The effect of intraoperative goal-directed fluid therapy in patients under anesthesia for gastrointestinal surgery

Abstract

BACKGROUND

Intraoperative fluid management is an important aspect of anesthesia management in gastrointestinal surgery. Intraoperative goal-directed fluid therapy (GDFT) is a method for optimizing a patient's physiological state by monitoring and regulating fluid input in real-time.

AIM

To evaluate the efficacy of intraoperative GDFT in patients under anesthesia for gastrointestinal surgery.

METHODS

This study utilized a retrospective comparative study design and included 60 patients who underwent gastrointestinal surgery at a hospital. The experimental group (GDFT group) and the control group, each comprising 30 patients, received intraoperative GDFT and traditional fluid management strategies, respectively. The effect of GDFT was evaluated by comparing postoperative recovery, complication rates, hospitalization time, and other indicators between the two patient groups.

RESULTS

Intraoperative blood loss in the experimental and control groups was 296.64 ± 46.71 mL and 470.05 ± 73.26 mL (P < 0.001), and urine volume was 415.13 ± 96.72 mL and 239.15 ± 94.69 mL (P < 0.001), respectively. The postoperative recovery time was 5.44 ± 1.1 days for the experimental group compared to 7.59 ± 1.45 days (P < 0.001) for the control group. Hospitalization time for the experimental group was 10.87 ± 2.36 days vs 13.65 ± 3 days for the control group (P < 0.001). The visual analogue scale scores of the experimental and control groups at 24 h and 48 h post-surgery were 3.38 ± 0.79 and 4.51 ± 0.86, and 2.05 ± 0.57 and 3.51 ± 0.97 (P < 0.001), respectively. The cardiac output of the experimental and control groups was 5.99 ± 1.04 L/min and 4.88 ± 1.17 L/min, respectively, while the pulse pressure variability for these two groups was 10.87 ± 2.36% and 17.5 ± 3.21%, respectively.

CONCLUSION

The application of GDFT in gastrointestinal surgery can significantly improve postoperative recovery, reduce the incidence of complications, and shorten hospital stays.

Key Words: Intraoperative goal-directed fluid therapy; Gastrointestinal surgery; Anesthesia management; Postoperative recovery; Complications; Length of stay

Core Tip: In this study, intraoperative goal-directed fluid therapy (GDFT) showed significant clinical benefits in gastrointestinal surgery, including reduced intraoperative bleeding, accelerated postoperative recovery, and alleviated postoperative pain. This fluid management strategy helped maintain patients’ hemodynamic stability, reduced the incidence of intraoperative and postoperative complications, and improved the success rate of surgical treatment and patients’ quality of life. However, the establishment of specific implementation methods and standards for GDFT requires further research and optimization to ensure safety and efficacy and to provide more accurate guidance for its clinical application.

INTRODUCTION

Gastrointestinal surgery is one of the most common procedures in the field of general surgery[1], involving the stomach, intestines, liver, pancreas, spleen, and other internal abdominal organs[2,3]. With advancements in surgical technology and anesthesia methods, the safety and success rates of surgery have significantly improved[4,5]. However, intraoperative fluid management remains a critical challenge[6]. Traditional fluid management strategies often rely on experience and basic physiological parameters, which may lead to excessive or insufficient fluid input, thereby affecting postoperative recovery and complication rates. Intraoperative goal-directed fluid therapy (GDFT) is an emerging fluid management strategy that dynamically adjusts fluid input volume by monitoring the patient's hemodynamic parameters in real-time to optimize the patient's physiological state[7,8]. GDFT has shown superiority in many surgical fields; however, its application in gastrointestinal surgery requires further research and verification[9,10].

