Fluid loading therapy to prevent spinal hypotension in women undergoing elective caesarean section: Network meta-analysis, trial sequential analysis and meta-regression

Hemodynamic changes in the prone position according to fluid loading after anaesthesia induction in patients undergoing lumbar spine surgery: a randomized, assessor-blind, prospective study

INTRODUCTION

A change from the supine to prone position causes hemodynamic alterations. We aimed to evaluate the effect of fluid preloading in the supine position, the subsequent hemodynamic changes in the prone position and postoperative outcomes.

PATIENTS AND METHODS

This prospective, assessor-blind, randomized controlled trial was conducted between March and June 2023. Adults scheduled for elective orthopaedic lumbar surgery under general anaesthesia were enrolled. In total, 80 participants were randomly assigned to fluid maintenance (M) or loading (L) groups. Both groups were administered intravenous fluid at a rate of 2 ml/kg/h until surgical incision; Group L was loaded with an additional 5 ml/kg intravenous fluid for 10 min after anaesthesia induction. The primary outcome was incidence of hypotension before surgical incision. Secondary outcomes included differences in the mean blood pressure (mBP), heart rate, pleth variability index (PVi), stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index and cardiac index before surgical incision between the two groups. Additionally, postoperative complications until postoperative day 2 and postoperative hospital length of stay were investigated.

RESULTS

Hypotension was prevalent in Group M before surgical incision and could be predicted by a baseline PVi >16. The mBP was significantly higher in Group L immediately after fluid loading. The PVi, SVV and PPV were lower in Group L after fluid loading, with continued differences at 2-3 time points for SVV and PPV. Other outcomes did not differ between the two groups.

CONCLUSION

Fluid loading after inducing general anaesthesia could reduce the occurrence of hypotension until surgical incision in patients scheduled for surgery in the prone position. Additionally, hypotension could be predicted in patients with a baseline PVi >16. Therefore, intravenous fluid loading is strongly recommended in patients with high baseline PVi to prevent hypotension after anaesthesia induction and in the prone position.

TRIAL NUMBER

KCT0008294 (date of registration: 16 March 2023).

Up-and-Down Determination of Different Crystalloid Coload Volumes on the ED 90 of Prophylactic Norepinephrine Infusion for Preventing Postspinal Anesthesia Hypotension During Cesarean Section

Background

Fluid loading improves hemodynamic stability and reduces the incidence rate of post-spinal anesthesia hypotension when prophylactic vasopressors are administered. We investigated the impact of different crystalloid coload volumes on the 90% effective dose (ED) of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension in non-hypertensive patients undergoing cesarean section.

Methods

Patients were randomly allocated to receive one of the different crystalloid coload volumes (0mL/kg [0mL/kg Group], 5mL kg [5mL/kg Group], and 10mL kg [10mL/kg Group]) in combination with prophylactic norepinephrine infusion immediately after the induction of spinal anesthesia. The prophylactic norepinephrine infusion doses were determined using the up-and-down sequential allocation methodology, with an initial dose of 0.025 μg/kg/min and a gradient of 0.005 μg/kg/min. The primary endpoint was the effective dose at which 90% (ED 90) of patients responded to prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension.

Results

The estimated effective dose of norepinephrine infusion, at which 90% (ED 90) of patients responded, was found to be 0.084 (95% CI, 0.070 to 0.86), 0.074 (95% CI, 0.059 to 0.077), and 0.063 (95% CI, 0.053 to 0.064) μg/kg/min in the three groups, respectively.

Conclusion

A crystalloid coload of 5 mL/kg or 10 mL/kg, as opposed to the groups receiving 0 mL/kg crystalloid coloads, resulted in a reduction of approximately 11.9% and 25.0%, respectively, in the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean section.

