Nociception Level Index as Monitorization of Pain at the Intensive Care
Condition: Intensive Care, Surgical; Anesthesia, General
Study type: Interventional

Summary: 
      The aim of our study is to evaluate the effectiveness of a nociception monitor in providing
      adequate postoperative analgesia for patients needing critical care after surgery. Besides,
      the study searches to determine the difference between the amount of analgesic medication
      used when guided by nociception or standard pain management protocols. It is also aimed to
      reveal the incidence of delirium when pain management is managed under the nociception level
      index (NOL) guidance.

      60 postoperative patients admitted to the postanesthesia care unit (PACU) after general
      anesthesia for surgery for more than 2 hours will be included and allocated into 2
      groups(n=30): the control group (Group A) and the study group (Group B). Group Standard of
      care will be followed with standard monitorization only along with pain scales and receive
      rescue analgesia according to them. However, Group NOL will acquire NOL monitorization
      throughout the ICU stay and have the same rescue analgesia under NOL guidance with concurrent
      pain scales. Data to be recorded are total postoperative analgesic consumption, NOL values
      along with CPOT scores, and delirium.
    

Detailed description: 
      the investigators designed a prospective study after approval of our Institutional ethics
      committee (dossier no:212-2022) and planned to allocate 60 patients (2 groups; 1:1
      allocation; n=30). This study is designed under the Declaration of Helsinki and written
      informed consent will be obtained before surgery. Patients within the study should have
      general anesthesia for surgery for more than 2 hours and also planned for follow-up at the
      postanesthesia care unit (PACU). Among these, an investigator selects patients aged over 18
      and having American society of anesthesiology (ASA) scores I-III. Exclusion criteria are
      refusal to participate in the study; patients with additional organ failure especially lung
      failure (Pao2/fio2 value below 200); history of allergies to drugs used in the study
      protocol; patients receiving deep anesthesia with sedation infusion RASS -2 (unable to be
      awakened by uncooperative audible stimulus); patients with head trauma expected to have a low
      postoperative Glasgow coma score (GCS); the presence of surgical complication, arrhythmia,
      and sepsis during the hospital stay.

      Randomization is designed with concealed opaque envelope in a 1:1 ratio into 2 groups (n=
      30): the control group (Group Standard of care) and the study group (Group NOL). When the
      inclusion/exclusion criteria are met, on the day of the surgery the anesthetist in the
      operating room will choose one envelope to apply the designed protocol for each group. Data
      obtained at the clinical follow-up will be gathered by informed nurses at the ICU. All
      evaluations at the surgical wards especially for delirium and cognitive dysfunction will be
      evaluated by the same independent anesthetist who is blind to the study groups.

      All patients will receive standard analgesia protocol as 1 gr paracetamol (maximum dose 4x1
      and minimum dose interval as 6 hours) and rescue analgesia as 1mg/kg tramadol (maximum dose
      4x1 and minimum dose interval as 6 hours). Moreover, if analgesia is not ensured 0,05 mg/kg
      morphine (IV) bolus doses are planned when their pain scales or NOL values are high (NRS >4;
      CPOT>2; NOL >25 over 1 minute). NRS and CPOT will be used as pain scales at postoperative
      6th, 8th, 12th, and 24th hours for all patients. The Group Standard will be followed with
      standard monitorization only along with pain scales and receive rescue analgesia according to
      them. However, Group NOL will acquire NOL monitorization throughout the ICU stay and have the
      same rescue analgesia under NOL guidance with concurrent pain scales. The total amount of
      analgesics used during the ICU stay will be noted. Delirium and cognitive dysfunction will be
      evaluated at the 24th hour before discharge by CAM-ICU score and by 4AT at the surgical ward
      on the postoperative 3rd day before hospital discharge.
    

Intervention name(s): nociception level index monitor
Intervention type(s): Device
Intervention description(s): The nociception level index (NOL) is one of the new electrophysiological devices to asses pain-related nociception and differs with its multi-parameter evaluation. It is generated from five different parameters (heart rate, heart rate variability, skin conductance level, photo-plethysmography waveform amplitude, number of skin conductance fluctuations, and their time derivatives)
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Group A will be followed with standard monitorization only along with pain scales and receive rescue analgesia according to them. However, Group B will acquire NOL monitorization throughout the ICU stay and have the same rescue analgesia under NOL guidance with concurrent pain scales.
Masking: Double (Care Provider, Outcomes Assessor)
Primary purpose: Supportive Care
Keywords: nociception level index; Postoperative pain; behavioral pain scores; pain monitoring; delirium; postoperative cognitive dysfunction