Postoperative pain assessment in children: a pilot study of the usefulness of the analgesia nociception index

Machine learning model of facial expression outperforms models using analgesia nociception index and vital signs to predict postoperative pain intensity: a pilot study

BACKGROUND

Few studies have evaluated the use of automated artificial intelligence (AI)-based pain recognition in postoperative settings or the correlation with pain intensity. In this study, various machine learning (ML)-based models using facial expressions, the analgesia nociception index (ANI), and vital signs were developed to predict postoperative pain intensity, and their performances for predicting severe postoperative pain were compared.

METHODS

In total, 155 facial expressions from patients who underwent gastrectomy were recorded postoperatively; one blinded anesthesiologist simultaneously recorded the ANI score, vital signs, and patient self-assessed pain intensity based on the 11-point numerical rating scale (NRS). The ML models' area under the receiver operating characteristic curves (AUROCs) were calculated and compared using DeLong's test.

RESULTS

ML models were constructed using facial expressions, ANI, vital signs, and different combinations of the three datasets. The ML model constructed using facial expressions best predicted an NRS ≥ 7 (AUROC 0.93) followed by the ML model combining facial expressions and vital signs (AUROC 0.84) in the test-set. ML models constructed using combined physiological signals (vital signs, ANI) performed better than models based on individual parameters for predicting NRS ≥ 7, although the AUROCs were inferior to those of the ML model based on facial expressions (all P < 0.050). Among these parameters, absolute and relative ANI had the worst AUROCs (0.69 and 0.68, respectively) for predicting NRS ≥ 7.

CONCLUSIONS

The ML model constructed using facial expressions best predicted severe postoperative pain (NRS ≥ 7) and outperformed models constructed from physiological signals.

Pain Assessment Using the Analgesia Nociception Index (ANI) in Patients Undergoing General Anesthesia: A Systematic Review and Meta-Analysis

The analgesia nociception index (ANI) has emerged as a potential measurement for objective pain assessment during general anesthesia. This systematic review and meta-analysis aimed to evaluate the accuracy and effectiveness of ANI in assessing intra- and post-operative pain in patients undergoing general anesthesia. We conducted a comprehensive search of Ovid-MEDLINE, Ovid-EMBASE, Cochrane Central Register of Controlled Trials, Google Scholar, public clinical trial databases (ClinicalTrials and Clinical Research Information Service), and OpenSIGLE to identify relevant studies published prior to May 2023 and included studies that evaluated the accuracy and effectiveness of ANI for intra- or post-operative pain assessment during general anesthesia. Among the 962 studies identified, 30 met the eligibility criteria and were included in the systematic review, and 17 were included in the meta-analysis. For predicting intra-operative pain, pooled sensitivity, specificity, diagnostic odds ratio (DOR), and area under curve of ANI were 0.81 (95% confidence interval [CI] = 0.79-0.83; I2 = 68.2%), 0.93 (95% CI = 0.92-0.93; I2 = 99.8%), 2.32 (95% CI = 1.33-3.30; I2 = 61.7%), and 0.77 (95% CI = 0.76-0.78; I2 = 87.4%), respectively. ANI values and changes in intra-operative hemodynamic variables showed statistically significant correlations. For predicting post-operative pain, pooled sensitivity, specificity, and DOR of ANI were 0.90 (95% CI = 0.87-0.93; I2 = 58.7%), 0.51 (95% CI = 0.49-0.52; I2 = 99.9%), and 3.38 (95% CI = 2.87-3.88; I2 = 81.2%), respectively. ANI monitoring in patients undergoing surgery under general anesthesia is a valuable measurement for predicting intra- and post-operative pain. It reduces the use of intra-operative opioids and aids in pain management throughout the perioperative period.

