A clinical study to evaluate the fluid response in patients undergoing neurosurgery.

Not yet recruiting

Conditions: Other specified disorders of nervous system in diseases classified elsewhere,

Registration Number: CTRI/2023/08/056880

Lead Sponsor: AIIMS New delhi

Brief Summary: | |

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|**Perioperative management**

Â·         All patients will receive standard intra-operative monitoring, including heart rate (HR), peripheral oxygen saturation (SpO2), continuous electrocardiography (ECG) and noninvasive blood pressure monitoring (NIBP).

Â·         After pre-oxygenation, general anaesthesia will be   induced   with   propofol, fentanyl and rocuronium (0.8 to 1 mg kgâ€”1), and maintained with propofol (100 - 150 mcg kgâ€”1 minâ€”1) or sevoflurane (1to 2%) along with fentanyl (1 to 2 mcg kgâ€”1 hrâ€”1).

Â·         Anesthetic administration was targeted to maintain a bispectral index (BIS) of 40 to 60 throughout the surgical procedure.[22](file:///C:/Users/Sr%20Lounge-1/Downloads/3.%20complete%20PROTOCOL%20-%20TVC.docx#_bookmark21)

Â·         All patients will receive Sodium chloride(0.9%) solution at 4 ml/kg/hour as a maintenance fluid infusion during surgery and will be ventilated at baseline in volume-control mode with the following settings: VT of 6 ml/ kgPBW and positive end-expiratory pressure set 5 cmH2O to achieve and maintain a peripheral oxygen saturation of 96% and an end-tidal carbon dioxide (EtCo2) concentration between 30 and 35 mmHg.

Â·         The PBW (kg) will be calculated as follows: X 0.91[height (cm) - 152.4]; (X 50 for men and 45.5 for women).

Â·         After induction of general anesthesia, invasive blood pressure monitoring will be obtained by inserting a 20-G cannula into the radial artery.  A square-wave test will be used in all patients to exclude under or overdamping of the pressure signal.[23](file:///C:/Users/Sr%20Lounge-1/Downloads/3.%20complete%20PROTOCOL%20-%20TVC.docx#_bookmark22)

**Hemodynamic monitoring**

Radial artery catheter will be connected to the FlowTrac system (version 4.0; Edwards Lifesciences, Irvine, CA, USA). We will continuously monitor stroke volume (SV), stroke volume index (SVI), cardiac output (CO), cardiac index (CI) and SVV through FlowTrac /EV1000 system. 43,44 PPV will be continuously recorded on a Nihon -Kohden monitoring system (Nihon Kohden Corporation, Japan).

**Study protocol**

Measurements will be started during a period of hemodynamic stability (defined as changes in mean arterial pressure less than 10% over 5 min[7,26](file:///C:/Users/Sr%20Lounge-1/Downloads/3.%20complete%20PROTOCOL%20-%20TVC.docx#_bookmark10)) after positioning the patient in sitting. All readings will be taken before the skin incision.

The study protocol will start with recording an initial set of measurements (Baseline).  TVC will be applied by increasing the TV up to 8 ml/ kg PBW and PPV and SVV changes were recorded (âˆ† PPV and âˆ† SVV, respectively, calculated as percentage of variations between the values of PPV and SVV recorded at bassline -1 and 1 min after the VT increase).

Following this, the TV will be reduced back to 6 ml/ kg PBW and after 1 min, a set of measurements will be recorded (Baseline 2) and the fluid challenge (FC) of 250 ml of sodium chloride ( 0.9%) solution will be infused over 10 min and SV, SVI will be noted. Only the haemodynamic data, obtained from the first fluid challenge administered to each enrolled patient will be used for the analysis. Positive end-expiratory pressure will be kept constant during the study period. For the safety of the patient, the interruption of the protocol will be at discretion of the attending anesthetist.

**Sample size calculation**

Â·         The sample size of the study was calculated by means of the comparison of the areas under the ROC curves test (AUC). For this purpose, we predicted an AUC of at least   0.75, which is the threshold for considering a diagnostic test as accurate,[29](file:///C:/Users/Sr%20Lounge-1/Downloads/3.%20complete%20PROTOCOL%20-%20TVC.docx#_bookmark12)and compared it with the null hypothesis (AUC 0.50; no discriminating power). Accordingly, a sample size of 38 patients was calculated (type I error of 5% and type II error of 20%). With the expectation of a 10% dropout rate, 42 patients will be enrolled in the study.

**Statistical analysis**

A receiver operating characteristic (ROC) curve approach will be used to evaluate the reliability of TVC test in predicting fluid responsiveness. ROC curves will be constructed for PPV and SVV values before fluid challenge administration; for the percentage change in PPV and SVV between 6- and 8-ml/ kgPBW ventilation after 1 min of TVC application.

A patient will be considered fluid responsive if the SVI increased at least 10% after fluid challenge administration.[7,8](file:///C:/Users/Sr%20Lounge-1/Downloads/3.%20complete%20PROTOCOL%20-%20TVC.docx#_bookmark10) Cut-off values will be chosen with the highest Youden index and, finally, statistically significant ROC curves (*P*< 0.05) were compared using the De Long test.[27](file:///C:/Users/Sr%20Lounge-1/Downloads/3.%20complete%20PROTOCOL%20-%20TVC.docx#_bookmark10)  Normal distribution will be evaluated by means of the Dâ€™Agostino-Pearson test and, accordingly, data are expressed as median with interquartile [IQR] range or mean (SD).

Changes in continuous variables after TVC will be compared using a paired *t*test or Wilcoxon signed rank sum test, while an independent *t*test or Mannâ€“Whitney *U*test was used for subgroup comparisons, as appropriate. For dichotomous or categorical variables, a Chi-square test for comparison of proportions will be applied. Statistical analyses will be conducted using STATA and or R software.

For all comparisons, we will consider significant *P*values less than 0.05.

Detailed Description: Not available

Recruitment & Eligibility

Status: Not Yet Recruiting

Sex: All

Target Recruitment: 42

Inclusion Criteria

All elective neurosurgical patients (age >18 years, ASA I II) requiring sitting positioning will be considered eligible.

Exclusion Criteria

o Any recurrent cardiac arrhythmia; reduced ventricular systolic function.
left (ejection fraction <40%), o BMI more than 30 o Intra-operative use of vasopressors or inotropes before or during TVC o Chronic lung disease o Pre-operative use of beta blocking agents.

Study & Design

Study Type: Observational

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To assess the reliability of changes in pulse pressure variation (PPV) & stroke volume variation (SVV) values induced by tidal volume challenge in predicting fluid responsiveness in patients undergoing neurosurgery in the sitting position under 6 ml/kg (PBW)	To assess the reliability of changes in pulse pressure variation (PPV) & stroke volume variation (SVV) values induced by tidal volume challenge in predicting fluid responsiveness in patients undergoing neurosurgery in the sitting position under 6 ml/kg (PBW)

Secondary Outcome Measures

Name	Time	Method
To assess the reliability of pulse pressure variation (PPV) & stroke volume variation (SVV) at 6 ml/kg & 8 ml/kg.	Starting point - At the point when sitting postion of the patint is achieved with hemodynamic stability.

Trial Locations

Locations (1): AIIMS, New Delhi
🇮🇳
South, DELHI, India
AIIMS, New Delhi
🇮🇳South, DELHI, India
Dr Niraj Kumar
Principal investigator
9013770806
drnirajaiims@gmail.com