Ultrasound-guided subclavian vein catheterisation with a needle guide (ELUSIVE): protocol for a randomised controlled study.

INTRODUCTION: Central venous catheters are indispensable in modern healthcare. Unfortunately, they are accompanied by minor as well as major complications, leading to increased morbidity, mortality and costs. Immediate insertion-related complications (mechanical complications) have decreased due to the implementation of real-time ultrasound guidance, but they still occur and additional efforts to enhance patient safety are warranted. This study aims to investigate whether the use of a needle guide mounted on the ultrasound probe in subclavian catheterisations may decrease the number of catheterisations with >1 skin puncture (primary outcome). METHODS AND ANALYSIS: This is an investigator-initiated, non-commercial, randomised, controlled, parallel-group study conducted at Skåne University Hospital, Lund, Sweden. Adults (≥18 years) with a clinical indication for a subclavian central venous catheter and the ability to give written informed consent will be eligible for inclusion. Exclusion criteria include subclavian catheterisation deemed unsuitable based on the preprocedural ultrasound examination. Patients will be randomised to catheterisation by certified operators using a microconvex probe (long-axis, in-plane technique) with (n=150) or without (n=150) a needle guide. The ultrasound imaging from the procedures will be recorded and assessed by two reviewers individually. The assessors will be blinded for group affiliation. Secondary outcomes include the total number of skin punctures, mechanical complications, time to successful venous puncture, number of failed catheterisations and operator satisfaction with the needle guide at the end of the study period.Recruitment started on 8 November 2022 and will continue until the sample size is achieved. ETHICS AND DISSEMINATION: This study was approved by the Swedish Ethical Review Authority (#2022-04073-01) and the Swedish Medical Products Agency (#5.1-2022-52130; CIV-21-12-038367). The findings will be submitted to an international peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT05513378, clinicaltrials.gov.

Albumin infusion rate and plasma volume expansion: a randomized clinical trial in postoperative patients after major surgery.

BACKGROUND: Optimal infusion rate of colloids in patients with suspected hypovolemia is unknown, and the primary objective of the present study was to test if plasma volume expansion by 5% albumin is greater if fluid is administered slowly rather than rapidly. METHODS: Patients with signs of hypoperfusion after major abdominal surgery were randomized to intravenous infusion of 5% albumin at a dose of 10 ml/kg (ideal body weight) either rapidly (30 min) or slowly (180 min). Plasma volume was measured using radiolabeled albumin at baseline, at 30 min, and at 180 min after the start of infusion. Primary outcome was change in plasma volume from the start of infusion to 180 min after the start of infusion. Secondary outcomes included the change in the area under the plasma volume curve and transcapillary escape rate (TER) for albumin from 180 to 240 min after the start of albumin infusion. RESULTS: A total of 33 and 31 patients were included in the analysis in the slow and rapid groups, respectively. The change in plasma volume from the start of infusion to 180 min did not differ between the slow and rapid infusion groups (7.4 ± 2.6 vs. 6.5 ± 4.1 ml/kg; absolute difference, 0.9 ml/kg [95%CI, - 0.8 to 2.6], P = 0.301). Change in the area under the plasma volume curve was smaller in the slow than in the rapid infusion group and was 866 ± 341 and 1226 ± 419 min ml/kg, respectively, P < 0.001. TER for albumin did not differ and was 5.3 ± 3.1%/h and 5.4 ± 3%/h in the slow and in the rapid infusion groups, respectively, P = 0.931. CONCLUSIONS: This study does not support our hypothesis that a slow infusion of colloid results in a greater plasma volume expansion than a rapid infusion. Instead, our result of a smaller change in the area under the plasma volume curve indicates that a slow infusion results in a less efficient plasma volume expansion, but further studies are required to confirm this finding. A rapid infusion has no effect on vascular leak as measured after completion of the infusion. TRIAL REGISTRATION: EudraCT2013-004446-42 registered December 23, 2014.

The importance of albumin infusion rate for plasma volume expansion following major abdominal surgery - AIR: study protocol for a randomised controlled trial.

BACKGROUND: Administration of fluids to restore normovolaemia is one of the most common therapeutic interventions performed peri-operatively and in the critically ill, but no study has evaluated the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid. The present study is designed to test the hypothesis that a slow infusion of resuscitation fluid results in better plasma volume expansion than a rapid infusion. METHODS/DESIGN: The study is a single-centre, assessor-blinded, parallel-group, randomised prospective study. Patients over 40 years of age admitted to the post-operative care unit after a Whipple procedure or major gynaecological surgery and presenting with signs of hypovolaemia are eligible for inclusion. Patients are randomised in a 1:1 fashion with no stratification to either rapid (30 minutes) or slow (180 minutes) infusion of 5% albumin at a dose of 10 ml/kg ideal body weight. Plasma volume is measured using 125I human serum albumin at baseline (prior to albumin infusion) as well as at 30 minutes and 180 minutes after infusion start. The primary endpoint is change in plasma volume from baseline to 180 minutes after the start of 5% albumin infusion. Secondary endpoints include the integral of plasma volume over time from baseline to 180 minutes after the start of the infusion and transcapillary escape rate of albumin (%/h) from 180 minutes to 240 minutes after the start of albumin infusion. In addition, diuresis, change in central venous oxygen saturation, lactate and blood pressure will be evaluated. A total of 70 patients will be included in the study, and the study has 80% power to detect a difference of 4 ml/kg in plasma volume expansion between the two groups. DISCUSSION: The present study is the first clinical investigation of the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid. TRIAL REGISTRATION: EudraCT identifier: 2013-004446-42 . Registration date: 20 December 2013. ClinicalTrials.gov identifier: NCT02728921 . Registration date: 31 March 2016.