The validity and applications of the analgesia nociception index: a narrative review

Pain refers to the subjective, unpleasant experience that is related to illness or injury. In contrast to pain, nociception refers to the physiological neural processing of noxious stimuli, such as intra-operative surgical stimuli. One novel device, the Analgesia Nociception Index (ANI), aims to objectively measure intra-operative nociception by analyzing the heart rate variability in patients undergoing surgery. Through this method of nociceptive monitoring, the ANI device aims to provide an objective, continuous evaluation of patient comfort levels and allow anesthesiologists to better manage surgical stress and patient analgesia, perhaps with even better efficacy than current practices used to assess nociception. Additionally, ANI may have clinical application in settings outside of the operating room, such as in the intensive care unit. In this narrative review, we compiled and summarized the findings of many studies that have investigated ANI's validity and applications in different clinical settings. Currently, the literature appears mostly supportive of ANI's ability to detect nociception in both surgical and non-surgical settings. However, the ability for ANI to provide clinical benefits, such as decreased intra-operative opioid use, post-operative opioid use, and post-operative pain compared to standard practices appear controversial. Because of the wide variety of methodology, clinical settings, patient populations, and limitations in these studies, more investigation of ANI is needed before any firm conclusions can be drawn on its clinical benefits.

Analgesia Nociception Index (ANI) as a monitor of peri-operative nociception-antinociception balance in paediatric craniotomies: a prospective observational study

INTRODUCTION

Analgesia Nociception Index (ANI) as a monitor of peri-operative nociception-anti-nociception balance has not been studied in paediatric neurosurgery. The objectives were to study the correlation between ANI (Mdoloris Education system) and revised FLACC (r-FLACC) score for the prediction of acute postoperative pain in paediatric population undergoing elective craniotomies and to compare the changes in ANI values with heart rate (HR), mean arterial pressure (MAP) and surgical plethysmographic index (SPI) during various time points of intraoperative noxious stimulation and before and after opioid administration.

METHODS

This prospective observational pilot study included 14 patients between 2 and 12 years of age undergoing elective craniotomies. HR, MAP, SPI, ANI instantaneous (ANIi) and ANI mean (ANIm) values were recorded intraoperatively and before and after opioid administration. Postoperatively HR, MAP, ANIi and ANIm, and pain scores (r-FLACC scale) were recorded.

RESULTS

There was a statistically significant negative correlation between ANIi and ANIm with r-FLACC during the time course of PACU stay (r =  - 0.89, p < 0.001 and r =  - 0.88 and p < 0.001 respectively). Intraoperatively, in patients with ANIi values < 50, with additional fentanyl administration, there was an increasing trend in values beyond 50, which was statistically significant (p < 0.05) at 3, 4, 5 and 10 min. The trend in changes of SPI after opioid administration was not found to be significant for patients irrespective of the baseline SPI values.

CONCLUSION

The ANI is a reliable tool for objective assessment of acute postoperative pain as assessed by r-FLACC in children undergoing craniotomies for intracranial lesions. It may be used as a guide to nociception-antinociception balance during the peri-operative period in this population.

Analgesia Nociception Index Monitoring in the Evaluation of Postoperative Pain in Children: A Prospective Observational Pilot Study

PURPOSE

In this study, we aimed to evaluate the relationship between the analgesia nociception index (ANI) device and pain scales used in the postoperative pain assessment of pediatric patients who underwent laparoscopic appendectomy.

DESIGN

The study was designed as a correlation observational pilot study.

METHODS

Postoperative pain was evaluated using pediatric pain scales (face, legs, arms, cry, consolability scale; numerical rating scale; Wong-Baker scale) and ANI device in school-aged children and adolescents.

RESULTS

The mean age of the children was 14.00 ± 1.63 years, and the mean BMI was 22.52. We found a statistically significant positive correlation between the pain scale scores and a statistically significant negative relationship between the pain scale score and the ANI.

CONCLUSIONS

The ANI device can be used safely and constantly for the objective assessment of postoperative pain in pediatric patients.

