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
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 100
- 主要终点
- lvot-vtı
研究概览
简要总结
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.
详细描述
The study is planned to be conducted for one year after receiving approval from the non-invasive clinical research ethics committee. Documentation of eligibility and consent will be confirmed at the preoperative visit. During this visit, patients will provide demographic and past medical information, including medication use.
Preoperative transthoracic echocardiography measurements will be performed on all patients 15-30 minutes before induction. TTE will be performed by an experienced observer; the echocardiography device is equipped with an S4-2 transducer (4-2 MHz frequency range) in the left lateral decubitus position. LV Ejection Fraction (EF) measurements will be evaluated in the parasternal long-axis view. ΔVTI and ΔVpeak, and LVOT will be recorded.
Patients will be positioned supine, and the Inferior Vena Cava (IVC) will be imaged through the subxiphoid window. The cursor will be placed 1 cm distal to the hepatic vein IVC entry point, and the IVC diameter will be monitored in M-Mode for 30 seconds. The measurement will be taken at the site where the inferior vena cava diameter is measured during inspiration (IVCins) and expiration (IVCexp) while the patient is breathing normally. Inferior Vena Cava Collapse Ratio (IVC-CI) will be calculated using the formula IVC-CI = (IVCexp - IVCins) / IVCexp.
Intraoperative The patient will be administered the clinic's routine anesthesia protocol. Anesthesia will not be interfered with.
Our clinic's routine anesthesia protocol includes: fentanyl 1μg/kg IV, propofol 1.5 to 2.5 mg/kg IV, lidocaine 1 mg/kg IV, and rocuronium 0.6 mg/kg IV. Sevoflurane 2% is initiated after intubation. Perioperative mean blood pressure will be targeted above 65 mmHg. Hypotension below 65 mmHg MAP will be recorded intraoperatively and postoperatively.
研究设计
- 研究类型
- Observational
- 观察模型
- Other
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18-75 years
- •ASA Physical Status 1-3;
- •Patients scheduled for general anesthesia
排除标准
- •Patient is pregnant
- •Post-cardiac surgery
- •Severe pulmonary hypertension
- •Severe valvular disease
- •Hypertrophic or dilated cardiomyopathy
- •Presence of acute myocardial infarction
- •Patients with severe visual or hearing impairment/impairment
- •ASA physical status IV or V
- •Ischemic heart disease, conduction disturbance
- •History of long-term use of certain medications (β-blockers, angiotensin-converting enzyme inhibitors, analgesics, sedatives, or tricyclic antidepressants)
研究组 & 干预措施
with hypotension
Patients with a 30% decrease in SBP from baseline and a decrease in MAP below 65 mmHg in the first 10 minutes after anesthesia induction will be considered to have hypotension.
干预措施: Inotrope (Drug)
结局指标
主要结局
lvot-vtı
时间窗: 1 hour
The relationship between hypotension following induction of general anesthesia and respiratory variability in left ventricular outflow tract VTI peak velocity (Vpeak variability).
次要结局
- lv echo(1 hour)
研究者
ferdi gülaştı
asst. prof.dr
Aydin Adnan Menderes University