Prophylactic norepinephrine combined with 6% hydroxyethyl starch (130/0.4) co-load infusion for preventing postspinal anesthesia hypotension during cesarean section: a randomized, controlled, dose-finding trial

PURPOSE

Colloid and/or co-load may be more effective than crystalloid for preventing postspinal anesthesia hypotension. We tested five different prophylactic norepinephrine dosages combined with colloid co-load infusion in patients receiving cesarean section and spinal anesthesia.

METHODS

Patients were randomly allocated to receive different prophylactic norepinephrine dosages (0 [NE 0 group], 0.025 [NE 25 group], 0.05 [NE 50 group], 0.075 [NE 75 group], or 0.1 [NE 100 group] µg/kg/min) combined with 500 mL 6% hydroxyethyl starch (130/0.4) immediately following spinal anesthesia (n = 35 per group). The primary endpoint was the incidence of postspinal anesthesia hypotension (systolic blood pressure [SBP] < 80% of baseline). Secondary endpoints included severe hypotension, bradycardia, nausea or vomiting, hypertension, SBP stability control versus baseline, the 50% (effective dose, ED50) and 90% (ED90) dose effective for preventing postspinal anesthesia hypotension, Apgar scores, and umbilical cord blood gases.

RESULTS

The incidence of postspinal anesthesia hypotension was 48.6%, 31.3%, 17.1%, 14.3%, and 5.7% in the respective groups. As the prophylactic norepinephrine dosage increased, the incidence of postspinal anesthesia hypotension declined (p < 0.001), and SBP remained stable relative to baseline (median performance error [MDPE], p < 0.001; median absolute performance error [MDAPE], p = 0.001). The ED50 and ED90 values were -0.006 (95% CI -0.046-0.013) and 0.081 (95% CI 0.063-0.119) µg/kg/min. Other endpoints were comparable across the groups.

CONCLUSION

An initial prophylactic norepinephrine dosage of 0.05 µg/kg/min combined with 500 mL 6% hydroxyethyl starch (130/0.4) co-load infusion was optimal for preventing postspinal anesthesia hypotension during cesarean section.

TRIAL REGISTRATION

NCT05133817, registration date: 12 Nov, 2021.

Association of infraclavicular axillary vein diameter and collapsibility index with general anesthesia-induced hypotension in elderly patients undergoing gastrointestinal surgery: an observational study

BACKGROUND

The collapse index of inferior Vena Cava (IVC) and its diameter are important predictive tools for fluid responsiveness in patients, especially critically ones. The collapsibility of infraclavicular axillary vein (AXV) can be used as an alternative to the collapsibility of IVC (IVC-CI) to assess the patient's blood volume.

METHODS

A total of 188 elderly patients aged between 65 and 85 years were recruited for gastrointestinal surgery under general anesthesia. Ultrasound measurements AXV and IVC were performed before induction of general anesthesia. Patients were grouped in accordance to the hypotension after induction. ROC curves were used to analyze the predictive value of ultrasound measurements of AXV and IVC for hypotension after induction of anesthesia. Pearson linear correlation was used to assess the correlation of ultrasound measurements and decrease in mean arterial blood pressure (MAP).

RESULTS

The maximum diameter of AXV(dAXVmax) and the maximum diameter of IVC (dIVCmax) were not related to the percentage decrease in MAP; the collapsibility of AXV (AXV-CI) and IVC-CI were positively correlated with MAP changes (correlation coefficients:0.475, 0.577, respectively, p < 0.001). The areas under the curve (AUC) was 0.824 (0.759-0.889) for AXV-CI, and 0.874 (0.820-0.928) for IVC-CI. The optimal threshold for AXV-CI was 31.25% (sensitivity 71.7%, specificity 90.1%), while for IVC-CI was 36.60% (sensitivity 85.9%, specificity 79.0%). Hypotension and down-regulation of MAP during induction can be accurately predicted by AXV-Cl after correction for confounding variables.

CONCLUSION

Infraclavicular axillary vein diameter has no significant correlation with postanesthesia hypotension, whereas AXV-CI may predict postanesthesia hypotension during gastrointestinal surgery of the elderly.

