Effects of a restrictive fluid regimen in pediatric patients undergoing major abdominal surgery

Goal-directed fluid therapy guided by plethysmographic variability index versus conventional liberal fluid therapy in neonates undergoing abdominal surgery: A prospective randomized controlled trial

BACKGROUND

Intraoperative fluid therapy maintains normovolemia, normal tissue perfusion, normal metabolic function, normal electrolytes, and acid-base status. Plethysmographic variability index has been shown to predict fluid responsiveness but its role in guiding intraoperative fluid therapy is still elusive.

AIMS

The aim of the present study was to compare intraoperative goal-directed fluid therapy based on plethysmographic variability index with liberal fluid therapy in term neonates undergoing abdominal surgeries.

METHODS

A prospective randomized controlled study was conducted in a tertiary care centre, over a period of 18 months. A total of 30 neonates completed the study out of 132 neonates screened. Neonates with tracheoesophageal fistula, congenital diaphragmatic hernia, congenital heart disease, respiratory disorders, creatinine clearance <90 mL/min and who were hemodynamically unstable were excluded. Neonates were randomized to goal-directed fluid therapy group where the plethysmographic variability index was targeted at <18 or liberal fluid therapy group. Primary outcome was comparison of total amount of fluid infused intraoperatively in both the groups. Secondary outcomes included intraoperative and postoperative arterial blood gas parameters, biochemical parameters, use of vasopressors, number of fluid boluses, complications and duration of hospital stay.

RESULTS

There was no significant difference in total intraoperative fluid infused [90 (84-117.5 mL) in goal-directed fluid therapy and 105 (85.5-144.5 mL) in liberal fluid therapy group (p = .406)], median difference (95% CI) -15 (-49.1 to 19.1). There was a decrease in serum lactate levels in both groups from preoperative to postoperative 24 h. The amount of fluid infused before dopamine administration was significantly higher in liberal fluid therapy group (58 [50.25-65 mL]) compared to goal-directed fluid therapy group (36 [22-44 mL], p = .008), median difference (95% CI) -22 (-46 to 2). In postoperative period, the total amount of fluid intake over 24 h was comparable in two groups (222 [204-253 mL] in goal-directed fluid therapy group and 224 [179.5-289.5 mL] in liberal fluid therapy group, p = .917) median difference (95% CI) cutoff -2 (-65.3 to 61.2).

CONCLUSION

Intraoperative plethysmographic variability index-guided goal-directed fluid therapy was comparable to liberal fluid therapy in terms of total volume of fluid infused in neonates during perioperative period. More randomized controlled trials with higher sample size are required.

TRIAL REGISTRATION

Central Trial Registry of India (CTRI/2020/02/023561).

REstrictive versus StandarD FlUid Management in Mechanically Ventilated ChildrEn Admitted to PICU: study protocol for a pilot randomised controlled trial (REDUCE-1)

INTRODUCTION

Intravenous fluid therapy is the most common intervention in critically ill children. There is an increasing body of evidence questioning the safety of high-volume intravenous fluid administration in these patients. To date, the optimal fluid management strategy remains unclear. We aimed to test the feasibility of a pragmatic randomised controlled trial comparing a restrictive with a standard (liberal) fluid management strategy in critically ill children.

METHODS AND ANALYSIS

Multicentre, binational pilot, randomised, controlled, open-label, pragmatic trial. Patients <18 years admitted to paediatric intensive care unit and mechanically ventilated at the time of screening are eligible. Patients with tumour lysis syndrome, diabetic ketoacidosis or postorgan transplant are excluded.

INTERVENTIONS

1:1 random assignment of 154 individual patients into two groups-restrictive versus standard, liberal, fluid strategy-stratified by primary diagnosis (cardiac/non-cardiac). The intervention consists of a restrictive fluid bundle, including lower maintenance fluid allowance, limiting fluid boluses, reducing volumes of drug delivery and initiating diuretics or peritoneal dialysis earlier. The intervention is applied for 48 hours postrandomisation or until discharge (whichever is earlier).

ENDPOINTS

The number of patients recruited per month and proportion of recruited to eligible patients are feasibility endpoints. New-onset acute kidney injury and the incidence of clinically relevant central venous thrombosis are safety endpoints. Fluid balance at 48 hours after randomisation is the efficacy endpoint. Survival free of paediatric intensive care censored at 28 days is the clinical endpoint.

