Use of Behavioural Pain Scale in assessing pain during physical therapy procedures in sedated, mechanically ventilated patients in ICU: A cross-sectional observational study

Background: Critically ill patients who are sedated and mechanically ventilated, experience significant pain during physical therapy procedures but cannot communicate effectively due to sedation. Identification and evaluation of pain with validated behavioral observation tools in patients unable to self-report pain improve quality of care by administration of appropriate analgesia or sedation during routine physical therapy care of ventilated patients. Aims and Objectives: This study aimed to assess pain in sedated, mechanically ventilated patients using the Behavioural Pain Scale (BPS) during physical therapy procedures like body positioning and tracheal suctioning. Materials and Methods: Following ethical approval, 50 adult patients, sedated and mechanically ventilated, admitted in the ICUs in a tertiary care teaching hospital were assessed for pain severity using BPS during routine physical therapy procedures. Patients ≥18 years of age, both male and female, with Glasgow Coma Scale of (GCS) < 10, were included in the study. Patients with Ramsay Sedation Scale (RSS) of 3, 4, and 5, mechanically ventilated for at least 48 hours, who were unable to verbalize, patients who were undergoing routine physical therapy that included body positioning and tracheal suctioning for removal of secretion were included. Patients below 18 years of age, able to verbalize pain, and GCS score of ≤ 3, were excluded from the study. Conclusion: BPS is recommended for better pain evaluation during physical therapy procedures in sedated, mechanically ventilated adult patients in the ICU.


INTRODUCTION
As per the International Association for Study of Pain, pain is an unpleasant sensory and emotional experience associated with or resembling actual or potential tissue damage (Raja et al., 2020).Pain is a significant problem among mechanically ventilated patients in ICU (Mitra et al., 2020).Pain is felt during rest and procedures like a change of body position, joint mobilizations, muscle stretching, and tracheal suctioning.80% of ICU-discharged hospitalized patients have painful memories and discomfort associated with intubation.38% of patients remember the pain as their worst ICU memory even after six months (Shaikh et al., 2018).Physical therapy procedures act as stressors but no standard protocol for analgesia or sedation management during physiotherapy exists (Everingham et al., 2010).Pain during physical therapy may adversely affect the treatment outcomes.Physical therapists and other caregivers must use structured, valid, and reliable instruments to assess pain in the ICU, in a routine manner.Many studies have reinforced the importance of pain assessment instruments and their use by health professionals in the ICU (Hora TCNS da and Alvis IGN, 2020).
The need for direct patient communication is self-evident (Patel and Kress, 2012).Self-reporting of pain is the gold standard of pain assessment (Gerber et al., 2015).Mechanically ventilated patients cannot communicate effectively due to tracheal intubation, sedation, reduced level of consciousness, and administration of paralyzing drugs.The ability of such patients to self-report pain is limited.Visual Analog Scale (VAS) and Numeric Rating Scale (NRS) are commonly used self-reported pain assessment tools in patients who can communicate.When the patient cannot verbalize, reliable pain assessment tools for patients with diminished ability for communication have to be used (Naithani et al., 2008).Studies have shown that certain observable behaviors may be valid indicators of pain.The Behavioural Pain Scale (BPS) was developed by (Payen et al., 2001).It is used for assessing pain in patients who have undergone abdominal surgery or multiple traumas.
The BPS has also been used to evaluate pain in sedated, mechanically ventilated patients, unable to verbalize pain.BPS is a unidimensional, 12-item clinical observation tool that assesses pain on three behavioral indicators-patient's facial expression, lower limb movements, and tolerance of mechanical ventilation.Each behavioral indicator contains four descriptors rated on a 1-4 scale.
The score ranges from 3 (no pain) to 12 (highest pain).The scale has high inter-rater reliability (Al-Sutari et al., 2014).Studies have shown that BPS is an appropriate tool for evaluating pain in uncommunicative ICU patients (Oliveira et al., 2019).Unrelieved pain can cause multiple physiological and psychological complications.
Pain decreases patient cooperation with various care procedures, such as turning and physical therapy.It is reported that more than 30% of ICU patients have significant pain at rest, and more than 50% of ICU patients have significant pain during routine care like turning procedures (Allam, 2022).Pain remains under-evaluated and undertreated in sedated, intubated, and mechanically ventilated patients who cannot verbalize.Studies have shown that the BPS can be used to assess pain during routine medical and nursing procedures, but no study has used BPS to assess pain during standard physical therapy procedures.The purpose of this observational study, sampled from a population of sedated and mechanically ventilated critically ill patients, was to assess the usefulness of BPS in evaluating pain in sedated, mechanically ventilated patients during routine physical therapy procedures.