TRIAL REGISTRATION

This study was registered in the Clinical Trial Registry of China on 05/06/2022 (ChiCTR2200060596).

Comparison of crystalloid and colloid co-load combined with norepinephrine prophylaxis on post-spinal anesthesia hypotension during cesarean delivery: a randomized sequential allocation dose-finding study

Background

Fluid loading is an essential component of treatment for reducing the incidence of post-spinal anesthesia hypotension and is necessary to maintain intravascular volume, perfuse tissues, and control spinal anesthesia hypotension after sympathetic blockade. We performed a randomized sequential allocation dose-finding study to compare the effects of 10 mL/kg crystalloid and 6% hydroxyethyl starch (130/0.4) co-load on the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery.

Methods

Eighty patients were randomly allocated to receive either a 10 mL/kg crystalloid (Crystalloid Group, n = 40) or 6% hydroxyethyl starch (130/0.4) (Colloid Group, n = 40) co-load combined with prophylactic norepinephrine infusion during spinal anesthesia for cesarean delivery. The first patient received an initial prophylactic norepinephrine infusion rate of 0.025 μg/kg/min. Subsequent patients received a 0.005 μg/kg/min gradient dose of prophylactic norepinephrine. This dose was administered as a gradient based on its effectiveness for preventing post-spinal anesthesia hypotension (defined as SBP < 80% of baseline value) and determined by the up-and-down sequential allocation methodology. The primary study outcome was the ED90 of prophylactic norepinephrine infusion. Secondary outcomes included the incidence of post-spinal anesthesia hypotension, bradycardia, hypertension, Apgar scores, and umbilical artery blood gas values were also measured.

Results

The ED90 values of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery were 0.063 μg (95% CI: 0.050 to 0.064) and 0.062 μg (95% CI: 0.045 to 0.064) using isotonic regression analysis, and 0.068 μg (95% CI: 0.056 to 0.353) and 0.060 μg (95% CI: 0.050 to 3.590) using probit regression analysis in the Crystalloid Group and Colloid Group, respectively. The secondary outcomes were comparable between the two groups.

Conclusion

The administration of a 10 mL/kg 6% hydroxyethyl starch (130/0.4) does not provide additional benefits compared to crystalloid co-load in reducing the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery.

Subclavian vein ultrasound-guided fluid management to prevent post-spinal anesthetic hypotension during cesarean delivery: a randomized controlled trial

BACKGROUND

Hypotension frequently occurs after spinal anesthesia during cesarean delivery, and fluid loading is recommended for its prevention. We evaluated the efficacy of subclavian vein (SCV) ultrasound (US)-guided volume optimization in preventing hypotension after spinal anesthesia during cesarean delivery.

METHODS

This randomized controlled study included 80 consecutive full-term parturients scheduled for cesarean delivery under spinal anesthesia. The women were randomly divided into the SCVUS group, with SCVUS analysis before spinal anesthesia with SCVUS-guided volume management, and the control group without SCVUS assessment. The SCVUS group received 3 mL/kg crystalloid fluid challenges repeatedly within 3 min with a 1-min interval based on the SCV collapsibility index (SCVCI), while the control group received a fixed dose (10 mL/kg). Incidence of post-spinal anesthetic hypotension was the primary outcome. Total fluid volume, vasopressor dosage, changes in hemodynamic parameters, maternal adverse effects, and neonatal status were secondary outcomes.

RESULTS

The total fluid volume was significantly higher in the control group than in the SCVUS group (690 [650-757.5] vs. 160 [80-360] mL, p < 0.001), while the phenylephrine dose (0 [0-40] vs. 0 [0-30] µg, p = 0.276) and incidence of post-spinal anesthetic hypotension (65% vs. 60%, p = 0.950) were comparable between both the groups. The incidence of maternal adverse effects, including nausea/vomiting and bradycardia (12.5% vs. 17.5%, p = 0.531 and 7.5% vs. 5%, p = 1.00, respectively), and neonatal outcomes (Apgar scores) were comparable between the groups. SCVCI correlated with the amount of fluid administered (R = 0.885, p < 0.001).

