Evaluation of prevalence and intensity of pain in sedated and ventilated adult patients using Critical Care Pain Observation Tool (CPOT) in a mixed medical-surgical ICU in a tertiary cancer care centre

IntroINTRODUCTION :

Pain assessment is considered a fifth vital sign.Pain is a common phenomenon among ICU patients and in the presence oflife-threatening illness or injury, investigation and management of pain isoften ignored by the health care team. Pain assessment is considered a fifthvital sign. Pain is a common phenomenon among ICU patients and in the presenceof life-threatening illness or injury, investigation and management of pain isoften ignored by the health care team. Routine painassessment leads to improved clinical outcomes, and the newly released clinicalpractice guidelines of the Society of Critical Care Medicine (2012 SCCMguideline) and the Clinical Practice Guidelines for Pain, Agitation andDelirium, 2013 (PAD guidelines ) strongly recommends the implementation ofroutine pain assessment.

BACKGROUND :

According to the PAD guidelines 2013, the BehavioralPain Scale (BPS) and the Critical-Care Pain Observation Tool (CPOT) are themost valid and reliable behavioral pain scales for monitoring pain in medical,postoperative, or trauma (except for brain injury) adult ICU patients who areunable to self-report and in whom motor function is intact and behaviors areobservable. The CPOT scale has four sections to beassessed : facial expression, body movements, muscle tension, and compliancewith the ventilator for intubated patients or vocalization for extubatedpatients. Items in each section are scored from 0 to 2, with a possible totalscore ranging from 0 to 8. . A score more than 2 indicates an unacceptablelevel of pain requiring an intervention such as administration of an analgesicbolus to bring down the pain. If CPOT score goes down by 2 points, it provesthat the high score was due to pain which has been controlled by theintervention.  Studies have shown thatuse of the CPOT scale provides guidance to Intensivists in making decisions forpain management as well as a decrease in the administration of analgesics andsedatives was observed post-implementation of the scale.It also helps inevaluation of the effectiveness of analgesics by checking the score before andafter its administration. The APS and the designated ICU Intensivist areresponsible for pain management in critically ill patients admitted to the ICU. As per protocol, mechanically ventilated patients are put on a continousinfusion of sedatives and analgesics. Sedation is titrated according tosedation scales but there is no scale used for assessment of pain. Titration ofthe analgesics is on the basis of subjective assessment of the intensivist.This could be leading to administration of excess or insufficient analgesics.Insufficient analgesic administration could lead to overstimulation of thesympathetic nervous system impeding the healing process. Excess analgesics cancause respiratory depression, bradycardia and hypotension.

Objective:

·         PRIMARY : To assess pain status in adult sedated, ventilated patients, managed using the current pain management protocols in the ICU, using the CPOT score

·         SECONDARY: To evaluate whether the use of CPOT to titrate pain medications will result in better pain management.

Patients and Methods

A. Ethics

The study will be initiated after obtaining the approval of The Institutional Ethics Committee Written informed consent will be taken from the legally accepted representatives of all participating patients.

B. Setting

A 23 bed mixed medical-surgical intensive care unit at Tata Memorial hospital

C. Design

Prospective consecutive 12 monthS observational to study approximately 300 subjects.

D. Patients

Inclusion Criteria

1. Patients above 18 years of age

2. Patients sedated and ventilated for more than 12 hours during their ICU stay.

3. RASS (Richmond Agitation Sedation Scale) score [ APPENDIX 2 ] = 0 to -3 (optimal sedation where response to pain can be noted)

Exclusion Criteria:

1. Pediatric patients

2. Patients sedated and ventilated for less than 12 hours during their ICU stay

3. Patients in whom an epidural catheter has been inserted and is in use.

4. Patients who do not have intact motor function.

5. RASS (Richmond Agitation Sedation Scale) score > 0 and < -3

E. Sample size

A convenience sample size is being used in this study. The study will be done over a 4 month period. It is expected that approximately 70 patients will be admitted per month. Thus, approximately 300 patients will be studied.