MATERIALS AND METHODS
This cross-sectional, single-center observational study was conducted for two months in medical, surgical, and renal ICUs of a tertiary teaching hospital in India.After the approval by the Institutional Ethical Committee, informed consent was obtained from a responsible family member of each patient.They were explained the purpose of the study and the type of data to be collected and assured of the confidentiality of the data.This study did not require deviation from the routine patient care prescribed to the patients in ICU.Patients 18 years and older, male and female, Glasgow Coma Scale of < 10, were included in the study.Sedated patients with Ramsay Sedation Scale of 3, 4, and 5 (avoiding too agitated or deeply sedated patients) and mechanically ventilated for at least 48 hours, who were unable to verbalize and were undergoing routine physical therapy that included body positioning and tracheal suctioning for removal of secretion for a wide range of diagnostic conditions were included in the study.
Patients below 18 years of age, able to verbalize pain, GCS score of ≤ 3 (patients in a deep coma), patients with quadriplegia, peripheral neuropathy, and on neuromuscular blocking agents or drugs that can inhibit expression of pain behavior, discontinued mechanical ventilation due to weaning or brain death and those who were not undergoing routine physiotherapy following mechanical ventilation, were excluded from the study.137 patients were admitted to the ICUs during the period of study.71 patients fulfilled the inclusion criteria.Consent could not be obtained from 18 patients.Two were extubated and one expired before the data collection.Data was collected for the remaining 50 patients between October 2022 and December 2022 (Figure 1).A structured, observational method was used for data collection.Physical therapy procedures were carried out by two physiotherapists who were routinely involved in the treatment of ICU patients.They were also trained in BPS administration.None of the BPS administrators were blinded to the study.
Data was collected with the help of three instruments.The first instrument comprised of patient's demographic data, diagnostic categories, and physiological variables like systolic and diastolic blood pressure and heart rate, duration of mechanical ventilation, and type of analgesia used during mechanical ventilation.Demographic data (Table 1) was collected from hospital records within 24 hours of ICU admission.The second instrument comprised the Glasgow Coma Scale (GCS) score to assess patients' level of consciousness, the Ramsay Sedation Scale (RSS) score to assess patients' depth of sedation, and the CAM ICU scale to evaluate the presence of delirium.
Patients with RSS scores of 3, 4, 5 only was included in the study.None of the patients showed ICU delirium.The third instrument comprised the BPS score of each patient during rest, change of body position, and tracheal suctioning.The validity and reliability of the instruments were evaluated by three therapists, experienced in the physical therapy management of ICU patients.
Patients' systolic and diastolic blood pressure and heart rate were measured during rest, change in body position, and tracheal suctioning.Patients' pain was evaluated using the BPS.BPS includes three behavioral indicators-facial expression, upper limb movements, and compliance with a ventilator (Table 2).A guide for BPS administration was prepared for the investigators (Table 3).All investigators adhered to it.Observations were recorded between 8 a.m. and 12 noon.

RESULTS
This study objectively evaluated the usefulness of the BPS in evaluating pain during physical therapy in sedated, mechanically ventilated patients in ICU, who are unable to verbalize.The mean age of patients was 54.36±18.29.70% of the patients included in this study were males.50% of the patients were 50 years or above.Patients with a wide range of diagnostic conditions were included in the study (Table 4).Most patients (54%) received opioid analgesics (fentanyl, midazolam, serenace, calmpose) following intubation.44% of patients received paracetamol or metamizole.2% of patients did not receive analgesia.