Analgesia nociception index and high frequency variability index: promising indicators of relative parasympathetic tone

At present, there is no objective and absolute measure of nociception, although various monitoring techniques have been developed. One such technique is the Analgesia Nociception Index (ANI), which is calculated from heart rate variability that reflects the relative parasympathetic tone. ANI is expressed on a non-unit scale of 0-100 (100 indicates maximal relative parasympathetic tone). Several studies indicated that ANI-guided anesthesia may help reduce intraoperative opioid use. The usefulness of ANI in the intensive care unit (ICU) and during surgery has also been reported. However, some limitations of ANI have also been reported; for example, ANI is affected by emotions and some drugs. In 2022, a high frequency variability index (HFVI), which was renamed from ANI and uses the same algorithm as ANI, was commercialized; therefore, ANI/HFVI are currently in the spotlight. Unlike ANI, HFVI can be displayed along with other biometric information on the Root® monitor. ANI/HFVI monitoring may affect the prognosis of not only patients in the perioperative period but those in ICU, those who receive home medical care, or outpatients. In this article, we present an updated review on ANI that has been published in the last decade, introduce HFVI, and discuss the outlooks of ANI/HFVI.

Evaluation of Nociception during Pediatric Surgery: A Topical Review

The association between intraoperative nociception and increased patient's morbidity is well established. However, hemodynamic parameters, such as heart rate and blood pressure, may result in an inadequate monitor of nociception during surgery. Over the last two decades, different devices have been marketed to "reliably" detect intraoperative nociception. Since the direct measure of nociception is impractical during surgery, these monitors measures nociception surrogates such as sympathetic and parasympathetic nervous systems responses (heart rate variability, pupillometry, skin conductance), electroencephalographic changes, and muscular reflex arc. Each monitor carries its own advantages and disadvantages. The manuscript aims to give an overview of the most up-to-date information available in the literature on current nociceptor monitors available in clinical practice, with particular focus on their applications in pediatrics.

Nociception associated with pain/distress in young children sedated for dental treatment: a clinical study with objective and subjective measures

PURPOSE

To evaluate the association between children's pain/distress levels and patient characteristics (age, sex, history of dental pain), sedation type (level of sedation, sedative regimen), nociception and pain intensity reported by the parents in sedated children undergoing minimally invasive dental treatment.

METHODS

This clinical study evaluated secondary outcomes of an RCT that evaluated the efficacy of dexmedetomidine sedation with or without ketamine. Only children who had nociception levels recorded using the Analgesia Nociception Index (ANI) were included (0-100; 0 = highest nociception). FLACC scale (Face, Legs, Activity, Cry and Consolability) was used to assess children's pain/distress (0-10; 0 = no pain/distress). Parental proxy report of the child's pain intensity during the treatment was performed using the Visual Analogue Scale (VAS; 0-100; 0 = no pain). The association between ANI, children's age and sex, dental pain history, sedation level, sedative regimen, and VAS with the FLACC was verified using the generalised estimation equation analysis (alpha 0.05).

RESULTS

Participants were 31 children (51.6% boys) and their parents (90.3% mothers). Median FLACC was 3.3 (25th-75th percentiles 1.7-8.2), ANI 80.9 (74.7-85.8), and VAS 10 (1-23). FLACC associated with ANI (OR 0.96; 95% CI 0.93-0.99; p = 0.02), moderate sedation (0.13; 0.03-0.50; p = 0.003), and VAS (1.05; 1.01-1.10; p = 0.01).

CONCLUSION

Pain/distress was generally low and more prominent with minimal (versus moderate) sedation and higher nociception.

Evaluation of the Analgesia Nociception Index and videopupillometry to predict post-tonsillectomy morphine requirements in children: a single-centre, prospective interventional study

Background

Tonsil surgery causes significant and challenging postoperative pain. The Analgesia Nociception Index (ANI) and videopupillometry are two techniques of interest to monitor nociception in adults and may predict postoperative morphine requirements. We hypothesised that these techniques could predict the need for morphine after tonsillectomy in children. The main objective was to assess the prognostic significance of ANI and videopupillometry, measured at the end of surgery, on morphine consumption determined by a Face, Legs, Activity, Cry, Consolability (FLACC) scale score >3 in the Post Anesthesia Care Unit (PACU).

Methods

A single-centre, prospective, interventional study evaluating children between 2 and 7 yr old undergoing tonsil surgery was performed. ANI and videopupillometry with tetanic stimulation were measured under general anaesthesia 4 min after the end of the surgical procedure. Each child was evaluated every 10 min by a nurse using the FLACC scale in the PACU and blinded to the measurements performed in the operating theatre.

