Assessing pain in critically ill brain-injured patients: a psychometric comparison of 3 pain scales and videopupillometry

Assessing pain in paralyzed critically ill patients receiving neuromuscular blocking agents: A monocenter prospective cohort

INTRODUCTION

Given the absence of established recommendations for pain assessment in pharmacologically paralyzed Intensive-Care-Units (ICU) patients under Neuro-Muscular-Blocking Agents (NMBA), this study assessed the validity of various parameters for evaluating pain in this specific population.

PATIENTS AND METHODS

Four electrophysiological parameters (instant-Analgesia-Nociception-Index (ANI), Bispectral index (BIS), Heart Rate (HR) and Mean Arterial Blood Pressure (ABP)) and one clinical parameter (Behavioural-Pain-Scale (BPS)) were recorded during tracheal-suctioning in all consecutive ICU patients who required a continuous infusion of cisatracurium, before and just after paralysis recovery measured by Train-of-Four ratio. The validity of the five pain-related parameters was assessed by comparing the values recorded during different situations (before/during/after the nociceptive procedure) (discriminant-validity, primary outcome), and the effect of paralysis was assessed by comparing values obtained during and after paralysis (reliability, secondary outcome).

RESULTS

Twenty patients were analyzed. ANI, BIS, and HR significantly changed during the nociceptive procedure in both paralysis and recovery, while BPS changed only post-recovery. ANI and HR were unaffected by paralysis, unlike BIS and BPS (mixed-effect model). ANI exhibited the highest discriminant-validity, with values (min 0/max 100) decreasing from 71 [48-89] at rest to 41 [25-72] during tracheal suctioning in paralyzed patients, and from 71 [53-85] at rest to 40 [31-52] in non-paralyzed patients.

CONCLUSIONS

ANI proves the most discriminant parameter for pain detection in both paralyzed and non-paralyzed sedated ICU patients. Its significant and clinically relevant decrease during tracheal suctioning remains unaltered by NMBA use. Pending further studies on analgesia protocols based on ANI, it could be used to assess pain during nociceptive procedures in ICU patients receiving NMBA.

Nociception assessment with videopupillometry in deeply sedated intensive care patients: Discriminative and criterion validations

BACKGROUND

Nociceptive assessment in deeply sedated patients is challenging. Validated instruments are lacking for this unresponsive population. Videopupillometry is a promising tool but has not been established in intensive care settings.

AIM/OBJECTIVE

To test the discriminate validity of pupillary dilation reflex (PDR) between non-noxious and noxious procedures for assessing nociception in non-neurological intensive care unit (ICU) patients and to test the criterion validity of pupil dilation using recommended PDR cut-off points to determine nociception.

METHODS

A single-centre prospective observational study was conducted in medical-surgical ICU patients. Two independent investigators performed videopupillometer measurements during a non-noxious and a noxious procedure, once a day (up to 7 days), when the patient remained deeply sedated (Richmond Agitation-Sedation Scale score: -5 or -4). The non-noxious procedures consisted of a gentle touch on each shoulder and the noxious procedures were endotracheal suctioning or turning onto the side. Bivariable and multivariable general linear mixed models were used to account for multiple measurements in same patients. Sensitivity and specificity, and areas under the curve of the receiver operating characteristic curve were calculated.

RESULTS

Sixty patients were included, and 305 sets of 3 measurements (before, during, and after), were performed. PDR was higher during noxious procedures than before (mean difference between noxious and non-noxious procedures = 31.66%). After testing all variables of patient and stimulation characteristics in bivariable models, age and noxious procedures were kept in the multivariable model. Adjusting for age, noxious procedures (coefficient = -15.14 (95% confidence interval = -20.17 to -15.52, p < 0.001) remained the only predictive factor for higher pupil change. Testing recommended cut-offs, a PDR of >12% showed a sensitivity of 65%, and a specificity of 94% for nociception prediction, with an area under the receiver operating curve of 0.828 (95% confidence interval = 0.779-0.877).

CONCLUSIONS

In conclusion, PDR is a potentially appropriate measure to assess nociception in deeply sedated ICU patients, and we suggest considering its utility in daily practices.

REGISTRATION

This study was not preregistered in a clinical registry.

TWEETABLE ABSTRACT

Pupillometry may help clinicians to assess nociception in deeply sedated ICU patients.

