Background: In response to noxious stimulation, pupillary dilation reflex (PDR) occurs even in anaesthetized patients. The aim of the study was to evaluate the ability of pupillometry with an automated increasing stimulus intensity to monitor intraoperative opioid administration.Methods: Thirty‐four patients undergoing elective surgery were enrolled. Induction by propofol anaesthesia was increased progressively until the sedation depth criteria (SeD) were attained. Subsequently, a first dynamic pupil measurement was performed by applying standardized nociceptive stimulation (SNS). A second PDR evaluation was performed when remifentanil reached a target effect‐site concentration. Automated infrared pupillometry was used to determine PDR during nociceptive stimulations generating a unique pupillary pain index (PPI). Vital signs were measured.Results: After opioid administration, anaesthetized patients required a higher stimulation intensity (57.43 mA vs 32.29 mA, P < .0005). Pupil variation in response to the nociceptive stimulations was significantly reduced after opioid administration (8 mm vs 28 mm, P < .0005). The PPI score decreased after analgesic treatment (8 vs 2, P < .0005), corresponding to a 30% decrease. The elicitation of PDR by nociceptive stimulation was performed without changes in vital signs before (HR 76 vs 74/min, P = .09; SBP 123 vs 113 mm Hg, P = .001) and after opioid administration (HR 63 vs 62/min, P = .4; SBP 98.66 vs 93.77 mm Hg, P = .032).Conclusions: During propofol anaesthesia, pupillometry with the possibility of low‐intensity standardized noxious stimulation via PPI protocol can be used for PDR assessment in response to remifentanil administration.

Pupillary response by pupillary dilatation reflex (PDR) is a robust reflex, even measurable during general anaesthesia. However, the ability of infrared pupillometry to detect PDR differences obtained by intraoperative opioid administration in anaesthesized patients remains largely unknown. We analyzed the performance of automated infrared pupillometry in detecting differences in pupillary dilatation reflex response by a inbuilt standardized nociceptive stimulation program in patients under general anesthesia with a standardized propofol/fentanyl scheme. In this single center, interventional cohort study 38 patients (24-74 years) were enrolled. Patients were anesthetized with propofol until loss of consciousness. Two dynamic pupil measurements were performed in each patient (before opioid administration and after opioid steady state). Automated infrared pupillometry was used to determine PDR during nociceptive stimulations (10-60 mA) applied by a inbuilt pupillary pain index protocol (PPI) to the skin area innervated by the median nerve. Increasing stimulations by protocol are device specific and automatically performed until pupil dilation of > 13%. Pupil characteristics, blood pressure, heart rate values were collected. After opioid administration, patients needed a higher stimulation intensity (45.26 mA vs 30.79 mA, p = 0.00001). PPI score showed a reduction after analgesic treatment (5.21 vs 7.68, p = 0.000001), resulting in a 32.16% score reduction. PDR via automated increased tetanic stimulation may reflect opioid effect under general anaesthesia. Further research is required to detect possible confounding factors such as medication interaction and optimization of individualized opioid dosage.

Objective Nociceptive Assessment In Ventilated Icu Patients A Feasibility Study Using Pupillometry And The Nociceptive Flexion Reflex. JoVE publishes peer-reviewed scientific video protocols to accelerate biological, medical, chemical and physical research. Watch our scientific video articles. JoVE is the world-leading producer and provider of science videos with the mission to improve scientific research, scientific journals, and education. Millions of scientists, educators and students at thousands of universities, colleges, hospitals and biopharmaceutical companies worldwide use JoVE for their research, teaching and learning.

