Overview

Hypotension after induction of general anesthesia, or post-induction hypotension, is quite common in clinical practice, and if severe or prolonged, may cause organ hypo-perfusion and ischemia, and may increase the incidence of postoperative adverse outcomes such as myocardial injury, ischemic stroke, acute kidney injury, and even increase 1-year mortality (Gergory et al 2021).

Patients with chronic liver disease (CLD) are highly susceptible to hypotension following the induction of general anesthesia (GA). This is due to a combination of factors related to the disease's effects on the cardiovascular system, drug metabolism, and overall physiology.

Several key physiological changes in CLD patients contribute to their increased risk of post-induction hypotension ie, Vasodilation as Chronic liver disease, particularly cirrhosis, causes a systemic, peripheral vasodilation. This is a crucial hallmark of the condition. In a normal state, the body uses compensatory mechanisms to maintain blood pressure, but after induction of anesthesia, patients are at particular risk of hypotension due to preexisting hypovolemia, the cardiovascular depressant and vasodilatory effects of induction agents, and a lack of surgical stimulation (Checketts et al,2013) Doppler corrected flow time (FTc) refers to the left ventricular ejection time corrected by heart rate and is known to be proportional to left ventricular preload and cardiac inotropy and inversely proportional to systemic vascular resistance and It provides a real-time assessment of a patient's hemodynamic status.A shortened cFT value often indicates a state of hypovolemia (low blood volume) or reduced cardiac output, which are key contributing factors to hypotension. (singer et al .1991) Corrected carotid flow time (cFT) and respiratory variation of peak blood flow velocity in the common carotid artery (ΔVpeak) can be good predictors of fluid responsiveness in spontaneous breathing patients are a promising, non-invasive parameter used to predict hypotension, particularly in surgical settings. It is a valuable tool if used in conjunction with other clinical parameters and is part of a broader trend toward using point-of-care ultrasound (POCUS) to guide patient management and improve outcomes.(Appala et al.2023)(wang et al.2022) Recently several investigators Ie. Maitra et al. demonstrated that the carotid artery FTc is a good predictor of postinduction hypotension in ASA status I and II adult patients, but their study did not include high risk population like chronic liver disease patients. (Maitra et al.2023).

Aim and Importance of the Study. The primary aim of the study was to determine whether corrected carotid flow time can predict hypotension after induction of GA in patients with chronic liver disease.

Secondary Aim: To identify the optimal cutoff values for cFT and ΔVpeak that best predict PIH in this patient population.

Exploratory Aim: To assess if a combination of cFT, ΔVpeak, and other clinical variables (e.g., Child-Pugh score, baseline blood pressure) improves the predictive power for PIH.

determine The cutoff value in this category of patients And effect of fluid responsiveness

Research Methodology Ethics Statement After approval of Ain Shams medical ethical committee and anesthesia and ICU Department commmitte the study will enroll Patients AsA1:4 data collection will adhere to the tenets of the Declaration of Helsinki for research involving human subjects.

All participants will receive oral information about the purpose of the study. Informed Consent: Patients will be informed about the study procedures, risks, and benefits, and written informed consent will be obtained.

Patient Safety: A physician will always be present to manage any episodes of hypotension according to standard clinical protocols, regardless of the study measurements.

Data Confidentiality: All patient data will be de-identified and handled in a confidential manner.

Research Design A prospective, single-center, observational cohort study. Patients will be recruited and monitored before and after general anesthesia induction. Patients were categorized into two groups, PIH and Non-PIH, dependent upon the presence of hypotension during the study.

Population and Sample of the Research The sample size will be calculated using

Patient Demographics:

Collect age, sex, BMI, and relevant clinical history (e.g., CLD etiology, Child-Pugh and MELD scores) Detailed medication history, history of variceal bleeding, and presence of ascites or encephalopathy.".

ASA status Type of surgery Procedures MONITORING

Baseline Measurements

For the ultrasound parameters,it is the average of three readings In supine position .

We 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 was the site of continuous arterial pressure monitoring with

Eligibility

Inclusion Criteria:

• • Adult patients (≥ 18 years) with a confirmed diagnosis of CLD (e.g., cirrhosis, non-alcoholic steatohepatitis)
  • scheduled for elective surgery under general anesthesia.
  • ASA 2,3,4
  • ASA 4 patients will be included only if their baseline MAP is \>65 mmHg, as per the exclusion criteria

Exclusion Criteria:

• • Refusal to participate
  • Patients with known cardiac disease (e.g., severe valvular disease, congestive heart failure),
  • pre-existing severe hypotension (e.g., mean arterial pressure \<65 mmHg
  • emergency surgery
  • anatomical variations preventing adequate ultrasound visualization of the carotid artery.
  • Carotid artery stenosis.
  • Mean arterial pressure (MAP) \> 120 mmHg before anesthesia
  • any previous record of neck surgery or trauma.
  • acute renal injury.
  • oral angiotensin receptor blockers or angiotensin-converting enzyme inhibitors (ACEI)
  • lateral, prone, and lithotomy operations
  • body mass index (BMI) \> 30 kg/m2 or \< 15 kg/m2