CONCLUSIONS

SCVUS-guided volume management did not ameliorate post-spinal anesthetic hypotension but reduced the volume of the preload required before spinal anesthesia. Reducing preload volume did not increase the incidence of maternal and neonatal adverse effects nor did it increase the total vasopressor dose. Moreover, reducing preload volume could relieve the heart burden of parturients, which has high clinical significance.

CLINICAL TRIAL REGISTRATION

The trial was registered with the Chinese Clinical Trial Registry at chictr.org.cn (registration number, ChiCTR2100055050) on December 31, 2021.

Reply to Akça, B.; Bilotta, F. Time and Type of Administered Fluids during Cesarean Section Might Not Matter for Hemodynamic Outcomes, but There Are Significant Patient Safety Concerns Regarding Colloid Use in Parturients. Comment on "Theodoraki et al. Colloid Preload versus Crystalloid Co-Load in the Setting of Norepinephrine Infusion during Cesarean Section: Time and Type of Administered Fluids Do Not Matter. J. Clin. Med. 2023, 12, 1333"

We would like to take this opportunity to thank Drs Akça and Bilotta for their interest and their insightful comments [...].

Colloid Preload versus Crystalloid Co-Load in the Setting of Norepinephrine Infusion during Cesarean Section: Time and Type of Administered Fluids Do Not Matter

Background and Goal of Study: Spinal anesthesia for cesarean section is frequently associated with a high incidence of hypotension, which may bring about untoward effects for both the mother and fetus. Recently, norepinephrine has emerged as a promising alternative in maintaining blood pressure in the obstetric setting. Fluid administration is another technique still widely used to prevent maternal hypotension. The optimal fluid strategy to prevent maternal hypotension has not been elucidated yet. It has been recently suggested that the main strategy in the prevention and management of hypotension should be the combination of vasoconstrictive medications and fluid administration. The aim of this randomized study was to compare the incidence of maternal hypotension in parturients receiving either colloid preload or crystalloid co-load in the setting of prophylactic norepinephrine infusion during elective cesarean section under combined spinal-epidural anesthesia. Materials and Methods: After ethics committee approval, 102 parturients with full-term singleton pregnancies were randomly allocated to either 6% hydroxyethyl starch 130/0.4 5 mL/kg before the onset of spinal anesthesia (colloid preload group) or Ringer's lactate solution 10 mL/kg concurrent with the subarachnoid injection (crystalloid co-load group). In both groups, norepinephrine 4 μg/min starting simultaneously with the administration of the subarachnoid solution was also administered. The primary outcome of the study was the incidence of maternal hypotension, defined as systolic arterial pressure (SAP) <80% of baseline. The incidence of severe hypotension (SAP < 80 mmHg), total dose of vasoconstrictive agents administered, as well as the acid-base status and Apgar score of the neonate and any incidence of maternal side effects were also recorded. Results: Data analysis was performed on 100 parturients: 51 in the colloid preload group and 49 in the crystalloid co-load group. No significant differences were demonstrated between the colloid preload group and the crystalloid co-load group in the incidence of hypotension (13.7% vs. 16.3%, p = 0.933) or the incidence of severe hypotension (0% vs. 4%, p = 0.238). The median (range) ephedrine dose was 0 (0-15) mg in the colloid preload group and 0 (0-10) mg in the crystalloid co-load group (p = 0.807). The incidence of bradycardia, reactive hypertension, requirement for modification of vasopressor infusion, time to the first occurrence of hypotension, and maternal hemodynamics did not differ between the two groups. There were no significant differences in other maternal side effects or neonatal outcomes between groups. Conclusions: The incidence of hypotension with a norepinephrine preventive infusion is low and comparable with both colloid preload and crystalloid co-load. Both fluid-loading techniques are appropriate in women undergoing cesarean delivery. It appears that the optimal regimen for prevention of maternal hypotension is a combined strategy of a prophylactic vasopressor such as norepinephrine and fluids.

