Clinical Research Directory

Carotid Artery Corrected Flow Time and Respiratory Variation of Blood Flow Peak Velocity for Prediction of Hypotension After Induction of General Anaesthesia in Adult Patients With Chronic Liver Disease

Baseline Measurements For the ultrasound parameters, it is the average of three readings In supine position . The investigators will continuously monitoring during induction and 10 minutes after. Hemodynamic Monitoring: * Heart rate from ECG * SpO2 * Etco2 * Blood pressure . invasive Blood pressure * The radial artery level is the site of continuous arterial pressure monitoring with an arterial catheter. * Ultrasound Measurements: The patient will be positioned in a supine position, with the right side of the neck completely exposed. The transverse part Of the main carotid artery beneath the thyroid cartilage will be precisely identified using ultrasound device (sonosite edge portablp.fojy usa)via a linear array probe (4-15 MHz), with the marker directed toward the patient's head. Thus, the sampling line will be positioned at the center of the carotid lumen, around 2 cm from the carotid bifurcation, and the electronic angle correction cursor will be pointed in the direction of blood flow. Insonation angles between the ultrasound beam and blood flow will be maintained at or \< 60°. Next, the carotid blood flow waveform will be acquired, and the consecutive stable carotid pulse Doppler flow spectrum will be determined with an optimal level of image quality. The Correction: To get the corrected carotid flow time (ccFT), the measured FT will be adjusted for the patient's heart rate (HR). A commonly used formula is Wodey's formula. A single, experienced sonographer will perform all measurements, and a subset of measurements will be reviewed by a second blinded observer to assess inter-rater reliability." Peak Velocity: Measure the peak systolic blood flow velocity at the same location. Respiratory Variation (ΔVpeak): Calculate the difference between the maximum and minimum peak velocities during a single respiratory cycle: \\Delta V\_{peak} = (V\_{peak(max)} - V\_{peak(min)}) / ((V\_{peak(max)} + V\_{peak(min)})/2) \\times 100\\%. The patient should be asked to breathe normally during this measurement. Flow time (FT), which is known as the time period between the systolic increase phase and dicrotic notch, was calculated and then adjusted for heart rate (HR) via equations outlined below. Wodey's (W) equation∶ FTc(W) = FT + 1.29 ∗ (HR - 60) Anasthesia: Patients will have routine fasting for at least 6 to 8 h and will not allowed to drink any solution or fluid 2 to 4 h prior to surgery. No premedication will be given A standardized induction protocol will be used. At the operating theatre, a three-lead electrocardiogram (ECG), pulse oximetry (SpO2), and noninvasive arterial pressure monitoring will be applied. After pre-oxygenation for 5 min anesthesia induction of propofol 1\_2mg , fentanyl 1 ug/kg, and 0.15 mg/kg cisatracurium . After 3 min of mask ventilation, direct laryngoscopy will be employed for tracheal intubation. . Respiratory setting of anesthesia machine (Aestiva, GE/Datex-Ohmeda) will be set as follows: volume-controlled ventilation (VCV), inspiratory-expiratory (I:E) ratio of 1:2, respiratory rate of 8-10 bpm, tidal volume of 8 mL/kg of ideal weight \[45.5 + 0.91x (height in cm-152.4)\], and PEEP of 5 cm H2O in 50% oxygen with air. Respiratory settings will be adjusted to maintain the PETCO2 at less than 50 mmHg. Anesthesia will be maintained with sevoflurane (1.5-2.5%) and intermittent injection of cisatracurium 0.02mg/kg as needed to keep the entropy scale between 40 and 60 and for muscle relaxation. The mean arterial pressure was kept between 60 and 80 mmHg. Hemodynamic Data Collection: Invasive mean arterial pressure (MAP) will be continuously recorded for 5-10 minutes post-induction. Hypotension Definition: Hypotension will be defined as a decrease in MAP by \>20% from the baseline value or an absolute MAP of \<65 mmHg for more than one minute.This definition is clinically relevant and widely used in the anesthesia literature. Postinduction hypotension will be treated with 250 ml saline iv boluse repeated if successfully restore blood pressure. If refractory to fluid we will inject intravenous ephedrine in 3 mg bolus doses and repeated when necessary. Significant bradycardia (heart rate \< 40 beats/min) will be treated with intravenous boluses of atropine (0.5 mg). Study duration 3 months or end of recruitment of sample

PPV for Predicting PIH in the Elderly

The purpose of this observational study is to investigate the predictive power of pulse pressure variability during forced inhalation（PPVfi） on the occurrence of hypotension in elderly patients after induction of general anesthesia. The main question it aims to answer is: Can the PPVfi predict the occurrence of hypotension in elderly patients after induction of general anesthesia? By recording the PPV of patients during forced inhalation before anesthesia induction, with the incidence of hypotension as the state variable and PPV as the test variable, the area under the ROC curve was calculated to determine the optimal threshold, sensitivity, and specificity of PPV.