The application of intraoperative GDFT in clinical settings has gradually increased in recent years[11,12]. Studies have demonstrated that GDFT can optimize tissue perfusion and oxygenation by precisely controlling fluid input and reducing the occurrence of postoperative complications[13,14]. For example, in cardiac and major vascular surgeries, GDFT significantly reduced the incidence of postoperative acute kidney injury and cardiovascular events[15,16]. Similarly, in abdominal surgery, GDFT effectively reduced postoperative infections and expedited recovery[17]. However, studies on the utilization of GDFT in gastrointestinal surgery are relatively limited and they are confounded by contradictory findings[18]. Traditional fluid management strategies typically rely on estimating fluid input volume based on the patient's weight, preoperative status, and basic physiological parameters[19]. However, this method lacks real-time dynamic adjustment, which may result in either insufficient or excessive fluid input, consequently affecting postoperative recovery. Insufficient fluid input can lead to hypovolemia and inadequate tissue perfusion, whereas excessive fluid input can cause tissue edema and postoperative complications, such as pulmonary edema and heart failure.

GDFT involves dynamically adjusting fluid input volume by monitoring the patient's hemodynamic parameters in real-time, such as cardiac output, pulse pressure variability, and central venous pressure. Commonly used monitoring equipment include esophageal Doppler and pulse wave profile analyzers[20]. These devices provide real-time hemodynamic data to assist anesthesiologists in tailoring fluid therapy to a patient's specific condition. Firstly, the patient's volume responsiveness is assessed by preloading fluid; secondly, fluid input volume is dynamically adjusted based on real-time monitoring data; finally, vasoactive and inotropic drugs are administered in combination to further optimize the patient’s hemodynamic status. Through personalized fluid management, GDFT can more accurately maintain intraoperative hemodynamic stability and reduce complications[21]. Gastrointestinal surgery involves procedures on multiple organs, often requiring prolonged operative times and extensive tissue trauma, which presents challenges for intraoperative fluid management. Surgical procedures can lead to significant bleeding and fluid loss, requiring prompt and effective fluid replenishment. In addition, the slow recovery of gastrointestinal function after surgery and susceptibility to complications such as intestinal obstruction and delayed gastric emptying elevate the necessity for postoperative fluid management.

The implementation of GDFT in gastrointestinal surgery can enhance the precision of intraoperative fluid input volume and improve intraoperative hemodynamic stability, thereby improving postoperative recovery. In this study, we evaluated the implementation of GDFT in gastrointestinal surgical anesthesia through a retrospective comparative analysis, providing a scientific basis for its clinical application, and bearing significant theoretical and practical implications. The primary objective was to evaluate the efficacy of intraoperative GDFT for gastrointestinal surgery. Specific objectives included comparing GDFT with traditional fluid management approaches in terms of postoperative recovery, complication rates, and length of hospital stay. Thus, this study explored the impact of GDFT on patients' postoperative prognosis, and provided a scientific rationale for its implementation in the clinical setting.

MATERIALS AND METHODS

Patient information

This study involved 60 patients who underwent gastrointestinal surgery at a hospital between January 2022 and December 2023 (Table 1). These patients required gastrointestinal surgery due to various gastrointestinal diseases, such as gastric cancer, colorectal cancer, and gastric ulcer. Of the study participants, 35 were males and 25 were females, with ages ranging from 30 years to 75 years and an average age of 52.6 ± 10.8 years. All patients provided informed consent, and the study received approval from the hospital ethics committee.

Table 1 Comparison of the general conditions of the two patient groups.

Parameter	Experimental group, n = 30	Control group, n = 30	t/F	P value
Age in years	50.4 ± 10.14	52.25 ± 10.17	-0.33	0.75
Sex: Male/female	18/12	17/13	0.54	0.59
Weight in kg	68.22 ± 12.28	64.82 ± 10.75	1.14	0.26
ASA classification: I/II/III	8/15/7	9/14/7	-2.63	0.92
Type of surgery: gastrectomy/bowel resection	16/14	15/15	-1.48	0.81

ASA: American Society of Anesthesiologists.

Study design

The study adopted a retrospective comparative design, wherein patients meeting the inclusion criteria were divided into two groups: an experimental group (GDFT group) and a control group (traditional fluid management group), each comprising 30 patients. The clinical usability of intraoperative GDFT was evaluated by comparing postoperative recovery, complication rates, hospitalization durations, and other relevant indicators between the two patient groups.

