BACKGROUND: Sonography is an established diagnostic procedure in hospitals, but is not routinely used in prehospital emergency medicine. Several studies have addressed the use of ultrasound during helicopter flights and in emergency rooms, few in prehospital settings, but most focused on abdominal blunt trauma. Several case reports describe crucial decisions distinguished by ultrasound.
METHODS: In this study, four different handheld ultrasound systems in 4 helicopters and one emergency vehicle were used over a cumulative period of 3 years. Incidence, feasibility, indication, diagnoses and exploration time (in subgroups) were investigated in an overall profile of emergency patients, encompassing the area of internal medicine.
RESULTS: On 971 missions ultrasound systems were available. In 17% of the cases ultrasound was considered valuable, in 144 patients (14.8%) sonographic studies were performed. Additional information could be given in 130 cases (90%). Compared with the available clinical data (return rate of 76%) there were no false-positive findings during this study, resulting in a specificity and positive predictive value of 100%, showing this technique to be reliable. Sensitivity was 85%, accuracy was 96% and negative predictive value was 95%.
CONCLUSION: Ultrasound is the only imaging modality and a useful diagnostic tool in prehospital emergency medicine. Helpful information can be provided in at least one of six cases (or even more) in a trauma-dominated collective. Examination time is short; it will not significantly delay medical care. Ultrasound examination could improve triage in cases of more than one patient in disaster medicine, but further studies are necessary.
The potential benefit of point-of-care ultrasound by medical retrieval teams is unclear. In the present case report, the diagnosis of an abdominal aortic aneurysm by a critical care retrieval team equipped with a portable ultrasound machine resulted in significant corrective alteration in patient management and subsequent disposition at the receiving institution.
BACKGROUND: Ultrasound plays a central role in the evaluation of both trauma and medical emergencies. The development of portable sonography devices could extent its application into the pre-hospital arena. The aim of our study was to evaluate feasibility of pre-hospital ultrasound in the Norwegian Air Rescue setting.
MATERIAL AND METHODS: During a 3-month period, we conducted a prospective study using sonography in pre-hospital patient management. All examinations were carried out by the same ultrasound-certified physician using a Primedic Handyscan in a standardized focused protocol for abdominal and lung sonography and a subcostal 2-chamber long axis view. Inclusion criteria were abdominal/thoracic and obstetric trauma, circulatory/respiratory compromise, pulseless electric activity (PEA) in cardiac arrest, acute abdomen and monitoring during transport. Allowed examination time was restricted to 3 min on the scene. The patient's gender, age, symptoms, trauma mechanism, quality of visualization and diagnose made were recorded. Pre-hospital results were compared with in-hospital findings.
RESULTS: Thirty-eight patients were entered into the study. Three patients had to be excluded due to technical difficulties. Nineteen medical, 15 traumas and 1 obstetric patient were included. Good visualization was obtained in 74% (n= 26), moderate in 26% (n = 9). Median examination time was 2.5 min (range 1-3 min). Nine patients (26%) showed positive sonography findings. Sensitivity was 90%, specificity 96%. Diagnostic usefulness was high in undetermined cardiac arrest and hypotension and massive hematoperitoneum.
CONCLUSION: Pre-hospital ultrasound when applied by an proficient examiner using a goal-directed, time sensitive protocol is feasible, does not delay patient management and provides diagnostic and therapeutic benefit. Further studies are warranted to identify the exact indications and role of pre-hospital sonography.
OBJECTIVE: To evaluate the usefulness of ultrasonographic examinations as a diagnostic tool for emergency physicians in out-of-hospital settings.