ETHICS AND DISSEMINATION

Ethics approval was gained from the Children's Health Queensland Human Research Ethics Committee (HREC/21/QCHQ/77514, date: 1 September 2021), and University of Zurich (2021-02447, date: 17 March 2023). The trial is registered with the Australia New Zealand Clinical Trials Registry (ACTRN12621001311842). Open-access publication in high impact peer-reviewed journals will be sought. Modern information dissemination strategies will also be used including social media to disseminate the outcomes of the study.

TRIAL REGISTRATION NUMBER

ACTRN12621001311842.

PROTOCOL VERSION/DATE

V5/23 May 2023.

Goal-directed fluid therapy guided by Plethysmographic Variability Index (PVI) versus conventional liberal fluid administration in children during elective abdominal surgery: A randomized controlled trial

BACKGROUND

PVI has been shown to be an accurate predictor of fluid responsiveness in paediatric patients. Evidence regarding the role of PVI to guide intraoperative fluid therapy in paediatric abdominal surgery is lacking. We aimed to assess the effect of PVI-guided fluid therapy on the volume of intraoperative fluids administered and post-operative biochemical and recovery profile in children undergoing elective abdominal surgery.

METHODS

42 children, 6 months-3 years scheduled for elective open bowel surgery were randomised to receive either 'conventional liberal intraoperative fluids' (liberal group) or 'goal-directed intraoperative fluids' (GDT group). PVI <13 was targeted in the GDT group. The primary outcome was the volume of intraoperative fluids administered. Postoperative serum lactate, base excess, hematocrit, recovery of bowel function and duration of postoperative hospital stay were the secondary outcomes.

RESULTS

The mean fluid administered intra-operatively was significantly lower in the GDT group as compared to the liberal group (24.1 ± 9.6 mL/kg vs 37.0 ± 8.9 mL/kg, p < 0.001). The postoperative hemoglobin concentration (g%) was significantly lower in the liberal group as compared to the GDT group (8.1 ± 1.3 vs 9.2 ± 1.4, p = 0.008). Recovery of bowel function (hours) was significantly delayed in the liberal group as compared to the GDT group (58.2 ± 17.9 vs 36.5 ± 14.1, p < 0.001).

CONCLUSION

Intraoperative PVI-guided fluid therapy significantly reduces the volume of intravenous crystalloids administered to children undergoing open bowel surgery. These children also had faster recovery of bowel function and less hemodilution in the immediate postoperative period, compared to those who received liberal intraoperative fluid therapy.

TYPE OF STUDY

Randomized Clinical Trial.

LEVEL OF EVIDENCE

Treatment Study (LEVEL 1).

Pediatric robotic surgery: issues in management-expert consensus from the Italian Society of Pediatric and Neonatal Anesthesia and Intensive Care (SARNePI) and the Italian Society of Pediatric Surgery (SICP)

BACKGROUND

Pediatric robotic-assisted surgeries have increased in recent years; however, guidance documents are still lacking. This study aimed to develop evidence-based recommendations, or best practice statements when evidence is lacking or inadequate, to assist surgical teams internationally.

METHODS

A joint consensus taskforce of anesthesiologists and surgeons from the Italian Society of Pediatric and Neonatal Anesthesia and Intensive Care (SARNePI) and the Italian Society of Pediatric Surgery (SICP) have identified critical areas and reviewed the available evidence. The taskforce comprised 21 experts representing the fields of anesthesia (n = 11) and surgery (n = 10) from clinical centers performing pediatric robotic surgery in the Italian cities of Ancona, Bologna, Milan, Naples, Padua, Pavia, Perugia, Rome, Siena, and Verona. Between December 2020 and September 2021, three meetings, two Delphi rounds, and a final consensus conference took place.

RESULTS

During the first planning meeting, the panel agreed on the specific objectives, the definitions to apply, and precise methodology. The project was structured into three subtopics: (i) preoperative patient assessment and preparation; (ii) intraoperative management (surgical and anesthesiologic); and (iii) postoperative procedures. Within these phases, the panel agreed to address a total of 18 relevant areas, which spanned preoperative patient assessment and patient selection, anesthesiology, critical care medicine, respiratory care, prevention of postoperative nausea and vomiting, and pain management.

CONCLUSION

Collaboration among surgeons and anesthesiologists will be increasingly important for achieving safe and effective RAS procedures. These recommendations will provide a review for those who already have relevant experience and should be particularly useful for those starting a new program.

