Anaesthesia
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Review Meta Analysis
The influence of clinical risk factors on pre-operative B-type natriuretic peptide risk stratification of vascular surgical patients.
The role of the revised cardiac risk index in risk stratification has recently been challenged by studies reporting on the superior predictive ability of pre-operative B-type natriuretic peptides. We found that in 850 vascular surgical patients initially risk stratified using B-type natriuretic peptides, reclassification with the number of revised cardiac risk index risk factors worsened risk stratification (p < 0.05 for > 0, > 2, > 3 and > 4 risk factors, and p = 0.23 for > 1 risk factor). ⋯ The only independent predictor was B-type natriuretic peptide stratification (OR 5.1, 95% CI 1.8-15 for the intermediate class, and OR 25, 95% CI 8.7-70 for the high-risk class). The clinical risk factors in the revised cardiac risk index cannot improve a risk stratification model based on B-type natriuretic peptides.
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Our aim was to compare peri-operative core temperatures and the incidence of hypothermia in obese and non-obese women with active forced-air warming. Twenty female patients scheduled for abdominal surgery were allocated to two groups according to body mass index. Ten obese (30.0-34.9 kg.m(-2) ) and 10 non-obese (18.5-24.9 kg.m(-2) ) women received forced-air warming on their lower limbs. ⋯ The incidences of intra-operative hypothermia were lower in the obese group (10%) compared with non-obese group (60%; p = 0.019). In the postoperative recovery phase, the mean (SD) core temperature data were higher in the obese group than in the non-obese group (36.2 (0.4) vs 35.6 (0.5) °C, respectively (p < 0.001)). In conclusion, obese female patients have higher peri-operative core temperature and a lower incidence of hypothermia compared with non-obese female patients during abdominal surgery with active forced-air warming.
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Randomized Controlled Trial
Combined spinal epidural vs epidural labour analgesia: does initial intrathecal analgesia reduce the subsequent minimum local analgesic concentration of epidural bupivacaine?
Labour analgesia initiated using a combined spinal-epidural (CSE) technique may reduce subsequent epidural bupivacaine requirements compared with an epidural-only technique. We compared the minimum local analgesic concentrations (MLAC) of epidural bupivacaine following initial intrathecal or epidural injection. In a prospective, double-blind study, 115 women requesting epidural analgesia were randomly assigned to receive either an epidural with bupivacaine 20 mg and fentanyl 40 μg or a CSE with intrathecal bupivacaine 2.5 mg and fentanyl 5 μg. ⋯ When further analgesia was requested, bupivacaine 20 ml was given, and the concentration was determined using the technique of up-down sequential allocation. The MLAC of bupivacaine in the epidural group was 0.032% wt/vol (95% CI 0.020-0.044) compared with 0.047% wt/vol (95% CI 0.042-0.052) in the CSE group. Bupivacaine requirements for the second injection were increased following intrathecal analgesia by a factor of 1.45 (p = 0.026) compared with epidural analgesia.
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Blood pressure measurement is an essential physiological measurement for all critically ill patients. Previous work has shown that non-invasive blood pressure is not an accurate reflection of invasive blood pressure measurement. In a transport environment, the effects of motion and vibration may make non-invasive blood pressure less accurate. ⋯ Thus, our data show that non-invasive blood pressure is not a precise reflection of invasive intra-arterial blood pressure. Mean blood pressure measured non-invasively may be a better marker of invasive blood pressure than systolic blood pressure. Our data show no evidence of non-invasive blood pressures being less accurate in an aeromedical transport environment.