Results

Eighty-nine children were analysed and 39 (44%) received morphine in the PACU. Neither ANI values nor videopupillometry values were predictive of postoperative morphine consumption (areas under the receiver operating characteristic curve 0.54, 95% confidence interval [CI; 0.42-0.65], and P=0.57; and 0.52, 95% CI [0.41-0.63], and P=0.69, respectively). Neither ANI values nor videopupillometry values were correlated to the maximum FLACC scale score in the PACU with ρ=0.04 (P=0.71) and ρ=0.06 (P=0.57), respectively.

Conclusions

Neither ANI nor videopupillometry performed at the end of surgery can predict morphine consumption in the PACU in children undergoing tonsillectomy.

Validation of the Indonesian Version of the Face, Legs, Activity, Cry, Consolability (FLACC) Scale in Postoperative Cleft Lip and/or Cleft Palate Patients

Background:

The face, leg, activity, cry, and consolability (FLACC) scale is a validated pain measurement instrument that is used on postoperative patients with limited verbal ability, including postoperative cleft lip and/or cleft palate patients.

Objective:

This research aimed to test the validity and reliability of the Indonesian version of the FLACC scale as a measuring instrument for pain intensity experienced by postoperative cleft lip and/or cleft palate patients.

Methods:

The procedure was initiated by a back-translation process of the FLACC. Once the back-translation process is completed, a calibration process of the field researchers was conducted. Twenty-eight participants that went through a cleft lip and/or cleft palate surgery at the Unpad Dental Hospital were then enrolled. Two calibrated field researchers measured the postoperative pain intensity in three different time points, shortly after the patients regained full consciousness (T0), four hours (T1), and eight hours after the first measurement (T2). The collected data were analysed by SPSS version 23. The Spearman correlation analysis was performed to test the validity, while a Cronbach’s alpha value was calculated to test the reliability.

Results:

Based on the results of the Spearman correlation analysis, the Indonesian version of the FLACC scale was considered to be valid as the r values of each sub-scale were all higher than the r table value (r value > 0.317). Reliability was marked by the obtained Cronbach’s alpha value of 0,875.

Conclusion:

The Indonesian version of the FLACC scale was considered to be valid and reliable to be used as a pain measurement tool in postoperative cleft lip and/or cleft palate patients.

Comparison between Analgesia Nociception Index (ANI) and self-reported measures for diagnosing pain in conscious individuals: a systematic review and meta-analysis

The Analgesia Nociception Index (ANI), an objective measure of pain based on heart rate variability (HRV), has its usefulness in awake patients still unclear. This systematic review and meta-analysis aimed to assess ANI's accuracy compared to self-reported pain measures in conscious individuals undergoing medical procedures or painful stimuli. PubMed, Ovid, Web of Science, Scopus, Embase, and grey literature were searched until March 2021. Of the 832 identified citations, 16 studies complied with the eligibility criteria. A meta-analysis including nine studies demonstrated a weak negative correlation between ANI and NRS for pain assessment in individuals in the post-anesthetic recovery room (r = − 0.0984, 95% CI = − 0.397 to 0.220, I² = 95.82%), or in those submitted to electrical stimulus (r = − 0.089; 95% CI = − 0.390 to 0.228, I² = 0%). The evidence to use ANI in conscious individuals is weak compared to self-report measures of pain, yet ANI explains a part of self-report. Therefore, some individuals may be benefited from the use of ANI during procedures or in the immediate postoperative period.

Emergence agitation in paediatric day case surgery: A randomised, single-blinded study comparing narcotrend and heart rate variability with standard monitoring

BACKGROUND

Postoperative emergence agitation remains a significant challenge in paediatric anaesthesia. Although short-lived, it may cause harm to the patient and negative experiences for all. Differentiating agitation, delirium and pain is difficult. Electroencephalography allows precise titration of anaesthetic depth, and heart rate variability monitoring permits immediate intervention regarding nociception and pain. We examined if one of these measures could be used to reduce postoperative agitation in an unselected paediatric day surgical population.

