31 research outputs found
Effect of Intraoperative Goal-directed Balanced Crystalloid versus Colloid Administration on Major Postoperative Morbidity
BACKGROUND:
Crystalloid solutions leave the circulation quickly, whereas colloids remain for hours, thus promoting hemodynamic stability. However, colloids are expensive and promote renal toxicity in critical care patients. This study tested the hypothesis that goal-directed colloid administration during elective abdominal surgery decreases 30-day major complications more than goal-directed crystalloid administration.
METHODS:
In this parallel-arm double-blinded multicenter randomized trial, adults having moderate- to high-risk open and laparoscopically assisted abdominal surgery with general anesthesia were randomly assigned to Doppler-guided intraoperative volume replacement with 6% hydroxyethyl starch 130/0.4 (n = 523) or lactated Ringer's solution (n = 534). The primary outcome was a composite of serious postoperative cardiac, pulmonary, infectious, gastrointestinal, renal, and coagulation complications that were assessed with a generalized estimating equation multivariate model. The primary safety outcome was a change in serum creatinine concentration up to 6 months postoperatively, compared to baseline concentrations.
RESULTS:
A total of 1,057 patients were included in the analysis. Patients assigned to crystalloid received a median [quartile 1, quartile 3] amount of 3.2 l [2.3, 4.4] of crystalloid, and patients assigned to colloid received 1.0 l [0.5, 1.5] of colloid and 1.8 l [1.2, 2.4] of crystalloid. The estimated intention-to-treat common effect relative risk for the primary composite was 0.90 for colloids versus crystalloids (95% CI: 0.65 to 1.23, P = 0.51), and 18% (91 of 523) of colloid patients and 20% (103 of 534) of crystalloid patients incurred at least one component of the primary outcome composite. There was no evidence of renal toxicity at any time.
CONCLUSIONS:
Doppler-guided intraoperative hydroxyethyl starch administration did not significantly reduce a composite of serious complications. However, there was also no indication of renal or other toxicity
Bioimpedance spectroscopy for assessment of volume status in patients before and after general anaesthesia
BackgroundTechnically assisted assessment of volume status before surgery may be useful to direct intraoperative fluid administration. We therefore tested a recently developed whole-body bioimpedance spectroscopy device to determine pre- to postoperative fluid distribution.MethodsUsing a three-compartment physiologic tissue model, the body composition monitor (BCM, Fresenius Medical Care, Germany) measures total body fluid volume, extracellular volume, intracellular volume and fluid overload as surplus or deficit of 'normal' extracellular volume. BCM-measurements were performed before and after standardized general anaesthesia for gynaecological procedures (laparotomies, laparoscopies and vaginal surgeries). BCM results were blinded to the attending anaesthesiologist and data analysed using the 2-sided, paired Student's t-test and multiple linear regression.ResultsIn 71 females aged 45 ± 15 years with body weight 67 ± 13 kg and Duration of anesthesia 154 ± 69 minutes [corrected] duration of anaesthesia 154 ± 68 min, pre- to postoperative fluid overload increased from -0.7 ± 1.1 L to 0.1 ± 1.0 L, corresponding to -5.1 ± 7.5% and 0.8 ± 6.7% of normal extracellular volume, respectively (both pConclusionsRoutine intraoperative fluid administration results in a significant, and clinically meaningful increase in the extracellular compartment. BCM-measurements yielded plausible results and may become useful to guide intraoperative fluid therapy in future studies
Hemodynamic effects of intraoperative 30% versus 80% oxygen concentrations: an exploratory analysis
BackgroundSupplemental oxygen leads to an increase in peripheral vascular resistance which finally increases systemic blood pressure in healthy subjects and patients with coronary artery disease, heart failure, undergoing heart surgery, and with sepsis. However, it is unknown whether this effect can also be observed in anesthetized patients having surgery. Thus, we evaluated in this exploratory analysis of a randomized controlled trial the effect of 80% versus 30% oxygen on intraoperative blood pressure and heart rate.MethodsWe present data from a previous study including 258 patients, who were randomized to a perioperative inspiratory FiO2 of 0.8 (128 patients) versus 0.3 (130 patients) for major abdominal surgery. Continuous arterial blood pressure values were recorded every three seconds and were exported from the electronic anesthesia record system. We calculated time-weighted average (TWA) and Average Real Variability (ARV) of mean arterial blood pressure and of heart rate.ResultsThere was no significant difference in TWA of mean arterial pressure between