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

The Pleth Variability Index as a Guide to Fluid Therapy in Dogs Undergoing General Anesthesia: A Preliminary Study

The aim of this prospective, randomized clinical trial was to evaluate the use of the pleth variability index (PVi) to guide the rate of intraoperative fluid therapy compared to a traditional fixed-fluid-rate approach in ASA 1-2 dogs undergoing surgery. Twenty-seven dogs met the inclusion criteria and were randomly assigned to the conventional fluid management group (CFM, n = 12) or the PVi-guided group (PVi, n = 15). The CFM group received a fixed rate of 5 mL kg-1 h-1 of crystalloid solution, while in the PVi group the rate was continuously adjusted based on the PVi: PVi < 14% = 3 mL kg-1 h-1; 14% ≤ PVi ≥ 20% = 10 mL kg-1 h-1; and PVi > 20% = 15 mL kg-1 h-1. Hypotension (MAP < 65 mmHg) in the CFM was treated with a maximum of two fluid boluses (5 mL kg-1 in 10 min) and in the case of no response, dobutamine (1-3 mcg kg-1 min-1) was administered. In the PVi group, the treatment of hypotension was similar, except when the PVi > 14%, when dobutamine was started directly. Total fluid volume was significantly lower in the PVI group (0.056 ± 0.027 mL kg-1 min-1) compared to the CFM group (0.132 ± 0.115 mL kg-1 min-1), and the incidence of hypotension was lower (p = 0.023) in the PVi group (0%) compared to the CFM group (41%). The mean arterial pressure (MAP) was significantly higher in the PVi group during surgery. Dobutamine was never administered in either group. Preliminary data suggest that the PVi may be considered as a potential target to guide fluid therapy in dogs; larger studies are needed, especially in cases of cardiovascular instability.

Comparison of Dynamic Measures in Intraoperative Goal-Directed Fluid Therapy of Patients with Morbid Obesity Undergoing Laparoscopic Sleeve Gastrectomy

INTRODUCTION

Obesity increases the risk of morbidity and mortality during surgical procedures. Goal-directed fluid therapy (GDFT) is a new concept for perioperative fluid management that has been shown to improve patient prognosis. This study aimed to investigate the role of the Pleth Variability Index (PVI), systolic pressure variation (SPV), and pulse pressure variation (PPV) in maintaining tissue perfusion and renal function during GDFT management in patients undergoing laparoscopic sleeve gastrectomy (LSG).

MATERIALS AND METHODS

Two hundred ten patients were enrolled in our prospective randomized controlled clinical trial. Demographic data, hemodynamic parameters, biochemical parameters, the amount of crystalloid and colloid fluid administered intraoperatively, and the technique of goal-directed fluid management used were recorded. Patients were randomly divided into three groups: PVI (n = 70), PPV (n = 70), and SPV (n = 70), according to the technique of goal-directed fluid management. Postoperative nausea and vomiting, time of return of bowel movement, and hospital stay duration were recorded.

RESULTS

There was no statistically significant difference between the number of crystalloids administered in all three groups. However, the amount of colloid administered was statistically significantly lower in the SPV group than in the PVI group, and there was no significant difference in the other groups. Statistically, there was no significant difference between the groups in plasma lactate, blood urea, and creatinine levels.

CONCLUSION

In LSG, dynamic measurement techniques such as PVI, SPV, and PPV can be used in patients with morbid obesity without causing intraoperative and postoperative complications. PVI may be preferred over other invasive methods because it is noninvasive.

The Effect of Pneumoperitoneum-induced Hypertension During Laparoscopic Cholecystectomy Under General Anesthesia on Postoperative Pain: A Randomized Clinical Trial

Background

Acute postoperative pain is a significant cause of morbidities. This study aimed to evaluate the effect of intraoperative blood pressure during laparoscopic cholecystectomy under general anesthesia on postoperative pain in patients without underlying disorders.

Methods

In this randomized clinical trial, 72 patients undergoing general anesthesia for elective laparoscopic cholecystectomy were randomly assigned into two groups: Group A with higher than baseline preoperative blood pressure (MAP allowed to increase up to 20% higher than baseline MAP by inducing pneumoperitoneum) and group B with normal to low blood pressure (MAP deliberately controlled at a tight limit from normal baseline MAP values to 20% less than baseline by titrating TNG infusion). The Visual Analog Scale (VAS) after 2, 8, 12, and 24 hours of surgery, and the total dose of meperidine used to manage postoperative pain were recorded and compared between the two groups.

Results

The pain scores in group A were significantly lower than group B (P = 0.001). The postoperative analgesia request time was different between the two groups (P = 0.53). During the first 24 hours, the total meperidine consumption dose in group A was significantly lower than in group B (P = 0.001).

Conclusions

High intraoperative blood pressure may affect the postoperative pain after laparoscopic cholecystectomy and lead to less postoperative pain score and analgesic requirements.

Comparison of RAMP and New Modified RAMP Positioning in Laryngoscopic View During Intubation in Patients with Morbid Obesity: A Randomized Clinical Trial

Background

The prevalence of obesity is increasing worldwide, and anesthesiologists are facing challenges in the airway management of such patients. Excessive adipose tissue influences pharyngeal spaces and affects the laryngoscopic grade. Standard ramp positioning is time-consuming and difficult to prepare, and requires expensive equipment.

Objectives

The aim of this study was to compare the standard ramp position with the proposed low-cost and easily accessible modified ramp position in laryngoscopic view during the intubation of patients with morbid obesity.

Methods

In this single-blind clinical trial, 84 patients candidate for bariatric surgery at Rasoul Akram Hospital in 2020 were assigned to the rapid airway management positioner (RAMP) (R) and new modified RAMP (MR) groups by the block randomization method. The laryngoscopic view of the glottis based on the Cormack-Lehane scale, ventilation quality, duration of intubation, intubation attempts, oxygen saturation at the end of intubation, and the need for backward, upward, rightward pressure (BURP) maneuver for successful intubation were recorded. Normal distribution tests and Mann-Whitney and Kruskal-Wallis tests were used to analyze the data.

Results

The results showed no significant differences between the two groups regarding ventilation score, laryngoscopy grade, number of intubation attempts, duration of intubation, and the need for BURP maneuvers during intubation (P > 0.05).

Conclusions

The two methods are not significantly different, and the new modified ramp position can be used with more ease and availability and less cost.

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.