All data were collected by dedicated researchers and recorded in an electronic database. Prior to data entry, double checks were performed to ensure accuracy and completeness. The sample size for the study was determined based on the difference between the previous research results and the anticipated effect size. Power analysis calculated that a minimum of 30 patients per group was required to achieve 80% statistical power with the significance level (α) set at 0.05.

Inclusion and exclusion criteria

Inclusion criteria: Patients aged between 18 years and 75 years, regardless of sex; requirement for gastrointestinal surgery due to gastrointestinal diseases; preoperative American Society of Anesthesiologists classification ranging from I to III; surgeries expected to last more than two hours; patients and their families providing informed consent by signing the consent form.

Exclusion criteria: Severe cardiopulmonary insufficiency; pregnant or breastfeeding women; severe renal insufficiency necessitating dialysis prior to surgery; requirement for a large volume of blood transfusion (more than 1000 mL) during surgery; severe electrolyte imbalance or metabolic disease observed before surgery.

Patient groups

The research subjects were randomly divided into two groups, with 30 individuals in each group. The experimental group (GDFT group) patients received intraoperative GDFT, while those in the control group were treated using traditional fluid management strategies.

Interventions

Experimental group (GDFT group) patients underwent the following interventions: (1) Preoperative preparation: all patients underwent routine anesthesia evaluation before surgery, including electrocardiography, chest radiography, blood tests, liver and kidney function tests, and electrolyte assessments. Patients were instructed not to eat for six hours and not to drink for two hours before surgery; (2) Anesthesia induction: general anesthesia was induced by administration of routinely used drugs such as midazolam, propofol, fentanyl, and rocuronium. Anesthesia was maintained by administration of propofol, remifentanil, and atracurium besylate; (3) Fluid management: real-time monitoring of the patient's cardiac output, pulse pressure variability, and other hemodynamic parameters was conducted using esophageal Doppler or pulse wave profile analyses. Based on the monitoring results, the fluid input volume was dynamically adjusted to maintain hemodynamic stability. Vasoactive and inotropic drugs were administered when necessary; and (4) Intraoperative monitoring: physiological parameters such as electrocardiogram, blood pressure, pulse oxygen saturation, end-tidal carbon dioxide partial pressure, and urine output were monitored intraoperatively.

Control group (traditional fluid management group) patients underwent interventions similar to the experimental group with the following exception: Fluid management: traditional fluid management strategies were used for fluid replenishment based on the patient's weight, preoperative status, and surgical progress. This involved administering crystalloids at a rate of 10 mL/kg/h with adjustments made in response to intraoperative blood loss and urine output.

Observation indicators

Postoperative complication rate: Included infections, pneumonia, myocardial infarction, acute kidney injury, etc., occurring after surgery.

Postoperative recovery time: The duration from the end of the operation to the patient's return to a normal diet and activities.

Length of stay: The total time from admission to discharge.

Intraoperative bleeding: The total amount of blood lost during surgery.

Postoperative infection rate: Included surgical site infection, lung infection, etc., occurring within 30 days post-surgery.

Postoperative pain score: The degree of the patient's pain level at 24- and 48-h post-surgery evaluated using the visual analogue scale (VAS).

Time to first ambulation after surgery: The duration from the end of surgery to the first time the patient got out of bed.

Postoperative first bowel movement time: The time interval from the end of surgery to the patient's first bowel movement.

Intraoperative urine output: The patient's urine output during surgery.

Hemodynamic parameters: Included cardiac output, pulse pressure variability, and central venous pressure.

Statistical analysis

Statistical analysis was conducted using SPSS 26.0 software. Measurement data were presented as mean ± standard deviation, and an independent-samples t-test was used for comparison between groups. Count data were presented as frequency and percentage, and either a χ² test or Fisher's exact test was used for intergroup comparisons of this data type. P < 0.05 indicated a statistically significant difference.

