Continuous Versus Bolus Administration of Norepinephrine to Treat Hypotension During Anesthetic Induction (INDUCT)

Continuous Versus Bolus Administration of Norepinephrine to Treat Hypotension During Anesthetic Induction

Continuous Versus Bolus Administration of Norepinephrine to Treat Hypotension During Anesthetic Induction - the INDUCT Randomized Trial

Intraoperative hypotension is common in patients having non-cardiac surgery with general anesthesia and is associated with organ injury and death. The timely treatment of intraoperative hypotension is thus important to avoid postoperative complications. About one third of intraoperative hypotension occurs during anesthetic induction - i.e., between the start of anesthetic induction and surgical incision. Hypotension during anesthetic induction is associated with postoperative acute kidney injury. Unmodifiable risk factors for hypotension during anesthetic induction include age, male sex, and a high American Society of Anesthesiologists physical status class. However, hypotension during anesthetic induction is mainly driven by modifiable factors - specifically, anesthetic drugs that cause vasodilation. In most German hospitals, norepinephrine is the first-line vasopressor to treat hypotension during anesthetic induction. Norepinephrine is usually given as repeated manual boluses of 5, 10, or 20 μg. The continuous administration of norepinephrine via a perfusion pump is usually started only later. It remains unknown whether giving norepinephrine continuously - compared to giving it as repeated manual boluses - reduces hypotension during anesthetic induction. We thus propose to investigate whether giving norepinephrine continuously - compared to giving it as repeated manual boluses - reduces hypotension during anesthetic induction in non-cardiac surgery patients.

In patients randomized to continuous norepinephrine administration, hypotension (= mean arterial pressure < 65mmHg) will be treated with continuous norepinephrine infusion. The norepinephrine perfusion line will be connected to the saline infusion line using a three-way valve. Treating anesthesiologists will be free to reduce or increase the norepinephrine infusion rate anytime.

Absolute [n] and relative [%] number of patients with any MAP measurement >100, >110, >120 and >140 mmHg

Absolute [n] and relative [%] number of patients with any MAP measurement <65, <60, <50, and <40 mmHg

Absolute [n] and relative [%] number of patients with at least one 1-minute episode of a MAP <65, <60, <50, and <40 mmHg

Inclusion Criteria: non-cardiac surgery >45 years of age American Society of Anesthesiologists physical status classification II, III, and IV. Exclusion Criteria: Planned intraarterial blood pressure monitoring during anesthetic induction with an arterial catheter Emergency surgery Transplant surgery History of organ transplant Pregnancy Heart rhythms other than sinus rhythm Impossible Finger-cuff blood pressure monitoring Rapid sequence induction