The rescuer during a 30 minutes BLS-Sequence

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Society of cardiovascular anesthesiologists: the effect of blood pressure regulation during aortic coarctation repair on brain, kidney, and muscle oxygen saturation measured by near-infrared spectroscopy: a randomized, clinical trial

In this study, we compared the effects of 3 frequently used arterial blood pressure-regulating agents on brain (rScO2), renal (SrO2), and muscle (SmO2) oxygen saturation, during aortic coarctation repair in children. Based on the reported adverse effect of sodium nitroprusside (SNP) on left-sided rScO2 during aortic coarctation repair, we tested the hypothesis that the alterations in left rScO2 occurring with SNP would not be present with sevoflurane and nitroglycerin (NTG). Additionally, we explored the effects of blood pressure regulation with SNP, NTG, or sevoflurane on right-sided rScO2, SrO2, and SmO2. Children with isolated aortic coarctation undergoing surgical repair through a left thoracotomy without the use of cardiopulmonary bypass were considered eligible for the study. During aortic cross-clamping, control of mean arterial blood pressure (MAP) was conducted according to randomization by the use of SNP, NTG, or sevoflurane to obtain a mean target right brachial blood pressure of 120% to 150% of the MAP value before cross-clamping. Bilateral rScO2, SrO2, and SmO2 were recorded continuously with near-infrared spectroscopy. As a primary end point, the maximal relative change in left-sided rScO2 in response to aortic cross-clamping was compared among treatment groups. Ten patients per group were included. No significant difference among treatment groups was observed in maximal relative change in left-sided rScO2 (SNP versus sevoflurane: mean difference -0.7%, 99% confidence interval [CI] -31% to 29%, P = 1.0; SNP versus NTG: mean difference -1.8%, 99% CI -32% to 28%, P = 1.0; sevoflurane versus NTG: mean difference -1.1%, 99% CI -31% to 29%, P = 1.0). Additional analyses also detected no difference between groups in right rScO2 (P = 0.4). Compared with NTG, treatment with SNP resulted in a significantly larger (-64% ± 17% vs -34% ± 25%, P = 0.01) and faster (-9 ± 4 %·min(-1) vs -4 ± 3 %·min(-1), P = 0.004) decrease in SmO2. Right-sided rScO2 and MAP showed a poor correlation for NTG (r = -0.2, P = 0.93), whereas borderline for sevoflurane (r = 0.44, P = 0.09) and SNP (r = 0.56, P = 0.04). The mean differences in left-sided rScO2 among the patients treated with SNP, NTG, or sevoflurane for proximal hypertension during aortic cross-clamping were no more than 32%. Additional analysis demonstrated a low MAP-rScO2 dependence with the use of NTG. Because NTG also resulted in a smaller and slower decrease of oxygen saturation in peripheral tissues, our data suggest that its use might be preferable for proximal blood pressure control during surgical procedures involving aortic cross-clampin

Physiological responses in female rescuers during 30 minutes sustained CPR with feedback : a comparison between medicine and physical education students

Objectives: Since fatigue seems related to poorer physical fitness rather than to gender, we analyzed the physiological responses in female medicine and physical education students during a 30 minutes sustained cardiopulmonary resuscitation (CPR) sequence. Methods: Handgrip strength and maximal aerobic power (VO2 max) determined strength and endurance. Twentythree medicine (M) and 27 physical education (PE) female students performed 30 minutes CPR. Compression quality and ECG were continuously monitored, heart rate and non-invasive blood pressure (NIBP) every 2 minutes. Capillary pH, PcCO2, lactate, potassium and sodium bicarbonate were analyzed every 10 minutes. Results: Handgrip strength (PE 37 kg vs. M 35 kg; p 5 cm was comparable in both groups (PE 80%; M 79%; p=0.67). Mean heart rate during CPR was higher in the M group (148 bpm) compared to the PE group (132 bpm; p<0.05). No intergroup differences in NIBP, pH, PcCO2, potassium and sodium bicarbonate were observed. Mean lactate during CPR was higher in the M group: 3.5 mmol/l (SD 1.4) compared to the PE group: 2.5 mmol/l (SD 0.7) (p<0.05). Conclusion : A high quality sustained CPR effort was well tolerated by all female rescuers. Poorer physical condition (M group) resulted in more drop out after 10 and 20 minutes and in a higher heart rate and blood lactate over time. Improving physical condition may result in less physiological strain and lower perceived exertion