The Role of Left Ventricular Outflow Tract (LVOT) Velocity-time Integral (VTI) and Respiratory Variability at Peak Rate (Vpeak) in Predicting Hypotension After General Anesthesia Induction

Preoperatively, patients will undergo transthoracic echocardiography measurements approximately 15-30 minutes before induction. TTE will be performed on all patients by an experienced observer; the echocardiography device will be equipped with an S4-2 transducer (4-2 MHz frequency range) in the left lateral decubitus position. VTI and Vpeak values of the LVOT were measured from manually drawn contours using pulsatile wave Doppler technique in the apical five-chamber view. The Doppler beam was aligned with the aortic blood flow, and the signal was captured at an appropriate angle (\<20°). The maximum (VTImax) and minimum (VTImin) VTI, as well as the maximum (Vpeakmax) and minimum (Vpeakmin) Vpeak values, were determined over three respiratory cycles. ΔVTI was calculated with the following formula: ΔVTI = \[2 × (VTImax - VTImin) / (VTImax + VTImin)\] × 100%. ΔVpeak was calculated with the following formula: ΔVpeak = \[2 × (Vpeakmax - Vpeakmin) / (Vpeakmax + Vpeakmin)\] × 100%. These parameters were analyzed to evaluate the hemodynamic status of patients and estimate fluid responsiveness. Patients with a 30% decrease from baseline in SBP and a decrease in MAP below 60 mmHg in the first 10 minutes after anesthesia induction were considered to have hypotension. Patients were divided into two groups: "with" and "without" hypotension.

Carotid Artery Corrected Flow Time and Inferior Vena Cava Collapsibility Index for Prediction of Hypotension After Induction of General Anesthesia in Geriatric Patients Undergoing Elective Surgery

In this observational study, we will assess cFT by Carotid ultrasound and IVC collapsibility index for prediction of hypotension after induction of general anesthesia in geriatric patients undergoing elective surgery.

The Impact of Ultrasound-Guided Superficial and Deep Paravertebral Nerve Blocks at the Superior Costotransverse Ligament on Hemodynamics During the Induction Phase of Thoracoscopic Lung Lobectomy: A Multicenter, Double-Blind, Randomized Controlled Trial

This study aims to determine whether performing a paravertebral nerve block at the superficial surface of the superior costotransverse ligament (SCTL) (without needle penetration of the SCTL) is more effective in maintaining hemodynamic stability during the induction phase of thoracoscopic lung lobectomy compared to the deep surface of the SCTL (with needle penetration of the SCTL). This is a multicenter, double-blind, randomized controlled trial enrolling a total of 168 participants across five hospitals. To investigate the effects of different nerve block methods on hemodynamics during induction, participants will be allocated to either the deep plane SCTL block group (T group) or the superficial plane SCTL block group (S group) using a stratified randomization scheme. The stratification accounts for a 40% proportion of hypertensive patients within each treatment group at each center. Thirty minutes before surgery, patients will receive either an ultrasound-guided deep SCTL block (needle penetrating the SCTL) or a superficial SCTL block (needle not penetrating the SCTL) in the pre-anesthesia room. The target vertebral levels for the block are T4 and T6, and 20 mL of 0.375% ropivacaine hydrochloride solution will be injected slowly at each site. Researchers will document whether subpleural compression is observed on ultrasound imaging and monitor for complications such as hemothorax, pneumothorax, local hematoma, local anesthetic toxicity, epidural anesthesia, or total spinal anesthesia during the procedure. Another investigator, blinded to the group allocation, will evaluate patients after the nerve block procedure, recording any occurrences of hemothorax, pneumothorax, local hematoma, local anesthetic toxicity, epidural block, or total spinal anesthesia. Cold sensitivity tests using the temperature method will be conducted at the midaxillary line within the corresponding blocked regions at 5, 10, 20, and 30 minutes post-block, and the sensory blockade level will be recorded. Thirty minutes after the block, anesthesia induction will be performed using target-controlled infusion (TCI) of propofol and remifentanil, along with rocuronium (0.6 mg/kg). Heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), cardiac index (CI), and stroke volume index (SVI) will be measured every minute from induction until 5 minutes after intubation. Hypotension is defined as a MAP decrease of 20% or an absolute MAP \< 65 mmHg, while severe hypotension is defined as a MAP decrease of 30% or an absolute MAP \< 55 mmHg. Hemodynamic stability will be maintained using vasoactive medications as needed. The study will record intraoperative consumption of propofol and remifentanil, anesthesia duration, intraoperative intravenous fluid volume, urine output, blood loss, and extubation time. Postoperative assessments will include resting and movement-evoked (coughing) VAS scores at 4 and 24 hours, opioid consumption within 24 hours (oxycodone usage, first demand time, number of effective and actual demands), and additional analgesic requirements. The QOR-15 score at 24 hours and puncture-related complications within 72 hours postoperatively will be documented, along with a patient satisfaction survey at 72 hours. For the imaging study evaluating drug diffusion following each block method using CT (3D) imaging, 40 patients will be recruited at Nanjing First Hospital. Patients requiring preoperative CT-guided localization and puncture will receive an ultrasound-guided deep SCTL block (T group) or superficial SCTL block (S group) 30 minutes before the procedure, with 10 patients in each group. The block sites will be at the surgical side T4 and T6 levels, using 20 mL of a nerve block solution containing 0.375% ropivacaine mixed with 2 mL of iohexol (total 20 mL). Following the nerve block, patients will be placed in the supine position, and after 30 minutes, a blinded investigator will assess sensory loss using cold stimulation at the anterior chest wall (midclavicular line), lateral chest wall (posterior axillary line), and posterior chest wall (paravertebral region). Subsequently, patients will undergo routine CT-guided lesion localization and 3D imaging technology will be used to evaluate drug diffusion patterns for the two block techniques. Any adverse events occurring during the trial will be managed according to the study protocol and recorded accordingly.

