Echocardiography in the emergency department.

Point-of-care echocardiography using portable machines is an exciting development in emergency medicine. Recent improvements in ultrasound quality mean that emergency physicians are finding echocardiography useful in a variety of clinical settings. Evidence suggests that emergency physicians are able to master the skills of basic echocardiography sufficiently to improve patient care in the resuscitation scenario. Patients with clinical conditions such as breathlessness, undifferentiated shock, chest pain and cardiac arrest may benefit. There is a steep learning curve involved in acquiring these skills and the specialty needs to take care in the way that its practitioners are accredited and perform echocardiography.

The experience of Teesside helicopter emergency services: doctors do not prolong prehospital on-scene times.

BACKGROUND: The benefits of helicopter emergency medical services (HEMSs) attending the severely injured have been documented in the past. The benefits of doctors attending HEMS casualties have been demonstrated in particular in inner-urban and metropolitan areas. However, for UK regions with potentially less major trauma, concerns have been raised by ambulance services that a willingness of doctors to "stay and play" may lead to unnecessary delays on-scene without any additional benefit to the patient. AIMS: To identify factors that do prolong on-scene time, establish whether doctors "stay and play" on-scene compared with paramedics and document how often advanced medical skills may have to be used by HEMS doctors working outside the London HEMS environment. METHODS: Patient report form data were studied with regard to the number of and mean on-scene times of missions flown to (A) road-traffic collisions (RTCs), (B) other trauma calls (OTCs) and (C) medical emergencies. Trauma missions (categories A and B) were further subcategorised with regard to associated patient entrapment. Any advanced medical interventions (AMIs) performed by HEMS doctors were recorded and categorised. Finally, we looked at the difference in on-scene times for physician-paramedic partnerships (PPPs) and conventional paramedic crews (CPCs) for the above categories and subcategories. RESULTS: A total of 203 patient report forms were identified and examined. In all, 44.3% of missions were flown to RTCs with a further 44.3% for OTCs and 11.4% to medical emergencies. AMIs were performed by HEMS doctors in 34.1% of PPP missions, with a prehospital rapid sequence induction rate of 3.8%. Overall mean on-scene time was 25 min, with no difference for PPP and CPC missions. The mean on-scene time was prolonged by 6 min for RTCs (p = 0.006) and by 23 min for patient entrapment (p<0.001). No significant differences were found for the comparison between PPPs and CPCs in any of the subgroups A-C. However, there seemed to be a trend towards reduced on-scene times of PPPs for medical emergencies and patient entrapments. DISCUSSION: This study did not show any significant prolongation of mean on-scene times for PPP missions either overall or for any of the subgroups A-C. The fact that AMIs were performed in a large number of missions attended by HEMS doctors seems to further justify their current role in providing improved care at the roadside without leading to any delays in transfer to definitive care.

The tuning fork test--a useful tool for improving specificity in "Ottawa positive" patients after ankle inversion injury.

The Ottawa ankle rules are a clinical instrument calibrated towards a high sensitivity in order not to miss any fractures of the ankle or mid-foot. This is at the cost of a mean specificity of around only 32%. The aim of this study was to determine the suitability of tuning fork testing in combination with existing Ottawa guidance for increasing the specificity in detecting fractures of the lateral malleolus. A prospective pilot study was carried out, in which a single trained investigator examined all patients with already "Ottawa positive" findings for possible lateral malleolus injury by applying a tuning fork (C(o) 128 Hz). The tuning fork test findings were compared with formal reports of plain ankle radiographs using simple cross-table analysis. The observed prevalence of ankle fractures was 5 of 49 (10%). Sensitivity and specificity were calculated as 100% and 61%, respectively, for tuning fork testing on the tip of the lateral malleolus (TLM), and as 100% and 95%, respectively, for testing on the distal fibula shaft (DFS). The associated positive and negative likelihood ratios were 2.59 and 0 (TLM), and 22 and 0 (DFS), respectively. The data were significant, with p = 0.014 (TLM) and p<0.001 (DFS). This study suggests that additional tuning fork testing of "Ottawa positive" patients may lead to a marked reduction in ankle radiographs, with consequently reduced radiation exposure and journey time. This may be particularly relevant in situations where radiological facilities are not readily available (expedition medicine) or where access to these has to be prioritised (major incidents, natural catastrophes).

Introducing fluorine-18 fluoromisonidazole positron emission tomography for the localisation and quantification of pig liver hypoxia.

Fluorine-18 labelled fluoromisonidazole ([18F]FMISO) has been shown to accumulate in hypoxic tissue in inverse proportion to tissue oxygenation. In order to evaluate the potential of [18F]FMISO as a possible positron emission tomography (PET) tracer for imaging of liver tissue hypoxia, we measured the [18F]FMISO uptake in 13 domestic pigs using dynamic PET scanning. Hypoxia was induced by segmental arterial hepatic occlusion. During the experimental procedure the fractional concentration of inspired oxygen (FiO2) was set to 0.67 in group A (n=6) and to 0.21 in group B (n=7) animals. Before and after arterial occlusion, the partial pressure of O2 in tissue (TPO2) and the arterial blood flow were determined in normal flow and flow-impaired liver segments. Standardised uptake values [SUV=kBq tissue (in g) / body weight (in kg) x injected dose (in kBq)] for [18F]FMISO were calculated from PET images obtained 3 hours after injection of about 10 MBq/kg body weight [18F]FMISO. Immediately before PET scanning, the mean arterial blood flow was significantly decreased in arterially occluded segments [group A: 0. 41 (0.32-0.52); group B: 0.24 (0.16-0.33) ml min-1 g-1] compared with normal flow segments [group A: 1.05 (0.76-1.46); group B: 1.14 (0.83-1.57) ml min-1 g-1; geometric mean (95% confidence limits); P<0.001 for both groups]. After PET scanning, the TPO2 of occluded segments (group A: 5.1 (4.1-6.4); group B: 3.5 (2.6-4.9) mmHg] was significantly decreased compared with normal flow segments [group A: 26.4 (21.2-33.0); group B: 18.2 (13.3-25.1) mmHg; P<0.001 for both groups]. During the 3-h PET scan, the mean [18F]FMISO SUV determined in occluded segments increased significantly to 3.84 (3.12-4.72) in group A and 5.7 (4.71-6.9) in group B, while the SUV remained unchanged in corresponding normal liver tissue [group A: 1.4 (1.14-1. 71); group B: 1.31 (1.09-1.57); P<0.001 for both groups]. Regardless of ventilation conditions, a significant inverse exponential relationship was found between the TPO2 and the [18F]FMISO SUV (r2=0. 88, P<0.001). Our results suggest that because tracer delivery to hypoxic tissues was maintained by the portal circulation, the [18F]FMISO accumulation in the liver was found to be directly related to the severity of tissue hypoxia. Thus, [18F]FMISO PET allows in vivo quantification of pig liver hypoxia using simple SUV analysis as long as tracer delivery is not critically reduced.