the 80% (80 mmHg [76, 85]) and 30% (81 mmHg [77, 86]) oxygen group (effect estimate −0.16 mmHg, CI –1.83 to 1.51; p = 0.85). There was also no significant difference in TWA of heart rate between the 80 and 30% oxygen group (median TWA of heart rate in the 80% oxygen group: 65 beats.min−1 [58, 72], and in the 30% oxygen group: 64 beats.min−1 [58; 70]; effect estimate: 0.12 beats.min−1, CI –2.55 to 2.8, p = 0.94). Also for ARV values, no significant differences between groups could be detected.ConclusionIn contrast to previous results, we did not observe a significant increase in blood pressure or a significant decrease in heart rate in patients, who received 80% oxygen as compared to patients, who received 30% oxygen during surgery and for the first two postoperative hours. Thus, hemodynamic effects of supplemental oxygen might play a negligible role in anesthetized patients.Clinical Trail Registrationhttps://clinicaltrials.gov/ct2/show/NCT03366857?term=vienna&cond=oxygen&draw=2&rank=
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Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial
Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users
Alternative blood transfusion triggers: a narrative review
Abstract Background Anemia, characterized by low hemoglobin levels, is a global public health concern. Anemia is an independent factor worsening outcomes in various patient groups. Blood transfusion has been the traditional treatment for anemia; its triggers, primarily based on hemoglobin levels; however, hemoglobin level is not always an ideal trigger for blood transfusion. Additionally, blood transfusion worsens clinical outcomes in certain patient groups. This narrative review explores alternative triggers for red blood cell transfusion and their physiological basis. Main Text The review delves into the physiology of oxygen transport and highlights the limitations of using hemoglobin levels alone as transfusion trigger. The main aim of blood transfusion is to optimize oxygen delivery, necessitating an individualized approach based on clinical signs of anemia and the balance between oxygen delivery and consumption, reflected by the oxygen extraction rate. The narrative review covers different alternative triggers. It presents insights into their diagnostic value and clinical applications, emphasizing the need for personalized transfusion strategies. Conclusion Anemia and blood transfusion are significant factors affecting patient outcomes. While restrictive transfusion strategies are widely recommended, they may not account for the nuances of specific patient populations. The search for alternative transfusion triggers is essential to tailor transfusion therapy effectively, especially in patients with comorbidities or unique clinical profiles. Investigating alternative triggers not only enhances patient care by identifying more precise indicators but also minimizes transfusion-related risks, optimizes blood product utilization, and ensures availability when needed. Personalized transfusion strategies based on alternative triggers hold the potential to improve outcomes in various clinical scenarios, addressing anemia’s complex challenges in healthcare. Further research and evidence are needed to refine these alternative triggers and guide their implementation in clinical practice
Crystalloid fluid choice in the critically ill : Current knowledge and critical appraisal.
Intravenous infusion of crystalloid solutions is one of the most frequently administered medications worldwide. Available crystalloid infusion solutions have a variety of compositions and have a major impact on body systems; however, administration of crystalloid fluids currently follows a "one fluid for all" approach than a patient-centered fluid prescription. Normal saline is associated with hyperchloremic metabolic acidosis, increased rates of acute kidney injury, increased hemodynamic instability and potentially mortality. Regarding balanced infusates, evidence remains less clear since most studies compared normal saline to buffered infusion solutes.; however, buffered solutes are not homogeneous. The term "buffered solutes" only refers to the concept of acid-buffering in infusion fluids but this does not necessarily imply that the solutes have similar physiological impacts. The currently available data indicate that balanced infusates might have some advantages; however, evidence still is inconclusive. Taking the available evidence together, there is no single fluid that is superior for all patients and settings, because all currently available infusates have distinct differences, advantages and disadvantages; therefore, it seems inevitable to abandon the "one fluid for all" strategy towards a more differentiated and patient-centered approach to fluid therapy in the critically ill
Supplemental oxygen, but not supplemental crystalloid fluid, increases tissue oxygen tension in healthy and anastomotic colon in pigs