Pressure Recording Analytical Method Parameters and Their Relationship With Hypotension in Hypertensive Patients

Perioperative anesthesiologists can benefit from easily obtainable hemodynamic variables detecting or quantifying the lack of an adequate compensatory capacity of the cardiovascular system in order to optimize patient management and improve patient outcomes. Parameters of the Pressure Recording Analytical Method (PRAM; Vygon, Padua, Italy) of the MostCare system, specifically cardiac cycle efficiency has been proposed as such variables. Yet, their value in anesthesia and especially in hypertensive patients is not studied. The goal of the PRAM-in-HYPO study is to prospectively evaluate the relationship between cardiac reserve and efficiency and cardiovascular risk factors in patients wo will undergo major surgical procedures using the state-of-the-art hemodynamic monitors. Also the investigators aim to build a predictive model to identify patients with decreased cardiac reserve due to hypertension and other cardiovascular risk factors, who are susceptible to post-induction hypotension. The investigators seek to include high-risk patients or patients presenting for major surgery, who are monitored with an advanced hemodynamic monitor to adequately evaluate the differences in cardiac reserve and cardiac efficiency.

Evaluation of Post-Induction Hypotension Treatment with PRAM Method

The goal of this observational study is to compare post-induction hypotension treatments with PRAM method in Gynecologic Oncological Cases. The goal of this observational study is to compare post-induction hypotension treatments with PRAM method in Gynecologic Oncological Cases.

Predictive Hemodynamic Monitoring During Elective Cesarean Section

Single shot spinal anesthesia (SA) is the most commonly used technique for Caesarean section (CS) . SA is associated with maternal hypotension (Post Spinal Hypotension - PSH) often accompanied by nausea, vomiting, bradycardia and fetal acidosis. Preventive administration of vasopressors is widely used to counterbalance hypotension. Routine prophylactic infusion of phenilephrine and norepinephrine raises concerns for unnecessary treatment, reactive hypertension, baroreceptor-mediated bradycardia, and effects on fetal acidosis. Non-invasive continuous measurement of arterial pressure using a finger cuff is well established. Hypotension Prediction Index - HPI is an algorithm that could predict the onset of hypotension in working on invasive and non-invasive arterial waveform signal. The aim of this prospective randomized study is to compare the amount of PSH during elective caesarean section among two groups of patients receiving standard intermittent hemodynamic monitoring versus continuous ClearSight-HPI monitoring. The primary hypothesis is that hemodynamic management HPI-guided reduces the incidence, entity and duration of post-spinal hypotension, defined as mean arterial pressure (MAP) lower than 65 mmHg lasting more than one minute. Our secondary aim was to study the impact of maternal PSH during CS on foetal outcome evaluated by comparing neonatal Apgar scores at 1 and 5 minutes after birth, and umbilical cord arterial and venous pH in the two groups.

Effect of Timing of Dexamethasone During Induction on Postoperative Outcomes

This study aims to investigate how the timing of dexamethasone administration during anesthesia induction affects patient outcomes after surgery. Dexamethasone is commonly used to reduce nausea and inflammation during and after surgery. However, it is not yet known if administering dexamethasone at different times during induction (before, during, or after specific anesthetic drugs) leads to better recovery and fewer postoperative complications. Participants will be randomly assigned to one of three groups: one group will receive dexamethasone before fentanyl, another after the muscle relaxant, and a third group will not receive dexamethasone. This approach will help us understand if the timing of dexamethasone affects patient outcomes such as nausea, pain, and recovery quality. The study is triple-blinded, meaning that the participants, care providers, and investigators will not know which group the participants are in, to ensure unbiased results.