Enhanced analysis of somatosensory evoked potentials at 20-30 milliseconds can predict neurological outcome after cardiac arrest.

OBJECTIVE: This study attempted to test the effectiveness of an enhanced analysis of the 20-30 ms complex of somatosensory evoked potentials, in predicting the short-term outcome of comatose survivors of out of hospital cardiac arrest and compare it with the current clinical practice. METHODS: Single-centre, prospective, observational study. Median nerve SSEP recording performed at 24-36 h post-return of spontaneous circulation. Recording was analysed using amplitude measurements of P25/30 and Peak-To-Trough of 20-30 ms complex and thresholds to decide P25/30 presence. Neurological outcome was dichotomised into favourable and unfavourable. RESULTS: 89 participants were analysed. 43.8% had favourable and 56.2% unfavourable outcome. The sensitivity, specificity, positive and negative predictive values of the present SSEP and favourable outcome were calculated. P25/30 presence and size of PTT improved positive predictive value and specificity, while maintained similar negative predictive value and sensitivity, compared to the current practice. Inter-interpreter agreement was also improved. CONCLUSIONS: Enhanced analysis of the SSEP at 20-30 ms complex could improve the short-term prognostic accuracy for short-term neurological outcome in comatose survivors of cardiac arrest. SIGNIFICANCE: Peak-To-Trough analysis of the 20-30 ms SSEP waveform appears to be the best predictor of neurological outcome following out of hospital cardiac arrest. It is also the easiest and most reliable to analyse.

Inaccuracies in calculating predicted body weight and its impact on safe ventilator settings.

In many centres, height is used as a determinant for calculating predicted body weight. This predicted body weight is then multiplied to generate the desired tidal volume. The approach exhibits some mathematical effects: (1) any errors in height measurement are multiplied by 5.5 when generating the tidal volume (assuming 6 ml/kg); (2) any errors in height measurement have a greater impact on shorter patients. The aim of this study was to: (1) establish the current practice of setting a tidal volume in England; (2) assess the implications of inaccurate height measurements on tidal volume settings using the most common practice; (3) identify the most accurate and precise method of determining height to aid accurate application of a lung protective strategy. The six extra corporeal membrane oxygenation centres in the UK, and the 34 intensive cares with the highest admission figures were identified from the intensive care national audit and research centre database. Most frequent practice was to use of a 1-m tape on the supine patient on admission. Inaccuracies in height estimation using a 1-m tape resulted in a standard deviation of 23 ml and a spread of over 120 ml tidal volume in individual patients.There are a number of methods of estimating height in a supine patient but the most accurate appeared to be simply using a 2-m tape.

Disproportionate impact of pandemic (H1N1) 2009 influenza on Indigenous people in the Top End of Australia's Northern Territory.

OBJECTIVE: To describe the impact of pandemic (H1N1) 2009 influenza (nH1N1) on Indigenous people in the Top End of the Northern Territory at community, hospital and intensive care unit (ICU) levels. DESIGN, SETTING AND PARTICIPANTS: We analysed influenza notifications for the Top End from 1 June to 31 August 2009, as well as data on patients admitted through Top End emergency departments with an influenza-like illness. In addition, data on patients with nH1N1 who were admitted to Royal Darwin Hospital (RDH) and the RDH ICU were prospectively collected and analysed. MAIN OUTCOME MEASURES: Age-adjusted notification rates for nH1N1 cases, Top End hospital admission rates for patients with nH1N1 and RDH ICU admission rates for patients with nH1N1, stratified by Indigenous status. RESULTS: There were 918 nH1N1 notifications during the study period. The age-adjusted hospital admission rate for nH1N1 was 82 per 100 000 (95% CI, 68-95) estimated resident population (ERP) overall, with a markedly higher rate in the Indigenous population compared with the non-Indigenous population (269 per 100 000 versus 29 per 100 000 ERP; adjusted incidence rate ratio, 12 [95% CI, 7.8-18]). Independent predictors of ICU admission compared with hospitalisation were hypoxia (adjusted odds ratio [aOR], 4.5; CI, 1.5-13.1) and chest x-ray infiltrates (aOR, 4.3; CI, 1.5-12.6) on hospital admission. CONCLUSIONS: Pandemic (H1N1) 2009 influenza had a disproportionate impact on Indigenous Australians in the Top End, with hospitalisation rates higher than those reported elsewhere in Australia and overseas. These findings have implications for planning hospital and ICU capacity during an influenza pandemic in regions with large Indigenous populations. They also confirm the need to improve health and living circumstances and to prioritise vaccination in this population.