Effect of Crystalloid or Colloid Fluid Loading and Vasopressor Pre-Treatment on the Timing of Hypotension in Cesarean Section with Subarachnoid Block

BACKGROUND: Cesarean section (C-section) is the most frequently performed surgery in obstetrics, generally using subarachnoid block (SAB) or epidural block for anesthesia. The previous studies have shown the effectiveness of fluid loading and vasopressor pretreatment in preventing maternal hypotension (decreased blood pressure), the most common side effect of SAB. However, the timing of hypotension in response to these treatments has not been analyzed. AIM: This study therefore aimed to compare the effects of crystalloid or colloid fluid loading and vasopressor pre-treatment on the timing of hypotension in cases of C-section under SAB anesthesia. METHODS: The study was a single-blind randomized controlled clinical trial with three treatment groups: Group I, 10 mL/kgBW crystalloid solution (Ringer’s lactate) loading 10 min before SAB; Group II, 5 mL/kgBW colloid fluid (gelatin) loading 10 min before SAB; and Group III, pretreatment with 0.1 mg/kgBW vasopressor (ephedrine) intravenous bolus just before SAB. RESULTS: Significant differences in mean blood pressure between groups were observed between the second and 8th min (p < 0.05). Hypotension was observed in the crystalloid group within the first 5 min, while average blood pressure was relatively stable all groups after the first 10 min. In addition, hypotension occurred more frequently in the crystalloid group (nine subjects, 45%), compared with the colloid and vasopressor groups (two subjects per group, 10%; p < 0.05). CONCLUSION: Hypotension occurred more rapidly and more frequently when crystalloid loading was utilized, compared with colloid loading or vasopressor pretreatment. Administration of colloid fluid loading and vasopressor pretreatment has been shown to prevent hypotension in SAB anesthesia.

Association of propofol induction dose and severe pre-incision hypotension among surgical patients over age 65

STUDY OBJECTIVE

We aimed to study the association between propofol induction dose (mg/kg) and pre-incision severe hypotension (Mean Arterial Pressure (MAP) ≤ 55 mmHg) among patients ≥65 years of age.

DESIGN

Retrospective Observational.

SETTING

40 centers participating in the Multicenter Perioperative Outcomes Group consortium.

PATIENTS

Patients ≥65 years of age undergoing non-cardiac, non-vascular surgery who received propofol for general anesthetic induction prior to endotracheal intubation between January 2014 and December 2018.

INTERVENTIONS

None.

MEASUREMENTS

The primary exposure was total propofol induction dose in mg/kg, and the primary outcome was occurrence of severe hypotension (MAP≤55 mmHg) prior to surgical incision, stratified by non-invasive vs. invasive blood pressure monitoring type.

MAIN RESULTS

Among 320,585 total patients, 22.6% experienced the outcome of pre-incision severe hypotension (MAP≤55 mmHg). When stratified by blood pressure monitoring type, 20.7% with non-invasive blood pressure measurements, and 35.0% with invasive blood pressure measurements had the outcome. After controlling for a variety of patient and procedural factors, there was a significant independent association between propofol induction dose and pre-incision hypotension (Non-invasive blood pressure cohort odds ratio (OR) 1.10; 95% confidence interval (CI) 1.07 to 1.13; p < 0.001; and Invasive blood pressure cohort OR 1.15; 95%CI 1.10 to 1.21; adjusted p < 0.001). The association was robust to alternative definitions of the outcome, including less severe hypotension (MAP≤65 mmHg) and blood pressure drop from baseline as a continuous measure. Although no threshold safe induction dose was identified at which hypotension was avoided, an analysis of propofol dose greater or less than 1.5 mg/kg (i.e. the maximum FDA-defined typical induction dose) demonstrated that doses in excess of the FDAs threshold were positively associated with odds of severe hypotension (Non-invasive cohort: OR 1.05; 95% CI 1.02 to 1.08; p < 0.001; Invasive cohort: OR 1.11; 95%CI 1.05 to 1.17; adjusted p < 0.001).

