A. Jain

Comparison of the point-of-care blood gas analyzer versus the laboratory auto-analyzer for the measurement of electrolytes

BackgroundElectrolyte values are measured both by arterial blood gas (ABG) analyzers and central laboratory auto-analyzers (AA), but a significant time gap exists between the availability of both these results, with the ABG giving faster results than the AA. The authors hypothesized that there is no difference between the results obtained after measurement of electrolytes by the blood gas and auto-analyzers.MethodsAfter approval by the ethics committee, an observational cohort study was conducted in which 200 paired venous and arterial samples from patients admitted to the Medical Intensive Care Unit (ICU) of Apollo Hospital, Hyderabad, India, were analyzed for electrolytes on the ABG machine and the AA. Analyses were done on the ABL555 blood gas analyzer and the Dade Dimension RxL Max, both located in the central laboratory. Statistical analyses were performed using paired Student’s t test.ResultsA total of 200 paired samples were analyzed. The mean ABG sodium value was 131.28 (SD 7.33), and the mean AA sodium value was 136.45 (SD 6.50) (p < 0.001). The mean ABG potassium value was 3.74 (SD 1.92), and the mean AA potassium value was 3.896 (SD 1.848) (p = 0.2679).ConclusionBased on the above analysis, the authors found no significant difference between the potassium values measured by the blood gas machine and the auto-analyzer. However, the difference between the measured sodium was found to be significant. We therefore conclude that critical decisions can be made by trusting the potassium values obtained from the arterial blood gas analysis.

Cardioembolic but Not Other Stroke Subtypes Predict Mortality Independent of Stroke Severity at Presentation

Introduction. Etiology of acute ischemic stroke (AIS) is known to significantly influence management, prognosis, and risk of recurrence. Objective. To determine if ischemic stroke subtype based on TOAST criteria influences mortality. Methods. We conducted an observational study of a consecutive cohort of patients presenting with AIS to a single tertiary academic center. Results. The study population consisted of 500 patients who resided in the local county or the surrounding nine-county area. No patients were lost to followup. Two hundred and sixty one (52.2%) were male, and the mean age at presentation was 73.7 years (standard deviation, SD = 14.3). Subtypes were as follows: large artery atherosclerosis 97 (19.4%), cardioembolic 144 (28.8%), small vessel disease 75 (15%), other causes 19 (3.8%), and unknown 165 (33%). One hundred and sixty patients died: 69 within the first 30 days, 27 within 31–90 days, 29 within 91–365 days, and 35 after 1 year. Low 90-, 180-, and 360-day survival was seen in cardioembolic strokes (67.1%, 65.5%, and 58.2%, resp.), followed for cryptogenic strokes (78.0%, 75.3%, and 71.1%). Interestingly, when looking into the cryptogenic category, those with insufficient information to assign a stroke subtype had the lowest survival estimate (57.7% at 90 days, 56.1% at 180 days, and 51.2% at 1 year). Conclusion. Cardioembolic ischemic stroke subtype determined by TOAST criteria predicts long-term mortality, even after adjusting for age and stroke severity.

