Prediction of Nociception in Children Using the Nociceptive Flexion Reflex Threshold and the Bispectral Index-A Prospective Exploratory Observational Study

The variability in nociceptive flexion reflex threshold measurement is mostly caused by probabilistic effects of the estimation algorithms: a simulation study

OBJECTIVES

The nociceptive flexion reflex (NFR) and its threshold are frequently used to investigate spinal nociception in humans. Since this threshold (NFRT) is a probabilistic measure, specific algorithms are used for NFRT estimation based on the stochastic occurrence of reflexes at different stimulus intensities. We used a validated simulation model of the NFR to investigate the amount of NFRT measurement variability induced by different estimation algorithms in a steady setting of reduced external influences.

METHODS

We simulated the behavior of different estimation algorithms in subjects with an artificially steady baseline NFRT variability (standard deviation: 0 mA) or low baseline NFRT variability (standard deviation: 0.156 mA), equaling a quiet experimental setting. The obtained data were analyzed for NFRT measurement variability caused by the algorithms compared to the baseline variability reflecting other physiological influences.

RESULTS

The standard deviation of the NFRT estimated by the different algorithms ranged between 0.381 and 3.464 mA with 96.8% to 99.6% of the measurement variability attributed to the algorithm used. Out of the investigated algorithms the dynamic staircase algorithm was most precise.

CONCLUSION

The NFRT measurement variability observed during quiet and steady experimental sessions is mostly caused by the properties of the estimation algorithms, due to the probabilistic nature of the reflex occurrence. Our results give reference for choosing the optimal estimation algorithm to improve measurement precision.

Eyes on Newborns: How NICU Staff's Attention and Emotions Shape Neonatal Pain Assessment

BACKGROUND

Assessing pain in neonates is crucial for their management but is inherently subjective. This study investigated the effects of visual attention, gaze patterns, and empathic responses of neonatal healthcare professionals on their assessments of neonatal pain.

METHODS

Conducted at the Department of Neonatology, University Medical Center Hamburg-Eppendorf, we employed eye-tracking to monitor staff's responses to videos depicting neonates experiencing non-noxious thermal, brief noxious, and prolonged noxious stimuli. Videos were presented in two formats: full body view, providing contextual information, and face-only view, lacking contextual details. Pain assessments were measured using a Faces Pain Rating Scale (FPRS), exploring the impacts of contextual cues, professional experience, and job roles.

RESULTS

The study found brief and prolonged noxious stimuli eliciting significantly higher FPRS scores compared to non-painful stimuli, with the full body view resulting in higher pain ratings than the face-only view. The mouth region attracted focused attention. Nurses generally reported higher pain scores and exhibited larger pupil diameters compared to physicians, suggesting a stronger empathic response.

CONCLUSION

This research highlights the essential role of visual cues and empathic responses in neonatal pain assessment, demonstrating how professional roles and stimulus presentation format impact evaluations, and underlining the need for standardised protocols to improve neonatal pain management accuracy.

SIGNIFICANCE

The study emphasises the importance of visual cues and empathy in neonatal pain assessment, highlighting the roles of healthcare professionals and stimulus presentation formats. It addresses challenges in understanding neonatal pain, advocating for standardised protocols. Using eye-tracking technology, the research explores how professionals' visual attention and empathy affect pain evaluations, suggesting more objective assessment methods.

A scoping review of pain resulting from the endotracheal suctioning of paediatric intensive care patients

BACKGROUND

This scoping review was conducted to summarise and map studies on pain resulting from endotracheal suctioning in paediatric intensive care patients.

METHOD

This scoping review conducted in June 2022 was performed by screening articles published in English. Scopus, PubMed, Cochrane, Web of Science, MedLine and Ovid databases were used for screening. The keywords 'endotracheal suctioning', 'pain', 'paediatric intensive care' and their synonyms were used in the search.

RESULTS

During the review, 280 articles were accessed, and the full texts of 14 articles were evaluated for suitability. After some of the articles were excluded from the study, abstracts of nine articles were given below.

CONCLUSION

It is recommended that a greater number of randomised controlled studies should be conducted, because the number of studies with a high level of evidence on the effect of endotracheal suctioning on the pain levels of patients in the paediatric intensive care unit is very few.

