International Journal of Anesthesiology & Pain Medicine

Description

The majority of patients undergoing cardiac surgery require Cardiopulmonary Bypass (CPB) for circulatory support. During CPB, it is very important to keep the acid-base homeostasis and normal electrolyte levels. Coagulation, osmolality, and electrolyte levels, as well as the central nervous system and renal system, are all influenced by a CPB circuit prime, which can have an impact on the outcome of cardiac surgery. However, the selection of a CPB prime is typically influenced by personal preferences and preconceived notions. A recent survey revealed worldwide differences in CPB techniques and priming, but the reasons for these differences and how they affect clinical outcome are still unknown. There are still no general recommendations for selecting CPB prime solutions or tailoring a CPB prime to a patient's specific characteristics and conditions.

CPB prime solutions typically consist of crystalloid fluids and mannitol, a natural alditol with six carbon atoms. Mannitol has the ability to influence a variety of organ systems, has an osmotic diuretic effect, and expands volume. Mannitol may reduce the risk of postoperative acute kidney injury, according to some studies; however, other studies have reported adverse effects on the kidneys due to the induction of acute renal tubular injury. In one study, removing mannitol from the priming solution had no effect on clinical outcomes; instead, only financial benefits were found. Since few studies have been conducted on the effects of using mannitol in CPB prime solutions, there is no clear consensus regarding its use during cardiac surgery? As a result, we planned a prospective, randomized, and double-blind study to find out how mannitol affects the CPB prime solution. Measured plasma osmolality is a more precise method for determining electrolyte balance than calculated osmolality during CPB, according to a recent study and it should be included in studies evaluating the effect of CPB prime solutions. Because it is a reliable method for determining osmolality, the freezing point depression method was used to measure plasma osmolality in our study.

Effects of Propofol

The overall objective of this study was to compare the effects of mannitol in the CPB prime solution and a prime based on Ringer's acetate on patients with normal preoperative cardiac and renal functions following cardiac surgery. We also looked into renal function and the short-term postoperative outcome.

The design of this prospective, randomized, single-center study was a control trial with double blinding. The southern Swedish ethics committee approved the study, as well as ClinicalTrials.org. At the Department of Cardiothoracic Surgery, Anesthesia, and Intensive Care at Skane University Hospital in Lund, Sweden, 40 adult patients who were scheduled for elective isolated coronary artery bypass grafting (CABG) were recruited. The authors informed each patient orally and in writing prior to surgery, and written consent was obtained for participation in the study and publication of the results. September 2017 marked the beginning of data collection, which was completed in March 2018. The sealed envelope system was used to assign twenty patients to each arm. Non-study staff performed the coding, and the code key was made public after the data were collected. The study solution was prepared by non-study clinical staff and given to the blinded perfusionist prior to randomization. The following were the eligibility requirements: normal renal function, which is defined as an estimated glomerular filtration rate (eGFR) greater than 60 mL/min, and normal left ventricular function, which is defined as a left ventricular ejection fraction on a preoperative echocardiogram of at least 50%. Patients with a preoperative hematocrit of less than 24% and a weight of less than 50 kilograms were excluded. In our study, the eGFR was the mean of the relative eGFR based on creatinine and the relative eGFR based on cystatin C. The revised Lund-Malmö equation was used to calculate the eGFR based on creatinine, and the CAPA equation was used to calculate the eGFR based on cystatin C. Patients were anesthetized in accordance with local standards and guidelines. There was no standard for premedication. Included in anesthesia: Depending on the extent of the surgery, total intravenous anesthesia (TIVA) may include sufentanil or morphine before the end of the procedure; Sevoflurane in combination with oxygen and air is used for inhalational anesthesia. Acceleromyography was used to monitor patients taking neuromuscular blocking medications. After a train-of-four count of 0.90, patients were extubated. With or without propofol sedation, neuraxial anesthesia or peripheral nerve blocks were carried out. After the operation, patients were only admitted to the PACU if they did not meet the requirements for accelerated "Fast Track" care.

Postoperative Complications

The attending anesthesiologists were instructed to always provide patients with standard care. At their entry into the PACU, patients were assessed and monitored. In addition to adding verbal information to the electronic journal, the anaesthetic nurse handed the patient over to the PACU nurse. Standard monitoring included a three-lead electrocardiogram (ECG), heart rate, SpO2, non-invasive blood pressure, temperature, and screening for pain (numerical rating scale, NRS) and PONV. Within thirty minutes of the PACU's arrival, patients were scanned for residual urine.

The Danish Society for Anaesthesia and Intensive Medicine's DASAIM criteria were used to discharge the patient from the PACU without considering the Nu-DESC score. Sedation level was one of the parameters for discharge: awake or easy to wake up, frequency of breathing: 10 to 30 breaths per minute, SpO2 less than 90%, systolic blood pressure less than 90 mm Hg, heart rate less than 120 beats per minute, pain score NRS less than 3 cm (0-10 cm scale), and neither severe nor severe nausea. The patients remained in the PACU until they regained knee flexion if spinal anesthesia was used. The attending anaesthesiologist approved the patient's discharge if the patient had multiple comorbidities.

We were able to include a total of 1000 patients in the study when we enrolled approximately 55% of the surgical patients who were admitted to the PACU during the data collection period. 103 patients upon arrival or discharge from the PACU. All 103 patients with IE in the PACU had a positive Nu-DESC score when they arrived at the PACU, but only 18 and 17 patients had a positive Nu-DESC score when they arrived at the operating room and 17 patients had a positive Nu-DESC score when they left the PACU. The majority of patients had symptoms related to psychomotor retardation and disorientation.