BACKGROUND: Low tissue oxygen tension is an important factor leading to the development of wound dehiscence and anastomotic leakage after colon surgery. We tested whether supplemental fluid and supplemental oxygen can increase tissue oxygen tension in healthy and injured, perianastomotic, and anastomotic colon in an acutely instrumented pig model of anastomosis surgery. METHODS: Sixteen Swiss Landrace pigs were anesthetized (isoflurane 0.8%-1%) and their lungs ventilated. The animals were randomly assigned to low fluid treatment ("low" group, 3 mL x kg(-1) x h(-1) lactated Ringer's solution) or high fluid treatment ("high" group, 10 mL/kg bolus, 18 mL x kg(-1) x h(-1) lactated Ringer's solution) during colon anastomosis surgery and a subsequent measurement period (4 h). Two-and-half hours after surgery, tissue oxygen tension was recorded for 30 min during ventilation with 30% oxygen. Three hours after surgery, the animals' lungs were ventilated with 100% oxygen for 60 min. Tissue oxygen tension was recorded in the last 30 min. Tissue oxygen tension was measured with polarographic Clark-type electrodes, positioned in healthy colonic wall, close (2 cm) to the anastomosis, and in the anastomosis. RESULTS: In every group, tissue oxygen tension during ventilation with 100% oxygen was approximately twice as high as during ventilation with 30% oxygen, a statistically significant result. High or low volume crystalloid fluid treatment had no effect on colon tissue oxygen tension. CONCLUSIONS: Supplemental oxygen, but not supplemental crystalloid fluid, increased tissue oxygen tension in healthy, perianastomotic, and anastomotic colon tissue
Effect of Goal-Directed Crystalloid versus Colloid Administration on Perioperative Hemostasis in Partial Hepatectomy: A Randomized, Controlled Trial
The use of colloids may impair hemostatic capacity. However, it remains unclear whether this also holds true when colloids are administered in a goal-directed manner. The aim of the present study was to assess the effect of goal-directed fluid management with 6% hydroxyethyl starch 130/0.4 on hemostasis compared to lactated Ringer’s solution in patients undergoing partial hepatectomy. We included 50 patients in this prospective, randomized, controlled trial. According to randomization, patients received boluses of either hydroxyethyl starch or lactated Ringer’s solution within the scope of goal-directed fluid management. Minimum perioperative FIBTEM maximum clot firmness (MCF) served as the primary outcome parameter. Secondary outcome parameters included fibrinogen levels and estimated blood loss. In the hydroxyethyl starch (HES) group the minimum FIBTEM MCF value was significantly lower (effect size −6 mm, 95% CI −10 to −3, p < 0.001) in comparison to the lactated Ringer’s solution (RL) group. These results returned to normal within 24 h. We observed no difference in plasma fibrinogen levels (RL 3.08 ± 0.37 g L−1 vs HES 2.65 ± 0.64 g L−1, p = 0.18) or the amount of blood loss between the two groups (RL 470 ± 299 mL vs HES 604 ± 351 mL, p = 0.18). We showed that goal-directed use of HES impairs fibrin polymerization in a dose-dependent manner when compared with RL. Results returned to normal on the first postoperative day without administration of procoagulant drugs and no differences in blood loss were observed
Perioperative Supplemental Oxygen and Plasma Catecholamine Concentrations after Major Abdominal Surgery—Secondary Analysis of a Randomized Clinical Trial
Perioperative stress is associated with increased sympathetic activity that leads to increases in heart rate and blood pressure, which are associated with the development of perioperative myocardial ischemia. In healthy volunteers, it was shown that the administration of supplemental oxygen attenuated sympathetic nerve activity and subsequently led to lower plasma catecholamine concentrations. We therefore tested the hypothesis that perioperative supplemental oxygen attenuates sympathetic nerve in patients at risk for cardiovascular complications undergoing major abdominal surgery. We randomly assigned 81 patients to receive either 80% or 30% inspired oxygen concentration throughout surgery and the first two postoperative hours. We assessed noradrenaline, adrenaline, and dopamine plasma concentrations before the induction of anesthesia, two hours after surgery and on the third postoperative day. There was no significant difference in postoperative noradrenaline (effect estimated: −41.5 ng·L−1, 95%CI −134.3, 51.2; p = 0.38), adrenaline (effect estimated: 11.2 ng·L−1, 95%CI −7.6, 30.1; p = 0.24), and dopamine (effect estimated: −1.61 ng·L−1, 95%CI −7.2, 3.9; p = 0.57) concentrations between both groups. Based on our results, it seems unlikely that supplemental oxygen influences endogenous catecholamine release in the perioperative setting