OBJECTIVE

The primary outcome was postoperative agitation with a Richmond Agitation-Sedation Scale greater than 0. Secondary outcomes were: length of stay, postoperative nausea and vomiting, fentanyl and propofol consumption, pain scores and use of postoperative analgesics.

DESIGN

A randomised, single-blinded study constituting children aged 1 to 6 years, undergoing minor general day surgical procedures.

SETTING

Paediatric day surgical department 29th March 2019 to 12th June 2020.

PATIENTS

Ninety-eight children (ASA 1 or 2) were enrolled, and 93 children were included in the final analysis.

INTERVENTIONS

Children received standard monitoring (n=31), standard monitoring plus either Narcotrend (n=31), or Anaesthesia Nociception Index monitoring (n=31). Sevoflurane or fentanyl was titrated immediately according to monitor thresholds.

RESULTS

Kaplan-Meier analysis yielded a statistically significant difference between the groups (P = 0.016) with the lowest agitation levels in the Anaesthesia Nociception Index group, intermediate levels in the control group and the highest agitation levels in the Narcotrend monitored group. Intergroup pairwise comparison however, showed no difference. The Anaesthesia Nocioception Index group received slightly more fentanyl (P = 0.277). The control group patients had the highest pain scores despite receiving more caudal blocks and the Narcotrend group had more sevoflurane adjustments. Other secondary outcomes were comparable.

CONCLUSION

Children in the Anaesthesia Nociception Index group were the least agitated with the highest fentanyl doses, without increasing the length of stay in the PACU or postoperative nausea and vomiting.

CLINICAL REGISTRATION

The study was registered in RedCAP online trial database 1/11/2018 trial registration nr. OP720. https://open.rsyd.dk/OpenProjects/openProject.jsp?openNo=720&lang=da.

Effect of Intrapapillary Local Anesthetic on Postoperative Pain Following Dental Treatment Under General Anesthesia in Pediatric Patients

OBJECTIVE

This randomized, prospective, blinded study compared pain in children following dental treatment under general anesthesia (GA) using 1 of 2 established analgesia methods.

METHODS

Patients age 4 to 7 years were randomly assigned to a control group (intravenous [IV] analgesics) or experimental group (IV analgesics and intrapapillary local anesthetic infiltrations) between July 2017 and February 2018. During recovery from surgery, Faces, Legs, Activity, Cry, and Consolability (FLACC) scores were recorded upon regaining consciousness and reassessed every 15 minutes until discharge. Overall pain occurrence (FLACC ≥1) and moderate/severe pain occurrence (FLACC ≥4) were analyzed using mixed effects logistic regression (N = 88).

RESULTS

The experimental group had a 17% lower overall pain occurrence than the control group (16 vs 33%; p = .02). Moderate/severe pain occurrence between the groups was not significant (9 vs 22%; p = .23). The dental treatment subjects received (number of completed stainless steel crowns, extractions, and/or pulpotomies) did not significantly affect pain occurrence.

CONCLUSION

Local anesthesia intrapapillary infiltrations around stainless steel crowns decrease overall pain occurrence but not moderate/severe pain occurrence following dental treatment under GA in pediatric patients.

Scoping review of the association between postsurgical pain and heart rate variability parameters

Supplemental Digital Content is Available in the Text. This scoping review provides some evidence of a possible association between heart rate variability and postsurgical pain, although significant variability exists among included studies.

Surgical interventions can elicit neuroendocrine and sympathovagal responses, leading to cardiac autonomic imbalance. Cardiac complications account for approximately 30% of postoperative complications. Altered heart rate variability (HRV) was initially described in the 1970s as a predictor of acute coronary syndromes and has more recently been shown to be an independent predictor of postoperative morbidity and mortality after noncardiac surgery. In general, HRV reflects autonomic balance, and altered HRV measures have been associated with anesthetic use, chronic pain conditions, and experimental pain. Despite the well-documented relationship between altered HRV and postsurgical outcomes and various pain conditions, there has not been a review of available evidence describing the association between postsurgical pain and HRV. We examined the relationship between postsurgical pain and HRV. MEDLINE and EMBASE databases were searched until December 2020 and included all studies with primary data. Two reviewers independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Review of Interventions. A total of 8 studies and 1002 participants were included. Studies examined the association of postsurgical pain and HRV or analgesia nociception index derived from HRV. There was a statistically significant association between HRV measures and postsurgical pain in 6 of 8 studies. Heterogeneity of studies precluded meta-analyses. No studies reported cardiovascular outcomes. There is a potential association between postsurgical pain and HRV or analgesia nociception index, although results are likely impacted by confounding variables. Future studies are required to better delineate the relationship between postsurgical pain and HRV and impacts on cardiovascular outcomes.

