sparing is important. This can be assessed by checking anal tone, but anal wink or the bulbocavernosus reflex are alternatives and may be more useful and/or better tolerated.
A positive DRE is useful for diagnosis (though most patients will require further investigation regardless):
- 98.9% specific for bowel injury (i.e. PR hemorrhage detected) (LR+ 5.2)
- 99.8% specific for disrupted rectal wall integrity (LR+ 996)
A negative DRE does not rule out bowel injury as sensitivity is low:
- 6% sensitive for bowel injury (LR- 0.95),
- 33% sensitive for rectal mucosal tears (LR- 0.65 with non-significant CIs)
the above data is from Shlamovitz et al (2007).
INDICATIONS FOR DRE IN TRAUMA PATIENTS
Perform a DRE in a trauma patient if:
- pelvic fractures (complications and associated injuries may be detected)
- abnormal neurological findings
- penetrating abdominal or perineal trauma with possible rectal or other GI involvement
- abdominal tenderness
However, DRE may not be necessary initially even in these patients if further investigations or interventions are planned.
Do not perform a DRE in a trauma patient if the following apply (0 to 0.8% miss rate in an unvaildated study by Gulder et al, 2008):
- a normal neurological exam
- aged <65 years
- absence of blood at the urethral meatus
- should be performed selectively — in most trauma cases a DRE is not useful.
- can often be delayed or be performed at the time of a subsequent investigation (e.g. colonoscopy) or intervention (e.g. laparotomy) if necessary
- may be redundant in light of other clinical findings or if further investigation is indicated by other clinical findings
- may be best performed by an experienced practitioner
References and Links
- Trauma Tribulation 012 — Adding insult to injury?
- Ball CG, Jafri SM, Kirkpatrick AW, Rajani RR, Rozycki GS, Feliciano DV, Wyrzykowski AD. Traumatic urethral injuries: does the digital rectal examination really help us? Injury. 2009 Sep;40(9):984-6. PMID: 19535063.
- Esposito TJ, Ingraham A, Luchette FA, Sears BW, Santaniello JM, Davis KA, Poulakidas SJ, Gamelli RL. Reasons to omit digital rectal exam in trauma patients: no fingers, no rectum, no useful additional information. J Trauma. 2005 Dec;59(6):1314-9. PMID: 16394903.
- Guldner G, Babbitt J, Boulton M, O’Callaghan T, Feleke R, Hargrove J. Deferral of the rectal examination in blunt trauma patients: a clinical decision rule. Acad Emerg Med. 2004 Jun;11(6):635-41. PMID: 15175201.
- Guldner GT, Brzenski AB. The sensitivity and specificity of the digital rectal examination for detecting spinal cord injury in adult patients with blunt trauma. Am J Emerg Med. 2006 Jan;24(1):113-7. PMID: 16338517.
- Kortbeek JB, et al. Advanced trauma life support, 8th edition, the evidence for change. J Trauma. 2008 Jun;64(6):1638-50 .PMID: 18545134.
- Porter JM, Ursic CM. Digital rectal examination for trauma: does every patient need one? Am Surg. 2001 May;67(5):438-41. PMID: 11379644.
- Shlamovitz GZ, Mower WR, Bergman J, Crisp J, DeVore HK, Hardy D, Sargent M, Shroff SD, Snyder E, Morgan MT. Poor test characteristics for the digital rectal examination in trauma patients. Ann Emerg Med. 2007 Jul;50(1):25-33, 33.e1. PMID: 17391807.