Perfusion Index in Pain Assessment

Validation of Perfusion Index as a Tool for Pain Assessment in Critically Ill Intubated Patients

The perfusion index (PI) is the ratio of the pulsatile to the non-pulsatile blood flow in peripheral tissue. It represents a non-invasive measure of peripheral perfusion that can be continuously obtained from a pulse oximeter. This property explains the fact that it decreases with vasoconstriction and increases with vasodilatation.

An increase in PI was proved to be an early indicator for the success of general and regional anaesthesia, which cause initial peripheral vasodilatation before the onset of anaesthetic effect. Whereas a failed increase in PI would suggest failure of anaesthesia.

The PI has been reported to decrease when noxious stimulus was applied to anaesthetized volunteers. A recent study on critically ill non-intubated patients has demonstrated a good correlation between changes in PI and changes in Behavioral Pain Scale-non intubated values after a painful stimulus was applied.

Despite the rising use of perfusion index in anaesthesia and intensive care, few studies have investigated its capability as a pain assessment tool, and to our knowledge, it has not been investigated in intubated critically ill patients yet.

Study Overview

• Status: Completed
• Conditions: Pain, Postoperative
• Intervention / Treatment: Diagnostic test: Perfusion index

Detailed Description

All patients after admission will be monitored with the use of routine monitoring tools: Electrocardiogram, pulse oximetry, and automated noninvasive blood pressure (NIBP). Day-to-day investigations will be carried out to monitor and individualize treatment. Medical (and/or) surgical treatment will be performed, supervised by the attending intensivist and surgeon.

Sedation and analgesia protocol will be prescribed by the patient's primary intensivist. Another pulse oximeter probe (Masimo Radical 7; Masimo Corp., Irvine, CA, USA) will be attached to the patient's index finger during changing the patient's position (head of bed elevation) after abdominal surgery. This pulse oximeter will be connected to the Masimo monitor and shielded to prevent outside light from interfering with the signal.

Sedation will be assessed by using the Richmond Agitation- Sedation scale (RASS). Pain assessment will be achieved by using the behavioural pain scale intubated (BPS-IN).

Sedation and analgesia will be guided by the BPS and RASS. For analgesia the patients will receive a loading dose (0.05-0.2 mg/kg) morphine sulphate I.V., followed by (2-10 mg/h) infusion to keep the BPS between 3 and 6. If the pain score is more than 6, a rescue dose of 3 mg will be given, and then the pain will be reassessed after 5 min. If the patient received more than 2 boluses/h, the infusion dose will be increased by 2 mg/h.

For sedation, the patients will receive a loading dose of propofol 0.005 mg/kg/min IV for at least 5 min., followed by (0.005-0.05 mg/kg/min) IV infusion to achieve a RASS score of 0 to -1. A rescue dose of 5-10 mcg/kg/min over 5-10 min intervals if the RASS score is more than 0; allow a minimum of 5 min between adjustments for onset of peak effect.

• Study Type: Observational
• Enrollment (Actual): 32

Contacts and Locations

Study Locations

• Egypt
  • Giza, Egypt, 5421
    • Kasr Alainy Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Sedated intubated surgical ICU patients aged 18 to 60 years old

Description

Inclusion Criteria:

• Sedated intubated surgical ICU patients during the first two postoperative days following abdominal surgery.

Exclusion Criteria:

• Patients with a history of neurologic disorder (hemiparesis, quadriparesis, and neuropathy).
• Patients with an epidural catheter with local anaesthetic injection for the purpose of analgesia.
• Patients receiving neuromuscular blockade.
• Patients with peripheral vascular disease.
• Patients suffering from fever.
• Hypothermia.
• Use of vasopressors.
• Patients with altered level of consciousness (GCS <4).

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The correlation between delta PI and delta BPS	We observe the correlation between the changes in Perfusion index vales and the changes in Behavioral Pain Scale vales before and after the application of painful stimulus	1 minute before the painful stimulus and 1 minute after.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Systolic blood pressure	mmHg	1 minute before the painful stimulus and 1 minute after.
Diastolic blood pressure	mmHg	1 minute before the painful stimulus and 1 minute after.
Heart rate	beat per minute	1 minute before the painful stimulus and 1 minute after.
Richmond Agitation- Sedation scale	4: Combative; 3: Very agitated; 2: Agitated; 1: Restless 0: Alert and calm1: Drowsy2: Light sedation3: Moderate sedation4: Deep sedation5: Unarousable	1 minute before the painful stimulus and 1 minute after.
Sensitivity and specificity of PI to predict BPS > or = 6	By generating Receiver Operating Characteristic curve	1 minute before the painful stimulus and 1 minute after.

Collaborators and Investigators

• Sponsor: Cairo University

Study record dates

Study Major Dates

• Study Start (Actual): July 20, 2019
• Primary Completion (Actual): September 20, 2019
• Study Completion (Actual): September 20, 2019

Study Registration Dates

• First Submitted: June 13, 2019
• First Submitted That Met QC Criteria: June 13, 2019
• First Posted (Actual): June 17, 2019

Study Record Updates

• Last Update Posted (Actual): December 23, 2019
• Last Update Submitted That Met QC Criteria: December 19, 2019
• Last Verified: December 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Pain, Postoperative
• Other Study ID Numbers: S-8-2019

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No