RESULTS

Comparison of intraoperative indicators

Intraoperative blood loss was significantly lower in the experimental group than in the control group, measuring 296.64 ± 46.71 mL and 470.05 ± 73.26 mL, respectively (P < 0.001; Table 2). This suggests that intraoperative GDFT has a significant impact on reducing intraoperative bleeding. Additionally, the intraoperative urine output was significantly higher in the experimental group than the control group, measuring 415.13 ± 96.72 mL and 239.15 ± 94.69 mL, respectively (P < 0.001; Table 2), suggesting that GDFT can effectively maintain the patient's hemodynamic stability and enhance urine production. Overall, GDFT significantly improved intraoperative fluid management, helped reduce intraoperative bleeding, and maintained an appropriate urine output, thereby contributing to postoperative recovery.

Table 2 Comparison of intraoperative indicators between the two patient groups.

Intraoperative indicator, mL	Experimental group, n = 30	Control group, n = 30	t value	P value
Blood loss	296.64 ± 46.71	470.05 ± 73.26	-10.93	< 0.001
Urine output	415.13 ± 96.72	239.15 ± 94.69	7.12	< 0.001

Postoperative recovery

Postoperative recovery time and length of hospitalization was significantly lower in the experimental group than the control group. Measuring 5.44 ± 1.1 days and 7.59 ± 1.45 days vs 10.87 ± 2.36 days and 13.65 ± 3 days respectively (P < 0.001; Table 3). This suggests that intraoperative GDFT can significantly accelerate postoperative recovery and shorten hospital stays. Additionally, the first ambulation after operation in the experimental group and the first bowel movement was significantly lower than the control group, measuring 1.73 ± 0.58 days and 2.6 ± 0.6 days vs 3 ± 0.71 days and 4.33 ± 1.25 days, respectively (P < 0.001; Table 3). This indicates that intraoperative GDFT could significantly improve postoperative activity and bowel movement (Table 3).

Table 3 Comparison of postoperative recovery conditions between the two patient groups.

Postoperative condition	Experimental group, n = 30	Control group, n = 30	t value	P value
Recovery time in days	5.44 ± 1.1	7.59 ± 1.45	-6.47	< 0.001
Hospital stays in days	10.43 ± 2.49	13.65 ± 3	-4.53	< 0.001
Time to get out of bed for the first time after surgery in days	1.73 ± 0.58	3 ± 0.71	-7.63	< 0.001
Time to first bowel movement after surgery in days	2.6 ± 0.6	4.33 ± 1.25	-6.86	< 0.001

Postoperative pain comparison

The pain scores of the experimental group were significantly lower than those of the control group 24 and 48 h after operation. The VAS score at 24 h after surgery measured 3.38 ± 0.79 h and 4.51 ± 0.86 h, respectively (P < 0.001; Table 4), The VAS score at 48 h after surgery, measuring 2.05 ± 0.57 h and 3.51 ± 0.97 h, respectively (P < 0.001; Table 4), This suggests that intraoperative GDFT can effectively reduce early postoperative pain.

Table 4 Comparison of postoperative pain scores (visual analogue scale) between the two patient groups.

VAS score	Experimental group, n = 30	Control group, n = 30	t value	P value
24 h after surgery	3.38 ± 0.79	4.51 ± 0.86	-5.30	< 0.001
48 h after surgery	2.05 ± 0.57	3.51 ± 0.97	-7.13	< 0.001

VAS: Visual analogue scale.

Hemodynamic parameters

The central output and pulse pressure variability of the experimental group was significantly better than those of the control group (P < 0.001; Table 5). Intraoperative GDFT can effectively maintain intraoperative hemodynamic stability, increase cardiac output and reduce pulse pressure variability, thus contributing to postoperative recovery.

Table 5 Comparison of intraoperative hemodynamic parameters between the two patient groups.

