The NoLA study

INTERVENTION: NoL‐guided anesthesia versus standard of care. CONDITION: Verdoving, Perioperative care, Pain ; ; PRIMARY OUTCOME: 1. Opioid and propofol consumption in total dose and dose/min; and; ; 2. Incidence (number of episodes) and total duration of inadequate anesthesia. SECONDARY OUTCOME: 1. Differences in Pk (prediction probability) values of NoL, BIS, HR and MAP for ; predicting the balance of nociception‐anti nociception during the following ; states ; ; • Awake vs. loss of consiousness (LOC) ; ; • Anesthesia (after discontinuation of propofol and remifentanil) vs. opening ; eyes ; ; • LOC vs intubation ; ; • Normal stimulation vs maximum stimulation (as indicated by the surgeon); ; ; 2. Incidence of NoL values < 10 and > 20; ; ; 3. Time from reversal of neuromuscular blockade to extubation; ; ; 4. Pain and sedation scores, incidence of nausea/vomiting, hemodynamics, ; respiration and medication use (e.g. opioids and antiemetics) in the recovery ; room obtained at 15‐min interval; ; ; 5. PACU: time until Aldrete > 9 (readiness for discharge); ; ; 6. Incidence of memory/awareness. INCLUSION CRITERIA: 1. Age: 18‐80 years; 2. ASA I‐II‐III 3. Elective open abdominal surgery or laparoscopic assisted abdominal surgery.