CONCLUSIONS

In a multicenter cohort of geriatric surgical patients receiving propofol for general anesthetic induction and endotracheal intubation, severe pre-incision hypotension (MAP ≤55 mmHg) that has previously been associated with postoperative morbidity was common. The dose of propofol used was significantly associated with increased odds of this outcome after controlling for a number of clinically relevant factors. Future studies that are designed to test different approaches to anesthesia induction for reducing severe post induction pre-incision hypotension are warranted.

Interpretation of meta-analyses

Our article provides guidance on how to interpret a meta-analysis and introduces the reader to the basics of the underlying statistical analysis. The multiple steps of a meta-analysis including systematic literature search, risk of bias assessment, data extraction and data aggregation are addressed. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach allows to score the quality of the evidence of the results revealed by a meta-analysis. Trial sequential analysis has been suggested in recent years as a method to assess the power of a meta-analysis and the risks of false positive or false negative conclusions. We also provide information on other more complex meta-analytical approaches including network meta-analysis for the comparison of several treatments as well as recent developments such as individual patient data meta-analysis and living meta-analysis.

Comparative Dose–Response Study on the Infusion of Norepinephrine Combined with Crystalloid Coload versus Colloid Coload for Preventing Hypotension During Spinal Anesthesia for Cesarean Delivery

Background

Although the optimal infusion dose of norepinephrine combined with crystalloid coload for preventing spinal anesthesia-induced hypotension (SAIH) for cesarean delivery has been established, the infusion regimen of norepinephrine combined with colloid coload has not been fully quantified. The objective of this study was to compare and determine the median effective dose (ED₅₀) and 90% effective dose (ED₉₀) of norepinephrine infusion combined with crystalloid coload versus colloid coload for preventing SAIH during cesarean delivery.

Methods

Two hundred parturients were randomly assigned to receive norepinephrine infusion at 0.02, 0.04, 0.06, 0.08, or 0.10 µg/kg/min in combination with 10 mL/kg crystalloid coload or colloid coload to prevent SAIH. The study period was defined as the interval from the commencement of intrathecal injection to delivery of the neonate. The primary outcome was non-occurrence of hypotension, defined as systolic blood pressure (SBP) less than 80% of the baseline before delivery. The ED₅₀ and ED₉₀ of norepinephrine infusion dose were determined using probit regression analysis. By calculating the 95% confidence intervals (CIs) of relative median potency to determine whether the prophylactic infusion of norepinephrine requirement was different between the two groups.

Results

The derived ED₅₀ and ED₉₀ of norepinephrine infusion combined with crystalloid coload were 0.030 (95% CIs 0.020 to 0.038) and 0.097 (95% CIs 0.072 to 0.157) µg/kg/min, respectively. The ED₅₀ and ED₉₀ of norepinephrine infusion combined with colloid coload were 0.021 (95% CIs 0.013 to 0.029) and 0.070 (95% CIs 0.053 to 0.107) µg/kg/min, respectively. The estimate of relative median potency for norepinephrine between the two groups was 1.37 (95% CIs 0.94 to 2.23).

Conclusion

Under the conditions of this study, 10 mL/kg colloid coload reduced the dose of prophylactic norepinephrine infusion by approximately 30% in parturients during spinal anesthesia for cesarean delivery compared with the crystalloid coload.

