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Norepinephrine Infusion During Cardiopulmonary Bypass

Not Applicable
Completed
Conditions
Cardiac Surgery
Cardiopulmonary Bypass
Interventions
Drug: Placebo
Other: Increase infusion rate
Other: Decrease infusion rate
Registration Number
NCT04312971
Lead Sponsor
Imam Abdulrahman Bin Faisal University
Brief Summary

The primary objective is to test the efficacy and safety of the accuracy of continuous intravenous infusion of norepinephrine during cardiopulmonary bypass (CPB) on the prevention of hyperlactatemia after cardiac surgery.

"Efficacy" would be tested with measurement of the postoperative changes in lactic acid level over time from the baseline value before induction of general anesthesia.

"safety" would be tested with observing the post-cardiotomy need for inotropic and vasopressor support, the incidence of postoperative acute kidney injury (AKI), changes in cardiac troponin level (CnTnI), and signs of ischemic splanchnic injury.

Detailed Description

Rationale

1.1. Vasoplegia and cardiac surgery:

Vasoplegia Syndrome (VS), prevailing in about 20% of cardiac surgical procedures (1), is defined as low mean arterial pressure (MAP) with normal or high cardiac indices and which is resistant to treatment with the commonly used vasopressors. (2,3) Vasoplegia might occur either during or after the cardiopulmonary bypass periods or during the postoperative period during the intensive care unit (ICU) stay. (3) Many factors have been found to be related to the increased Vasoplegia during the cardiopulmonary bypass period such as left ventricular ejection fraction more than 40%, male patients, elderly patients, higher body mass index, long cardiopulmonary bypass time, hypotension upon the start of cardiopulmonary bypass, perioperative use of angiotensin-converting enzyme inhibitors (ACE) and presence of infective endocarditis. (4,5)

1.2. Effects of Cardiopulmonary bypass (CPB) on Post cardiotomy Vasoplegia.

Cardiopulmonary bypass itself may intensify the effects of vasoplegia due to hemodilution which decreases the blood viscosity, so, reducing the overall peripheral vascular resistance. Moreover, the interaction of blood with the tubing of the cardiopulmonary bypass machine results in the release of inflammatory mediators which play an important role in reducing the peripheral resistance and aggravating the hypotension. Although compensatory and auto-regulatory mechanisms play an important role in maintaining adequate tissue perfusion, hypotension during the cardiopulmonary bypass period may result in poor outcomes as postoperative stroke (4) especially if the mean arterial pressure is below 65 mmHg. (6)

1.3. Hyperlactatemia after cardiac surgery

Lactate was used as a marker for adequate tissue perfusion since the mid-1800s. Although the literature has illustrated the undesirable effects of high lactate levels, however, the cause, the prevention as well as treatment measures of hyperlactatemia remain obscure. Additionally, lactic acidosis or hyperlactatemia might occur in cases of refractory vasoplegia. A rise in lactate levels is common during cardiac surgery and is well known for its deleterious and its association with poor patients' outcomes. (7)

Owing to its detrimental effects, measures to reduce the effects and treat vasoplegia were used. Firstly, excluding any equipment or mechanical failure such as the arterial line monitor, adjusting the bypass flows for higher cardiac index (CI\>2.2), confirming the proper cannula position and ruling out any aortic dissection.

Secondly, adjusting some physiological parameters is of great value as checking hematocrit level for excessive hemodilution, adjusting the anesthetics with severe vasodilatory properties, excluding the possibility of a drug reaction or anaphylaxis and temperature management during hypothermic bypass.

Thirdly, the use of conventional vasopressor agents as phenylephrine, norepinephrine, and vasopressin. Finally, the use of some off-label agents as vitamin C, hydroxocobalamin, angiotensin 2, methylene blue and prostaglandin inhibitors. (8)

1.4. Why this clinical trial?

The use of norepinephrine during CPB has its own potential benefits. It is not clear if the use of continuous norepinephrine infusion during CPB would be effective and safe in lessening the postoperative hyperlactatemia and development of vasoplegia after cardiac surgery.

The here proposed randomized controlled clinical trial will test the use of continuous norepinephrine infusion during CPB with respect to the efficacy and safety to reduce the postoperative rise in blood lactate level.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
80
Inclusion Criteria
  • American Society of Anesthesiologists (ASA) physical status between ІІІ and ІV
  • Scheduled for any type of elective cardiac surgery using CPB
  • General anesthesia provided in an endotracheally intubated patient.
Exclusion Criteria
  • Decline consent to participate.
  • Emergency surgery.
  • Ejection fraction (EF%) less than 35%.
  • Scheduled for re-do surgery.
  • Scheduled for emergency surgery.
  • Preoperative ventilator or circulatory support.
  • Body mass index (BMI) greater than 40 Kg/m2.
  • History of alcohol abuse.
  • History of drug abuse.
  • Pregnancy.
  • Consent for another interventional study during anaesthesia
  • No written informed consent.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
PlaceboPlaceboInfusion of normal Saline 0.9%will be started following arterial cannulation before initiation of cardiopulmonary bypass and continued until aortic declamping time.
PlaceboIncrease infusion rateInfusion of normal Saline 0.9%will be started following arterial cannulation before initiation of cardiopulmonary bypass and continued until aortic declamping time.
PlaceboDecrease infusion rateInfusion of normal Saline 0.9%will be started following arterial cannulation before initiation of cardiopulmonary bypass and continued until aortic declamping time.
NorepinephrineIncrease infusion rateInfusion of norepinephrine (40 µg/ml) will be started following arterial cannulation before initiation of cardiopulmonary bypass and continued until aortic declamping time.
NorepinephrineDecrease infusion rateInfusion of norepinephrine (40 µg/ml) will be started following arterial cannulation before initiation of cardiopulmonary bypass and continued until aortic declamping time.
NorepinephrineNorepinephrineInfusion of norepinephrine (40 µg/ml) will be started following arterial cannulation before initiation of cardiopulmonary bypass and continued until aortic declamping time.
Primary Outcome Measures
NameTimeMethod
Changes in lactic acid levelFor 24 hours after surgery from the start of surgery

perioperative changes in lactic acid level measured from arterial or venous blood