Intraoperative parameter	Experimental group, n = 30	Control group, n = 30	t value	P value
Cardiac output in L/min	5.99 ± 1.04	4.88 ± 1.17	3.88	< 0.001
Pulse pressure variability as %	10.87 ± 2.36	17.5 ± 3.21	-9.10	< 0.001
Central venous pressure in mmHg	7.75 ± 1.44	9.42 ± 1.43	-4.54	< 0.001

DISCUSSION

In gastrointestinal surgery, fluid therapy plays an important role in ensuring patient safety, reducing postoperative complications, and facilitating rapid postoperative recovery[22]. Traditional fluid therapy strategies typically rely on static physiological indicators, such as heart rate, blood pressure, central venous pressure, and urine output, to guide fluid administration rates and volumes[23]. However, these indicators have limitations in reflecting the patient's real-time hemodynamic status and are easily influenced by various factors, such as anesthetic drugs, surgical stimulation, and changes in the patient’s pathophysiological status. With advancements in medical technology, GDFT has emerged as a promising approach for gastrointestinal surgery[24]. GDFT utilizes advanced hemodynamic monitoring technologies such as pulse-induced contour cardiac output and echocardiography, which can accurately assess a patient's volume status in real-time, providing individualized fluid therapy guide to anesthesiologists[25]. This treatment strategy allows for more precise fluid administration tailored to each patient's needs, thereby ensuring intraoperative hemodynamic stability and reducing the risks of fluid overload or depletion. The effectiveness of intraoperative GDFT in gastrointestinal surgery has attracted considerable attention. The results of our study demonstrate that GDFT can effectively reduce intraoperative blood loss, maintain hemodynamic stability, promote postoperative recovery, and reduce postoperative pain during gastrointestinal surgery. These findings are consistent with those of previous studies, yet they raise new questions and discussion points.

Firstly, GDFT can reduce intraoperative blood loss by optimizing hemodynamic stability. Intraoperative bleeding is a common complication in gastrointestinal surgery. It not only prolongs the operation time and increases the risk of adverse outcomes but also leads to an increase in the incidence of postoperative complications. We found that intraoperative bleeding volume was significantly reduced in the experimental group. This outcome may be attributed to GDFT's ability to adjust fluid management strategies according to the patient's hemodynamic status, thereby ensuring maintenance of effective blood volume and circulation status. Consequently, this approach reduces the risk of intraoperative bleeding. Secondly, GDFT has significant advantages in terms of postoperative recovery. Postoperative recovery and hospitalization time are important indicators in evaluating the effects of surgical treatment. This study found that the postoperative recovery and hospitalization times in the experimental group were significantly shorter than those in the control group. The time to first ambulation and the time to first bowel movement after surgery were also significantly shorter. This shows that GDFT can accelerate a patient's postoperative recovery process, reduce the incidence of postoperative complications, lower the utilization of medical resources, and enhance medical efficiency.

Furthermore, GDFT can effectively relieve postoperative pain, which is an important factor affecting patients' postoperative quality of life. The results of this study revealed that the postoperative pain scores in the experimental group were significantly lower than those in the control group, indicating that GDFT can effectively relieve postoperative pain, improve patient comfort, and promote postoperative recovery. Despite its advantages, the application of GDFT may encounter some limitations. Firstly, GDFT requires monitoring of a series of hemodynamic parameters, including cardiac output and central venous pressure. These measurements require specialized equipment and technical support, thereby increasing the cost and complexity of the procedure. Secondly, the lack of standardized implementation methods and criteria for GDFT presents a challenge. Different studies may adopt diverse fluid management strategies and objectives, potentially impacting the comparability and applicability of research outcomes. Future prospective studies with larger sample sizes and randomized designs would further strengthen these findings and validate the efficacy of GDFT in clinical practice.

CONCLUSION

In summary, intraoperative GDFT shows clear clinical advantages in gastrointestinal surgery, including reduced intraoperative bleeding, enhanced postoperative recovery, diminished postoperative pain, and improved quality of life for patients. However, further research is required to verify the safety and efficacy of GDFT, and to refine its implementation methods and standards for providing personalized fluid management strategies to patients.