Comparison of effect of plasmalyte and ringer lactate on acid base status and lactate in patients undergoing emergency gastrointestinal obstruction surgery- A pragmatic randomised control trial

Written informed consent explaining about the procedure, risks and any adverse events will be obtained from the patients before being enrolled into the study. The patient will be enrolled in 1:1 ratio. Relevant demographic data and investigation details will be obtained from the case sheet.

Anesthetic management:

Before anesthetic induction, standard ASA monitoring including pulse oximetry (SpO2), non-invasive blood pressure, 5 lead echocardiography (ECG) will be attached to patients. A wide bore iv cannula will be inserted. However, the attending anesthesia team will be allowed to use central venous catheter and/or arterial catheter if required according to their discretion. Regional anesthesia technique, choice and dosage of local anesthetic agent will be decided by the attending anesthesia team. Anesthesia induction will begin with preoxygenation for a minimum of 3 minutes followed by rapid sequence induction. Anesthesia induction will be achieved by inj. Fentanyl (2 mcg/kg), thiopentone (4-5 mg/kg) and succinylcholine (0.5-1 mg/kg).

Patients will be randomized into two arms. In one arm, patients will receive plasmalyte (Baxter India Pvt Ltd, Haryana, India) infusion throughout the intraoperative period. In the 2nd arm, patients will receive ringer lactate infusion throughout the intraoperative period. The amount of fluids will be decided by the attending anesthesia team according the hemodynamic parameters of the patients.    Blood loos will be replaced by crystalloid (ringer lactate or plasmalyte depending upon the arm the patients assigned to, colloids and packed cells in 1:3; 1:1 and 1:1 ratio. Pain management, and regional anesthesia management will be decided by the attending anesthesiologist. The mean blood pressure will be maintained preferably between 65-100 mm Hg. Hypotension and hypertension will be managed using mephenteramine/noradrenaline bolus or infusion and nitroglycerine/beta-blockers. However, the attending anesthesiologist will have freedom to choose or add inoconstrictor, inodilator, vasodilators of their own choice to manage hypotension or hypertension. Nonetheless, if the attending anesthesiologist prefer to manage hypotension by intravenous infusion, they will be allowed either plasmalyte or ringer lactate according the arm patients assigned to. Colloids and blood component infusion will be decided entirely by the attending anesthesia team.    Maintenance of anesthesia will be done using Isoflurane (1-2%) in FiO2 (40% with air) and supplemental fentanyl boluses (0.5 mcg/kg). Ventilator settings will be adjusted to maintain ETCO2 (end tidal carbon dioxide) between 35-45 mm Hg. Hemoglobin will be maintained > 8 gm/dl and PRBC will be transfused accordingly. Blood sugar will be maintained between 100-200 mg/dl. Hypothermia will be prevented to maintain core body temperature between 35-37 C.

Lactate, acid-base status, electrolytes and KIM-1 level were assessed just before study fluid administration and 1-2 hours after completion of surgery. Patients were monitored everday to asses the cardiovascular, pulmonary and renal complications till date of discharge from the hospital