Fluid management and vasopressor use during colorectal surgery: the search for the optimal balance

BackgroundAlthough it is known that excessive intraoperative fluid and vasopressor agents are detrimental for anastomotic healing, optimal anesthesiology protocols for colorectal surgery are currently lacking.ObjectiveTo scrutinize the current hemodynamic practice and vasopressor use and their relation to colorectal anastomotic leakage.DesignA secondary analysis of a previously published prospective observational study: the LekCheck study.Study settingAdult patients undergoing a colorectal resection with the creation of a primary anastomosis.Outcome measuresColorectal anastomotic leakage (CAL) within 30 days postoperatively, hospital length of stay and 30-day mortality.ResultsOf the 1548 patients, 579 (37%) received vasopressor agents during surgery. Of these, 201 were treated with solely noradrenaline, 349 were treated with phenylephrine, and 29 received ephedrine. CAL rate significantly differed between the patients receiving vasopressor agents during surgery compared to patients without (11.8% vs 6.3%, p < 0.001). CAL was significantly higher in the group receiving phenylephrine compared to noradrenaline (14.3% vs 6%, p < 0.001). Vasopressor agents were used more often in patients treated with Goal Directed Therapy (47% vs 34.6%, p < 0.001). There was a higher mortality rate in patients with vasopressors compared to the group without (2.8% vs 0.4%, p = 0.01, OR 3.8). Mortality was higher in the noradrenaline group compared to the phenylephrine and those without vasopressors (5% vs. 0.4% and 1.7%, respectively, p < 0.001). In multivariable analysis, patients with intraoperative vasopressor agents had an increased risk to develop CAL (OR 2.1, CI 1.3-3.2, p = 0.001).ConclusionThe present study contributes to the evidence that intraoperative use of vasopressor agents is associated with a higher rate of CAL. This study helps to create awareness on the (necessity to) use of vasopressor agents in colorectal surgery patients in striving for successful anastomotic wound healing. Future research will be required to balance vasopressor agent dosage in view of colorectal anastomotic leakage

Factors mediating the pressor response to isometric muscle contraction: An experimental study in healthy volunteers during lower body negative pressure.

Whilst both cardiac output (CO) and total peripheral resistance (TPR) determine mean arterial blood pressure (MAP), their relative importance in the pressor response to isometric exercise remains unclear. This study aimed to elucidate the relative importance of these two different factors by examining pressor responses during cardiopulmonary unloading leading to step-wise reductions in CO. Hemodynamics were investigated in 11 healthy individuals before, during and after two-minute isometric exercise during lower body negative pressure (LBNP; -20mmHg and -40mmHg). The blood pressure response to isometric exercise was similar during normal and reduced preload, despite a step-wise reduction in CO during LBNP (-20mmHg and -40mmHg). During -20mmHg LBNP, the decreased stroke volume, and consequently CO, was counteracted by an increased TPR, while heart rate (HR) was unaffected. HR was increased during -40 mmHg LBNP, although insufficient to maintain CO; the drop in CO was perfectly compensated by an increased TPR to maintain MAP. Likewise, transient application of LBNP (-20mmHg and -40mmHg) resulted in a short transient drop in MAP, caused by a decrease in CO, which was compensated by an increase in TPR. This study suggests that, in case of reductions of CO, changes in TPR are primarily responsible for maintaining the pressor response during isometric exercise. This highlights the relative importance of TPR compared to CO in mediating the pressor response during isometric exercise

Holomorphic embeddings of planar domains into C 2

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46245/1/208_2005_Article_BF01461006.pd

Paul L. Butzer - five years as Professor emeritus

SIGLEAvailable from TIB Hannover: RN 2414(497) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

The added value of cardiac index and pulse pressure variation monitoring to mean arterial pressure-guided volume therapy in moderate-risk abdominal surgery (COGUIDE): a pragmatic multicentre randomised controlled trial

There is disagreement regarding the benefits of goal-directed therapy in moderate-risk abdominal surgery. Therefore, we tested the hypothesis that the addition of non-invasive cardiac index and pulse pressure variation monitoring to mean arterial pressure-based goal-directed therapy would reduce the incidence of postoperative complications in patients having moderate-risk abdominal surgery. In this pragmatic multicentre randomised controlled trial, we randomly allocated 244 patients by envelope drawing in a 1:1 fashion, stratified per centre. All patients had mean arterial pressure, cardiac index and pulse pressure variation measured continuously. In one group, healthcare professionals were blinded to cardiac index and pulse pressure variation values and were asked to guide haemodynamic therapy only based on mean arterial pressure (control group). In the second group, cardiac index and pulse pressure variation values were displayed and kept within target ranges following a pre-defined algorithm (CI-PPV group). The primary endpoint was the incidence of postoperative complications within 30 days. One hundred and seventy-five patients were eligible for final analysis. Overall complication rates were similar (42/94 (44.7%) vs. 38/81 (46.9%) in the control and CI-PPV groups, respectively; p = 0.95). The CI-PPV group had lower mean (SD) pulse pressure variation values (9.5 (2.0)% vs. 11.9 (4.6)%; p = 0.003) and higher mean (SD) cardiac indices (2.76 (0.62) l min−1.m−2 vs. 2.53 (0.66) l min−1.m−2; p = 0.004) than the control group. In moderate-risk abdominal surgery, we observed no additional value of cardiac index and pulse pressure variation-guided haemodynamic therapy to mean arterial pressure-guided volume therapy with regard to postoperative complications

Imaging the right atrium in pulmonary hypertension: A systematic review and meta-analysis.

BACKGROUND: Right atrial (RA) imaging has emerged as a promising tool for the evaluation of patients with pulmonary hypertension (PH), albeit without systematic validation. METHODS: PubMed, Web of Science and the Cochrane library were searched for studies investigating the prognostic value of RA imaging assessment in patients with PH from 2000 to June 2021 (PROSPERO Identifier: CRD42020212850). An inverse variance-weighted meta-analysis of univariable hazard ratios (HRs) was performed using a random effects model. RESULTS: Thirty-five studies were included (3,476 patients with PH; 74% female, 86% pulmonary arterial hypertension). Risk of bias was low/moderate (Quality of Prognosis Studies checklist). RA area (HR 1.06; 95% confidence interval [CI] 1.04-1.08), RA indexed area (HR 1.09; 95% CI 1.04-1.14), RA peak longitudinal strain (PLS; HR 0.94; 95% CI 0.91-0.97) and RA total emptying fraction (HR 0.96; 95% CI 0.94-0.98) were significantly associated with combined end-points including death, clinical worsening and/or lung transplantation; RA volume and volume index showed marginal significant associations. RA area (HR 1.06; 95% CI 1.04-1.07), RA indexed area (HR 1.12; 95% CI 1.07-1.17) and RA PLS (HR 0.98; 95% CI 0.97-0.99) showed significant associations with mortality; RA total emptying fraction showed a marginal association. CONCLUSIONS: Imaging-based RA assessment qualifies as a relevant prognostic marker in PH. RA area reliably predicts composite end-points and mortality, which underscores its clinical utility. RA PLS emerged as a promising imaging measure, but is currently limited by the number of studies and different acquisition methods