Pectus excavatum and pectus carinatum are the most common chest wall deformities. Although minimally invasive correction (minimally invasive repair of pectus, MIRP) has become common practice, it remains associated with severe postoperative pain. Preoperative psychosocial factors such as anxiety and low self-esteem can increase postsurgical pain. Early detection of psychological symptoms, effective biopsychosocial perioperative management of patients, and prevention of pain chronification using an enhanced recovery pathway (ERP) may improve outcomes. However, the incidence of the latter is poorly described in adolescents undergoing MIRP. The objective of our study was to evaluate the implementation of an ERP containing early recovery goals and to assess persistent postsurgical pain 3 months postoperatively in pediatric patients undergoing MIRP. The ERP consists of a Web-based platform containing psychological screening questionnaires and extensive telemonitoring for follow-up of patients at home. A population-based cohort study was conducted with prospectively collected data from patients undergoing pectus surgery between June 2017 and December 2017. An ERP was initiated preoperatively; it included patient education, electronic health-based psychological screening, multimodal pre-emptive analgesia, nausea prophylaxis as well as early Foley catheter removal and respiratory exercises. After hospital discharge, patients were followed up to 10 weeks using a Web-based diary evaluating pain and sleep quality, while their rehabilitation progress was monitored via Bluetooth-connected telemonitoring devices. We enrolled 29 adolescents using the developed ERP. Pre-emptive multimodal analgesia pain rating scores were low at hospital admission. Optimal epidural placement, defined by T8-9 or T9-10, occurred in 90% (26/29) of the participants; thus, no motor block or Horner syndrome occurred. Mean bladder catheterization duration was 3.41 (SD 1.50) days in ERP patients. Numeric rating scale (NRS) scores for pain and the incidence of nausea were low, contributing to a fluent rehabilitation. Mean NRS scores were 2.58 (SD 1.77) on postoperative day (POD) 1, 2.48 (SD 1.66) on POD 2, and 3.14 (SD 1.98) on POD 3 in ERP-treated patients. Telemonitoring at home was feasible in adolescents after hospital discharge despite adherence difficulties. Although the pain scores at the final interview were low (0.81 [SD 1.33]), 33% (9/27) long-term follow-up ERP patients still experienced frequent disturbing thoracic pain, requiring analgesic administration, school absenteeism, and multiple doctor (re)visits. Allocating patients to the appropriate level of care preoperatively and immediately postoperatively may improve long-term outcome variables. Internet-based technologies and feasible, objective monitoring tools can help clinicians screen surgical patients for risk factors and initiate early treatment when indicated. Future research should focus on improving risk stratification and include a psychological assessment and evaluation of the effect of perioperative care pathways in children undergoing major surgery. ClinicalTrials.gov NCT03100669; https://clinicaltrials.gov/ct2/show/NCT03100669 (Archived by WebCite at http://www.webcitation.org/72qLB1ADX)

Background: The use of neostigmine after neuromuscular blockade (NMB) has been associated with postoperative respiratory complications. In previous studies, we found lower diaphragmatic activity after neostigmine reversal of NMB, compared to sugammadex. It is still unclear whether the adequate use of neostigmine guarantees normal respiratory muscle function after NMB. In this study, we wanted to assess the effect of commonly used degrees of NMB and their possible reversal strategies on respiratory muscle activity after the return of normal neuromuscular transmission. Methods: This is a randomized, controlled, parallel-group, single-centre, double-blind study in patients scheduled for intracranial surgery at a tertiary academic hospital in Belgium. All participants received target controlled propofol/remifentanil anesthesia and were randomized into one of five groups, receiving either a shallow NMB with no reversal (shallow/saline), a shallow NMB with sugammadex reversal (shallow/sugammadex), a moderate NMB with neostigmine reversal (moderate/neostigmine), a moderate NMB with sugammadex reversal (moderate/sugammadex), or a deep NMB with sugammadex reversal (deep/sugammadex). Primary and secondary outcome parameters were diaphragm and intercostal electromyographic (EMG) activity at the moment of resumed spontaneous breathing activity, defined as a maximal interval of 10 min after the first spontaneous breath. Results: For the five groups, a total of 55 patients could be included in the final analysis. Median time of spontaneous breathing analyzed was 5 min (IQR 3–9.5 min). Both the moderate/sugammadex and the moderate/neostigmine groups had lower levels of diaphragm EMG compared to the shallow/sugammadex group. The moderate/neostigmine group had lower levels of intercostal EMG activity compared to the shallow/saline group. Conclusions: In this study, the depth of neuromuscular blockade and type of reversal strategy impacts respiratory muscle activity at the moment of resumed spontaneous breathing and recovery of neuromuscular blockade. Both groups that received moderate NMB had lower levels of diaphragm EMG, compared to the shallow NMB group with sugammadex reversal. Compared to the shallow NMB group with no reversal, the moderate NMB with neostigmine reversal group had lower intercostal EMG activity. Trial registration: Clinicaltrials.gov NCT01962298 on October 9, 2013 and EudraCT 2013–001926-25 on October 10, 2013.