METHODS: Prospective study performed in a French teaching hospital. Eight emergency physicians given ultrasound training for out-of-hospital diagnosis of pleural, peritoneal, or pericardial effusion; deep venous thrombosis; and arterial flow interruption. After clinical examination, a probability of diagnosis ("clinical score") was assigned on visual analog scale from 0 (absent lesion) to 10 (present lesion). Clinical score between 3 and 7 was considered as clinically doubtful. After ultrasound examination, a second probability ("ultrasound score") was similarly determined. Potential usefulness of ultrasound examination was evaluated by calculating the absolute difference between clinical and ultrasound scores. Patients were followed up to determine final diagnosis: present or absent lesion. "Ultrasound usefulness score" (USS) was determined attributing a positive (when ultrasonography increased diagnostic accuracy) or a negative (when ultrasonography decreased diagnostic accuracy) value to the absolute difference between clinical and ultrasound scores.
RESULTS: One hundred sixty-nine patients were included and 302 ultrasound examinations performed. Median duration of examination was 6 minutes (5-10 minutes). The suspected lesion was found in 45 cases (17%). Mean USS was +2 (0-4). Ultrasonographic examination improved diagnostic accuracy (ie, positive USS) in 181 (67%) cases, decreased it (ie, negative USS) in 22 (8%) cases, and was not contributive (ie, USS was 0) in 67 (25%) cases. When initial diagnosis was uncertain (n = 115), diagnostic performance reached +4 (3-5) and ultrasonographic examination improved diagnostic accuracy in 103 (90%) cases.
CONCLUSION: Out-of-hospital ultrasonography increased diagnostic accuracy in out-of-hospital settings.
BACKGROUND: Blunt abdominal trauma with intra-abdominal bleeding is often underdiagnosed or even overlooked at trauma scenes. The purpose of this prospective, multicentre study was to compare the accuracy of physical examination and prehospital focused abdominal sonography for trauma (PFAST) to detect abdominal bleeding.
METHODS: Six rescue centres took part in the study from December 2002 to December 2003, including 230 patients with suspected abdominal injury. The accuracy of physical examination at the scene and PFAST were compared. Later examinations in the emergency department (ultrasonography and/or computed tomography) were used as the reference standard.
RESULTS: The complete protocol and follow-up was obtained in 202 patients. The sensitivity, specificity and accuracy of PFAST were 93 per cent, 99 per cent and 99 per cent, respectively, compared with 93 per cent, 52 per cent and 57 per cent for physical examination at the scene. Scanning with PFAST occurred a mean(s.d.) 35(13) min earlier than ultrasound in the emergency department. Abdominal bleeding was detected in 14 per cent of patients. Using PFAST led to a change in either prehospital therapy or management in 30 per cent of patients, and a change to admitting hospital in 22 per cent.
CONCLUSION: In this study, PFAST was a useful and reliable diagnostic tool when used as part of surgical triage at the trauma scene.
Sonography is an established diagnostic procedure in hospitals, but is not routinely used in prehospital emergency medicine. Several studies have addressed the use of ultrasound during helicopter flights and in emergency rooms, few in prehospital settings, but most focused on abdominal blunt trauma. Several case reports describe crucial decisions distinguished by ultrasound.
METHODS:
In this study, four different handheld ultrasound systems in 4 helicopters and one emergency vehicle were used over a cumulative period of 3 years. Incidence, feasibility, indication, diagnoses and exploration time (in subgroups) were investigated in an overall profile of emergency patients, encompassing the area of internal medicine.
RESULTS:
On 971 missions ultrasound systems were available. In 17% of the cases ultrasound was considered valuable, in 144 patients (14.8%) sonographic studies were performed. Additional information could be given in 130 cases (90%). Compared with the available clinical data (return rate of 76%) there were no false-positive findings during this study, resulting in a specificity and positive predictive value of 100%, showing this technique to be reliable. Sensitivity was 85%, accuracy was 96% and negative predictive value was 95%.
CONCLUSION:
Ultrasound is the only imaging modality and a useful diagnostic tool in prehospital emergency medicine. Helpful information can be provided in at least one of six cases (or even more) in a trauma-dominated collective. Examination time is short; it will not significantly delay medical care. Ultrasound examination could improve triage in cases of more than one patient in disaster medicine, but further studies are necessary.