Systematic Review of Definitions and Outcome Measures for Postoperative Ileus and Return of Bowel Function after Abdominal Surgery in Children

This review aims to objectify which definitions and outcome measures are used for the return of bowel function and postoperative ileus in children. PubMed and Embase were systematically searched from inception to December 17, 2020. Prospective studies conducted in children (aged 0-18 years) undergoing gastrointestinal surgery which reported on definitions and/or outcome measures for post-operative ileus or return of bowel function were evaluated. Definitions and outcome measures were extracted. From 4,027 references, 71 articles were included. From the 17 articles mentioning postoperative ileus, 8 (47%) provided a definition. In total, 34 outcome measures were used and 12 were unique. "Abdominal distension" was the most reported (41%) measure. In 41%, the outcome measures only described the return of gastric motility, while 18% described the return of intestinal motility. The return of bowel function was mentioned in 67 articles, none provided a definition. In total, 133 outcome measures were used and 37 were unique. Time to oral intake was the most reported (14%) measure. In 49%, the outcome measures only described the return of gastric motility, while 10% described the return of intestinal motility. High variation in definitions and outcome measures has limited the generalizability of research into postoperative bowel function in children. Without standardization, it will be impossible to compare research results and evaluate treatments. In children, the return of gastric motility seemingly should get more focus compared to adults. Therefore, we believe that a definition of postoperative ileus with an accompanying core outcome set, developed by a multidisciplinary team, specifically for children is required.

Perioperative fluid management in children: an updated review

Background: Perioperative fluid management in children has been a major topic for debate. Objectives: Our aim is to review the current evidence on perioperative fluid management in children including: type of fluid, administration rates, preoperative fluid intake and monitoring techniques. Design: Narrative review. Method: Following the PRISMA-S guidelines we performed a search (2010-March 2022) in databases Medline (through PubMed) and Cochrane Library. 4297 citations were found and screened by two independent researchers. After screening, 64 articles were withheld for our review. Results: The perioperative administration of isotonic fluids is safer than hypotonic solutions, concerning the development of hyponatremia. A balanced isotonic solution with 1-2,5% glucose should be used as perioperative maintenance IV fluid in children (1 month to 18 years). Colloids can be used in children when inadequate effect in volume correction is achieved with crystalloids. The preferred synthetic colloid for children is a third generation HES in a balanced solution. To date, most clinicians use the “4-2-1 rule” for calculating fluid rate. This may not be the optimal fluid rate, as little research has been done. Preoperative fasting for clear fluids should be limited to 1 hour, children should even be encouraged to drink up until 1 hour before induction. Respiratory variation of aortic blood flow peak velocity (ΔVpeak) with echocardiography is currently the most reliable technique for evaluating fluid responsiveness in children.

Lung Ultrasound Assisted Comparison of Volume Effects of Fluid Replacement Regimens in Pediatric Patients Undergoing Penile Hypospadias Repair: A Randomized Controlled Trial

Background

Effective perioperative fluid therapy is a great consideration.

Objectives

Using lung ultrasound (LUS), this study evaluated the preference of the conventional and restrictive fluid replacement regimens for their volume impact in pediatric patients undergoing a relatively long procedure with limited volume loss (hypospadias repair).

Methods

Eighty pediatric patients scheduled for hypospadias repair surgery were enrolled for conventional (CG) or restrictive fluid management groups (RG). The CG obtained Ringer's lactate at the conventional calculated doses, while the RG obtained infusion of Ringer's lactate at a rate of 3 mL/kg/h. B-line numbers in the LUS, recovery score, urine output, blood pressure (BP), heart rate HR, and oxygen saturation (SpO₂) were recorded.

Results

As evidenced by the LUS, RG showed a higher incidence of normal lung morphology with a mean and SD of 1.3 ± 2.2 for B-line numbers, whereas, in CG, they were 3.1 ± 2.2 with a P-value < 0.001. Urine output was 3.2 ± 0.8 and 2.9 ± 0.7 for CG and RG, respectively, with a P-value equal to 0.07. HR, BP, and SpO₂ differences between groups were statistically insignificant. The recovery score was higher in RG (5.8 ± 0.4) than in CG (5.1 ± 0.8) at the first postoperative 20 minutes, with a P-value < 0.001.

Conclusions

In lengthy procedures with limited volume loss, using a moderately restrictive regimen is preferred over the conventional intraoperative fluid regimen considering both respiratory dysfunctions and recovery score.

Effects of Liberal Versus Restrictive Fluid Therapy on Renal Function Indices in Laparoscopic Bariatric Surgery

Background

Earlier studies have suggested the liberal administration of fluids in favor of reducing the risk of rhabdomyolysis in obese patients, but the results are conflicting.

Objectives

The present study aimed at comparing the effects of liberal and restrictive fluid therapy on renal indices in laparoscopic gastric bypass surgery.