F. Study protocol

1. The prospective study will be conducted in the 23 bed mixed medical and surgical intensive care unit at Tata Memorial Hospital. The date, time, hospital admission diagnosis and ICU diagnosis of the enrolled patients will be noted. The rate of sedative  and / or analgesic infusion at the time of pain assessment will be noted.

2. The investigator will confirm with the treating team that the patient has not undergone any surgical intervention / mobilization/ procedure / painful stimulus half an hour before the CPOT score is calculated. The study will not be performed more than once in the same patient on the same day.

Pain will be assessed by the investigator using the CPOT scale, once a day, at a fixed time. Patient is considered to be in pain if the CPOT score is above 2 [14]. If the score is greater than 2 the patient will be given 50 mcg of fentanyl as rescue bolus and the score will be recalculated 10 minutes after giving the bolus.

The first CPOT score of each patient will also be assessed independently by an ICU resident who is not routinely using the CPOT Scale so as to evaluate the agreement of the scores by a person habituated in using the scale versus a person not who uses the scale infrequently.

The CPOT score will also be assessed independently by another person trained in using the scale who is not part of the study. He will calculate the CPOT score for each patient just after the investigator has calculated the score and after 10 minutes he will recalculate the CPOT score. He will be unaware of investigators CPOT scoring and whether the patient has received the rescue fentanyl bolus or not. Score of the independent trained assessor will be compared with that of the trained investigator for agreement between the scores. This is done to reduce the bias by the investigator assessing the CPOT score to improve the accuracy of the study.

Both the investigator and the independent assessor will be trained to using the scale in all sedated, ventilated patient in the ICU 15 days prior to the study.

The maximum number of days a patient can be assessed as part of the study is 5 days.

Interpretation of the CPOT Score by the Investigator and action therafter :

If the score of the patient is less than or equal to 2 out of 8 the inference is that there is likely minimal to no pain present. No further assessment will be done in that patient.

If the score of the patient is found to be greater than 2 out of 8, the inference is that the patient is in pain. The patient will then be given a rescue bolus of 50 mcg IV Fentanyl. The CPOT score will be recalculated 10 mins after giving the rescue bolus.

- CPOT score decreases by 2 or more points**:** It means that the patient’s CPOT score was high due to pain which has been relieved by administration of the rescue bolus.

- CPOT score decreases by 1 point: It could be because of high intensity of pain which is not relieved by a single rescue bolus of the analgesic. Thus, another rescue bolus of 50 mcg fentanyl will be given and the score will be recalculated after 10 minutes. Maximum 2 rescue boluses to be given in a patient.

**-**CPOT score increases or remains the same : It means that the patient’s CPOT score is high due to an underlying condition other than pain. The patient will not be reassessed further.

The ICU registrar will be informed of the initial and final CPOT scores and the number of boluses given, so that he can make the necessary changes in the further pain management of the patient.

Assessment of secondary objective- - By using CPOT we will be able to detect which patients are still in pain despite getting the usual pain management in ICU and we will give them a rescue analgesic. Thus by using CPOT we may be able to give the patient better pain management. If it is found that several patients are requiring rescue analgesic, we may need to consider revising our ICU pain management strategies.

Demographic data will be presented as mean±S.D or Frequency (Percentage). CPOT scores will be assessed as Frequency (Percentage) of scores being < or = 2 versus >2. Change in CPOT scores after giving rescue boluses will be compared using Paired t test or Wilcoxon signed test as per distribution of data. Categorical variables will be analyzed using Chi-square test or Fisher’s exact test. P-value < 0.05 will be considered statistical significant. IBM SPSS (Version24.0) will be used for analysis. Agreement between scores of trained and untrained investigators will be assessed using Kappa statistics. Agreement between scores of trained investigator and trained assessor  will also be assessed using Kappa statistics.