David C. Mackenzie

David MacKenzie discusses the importance of structural safety in the design and construction phase and ways in which risks can be mitigated.

Dural sinus thrombosis (DST), or cerebral venous thrombosis, is an uncommon cause of stroke. It has a variable presentation, and the symptoms and signs can be non-specific. The diagnosis of DST can be difficult to make and is often delayed or missed. Computed tomography venography or magnetic resonance venography are the typical imaging modalities used to diagnose DST. However, computed tomography venography and magnetic resonance venography both have limitation for emergency department patients. In this article, we report the use of point-of-care ultrasound to facilitate the diagnosis of DST.

Objectives: Unstructured clinical assessments of dehydration in children are inaccurate. Point‐of‐care ultrasound is a noninvasive diagnostic tool that can help evaluate the volume status; the corrected carotid artery flow time has been shown to predict volume depletion in adults. We sought to determine the ability of the corrected carotid artery flow time to identify dehydration in a population of children presenting with acute diarrhea in Dhaka, Bangladesh.Methods: Children presenting with acute diarrhea were recruited and rehydrated according to hospital protocols. The corrected carotid artery flow time was measured at the time of presentation. The percentage of weight change with rehydration was used to categorize each child's dehydration as severe (>9%), some (3%–9%), or none (<3%). A receiver operating characteristic curve was constructed to test the performance of the corrected carotid artery flow time for detecting severe dehydration. Linear regression was used to model the relationship between the corrected carotid artery flow time and percentage of dehydration.Results: A total of 350 children (0–60 months) were enrolled. The mean corrected carotid artery flow time was 326 milliseconds (interquartile range, 295–351 milliseconds). The area under the receiver operating characteristic curve for the detection of severe dehydration was 0.51 (95% confidence interval, 0.42, 0.61). Linear regression modeling showed a weak association between the flow time and dehydration.Conclusions: The corrected carotid artery flow time was a poor predictor of severe dehydration in this population of children with diarrhea.

Traumatic or spontaneous hemarthroses are an important cause of joint effusions, and can complicate innate or acquired coagulopathies. The elbow is an unusual location for a spontaneous hemarthrosis; we describe a previously unreported case of warfarin-induced spontaneous elbow hemarthrosis, diagnosed by point-of-care ultrasound. On the basis of clinical and ultrasound findings arthrocentesis was deferred, and the patient was successfully treated with warfarin reversal and conservative care. Physical examination is unreliable for the detection of a joint effusion, and misdiagnosis and can lead to unnecessary investigation or resource use. Point-of-care ultrasound allows accurate, prompt, direct visualization of a joint effusion, and non-invasive confirmation of a hemarthrosis. Ultrasound can facilitate accurate diagnosis and characterization of joint effusions to improve the care of patients with coagulopathy.

Objective: We delivered a point‐of‐care ultrasound training programme in a resource‐limited setting in Rwanda, and sought to determine participants' knowledge and skill retention. We also measured trainees' assessment of the usefulness of ultrasound in clinical practice.Methods: This was a prospective cohort study of 17 Rwandan physicians participating in a point‐of‐care ultrasound training programme. The follow‐up period was 1 year. Participants completed a 10‐day ultrasound course, with follow‐up training delivered over the subsequent 12 months. Trainee knowledge acquisition and skill retention were assessed via observed structured clinical examinations (OSCEs) administered at six points during the study, and an image‐based assessment completed at three points.Results: Trainees reported minimal structured ultrasound education and little confidence using point‐of‐care ultrasound before the training. Mean scores on the image‐based assessment increased from 36.9% (95% CI 32–41.8%) before the initial 10‐day training to 74.3% afterwards (95% CI 69.4–79.2; P < 0.001). The mean score on the initial OSCE after the introductory course was 81.7% (95% CI 78–85.4%). The mean OSCE performance at each subsequent evaluation was at least 75%, and the mean OSCE score at the 58‐week follow up was 84.9% (95% CI 80.9–88.9%).Conclusions: Physicians providing acute care in a resource‐limited setting demonstrated sustained improvement in their ultrasound knowledge and skill 1 year after completing a clinical ultrasound training programme. They also reported improvements in their ability to provide patient care and in job satisfaction.

Resuscitation with intravenous fluid can restore intravascular volume and improve stroke volume. However, in unstable patients, approximately 50% of fluid boluses fail to improve cardiac output as intended. Increasing evidence suggests that excess fluid may worsen patient outcomes. Clinical examination and vital signs are unreliable predictors of the response to a fluid challenge. We review the importance of fluid management in the critically ill, methods of evaluating volume status, and tools to predict fluid responsiveness.