Methods

In a double-blinded randomized clinical trial, 72 candidates of bariatric surgery were randomly assigned into two groups of restrictive and liberal fluid therapy. Indices, including BUN, creatinine, creatine kinase, GFR, and urine output were measured before and 24 hours after the surgery. The clinical trial was registered at IRCT.ir under code IRCT20170109031852N3.

Results

There was no significant difference in BUN, creatinine, creatinine kinase, and GFR indices between the two groups of liberal and restrictive fluid therapy both before and 24 hours after surgery (P > 0.05). Intragroup comparisons before and after surgery revealed that BUN decreased in both groups after the surgery (P < 0.05). Also, creatinine and GFR values improved in patients who received a liberal fluid regimen, whereas these indices remained statistically unchanged in the restrictive group before and 24 hours after the surgery (P > 0.05).

Conclusions

Two methods of liberal and restrictive fluid therapy have comparable effects on traditional renal functional indices in laparoscopic bariatric surgery. The clinical significance of observed differences in outcomes should be investigated in further studies. The use of early biomarkers of acute kidney injury is warranted.

The association between high-volume intraoperative fluid administration and outcomes among pediatric patients undergoing large bowel resection

BACKGROUND

Traditional intraoperative fluid administration practices have been challenged this century with data suggesting improved outcomes with restrictive or goal-directed fluid administration during adult bowel surgery. Minimal data on outcomes associated with differing intraoperative fluid administration practice exists for pediatric patients.

AIMS

We assessed factors and outcomes associated with high-volume fluid administration in pediatric patients undergoing colectomy. We hypothesized that high-volume fluid administration is associated with impaired recovery and, thus, increased length of stay.

METHODS

A database of perioperative practice and postoperative outcomes at a tertiary pediatric hospital was queried for colectomy encounters between July 2012 and March 2017. Data extracted included patient characteristics, perioperative clinical data, and postoperative outcomes. Encounters were stratified into two groups: greater than 90th percentile fluids administered (high-volume fluid administration group) vs less than 90th percentile fluids administered. Univariable tests, multivariable logistic regression, and propensity score matched group comparisons were used to asses outcomes associated with high-volume fluid administration.

RESULTS

A total of 209 colectomy encounters were identified from which 12 were excluded based on predetermined criteria. High-volume fluid administration was associated with length of stay >6 days (AOR 8.14, CI 1.75-37.8, P = 0.007), time to first meal >4 days (AOR of 5.91, CI 1.30-27.17, P = 0.02), and supplemental oxygen requirement >24 hours (AOR 3.60, CI 1.25-10.39, P = 0.02) after adjusting for ASA status, blood loss, transfusion, and open surgery. Similarly, propensity score matched patients with high-volume fluid administration vs controls were more likely to have length of stay >6 days (93% vs 54%, P = 0.007), time to first meal >4 days (93% vs 57%, P = 0.009), and supplemental oxygen requirement >24 hours (36% vs 12%, P = 0.033).

CONCLUSION

High-volume fluid administration during colectomy for pediatric patients is associated with worsened postoperative outcomes suggestive of impaired recovery.

Intraoperative fluid management: Past and future, where is the evidence?

Currently, there is no consensus about the optimum intraoperative fluid therapy strategy. There is growing body of evidence supports the beneficial effects of adopting “Goal-directed therapy” over either the “liberal” or “restrictive” fluid therapy strategies. In this narrative review, we have presented the evidence to support the optimum strategy for intraoperative therapy. In conclusion, whatever the intravenous fluid replacement strategy used, the anesthesiologist must be prepared to adjust the composition and rate of the fluids administered to provide sufficient intravascular fluid volume for adequate perfusion of vital organs without overwhelming the glycocalyx function with fluid overloads.

Pediatric anesthesia for minimally invasive surgery in pediatric urology

Laparoscopic or robotic minimally invasive approaches have become the standard of care for many urological pediatric surgical procedures. Anesthetic concerns for conventional and robotic laparoscopy are similar since they both require insufflations of CO₂ to allow visualization of surgical field and perform surgery. Even if required insufflation pressures and volumes are lower in pediatric patients (given the small size of the abdomen and laxity of the abdominal walls), the associated increase of intra-abdominal pressure, along with absorption of CO₂ and surgical positioning requirement, may result in neurendocrine and mechanical impact capable to mine cardiopulmonary function. Moreover, laparoscopic approach may require specific positioning. A correct positioning is essential to allow the surgical team to optimally and safely access to the patient. The knowledge of patient's health status, along with the multiple physiologic changes that can occur and specific potential complications, allow the anesthesiologist to provide a safer an aesthesia.