Assessing consciousness and cognition in disorders of consciousness

Detecting willful cognition in these patients is known to be challenging due to the patients' motor disabilities and high vigilance fluctuations but also due to the lack of expertise and use of adequate tools to assess these patients in specific settings. This review will discuss the main disorders of consciousness after severe brain injury, how to assess consciousness and cognition in these patients, as well as the challenges and tools available to overcome these challenges and reach an accurate diagnosis.

Continuous visualization and validation of pain in critically ill patients using artificial intelligence: a retrospective observational study

Machine learning tools have demonstrated viability in visualizing pain accurately using vital sign data; however, it remains uncertain whether incorporating individual patient baselines could enhance accuracy. This study aimed to investigate improving the accuracy by incorporating deviations from baseline patient vital signs and the concurrence of the predicted artificial intelligence values with the probability of critical care pain observation tool (CPOT) ≥ 3 after fentanyl administration. The study included adult patients in intensive care who underwent multiple pain-related assessments. We employed a random forest model, utilizing arterial pressure, heart rate, respiratory rate, gender, age, and Richmond Agitation-Sedation Scale score as explanatory variables. Pain was measured as the probability of CPOT scores of ≥ 3, and subsequently adjusted based on each patient's baseline. The study included 10,299 patients with 117,190 CPOT assessments. Of these, 3.3% had CPOT scores of ≥ 3. The random forest model demonstrated strong accuracy with an area under the receiver operating characteristic curve of 0.903. Patients treated with fentanyl were grouped based on CPOT score improvement. Those with ≥ 1-h of improvement after fentanyl administration had a significantly lower pain index (P = 0.020). Therefore, incorporating deviations from baseline patient vital signs improved the accuracy of pain visualization using machine learning techniques.

Ethical issues in neurocritical care

Medicine has always tried to push the limits of life. The technological and scientific progress made in resuscitation now makes it possible to keep patients who are more and more severely affected alive, by compensating for organ failure. The management of the brain-damaged patient poses specific ethical problems in intensive care. Most in-hospital deaths of patients with severe acute brain injury occur after a decision to withhold or withdraw life-sustaining treatments. In these patients, a problem is the difficulty in predicting outcome at an early stage. Our reasoning in the management of brain-damaged patients in the intensive care is based on the four main principles of medical ethics: autonomy, beneficence, non-maleficence and distributive justice. In the case of a patient suffering from cerebral palsy, consent is most often impossible to obtain. The respect of this autonomy, can be done by means of advance directives or testimonies of the support person and family. Non-malficence in the resuscitated brain-damaged patient consists of avoiding unreasonable obstinacy. Medical futility means that the proposed therapy should not be performed because available data show that it will not improve the patient's medical condition. A determination of medical futility can be made either in the presence of a vanishingly small probability of physiological effect or an exceedingly poor quality of outcome. However, a distinction must be made between loss of autonomy and unreasonable obstinacy. French law specifies that the physician must use collegial procedure in situations that may concern a brain-damaged patient. In terms of ethical decision-making, the concept of "window of opportunity" is often mentioned. The temporal approach taken is the guarantee of an absence of "a rush". It is important for the health care team and the family to share the progress of the treatment so that everyone understands the evolution of what is happening and the risks taken for the patient. The resuscitation of the brain-damaged patient poses specific and difficult ethical problems. One of the challenges is to be able to assume our decisions, understand them and defend them. It is also to maintain the coherence of our actions and the cohesion of our teams necessary for the good care of our patients.

Update on neuroimaging in disorders of consciousness

PURPOSE OF REVIEW

Neuroimaging has acquired a prominent place in the assessment of disorders of consciousness (DoC). Rapidly evolving technologies combined with state-of-the-art data analyses open new horizons to probe brain activity, but selecting appropriate imaging modalities from the plethora of available techniques can be challenging for clinicians. This update reviews selected advances in neuroimaging that demonstrate clinical relevance and translational potential in the assessment of severely brain-injured patients with DoC.

RECENT FINDINGS

Magnetic resonance imaging and high-density electroencephalography provide measurements of brain connectivity between functional networks, assessments of language function, detection of covert consciousness, and prognostic markers of recovery. Positron emission tomography can identify patients with preserved brain metabolism despite clinical unresponsiveness and can measure glucose consumption rates in targeted brain regions. Transcranial magnetic stimulation and near-infrared spectroscopy are noninvasive and practical tools with promising clinical applications.

SUMMARY

Each neuroimaging technique conveys advantages and pitfalls to assess consciousness. We recommend a multimodal approach in which complementary techniques provide diagnostic and prognostic information about brain function. Patients demonstrating neuroimaging evidence of covert consciousness may benefit from early adapted rehabilitation. Translating methodological advances to clinical care will require the implementation of recently published international guidelines and the integration of neuroimaging techniques into patient-centered decision-making algorithms.