Investigation of behavioral pain scale, critical care pain observation tool, nociceptive flexion reflex and pupillary dilatation reflex as predictors of behavioral reactions to nociceptive procedures in critically ill patients unable to self-report pain

BACKGROUND

Procedural pain is a common burden in critical care treatment and the prediction of nociceptive reactions remains challenging. Thus, we investigated the behavioral pain scale (BPS), the critical pain observational Tool (CPOT), the nociceptive flexion reflex (NFR), the pupillary dilation reflex (PDR), the Richmond agitation-sedation scale (RASS) as predictors of behavioral reactions to nociceptive procedures.

METHODS

In this monocentric, prospective, observational study we analyzed data of 128 critically ill adults unable to self-report pain to investigate the predictability of behavioral reactions to two procedures: endotracheal suctioning and turning. Next to routine clinical data, CPOT, BPS, PDR, NFR, RASS, propofol and sufentanil doses were recorded before the procedures.

RESULTS

For endotracheal suctioning, NFR, BPS, CPOT, RASS showed predictive performances significantly better than chance, but none of them performed significantly better than the sufentanil dose rate. For turning, BPS, CPOT, RASS showed predictive performances significantly better than chance, but only the RASS performed significantly better than the propofol dose rate.

CONCLUSIONS

Behavioral reactions to both investigated clinical procedures can be predicted by observational scales or nociceptive reflexes. For endotracheal suctioning, none of the predictors performed superior to using the sufentanil dose rate as a predictor. As using sufentanil as a predictor requires no extra effort in contrast to the other predictors, none of the here investigated tools seem advisable for predicting behavioral reactions to endotracheal suctioning. For patient turning, the RASS predicts reactions better than any other tool.

Discriminant properties of the Behavioral Pain Scale for assessment of procedural pain-related distress in ventilated children

OBJECTIVES

Children hospitalized in a pediatric intensive care unit (PICU) are frequently exposed to distressing and painful medical procedures and interventions. There is a lack of clinical scales to measure procedural pain-related distress in ventilated children. The Behavioral Pain Scale (BPS) was initially developed to detect procedural pain in critically ill adults. This study aims to assess the BPS's discriminant properties for measuring procedural pain-related distress in ventilated pediatric patients incorporating two instruments validated for pediatric patients.

METHODS

This prospective exploratory study was performed with ventilated children admitted to the interdisciplinary 14-bed PICU of the University Children's Hospital, University Medical Center Hamburg-Eppendorf, Germany. The nurse in charge and an independent observer simultaneously assessed the patients using German versions of the BPS, the COMFORT-B scale (CBS), and the modified Face, Legs, Activity, Cry, Consolability (mFLACC) scale immediately before and during endotracheal suctioning.

RESULTS

We analyzed 170 parallel assessments in n=34 ventilated children. Patients were (mean ± SD) 9.5 ± 4.8 years old. Internal consistency for the BPS was excellent (α=0.93). We found a high rater agreement for all clinical scales (BPS: k=0.73, CBS: k=0.80, mFLACC: k=0.71). Strong correlations were identified between BPS and CBS (r=0.89) and BPS and mFLACC (r=0.79). The BPS cutoff values showed likewise excellent results (area under the curve CBS >16: 0.97; mFLACC >2: 0.91).

CONCLUSIONS

In our population of ventilated children, the BPS was well suited to detect procedural pain-related distress compared with two validated pain scales. Further extensive validation studies should follow to support our findings.

Impact of Propofol Bolus Administration on the Nociceptive Flexion Reflex Threshold and Bispectral Index in Children—A Case Series

We analyzed the impact of propofol administration during continuous sedation and analgesia on the nociceptive flexion reflex threshold (NFRT) and Bispectral Index (BIS) in ventilated children. We examined patients who received propofol before planned endotracheal suctioning. Patients were clinically assessed using the modified Face, Legs, Activity, Cry, Consolability (mFLACC) scale and COMFORT-B (Comfort Behavior) scale. We continuously recorded the NFRT and BIS. We recorded 23 propofol administrations in eight patients with an average age of 8.6 ± 3.5 years. The median (minimum-maximum) scores for the mFLACC scale and COMFORT-B scale were 0 (0–5) and 6 (6–17), respectively, before the bolus. The administration of a weight-adjusted propofol bolus of 1.03 ± 0.31 mg/kg resulted in an increase in NFRT and burst-suppression ratio; BIS and electromyogram values decreased. Changes from baseline (95% CI) after propofol bolus administration were BIS −23.9 (−30.8 to −17.1), EMG -10.5 dB (−13.3 to −7.7), SR 14.8 % (5.6 to 24.0) and NFRT 13.6 mA (5.5 to 21.7). Further studies are needed to determine whether sedated children may benefit from objective pain and sedation monitoring with BIS and NFRT.