Spinal hypotension in obstetrics: Context-sensitive prevention and management

Spinal hypotension during caesarean section remains a common complication, with important attendant maternal and fetal adverse outcomes. Research elucidating the mechanisms of spinal hypotension has led to the development and refinement of effective management strategies, with a particular emphasis on prophylactic vasopressor administration. This has proved effective in well-resourced settings, with maternal comfort and the elimination of nausea now considered the primary aim of treatment. In resource-limited settings, sophisticated strategies are not feasible due to insufficient equipment, staff, and expertise. Therefore, in these areas spinal hypotension remains an important cause of maternal and fetal morbidity and mortality. Translational, context-sensitive research in resource-limited settings has shown promise in implementing pragmatic strategies based on research from resource-rich environments. We review the current best practice for the prevention and treatment of spinal hypotension, with a special emphasis on effective strategies in resource-limited settings. We further suggest a research agenda to address the knowledge gap in specific contexts.

Colloid coload versus crystalloid coload to prevent maternal hypotension in women receiving prophylactic phenylephrine infusion during caesarean delivery: a randomised controlled trial

BACKGROUND

The optimal fluid strategy to prevent maternal hypotension during caesarean delivery remains unclear. This study aim was to compare the incidence of post-spinal anaesthesia hypotension in women receiving either colloid or crystalloid coload in the setting of prophylactic phenylephrine infusion during caesarean delivery.

METHODS

Healthy mothers undergoing elective caesarean delivery under spinal anaesthesia were randomised to receive a rapid intravenous coload with 6% hydroxyethyl starch 130/0.4 10 mL/kg (colloid group) or balanced crystalloid solution (Plasma Solution A) 10 mL/kg (crystalloid group) during spinal anaesthesia. All women had a prophylactic phenylephrine infusion initiated at 25 μg/min immediately after the subarachnoid block and titrated to systolic blood pressure using a standardised protocol. The primary outcome was the incidence of hypotension (systolic blood pressure <80% of baseline) until delivery.

RESULTS

The incidence of hypotension was 50% in the colloid group and 62% in the crystalloid group (absolute difference, -12% [95% CI -33% to 9%]; relative risk, 0.8 [95% CI 0.56 to 1.14]; P=0.314). No significant difference between groups was found in the number of hypotensive episodes (median 0.5 [IQR 0 to 1] vs 1 [0 to 2], P=0.132) or phenylephrine dose (675 [IQR 425 to 975] μg vs 750 [625 to 950] μg, P=0.109). The incidence of severe hypotension, symptomatic hypotension, bradycardia, nausea, and the neonatal outcomes were not significantly different.

CONCLUSIONS

This study found no benefit of colloid coload compared with crystalloid coload for preventing maternal hypotension in the presence of prophylactic phenylephrine infusion during caesarean delivery.

An international survey of adherence to Surviving Sepsis Campaign Guidelines 2016 regarding fluid resuscitation and vasopressors in the initial management of septic shock

BACKGROUND

Our survey aimed to evaluate adherence to Surviving Sepsis Campaign (SSC) Guidelines 2016 among intensive care practitioners and to identify issues that remain controversial or lack clarity.

METHODS

Members of the European Society of Intensive Care Medicine (ESICM) were surveyed using an anonymous web-based survey written by an international group of experts. The primary outcome measure was the rate of adherence to specific recommendations. Secondary outcomes were to describe areas of controversy and lack of data and to associate specific practices with clinician characteristics.

RESULTS

Overall 820 questionnaires were completed. The SCC recommendations 2016 most adhered to were the choice of norepinephrine as first-line vasoactive drug (96.5%), vasopressor prescription based on therapeutic goal rather than dose (83.4%), targeting a specific mean arterial blood pressure during vasopressor use (77.9%), monitoring of blood pressure invasively (62.8%) and adding vasopressin or epinephrine as a second vasoactive agent (83.4%). We identified an internal conflict with regards to parallel versus sequential administration of fluids and vasoactive drugs and regional differences in practice that may be related to drug availabilities.

CONCLUSION

The use of vasopressors and fluid use in septic shock is largely compliant with current guidelines but several controversies should be addressed in future guideline iterations.