Validation of the Critical-Care Pain Observation Tool-Neuro in brain-injured adults in the intensive care unit: a prospective cohort study

Background

Pain assessment in brain-injured patients in the intensive care unit (ICU) is challenging and existing scales may not be representative of behavioral reactions expressed by this specific group. This study aimed to validate the French-Canadian and English revised versions of the Critical-Care Pain Observation Tool (CPOT-Neuro) for brain-injured ICU patients.

Methods

A prospective cohort study was conducted in three Canadian and one American sites. Patients with a traumatic or a non-traumatic brain injury were assessed with the CPOT-Neuro by trained raters (i.e., research staff and ICU nurses) before, during, and after nociceptive procedures (i.e., turning and other) and non-nociceptive procedures (i.e., non-invasive blood pressure, soft touch). Patients who were conscious and delirium-free were asked to provide their self-report of pain intensity (0–10). A first data set was completed for all participants (n = 226), and a second data set (n = 87) was obtained when a change in the level of consciousness (LOC) was observed after study enrollment. Three LOC groups were included: (a) unconscious (Glasgow Coma Scale or GCS 4–8); (b) altered LOC (GCS 9–12); and (c) conscious (GCS 13–15).

Results

Higher CPOT-Neuro scores were found during nociceptive procedures compared to rest and non-nociceptive procedures in both data sets (p < 0.001). CPOT-Neuro scores were not different across LOC groups. Moderate correlations between CPOT-Neuro and self-reported pain intensity scores were found at rest and during nociceptive procedures (Spearman rho > 0.40 and > 0.60, respectively). CPOT-Neuro cut-off scores ≥ 2 and ≥ 3 were found to adequately classify mild to severe self-reported pain ≥ 1 and moderate to severe self-reported pain ≥ 5, respectively. Interrater reliability of raters’ CPOT-Neuro scores was supported with intraclass correlation coefficients > 0.69.

Conclusions

The CPOT-Neuro was found to be valid in this multi-site sample of brain-injured ICU patients at various LOC. Implementation studies are necessary to evaluate the tool’s performance in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03561-1.

Update on diagnosis in disorders of consciousness

INTRODUCTION

New guidelines regarding the diagnosis of disorders of consciousness (DOC) (such as vegetative state and minimally conscious state) have recently been published by the American Academy of Neurology and the European Academy of Neurology. This follows an impressive number of prospective studies performed on DOC and recent multi-centric studies with larger sample size, which have gathered precious information on the recovery of cohort of patients through years and which now call for a better management of patients with DOC.

AREAS COVERED

This review will discuss recent updates on the clinical entities of DOC, the challenges for an accurate diagnosis and the last developments in diagnostic tools.

EXPERT OPINION

The authors will also discuss the impact of the new guidelines on their way of diagnosing patients and how diagnosis will most likely change in a near future.

Application of the Behavioural Indicators of Pain Scale in patients with traumatic brain injury

AIM

To develop and psychometrically test the Behavioural Indicators of Pain Scale (ESCID) in patients with traumatic brain injury (TBI).

DESIGN

A prospective observational study to test the psychometric properties of the Behavioural Indicators of Pain Scale in patients with TBI.

METHOD

A convenience sample of patients with TBI, who were non-communicative and using invasive mechanical ventilation was selected. Pain was evaluated by two observers who were blinded from each other. Assessments were performed at baseline via the performance of a painful procedure (aspiration of secretions) and a non-painful procedure (rubbing with a gauze). Assessments were repeated after application of procedures on days 1 and 6 of hospitalization in an intensive care unit. Data were collected between January-December 2016.

RESULTS

About 134 patients were included in the study. Of these, 76.1% were men. The mean age of participants was 45.2 (SD 17.5) years. The pain score significantly increased during the painful procedure when compared with the baseline measure and non-painful procedure (p < .001). Patients displayed a greater number of pain-indicating behaviours during the painful procedure on day 6, compared with day 1 (p < .05). This finding coincided with a reduced level of sedation and a greater level of consciousness.

CONCLUSION

The ESCID scale detects pain behaviours and discriminates among the different types of stimulation in patients with brain injury, who are uncommunicative and with mechanical ventilation, with good reliability. The ability for patients with brain injury to express behaviours is limited because of the low level of consciousness and the deep level of sedation.

IMPACT

This research will have an impact on the practice of pain assessment in patients with brain injury, representing a first step to adapt the content of the ESCID.