Performance of automated external defibrillators under conditions of in-flight turbulence.

INTRODUCTION: Modern automated external defibrillators (AEDs) are designed to prevent shock delivery when excessive motion produces rhythm disturbances mimicking ventricular fibrillation (VF). This has been reported as a safety issue in airline operations, where turbulent motion is commonplace. We aimed to evaluate whether all seven AEDs can deliver shock appropriately in a flight simulator under turbulent conditions. METHODS: The study was performed in a Boeing 747-400 full motion flight simulator in Hong Kong. An advanced life support manikin and arrhythmia generator were used to produce sinus rhythm (SR), asystole, and five amplitudes of VF, with a programmed change to SR in the event of an effective shock being delivered. All rhythms were tested at rest (no turbulence) and at four levels of motion (ground taxi vibration, and mild, moderate and severe in-flight turbulence). Success was defined as: 1. effective shock being delivered where the rhythm was VF successfully converted to SR; 2. no inappropriate shock being delivered for asystole or SR. RESULTS: Five AEDs produced acceptable results at all levels of turbulence. Another was satisfactory for VF except at very fine amplitudes. One model was deemed unsatisfactory for in-flight use as its motion detector inhibited shocks at all levels of turbulence. CONCLUSION: Some AEDs designed primarily for ground use may not perform well under turbulent in-flight conditions. AEDs for possible in-flight or other non-terrestrial use should be fully evaluated by manufacturers or end-users before introduction to service.

Validación del esfingomanómetro de muñeca OmronHEM-650 utilizando el protocolo de la Sociedad Británica de Hipertensión en pacientes atendidos en un servicio de urgencias de Hong Kong / Validation of the Omron HEM-650 wrist blood pressure device using the British Hypertension Society protocol in emergency patients in Hong Kong

Objetivos: Los dispositivos automáticos de muñeca para medir la presión arterial (PA) son más compactos y fáciles de usar, sobre todo cuando el acceso a la parte superior del brazo está restringido, por ejemplo, en situaciones de emergencia. Métodos: Hemos probado el dispositivo de muñeca Omron HEM-650 utilizando los criterios de validación del protocolo de la Sociedad Británica de Hipertensión en un gran servicio de urgencias (ED) de Hong Kong. Se realizaron 3 mediciones en 85 pacientes con el dispositivo Omron HEM-650 y el esfingomanómetro de mercurio. También se utilizó la medición automatizada convencional de PA con banda para el brazo mediante un dispositivo oscilométrico (Colin BP-88S NXT) para la comparación. Resultados: El Omron HEM-650 logra una calificación de grado B para las presiones arteriales sistólica y diastólica y demostró una precisión y fiabilidad aceptables en pacientes chinos en el servicio de urgencias. Conclusiones: El dispositivo de muñeca Omron HEM 650 se recomienda para su uso en pacientes adultos de urgencias. Se necesita más investigación para su uso en mujeres embarazadas y los pacientes en estado crítico (AU)

Aims: Automated wrist cuff blood pressure (BP) devices are more compact and easier to use, particularly when access to the upper arm is restricted, for example in emergencies. Methods: We tested the Omron HEM-650 wrist device using the validation criteria of the British Hypertension Society (BHS) protocol in a major emergency department (ED) in Hong Kong. 85 patients had three measurements each by both the Omron HEM-650 wrist device and the mercury sphygmomanometer. The conventional automated BP with arm cuff was also measured using an oscillometric (Colin BP-88S NXT) device for comparison. Results: The Omron HEM-650 achieved a grade B for both systolic and diastolic BP and demonstrated acceptable accuracy and reliability in Chinese patients in the emergency setting. Conclusions: The Omron HEM 650 wrist device can be recommended for use in adult emergency patients. Further research is warranted for its use in pregnant women and critically ill patients (AU)

[Validation of the Omron HEM-650 wrist blood pressure device using the British Hypertension Society protocol in emergency patients in Hong Kong]. / Validación del esfingomanómetro de muñeca Omron HEM-650 utilizando el protocolo de la Sociedad Británica de Hipertensión en pacientes atendidos en un servicio de urgencias de Hong Kong.

