A recent paper article reported that regional anesthesia has an advantage in clinical outcomes compared to general anesthesia in older patients undergoing hip surgery. However, spinal ansthesia-induced hypotension often occurs in the elderly. Especially, if propofol is administered intravenously for sedation during surgery, the incidence of hypotension could be higher. Perioperative hypotension is associated with imbalance in oxygen demand and supply, causing postoperative cardiac infarction or acute kidney damage. Since elderly patients, in particular, often have multiple comorbidities, these postoperative complications might induce fatal consequences, prevention of perioperative hypotension is critical to improve the patient's prognosis.

In the past, phenylephrine has been commonly used in the management of spinal anesthesia-induced hypotension. However, there have been arguments that using norepinephrine is more effective and safer than using phenylephrine in patients undergoing C-section under spinal anesthesia. Because phenylephrine, the peripheral vasoconstrictor, could cause the bradycardia and reduce cardiac output, it is thought that the use of norepinephrine in the management of hypotension could be an alternative in the elderly whose cardiovascular function is relatively weak. Therefore, we aimed to evaluate whether norepinephrine could effectively prevent hypotension in older patients scheduled to undergo hip surgery under spinal anesthesia with sedation using propofol.

-This study includes 70 patients who signed consent forms among those undergoing hip surgery under spinal anesthesia with sedation using propofol at a tertiary center (Asan Medical Center). The participants are randomly decided into two groups; control group vs norepinephrine group (35 participants in each group).
- Standard monitoring should be done when the participant arrives in the operating room. Oxygen is supplied using a facial mask to all patients and spinal anesthesia with 10mg of heavy marcaine and 15mcg of fentanyl is performed. At this point, the continuous infusion of drugs(normal saline or norepinephrine) begins according to the assigned group. After 5 minutes, assessment of anesthetic level is performed. Then, start the target controlled infusion of the propofol. Pleth variability index is monitored to evaluate the volume status of participants and normovolema is maintained based on pleth variability index during the surgery. Infusion of propofol and study drug is stopped when the surgery is finished.

Prevention

Group C: normal saline-0.15cc/kg/hr, intravenously continuous infusion, from the time point that the participants take the supine position after the intrathecal injection of local anesthetics to the end of surgery
Group N: norepinephrine-0.15cc/kg/hr (0.05mcg/kg/min),  intravenously continuous infusion, from the time point that the participants take the supine position after the intrathecal injection of local anesthetics to the end of surgery

There is no difference in anesthetic management in each group except the drug intravenously administered; normal saline vs norepinephrine.

Arm Label

Target Number of Participant

Arm Type

Arm Description

Group C: normal saline-0.15cc/kg/hr, intravenously continuous infusion, from the time point that the participants take the supine position after the intrathecal injection of local anesthetics to the end of surgery

Arm Label

Target Number of Participant

Arm Type

Arm Description

Group N: norepinephrine-0.15cc/kg/hr (0.05mcg/kg/min),  intravenously continuous infusion, from the time point that the participants take the supine position after the intrathecal injection of local anesthetics to the end of surgery

Gender

Age

Description

* American Society of Anesthesiologists Physical Status 1-3
* age: equal to or older than 70 years
* patients scheduled to undergo a hip surgery under spinal anesthesia with propofol sedation

* patients who don't agree to participate in this study
* patients with uncontrolled hypertension, hyperthyroidism, dementia, symptomatic coronary artery disease, or hemoglobin <10g/dL
* patients with allergy to propofol, fentanyl, or bupivacaine
* patients who are cont coagulopathy, severe aortic stenosis/mitral stenosis, active infection on lumbar region
* patients who are judged to be inappropriate for this study by authors

number of hypotensive episodes

intraoperative period

number of hypertensive episodes

intraoperative period

total amount of phenylephrine administered

intraoperative period

total amount of administered fluid

intraoperative

number of hypotensive episodes

during recovery period at post-anesthetic care unit

complications

postoperative period