Ultrasound in emergency medicine: a colorful future in black and white

From the experiment using an underwater bell to determine the speed of sound by J. D. Colladon in 1826, the generation of ultrasound waves by Francis Galton in 1876, the discovery of the piezoelectric effect by Pierre Curie in 1880, the development of sonar systems within a month of the sinking of the Titanic in 1912, to its early conception as the “hydrophone” by Paul Langevin and Constantin Chilowsky in 1915 and the development of medical ultrasonic systems since 1940, ultrasound is a technology that has now reached the “tipping point” and is being rapidly assimilated into multiple medical specialties beyond radiology. Emergency medicine (EM) has witnessed the addition of ultrasonography to the arsenal of emergency care. The history of ultrasound in EM, spanning 15 years, can be traced back to the publication of the first emergency ultrasound curriculum by Mateer et al. in 1994. Increasing portability and the ease of training has fueled its rapid ascent to the front lines of EM practice to improve patient care. Since the publication of the first formal policy statement for the use of ultrasound in EM by the American College of Emergency Physicians in 2001 [1], the concept of emergency screening ultrasound has gained favor with most of the residency training programs in the USA and is now an element of the core curriculum required by the Residency Review Committee for Emergency Medicine [2]. It was also recently incorporated in the guidelines of the College of Emergency Medicine, UK in 2006 [3]. A large body of research studies has provided strong evidence that with appropriate training emergency ultrasound done by emergency physicians can safely aid time-critical decisions and procedures in the emergency department (ED). The gamut of emergency ultrasound has gone from FAST (focused sonography for trauma) to comprehensive advanced scans and procedural guidance such as scans for shortness of breath, increased intracranial pressure (ICP), and central line placement. The ability of ultrasound to be incorporated in emergency medical services (EMS), telemedicine, and medical student education has mushroomed interest in the field. We are pleased to feature ultrasound in this issue of the International Journal of Emergency Medicine. The first of the ultrasound articles in this issue is a review on its use in EMS [4]. Not only does it highlight the current status of its use in Europe and the USA, but it also provides insight into the training programs, point of care use in resuscitation and trauma by EMS, and the potential application in mass casualty incident triage. There is still a long way to go as far as credentialing EMS personnel is concerned, because of the known learning curve in ultrasound applications. The growth of ultrasound in EM is twofold—first is the development and validation of new point of care applications aptly demonstrated in the brief research report on “Ultrasound as an aid to reduction of pediatric forearm fractures” [5]. This application of ultrasound helps visually demonstrate successful reductions. Although the study did not demonstrate a decrease in the treatment time or radiological exposure, further validation will likely do so. The novelty of ultrasound applications has only multiplied with time, but the result remains the same: success. The second prong of growth is the promulgation of basic training in developing systems of care as is exemplified in the study on “Introduction of a portable ultrasound unit into the health services of the Lugufu refugee camp, Kigoma District, Tanzania” [6]. The study demonstrates the feasibility and the ease with which ultrasound can be adapted to use in complex, underdeveloped care systems to enhance patient care and satisfaction. This article goes a step further to demonstrate that the initial expenditure for procuring the equipment is greatly offset by the time gain and the decreased stress on ancillary medical departments in developing systems. The socioeconomic pressures of health care in all economies ranging from developed, developing and the underdeveloped will benefit from this boom of ultrasound in EM. But at the same time we must be wary that ultrasound in EM does not become a victim of its own success. Appropriate training and credentialing is the need of the hour. The spiraling growth of ultrasound in EM has only one foreseen outcome, a future made colorful by black and white.

The impact of blood pressure hemodynamics in acute ischemic stroke: a prospective cohort study

ObjectiveTo assess relationships between blood pressure hemodynamic measures and outcomes after acute ischemic stroke, including stroke severity, disability and death.MethodsThe study cohort consisted of 189 patients who presented to our emergency department with ischemic stroke of less than 24 hours onset who had hemodynamic parameters recorded and available for review. Blood pressure (BP) was non-invasively measured at 5 minute intervals for the length of the patients emergency department stay. Systolic BP (sBP) and diastolic BP (dBP) were measured for each patient and a differential (the maximum minus the minimum BP) calculated. Three outcomes were studied: stroke severity, disability at hospital discharge, and death at 90 days. Statistical tests used included Spearman correlations (for stroke severity), Wilcoxon test (for disability) and Cox models (for death).ResultsLarger differentials of either dBP (p = 0.003) or sBP (p < 0.001) were significantly associated with more severe strokes. A greater dBP (p = 0.019) or sBP (p = 0.036) differential was associated with a significantly worse functional outcome at hospital discharge. Those patients with larger differentials of either dBP (p = 0.008) or sBP (0.007) were also significantly more likely to be dead at 90 days, independently of the basal BP.ConclusionA large differential in either systolic or diastolic blood pressure within 24 hours of symptom onset in acute ischemic stroke appears to be associated with more severe strokes, worse functional outcome and early death