Page 163 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

Abdominal prehospital ultrasound impacts treatment decisions in a Dutch helicopter emergency medical service 161
our setting, time intervals between US examinations are much shorter than theirs. The max- imum interval is never longer than the duration of patient contact: a mean of 42.6 minutes.
Our findings contrast with the sensitivity of 93%, and specificity of 99% that Walcher report- ed.10 We speculate the main explanation is that they used emergency department ultrasound or CT imaging as the gold standard while we compared to (more sensitive) CT imaging and laparotomy. To prevent bias, we scored every mention of free fluid in the reports. This strict protocol probably implicates that small and possibly irrelevant amounts of free abdominal fluid negatively impact PHUS sensitivity. Although small injuries and insignificant amounts of free abdominal fluid may often have no clinical implications and therefore are not relevant in the prehospital setting, we encourage physicians to remain vigilant and if possible repeat the examination, in accordance with earlier research.2,18
The few systematic reviews available question whether the reported beneficial influences of PHUS result in a better treatment for patients.13,14 According to O’Dochartaigh, it seems evident, that PHUS has a beneficial influence on diagnostics and logistics (the appropriate mode of transportation and destination hospital). Impact on survival, morbidity, and re- covery time that might result from improved treatment, however, was not found. Stengel reported in his review that negative emergency department US examinations might lead to a decrease in additional imaging causing an undesired and possibly detrimental delay in treatment of the patients with false negative PHUS results.13 They suggested the impact of US examination to be non-inferior at best.
We strongly agree with O’Dochartaigh that PHUS is beneficial. In our study, the proportion of policy changes is smaller than found in other studies, but it demonstrates that PHUS provides a significant contribution to medical decision making. It aids in selecting the most suitable trauma center, provides valuable extra time for trauma team preparation and po- tential operating and radiology room clearing. Moreover, PHUS probably influences patient care on many more levels, such as the urgency to act as experienced by the HEMS team. This impact will often not be reported or even acknowledged by physicians, and therefore we speculate our study underestimates the true scale PHUS-impacted patient care. Focusing on medical policy changes alone is probably insufficient to estimate the true value of PHUS. Using PHUS to confirm previous conclusions and justify a plan of work is equally important.
HEMS physicians often decide to refrain from escorting a patient to the hospital. Such a decision is based on more factors than the PHUS findings alone. Prehospital assessment of patients includes the trauma mechanism or illness, additional history taking, physical exam- ination, and repeated measurements of vital signs. Nevertheless, in 53 patients, physicians indicated that PHUS impacted their decision not to escort the patient to definitive care.
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