OBJECTIVES: Automated wrist cuff blood pressure (BP) devices are more compact and easier to use, particularly when access to the upper arm is restricted, for example in emergencies. MATERIAL AND METHODS: We tested the Omron HEM-650 wrist device using the validation criteria of the British Hypertension Society (BHS) protocol in a major emergency department (ED) in Hong Kong. 85 patients had three measurements each by both the Omron HEM-650 wrist device and the mercury sphygmomanometer. The conventional automated BP with arm cuff was also measured using an oscillometric (Colin BP-88S NXT) device for comparison. RESULTS: The Omron HEM-650 achieved a grade B for both systolic and diastolic BP and demonstrated acceptable accuracy and reliability in Chinese patients in the emergency setting. CONCLUSION: The Omron HEM 650 wrist device can be recommended for use in adult emergency patients. Further research is warranted for its use in pregnant women and critically ill patients.

OBJETIVO: Los dispositivos automáticos de muñeca para medir la presión arterial (PA) son más compactos y fáciles de usar, sobre todo cuando el acceso a la parte superior del brazo está restringido, por ejemplo, en situaciones de emergencia. METODO: Hemos probado el dispositivo de muñeca Omron HEM-650 utilizando los criterios de validación del protocolo de la Sociedad Británica de Hipertensión en un gran servicio de urgencias (ED) de Hong Kong. Se realizaron 3 mediciones en 85 pacientes con el dispositivo Omron HEM-650 y el esfingomanómetro de mercurio. También se utilizó la medición automatizada convencional de PA con banda para el brazo mediante un dispositivo oscilométrico (Colin BP-88S NXT) para la comparación. RESULTADOS: El Omron HEM-650 logra una calificación de grado B para las presiones arteriales sistólica y diastólica y demostró una precisión y fiabilidad aceptables en pacientes chinos en el servicio de urgencias. CONCLUSIONES: El dispositivo de muñeca Omron HEM 650 se recomienda para su uso en pacientes adultos de urgencias. Se necesita más investigación para su uso en mujeres embarazadas y los pacientes en estado crítico.

Medical volunteers in commercial flight medical diversions.

BACKGROUND: In-flight medical emergencies are difficult to manage and medical volunteers can be valuable when these events occur. The study objective was to examine the role of medical volunteers in medical emergencies which resulted in medical flight diversions. METHODS: This was a retrospective cohort study of medical diversions in a large Hong Kong commercial airline from December 2003 to November 2008. This study is derived from a database of in-flight medical events which has been previously reported. The presence of medical volunteers, the need for diversion, and the outcome for all in-flight medical events were recorded. The records of the medical diversion incidents were reviewed in detail and symptom-based categorization applied. RESULTS: Medical volunteers were available in 1439 (35.4%) of the 4068 medical events and in 39 (84.8%) of the 46 cases which required medical diversions. Suspected stroke cases, as categorized under the nonspecific category, was the most common, followed by chest pains and deaths. CONCLUSIONS: Medical volunteers presented more often for more serious events, and may be due to the airline medical incident policy and medical legal concerns for volunteers. This study identified measures which may reduce medical diversions, including cabin crew training for stroke screening, and promote the use of the Medical Information Form (MEDIF) and indemnity forms. Recommendations for medical diversion may require more specialized training than is currently given in undergraduate medical courses, and may benefit from better communication with ground-based medical advice services.

Effect of stress hormones on the expression of fibrinogen-binding receptors in platelets.

Acute coagulopathy is a common clinical complication after trauma, and contributes to posttraumatic multiple organ failure. The phenomenon may be due to the effect of stress hormones on platelet adhesion molecule expression after trauma. Catecholamine levels correlate with injury severity scores and changes of L-selectin expression on leucocytes, whilst adrenaline (ADR) (epinephrine) alone also activates platelets. This study thus investigates the effects of ADR and noradrenaline (NOR) (norepinephrine) on platelets, at doses similar to those found in the plasma of normal and trauma subjects. Blood was taken from 19 healthy subjects and placed in tubes containing sodium citrate. Anti-platelet-bound fibrinogen monoclonal antibody was used to identify the activated platelets while anti-CD41 was used to identify platelets with and without activation. Five increasing concentrations of ADR and NOR (1, 3, 5, 10, 30 nmol/l) as well as one negative control (0.9% normal saline) and one positive control (10 micromol/l adenosine diphosphate/ADP) were prepared for the stimulation. A whole blood protocol was used in order to minimize any activation artefacts, which might be created by centrifugation. The percentage of platelets expressing fibrinogen receptors increased significantly with ADR and NOR even at the lowest dose (1 nmol/l) and continued to increase in a dose-dependent manner. Although the effect of ADR was greater than NOR in stimulating platelets to express fibrinogen receptors, the average number of fibrinogen receptors on each platelet was constant. ADR and NOR activated platelets to express fibrinogen receptors at doses that are similar to those found in the plasma of trauma patients.