This study aims to evaluate whether the reduction in the amount of intraoperative norepinephrine required to prevent hypotension, facilitated by processed electroencephalography (pEEG) -guided general anesthesia, will lead to a decrease in postoperative complications, particularly acute kidney injury (AKI).
In major abdominal surgery, intraoperative hypotension (IOH) remains a prevalent concern, contributing significantly to postoperative complications. These complications include acute kidney injury (AKI), myocardial injury, and even mortality. While IOH is multifactorial, its occurrence is frequently associated with the need for vasopressor support, particularly norepinephrine, which is widely used to manage and prevent IOH. However, it is important to note that vasopressors, including norepinephrine, are themselves implicated in promoting AKI . The lack of consensus on a universal definition for IOH adds complexity to this issue. Currently, it remains unclear whether IOH should be defined based on absolute blood pressure thresholds or as a relative decrease from baseline. IOH is commonly defined as a systolic blood pressure of \<90 mm Hg or a mean arterial pressure (MAP) of \<65 mm Hg. Ephedrine is often the first-line vasopressor administered to treat IOH, with norepinephrine as a second-line option. The hemodynamic effects of these two agents differ: norepinephrine increases cardiac preload without significantly increasing afterload, thereby raising cardiac output. Ephedrine, however, increases cardiac output but with a greater increase in afterload, often leading to tachycardia, which can be detrimental to patients. The variable effectiveness of ephedrine and its associated side effects have led clinicians to consider norepinephrine as a more appropriate option for managing IOH, potentially with fewer cardiovascular side effects. Additionally, crystalloid fluid overload during abdominal surgery has been linked to poor postoperative outcomes, including anastomotic instability. Liberal fluid regimes may disrupt the physiological healing processes at surgical sites, suggesting that fluid management strategies aimed at minimizing overload could improve patient outcomes. Recent studies propose that early norepinephrine administration to maintain MAP, even before the onset of hypotension, may help reduce the need for large fluid volumes. One important factor contributing to IOH and vasopressor use is excessively deep general anesthesia. Processed electroencephalography (pEEG) can guide the optimization of anesthesia depth, potentially preventing overly deep anesthesia and, in turn, reducing the incidence of IOH and the need for vasopressor .
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
162
Processed electroencephalography (pEEG) can guide the optimization of anesthesia depth, potentially preventing overly deep anesthesia and, in turn, reducing the incidence of IOH and the need for vasopressors . Depth of anesthesia will be managed based on pEEG monitoring using Entropy with a target range of 40-60.
Depth of anesthesia will be managed based on clinical judgment, informed by clinical perception and vital signs.
Assiut University Hospitals
Asyut, Egypt
RECRUITINGIncidence of postoperative acute kidney injury (AKI) based on the KDIGO criteria.
Diagnosis and severity of PO-AKI will be assessed by serum-creatinine and/or urine output according to the KDIGO criteria . The latest serum creatinine before surgery will be defined as baseline value. Serum creatinine will be measured at least once a day for the first 3 days. Patients with serum creatinine increases of ≥0.3 mg/dl within 48 h or 1.5-1.9 times increases within 72 h after surgery will be diagnosed KDIGO stage 1, patients with serum creatinine increases of 2-2.9 times within 72 h will be diagnosed KDIGO stage 2, and patients with serum creatinine increases of ≥3 times or ≥4 mg/dl or with the need of renal replacement therapy (RRT) will be diagnosed KDIGO stage 3. Further, patients with a urine out- put \<0.5 ml/kg/h for ≥6 h will be diagnosed KDIGO stage 1, urine output \<0.5 ml/kg/h for ≥12 h KDIGO stage 2, and \<0.3 ml/kg/h for ≥24 h or anuria for ≥12 h KDIGO stage 3. Once the urine catheter removed, the urine output criterion will no longer be considered.
Time frame: Assessed at the third postoperative day.
1.Total dose of norepinephrine administrated
The total cumulative dose of norepinephrine administered intraoperatively and postoperatively will be recorded in micrograms.
Time frame: 48 hour
2.The volume of intraoperative fluid therapy.
The volume of crystalloids, colloids, and blood products administered intraoperatively will be recorded in (milliliters).
Time frame: 48 hour
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.