The effect of vitamin C on plasma volume in the early stage of sepsis in the rat.

BACKGROUND: Previous experimental studies have shown that vitamin C has several beneficial effects in sepsis and burns, such as decreased tissue oedema, improved endothelial barrier function and decreased transcapillary leakage of plasma markers. It has still not been investigated, though, if vitamin C has any impact specifically on plasma volume. The present study aims at testing the hypothesis that vitamin C decreases plasma volume loss in sepsis. METHODS: Anaesthetized male adult Sprague-Dawley rats were used in this prospective randomized study. All experiments were carried out at a university hospital laboratory. Sepsis was induced by caecal ligation and incision. After 3 h, vitamin C was given either as a bolus dose (66 mg/kg) followed by a continuous infusion (33 mg/kg/h) (n = 9), or as a single bolus dose (200 mg/kg) (n = 9). A sham group (n = 9) underwent the same surgical procedure, but no vitamin C was given. Plasma volume was measured ((125)I-dilution technique) at baseline, at 3 h after end of initiation of sepsis and at the end of the experiment 3 h later. Arterial blood samples for analyses of electrolytes, blood gases, haematocrit and lactate were taken at the same time points. RESULTS: There were no significant differences in plasma volumes or the physiological parameters analysed between any of the three groups at any time point. There was a significantly larger urine production in the single bolus dose group (200 mg/kg) compared to the sham group. CONCLUSIONS: Vitamin C treatment did not decrease the loss of plasma volume in the septic rat. The diuretic effect of vitamin C was in accordance with previous studies.

Plasma volume expansion by 0.9% NaCl during sepsis/systemic inflammatory response syndrome, after hemorrhage, and during a normal state.

OBJECTIVE: The objective of this study was to determine the degree of plasma volume expansion by 0.9% NaCl in relation to the infused volume, in sepsis/systemic inflammatory response syndrome (SIRS), after a standardized hemorrhage, and in a normal condition. DESIGN: Prospective, randomized animal study. SETTING: The study was performed at a university hospital laboratory. SUBJECTS: Thirty anesthetized adult male rats were included in the study. INTERVENTIONS: The study was performed in three groups: a sepsis/SIRS group (the S group), in which sepsis/SIRS was induced by cecal ligation and incision; a hemorrhage group (the H group), in which the rats were left without intervention for 4 h and bled 8 mL/kg thereafter; and a group that was left without intervention (the N group). Then, 4 h after baseline, all three groups were given an infusion of 0.9% NaCl (32 mL/kg) for 15 min. Baseline was defined as the time point when the surgical preparation was finished. MEASUREMENTS AND MAIN RESULTS: Plasma volumes were measured using I-albumin dilution technique at baseline, after 4 h, and 20 min after the end of infusion. The plasma volume-expanding effect 20 min after end of infusion was 0.6% ± 2.9% in the S group, 20% ± 6.4% in the H group, and 12% ± 11% in the N group, compared with just before start of infusion. CONCLUSIONS: The present study in rats showed that the plasma volume-expanding effect after an infusion of 0.9% NaCl was smaller in a septic/SIRS state than after hemorrhage and in a normal state. This indicates that the plasma volume-expanding effect of a crystalloid is dependent on pathophysiologic changes in sepsis/SIRS.

Importance of the infusion rate for the plasma expanding effect of 5% albumin, 6% HES 130/0.4, 4% gelatin, and 0.9% NaCl in the septic rat.

OBJECTIVES: To compare the plasma volume (PV) expanding effect of a fast infusion rate with that of a slow infusion rate of a fixed volume of 5% albumin, of the synthetic colloids, 6% hydroxyethyl starch 130/0.4 and 4% gelatin, and of 0.9% NaCl in a rat sepsis model and to compare the plasma-expanding effect among these fluids. DESIGN: Prospective, randomized animal study. SETTING: University hospital laboratory. SUBJECTS: One hundred and twelve adult male rats. INTERVENTIONS: Sepsis was induced by cecal ligation and incision followed by closure of the abdomen. After 3 hrs, an infusion of the PV expander under study was started at a volume of 12mL/kg for the colloids and of 48mL/kg for 0.9% NaCl, either for 15 mins or for 3 hrs. A control group underwent the same experimental procedure but no fluid was given. MEASUREMENTS AND MAIN RESULTS: Three hours after start of the infusion (end of experiment), the plasma-expanding effect was better with a slow than a fast infusion rate for the colloids, especially albumin, but the NaCl groups did not differ significantly from the control group. The PV for the control group was 28.7±3mL/kg. In the slow and the fast infusion groups, it was 38.9±4.3 and 32.6±4.2mL/kg for albumin (p < 0.001), 32.9±4.3 and 29.5±4.4mL/kg for hydroxyethyl starch 130/0.4 (p < 0.05), 31.8±3.9 and 28.2±4.1mL/kg for gelatin (p < 0.05), and 31.8±5.3 and 30.7±6.6mL/kg for NaCl (n.s), respectively. CONCLUSIONS: The study showed that the PV expansion by a colloid was greater when given at a slow than at a fast infusion rate, an effect more pronounced for albumin. This difference was not seen for NaCl. The PV-expanding effect was poor for NaCl and better for albumin than for the other colloids.