Patients with severe sepsis assigned to fluid resuscitation with HES 130/0.42 had an increased risk of death at day 90 and were more likely to require renal-replacement therapy, as compared with those receiving Ringer's acetate. (Funded by the Danish Research Council and others; 6S ClinicalTrials.gov number, NCT00962156.).
Internal jugular veins are the major cerebral venous outflow pathway in supine humans. In upright humans the positioning of these veins above heart level causes them to collapse. An alternative cerebral outflow pathway is the vertebral venous plexus. We set out to determine the effect of posture and central venous pressure (
The relationship between aortic flow and pressure is described by a three-element model of the arterial input impedance, including continuous correction for variations in the diameter and the compliance of the aorta (Modelflow). We computed the aortic flow from arterial pressure by this model, and evaluated whether, under orthostatic stress, flow may be derived from both an invasive and a non-invasive determination of arterial pressure. In 10 young adults, Modelflow stroke volume (MFSV) was computed from both intra-brachial arterial pressure (IAP) and non-invasive finger pressure (FINAP) measurements. For comparison, a computer-controlled series of four thermodilution estimates (thermodilution-determined stroke volume; TDSV) were averaged for the following positions: supine, standing, head-down tilt at 20 degrees (HDT20) and head-up tilt at 30 degrees and 70 degrees (HUT30 and HUT70 respectively). Data from one subject were discarded due to malfunctioning thermodilution injections. A total of 155 recordings from 160 series were available for comparison. The supine TDSV of 113+/-13 ml (mean+/-S.D.) dropped by 40% to 68+/-14 ml during standing, by 24% to 86+/-12 ml during HUT30, and by 51% to 55+/-15 ml during HUT70. During HDT20, TDSV was 114+/-13 ml. MFSV for IAP underestimated TDSV during HDT20 (-6+/-6 ml; P<0.05), but that for FINAP did not (-4+/-7 ml; not significant). For HUT70 and standing, MFSV for IAP overestimated TDSV by 11+/-10 ml (HUT70; P<0.01) and 12+/-9 ml (standing; P<0.01). However, the offset of MFSV for FINAP was not significant for either HUT70 (3+/-8 ml) or standing (3+/-9 ml). In conclusion, due to orthostasis, changes in the aortic transmural pressure may lead to an offset in MFSV from IAP. However, Modelflow correctly calculated aortic flow from non-invasively determined finger pressure during orthostasis.
Objectives To evaluate the long term effects of perioperative blockade on mortality and cardiac morbidity in patients with diabetes undergoing major non-cardiac surgery. Design Randomised placebo controlled and blinded multicentre trial. Analyses were by intention to treat. Setting University anaesthesia and surgical centres and one coordinating centre. Participants 921 patients aged > 39 scheduled for major non-cardiac surgery. Interventions 100 mg metoprolol controlled and extended release or placebo administered from the day before surgery to a maximum of eight perioperative days. Main outcome measures The composite primary outcome measure was time to all cause mortality, acute myocardial infarction, unstable angina, or congestive heart failure. Secondary outcome measures were time to all cause mortality, cardiac mortality, and non-fatal cardiac morbidity. Results Mean duration of intervention was 4.6 days in the metoprolol group and 4.9 days in the placebo group. Metoprolol significantly reduced the mean heart rate by 11% (95% confidence interval 9% to 13%) and mean blood pressure by 3% (1% to 5%). The primary outcome occurred in 99 of 462 patients in the metoprolol group (21%) and 93 of 459 patients in the placebo group (20%) (hazard ratio 1.06, 0.80 to 1.41) during a median follow-up of 18 months (range 6-30). All cause mortality was 16% (74/462) in the metoprolol group and 16% (72/459) in the placebo group (1.03, 0.74 to 1.42). The difference in risk for the proportion of patients with serious adverse events was 2.4% ( − 0.8% to 5.6%). Conclusions Perioperative metoprolol did not significantly affect mortality and cardiac morbidity in these patients with diabetes. Confidence intervals, however, were wide, and the issue needs reassessment. Trial registration Current Controlled Trials ISRCTN58485613.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.