Upper limbs
No movement 1

Partially bent 2
Fully bent with finger flexion 3 Permanently retracted 4

Compliance with ventilator
Tolerating movement 1 Coughing with movement 2

Fighting ventilator 3
Unable to control ventilation 4 The findings of this study show that the physiological parameters like SBP, DBP, and HR were minimal at rest but increased during body positioning and were maximum during tracheal suctioning (Table 5).The mean BPS score at rest was 6.59±0.42,which indicates the presence of some pain even at rest.The mean pain score during a change of body positioning and tracheal suctioning was significantly higher than at rest (Table 6).The difference was statistically significant.Pain assessment of patients with and without analgesia showed that patients on analgesia experienced significantly less pain than those without analgesia during rest and physical therapy procedures (Table 7).The results of this study show that despite sedation or administration of analgesia, pain is not adequately relieved in mechanically ventilated patients.Therefore, the use of appropriate pain assessment instruments for evaluating pain is required.It implies that maximum pain was experienced during tracheal suctioning.Studies have reported tracheal suctioning invoking significant changes in physiological parameters (Jeitziner et al., 2012).
This study found a positive correlation between pain intensity and an increase in heart rate and diastolic BP during physical therapy interventions, like body positioning and tracheal suctioning.These findings are consistent with international reports of the association of heart rate and BP with pain.Underestimation of a patient's pain is a well-known problem.However, while using the BPS, there is also a likelihood of over-estimation of patients' pain.Therefore, using the BPS with other pain scales may provide a more reliable assessment of a patient's pain (Ahlers et al., 2010).

Limitations of the study
This study has a few limitations.As it was a single-center study, the sample size was small.Patients with a wide range of diagnostic categories, different durations of ICU stay, and analgesia dosage were included in the study.We have not correlated the BPS score with the sedation level of the patients.However, patients with GCS ≤ 3 who could be unresponsive to pain were excluded from the study.

CONCLUSION
Almost all mechanically ventilated patients in the ICU have pain.Evaluation of pain is difficult in sedated patients who are unable to self-report.Appropriate instruments for pain evaluation should be used for such patients.In uncommunicative patients, physiological parameters and behavioral indicators are used to evaluate pain.The results of this study indicate that sedated mechanically ventilated patients experience pain during routine physical therapy procedures like body positioning and tracheal suctioning.
BPS may be used by physical therapists to assess pain in sedated mechanically ventilated patients.This would help in the appropriate evaluation of pain and ensure better pain management by administration of adequate analgesia during such procedures.As this is the first study to evaluate the effectiveness of BPS for evaluating pain during physical therapy procedures in sedated, mechanically ventilated patients in ICU, further studies may be undertaken on the perception of physiotherapists working in ICU towards acceptability and ease of application of BPS for evaluation of pain in sedated, mechanically ventilated patients in critical care settings.

Figure 1
Figure 1 Flow diagram showing enrolment, data collection, and analysis grimacing during tracheal suctioning (Figure2).During the change of body position, the mean BPS score was 7.58±1.02,which indicated moderate pain.The upper limb indicator for most patients was-no movement at rest, partially bent during body position and fully bent during tracheal suctioning (Figure3).During tracheal suctioning, the mean BPS score was 9.14±1.26indicating severe pain.The facial expression indicator for most patients was grimacing, the upper limb indicator was fully tight and compliance with the ventilator indicator showed patients fighting the ventilator (Figure4).

Figure 2 FacialFigure 3 Figure 4 Figure 5
Figure 2 Facial Expressions at Rest, Body Positioning and Tracheal Suctioning ventilated patients who are sedated and unable to self-report, require instruments that detect behaviors associated with pain.Observation of facial expression is a method used for pain assessment in ventilated subjects.During painful procedures, an increase in facial movements -eyes closed, brow lowered, eyelid tightened, cheeks raised, and parted lips are the indicators.Upper limb movements, muscle rigidity, and compliance with mechanical ventilator are other behavioral indicators of pain in sedated intubated patients (Azevedo-Santos and DeSantana, 2018).This study aims to evaluate the usefulness of BPS in evaluating pain at rest and during physical therapy procedures like change of body position and tracheal suctioning in sedated and mechanically ventilated patients in ICU, unable to verbalize pain.

Table 1
Demographic characteristics of patients at baseline

Table 2
The Behavioural Pain Scale

Table 3 A
Guide to BPS for Evaluators

Table 4
Diagnostic Category-Wise Distribution of Patients and RSS Score

Table 5
Physiological parameters during rest, body positioning, and tracheal suctioning

Table 6
BPS at Rest, Tracheal Suctioning and Body Positioning

Table 7
Pain assessment of patients with and without analgesia Most patients showed relaxed facial expressions during rest, partially tight during body positioning, and fully tight and