Duplex ultrasound screening can detect high rate of LDVT's in critically ill trauma patients

Dec 1 2011

A study published in the September 2011 issue of the Journal of Vascular Surgery®, the official publication of the Society for Vascular Surgery®, reports that a high rate of lower deep vein thromboses (LDVT's) in critically ill trauma cases can be detected through duplex ultrasound screening (DUS).

"Lower extremity deep vein thrombosis (LEDVT) is common in critically ill trauma patients, particularly in the first week following injury, regardless of injury pattern, deep vein thrombosis (DVT) risk factors or pharmacologic prophylaxis," said Amir Azarbal, MD of the department of surgery at Oregon Health and Sciences University (OHSU) in Portland, Oregon. "However, previous studies have underestimated DVT rates by not including calf vein thromboses (CVDTs) and not exclusively targeting critically ill patients."

The current study retrospectively reviewed the medical records of 264 intensive care unit trauma patients received DUS for LEDVT between January 2007 and December 2008. Patients were assessed for theh presence of injuries conferring high risk for LEDVT, patient specific DVT risk factors, and low molecular weight heparin (LMWH) prophylaxis.

Dr. Azarbal noted that American College of Chest Physician (ACCP) guidelines stratify DVT risk in trauma patients based only on injury pattern and pharmacologic prophylaxis, and screening is only recommended for patients with high-risk injuries who are unable to receive pharmacologic prophylaxis.

"Given that current ACCP guidelines recommend treatment of CVDVTs, we investigated the efficacy of duplex ultrasound (DUS) screening in critically ill trauma patients for all LEDVTs," he added.

Forty asymptomatic patients in the study had LEDVTs (15.2 percent) that were diagnosed by DUS screening. Twenty-four of these patients (60 percent) had a CVDVT. Thirty percent of all DVT's were diagnosed within one week of admission. Patients without high-risk injuries receiving LMWH had a 13 percent DVT rate, which did not differ significantly from the 19.7 percent DVT rate in high-risk injury patients not receiving LMWH.

"Current ACCP guidelines miss a substantial proportion of LEDVTs in critically ill trauma patients, especially when CVDVTs are included in the screening," said Dr. Azarbal. "Diagnosis of these otherwise undetected DVTs can lead to therapeutic anticoagulation, IVC filter placement or continued surveillance, depending on institutional practices."

"This study shows that DUS screening appears to be a useful adjunct to current protocols of DVT prevention, detection and treatment in trauma ICUs," said researchers who recommend routine DUS, and early and ongoing surveillance of all critically ill trauma patients for all LEDVTs regardless of injury patterns, DVT risk factors, or the presence of pharmacologic prophylaxis.

Source Society for Vascular Surgery