Secondary Outcome Measures
NameTimeMethod
Postoperative pneumoniaFor 30 days after surgery

Postoperative pneumonia for the first 30 days following surgery

Postoperative hypoxemiaFor 30 days after surgery

Postoperative decrease in peripheral oxygen saturation less than 90 for the first 30 days following surgery

Postoperative sternotomyFor 30 days after surgery

Postoperatively during hospital stay

Postoperative wound infectionFor 30 days after surgery

Postoperative wound infection for the first 30 days following surgery

Postoperative mediastinitisFor 30 days after surgery

Postoperative mediastinitis for the first 30 days following surgery

Postoperative strokeFor 30 days after surgery

Postoperative stroke for the first 30 days following surgery

Need for rescue doses of esmololFor the time of surgery

Use of rescue doses of esmolol

Need for rescue doses of atropineFor the time of surgery

Use of rescue doses of atropine

Need for rescue doses of glycopyrrolate.For the time of surgery

Use of rescue doses of glycopyrrolate

Intraoperative hypoxemiaFor the time of surgery

Decrease of peripheral oxygen saturation less than 92%

Number of patients who required pacemaker insertionFor the time of surgery

Need for pacemaker insertion following termination of cardiopulmonary bypass.

Mean Arterial Pressure (MAP)For 24 hours after surgery from the start of surgery

invasive arterial blood pressure measurement

Cardiac Index (CI)For 24 hours after surgery from the start of surgery

measured as l/min/m2

Systemic Vascular Resistance index (SVRI)For 24 hours after surgery from the start of surgery

measured as dynes.sec.m2/cm5

Stroke volume variation (SVV)For 24 hours after surgery from the start of surgery

measured as ml/min/m2

Need for rescue doses of phenylephrineFor the time of surgery

Use of rescue doses of phenylephrine

Need for rescue doses of norepinephrineFor the time of surgery

Use of rescue doses of norepinephrine

Need for rescue doses of ephedrineFor the time of surgery

Use of rescue doses of ephedrine

Need for rescue doses of nitroglycerineFor the time of surgery

Use of rescue doses of nitroglycerine

Need for rescue doses of labetalolFor the time of surgery

Use of rescue doses of labetalol

Mortality at 90 daysFor 90 days after surgery

Alive or dead on postoperative day 90

Postoperative need for reintubationFor 30 days after surgery

Postoperative need for reintubation during the first 30 days following surgery

Postoperative bleedingFor 30 days after surgery

Postoperative bleeding during the first 30 days following surgery

Postoperative cardiogenic shockFor 30 days after surgery

Postoperative cariogenic shock for the first 30 days following surgery

Postoperative acute kidney injuryFor 30 days after surgery

Postoperative acute kidney injury for the first 30 days following surgery

Postoperative splanchnic ischemiaFor 30 days after surgery

Postoperative mesenteric or splanchnic ischemia for the first 30 days following surgery

Postoperative myocardial ischemiaFor 30 days after surgery

Postoperative acute coronary syndrome for the first 30 days following surgery

Postoperative sternal dehiscenceFor 30 days after surgery

Postoperatively during hospital stay

Intraoperative hypercapniaFor the time of surgery

Increase in end tidal carbon dioxide more than 45 mm Hg

Intraoperative hypotensionFor the time of surgery

Number of drops in systolic arterial pressure \< 90 mmHg for 3 minutes or longer for any reasons

Intraoperative bradycardiaFor the time of surgery

Number of drops in heart rate lower than 40 beats.min-1 or 10% of baseline value for more than three minutes for any reasons.

Intraoperative myocardial ischemic episodesFor the time of surgery

Remarkable ischemic changes included those patients with ≥ 1- mv ST-segment depression or ≥ 2-mv ST-segment elevation lasting more than 1 minute

Number of patients who required direct current shocksFor the time of surgery

Need for direct current shock following termination of cardiopulmonary bypass..

Hospital StayFor 30 days after surgery

Length of hospital stay

Mortality at 30 daysFor 30 days after surgery

Alive or dead on postoperative day 30

Number of patients who need for epinephrineFor the time of surgery

Need for epinephrine following termination of cardiopulmonary bypass.

Number of patients who need for norepinephrineFor the time of surgery

Need for norepinephrine following termination of cardiopulmonary bypass.

Number of patients who need for dobutamineFor the time of surgery

Need for dobutamine following termination of cardiopulmonary bypass.

Number of patients who need for milrinoneFor the time of surgery

Need for milrinone following termination of cardiopulmonary bypass.

Number of patients who need for for Intra-Aortic Balloon PumpFor the time of surgery

Need for intra-aortic balloon counter pulsation pump following termination of cardiopulmonary bypass.

Intraoperative need for blood transfusionFor the time of surgery

The amount of transfused units of blood and blood products

Intraoperative fluid intakeFor the time of surgery

The amount of infused crystalloids and colloids

ICU StayFor 30 days after surgery

Length of ICU stay

Trial Locations

Locations (2)

Imam Abdulrahamn Bin Faisal University (Former, Dammam University)

🇸🇦

Dammam, Esatern, Saudi Arabia

Dammam University

🇸🇦

Khobar, Eastern, Saudi Arabia

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