Available Instruments to Assess Pain in Infants

Pain assessment in newborns and infants is challenging for clinicians. Although behavioral and behavioral-physiological scales are validated pain assessment instruments, their use in this age group has significant limitations. In this review, we summarize the methods currently available for assessing pain in neonates and infants. It is possible that these pain detection methods are also useful for assessing the quality of anesthesia and analgosedation in these populations. Further research should be aimed at confirming the usefulness of these tools in infants and identifying additional pain assessment options for clinical practice.

Using an App to monitor postoperative pain at home in pediatric patients

A prospective comparative study was conducted in 487 pediatric patients (69% male, mean age = 6.4 ± 4.0) to evaluate (a) the incidence, intensity, and characteristics of pain in pediatric patients at home during the first 24 hours and 5 days after surgery and (b) the factors associated with higher pain intensity, including the impact of an application (App) compared to the paper-and-pencil approach. Postoperative pain was assessed by patients or their parents at home using the 'Bambino Gesù' Children's Hospital (Ospedale Pediatrico Bambino Gesù, OPBG) tool for participants aged 4-17 years or the Faces, Legs, Arms, Cry, and Consolability scale for participants less than four years old. Participants were assigned to two groups: those who used the paper-and-pencil version of the pain scale and those who used the App. Overall, 209 of the 472 (44%) participants reported pain during the first 24 hours, and 92 of the 420 (22%) reported pain between one and five days after surgery. Higher pain intensity scores were associated with being in the App group, directly assessing own pain, and using the OPBG tool. The App was effective in facilitating pain assessment. Health professionals could empower pediatric patients and their parents in assessing pain at home through a dedicated App.

Perfusion index as an objective measure of postoperative pain in children undergoing adenotonsillectomy: a cohort study

Postoperative pain in children is usually undertreated because of their inability to complain. While several pain assessment scales have been developed, they have shortcomings such as subjectivity and being observer-dependent. This study aimed to assess the validity of the perfusion index as an objective measure of postoperative pain in children undergoing adenotonsillectomy. Children aged 3-7 years were enrolled. The Children's Hospital of Eastern Ontario Scale (CHEOPS) was used to assess postoperative pain. The perfusion index was measured at the same time intervals as CHEOPS. The highest CHEOPS before rescue analgesia was administered and CHEOPS when the patients became pain-free were recorded with the corresponding perfusion index. The primary outcome was the correlation between the postoperative CHEOPS and the corresponding postoperative perfusion index. The secondary outcomes were the ability of perfusion index changes to predict the presence of postoperative pain and patients' response to analgesics. The postoperative perfusion index was negatively correlated with CHEOPS at 30 and 90 min postoperatively. The change in the preoperative baseline perfusion index (ΔPI-pre) was moderately correlated with the highest CHEOPS (CHEOPS-1) (r = 0.61, p = 0.001). The change in the postoperative perfusion index (ΔPI-po) was negatively correlated with the change in the CHEOPS (ΔCHEOPS) (r = - 0.53, P = 0.0001). The ΔPI-pre was an excellent predictor of postoperative pain (AUROC 0.83 with 71% sensitivity, 83% specificity, and a cut-off value of ≥ 0.26). The perfusion index is a good objective measure for predicting the presence of postoperative pain in children undergoing adenotonsillectomy under general anesthesia. Trial registration: ClinicalTrials.gov; ID: (NCT03854604) registered on February 2019.

Association between postsurgical pain and heart rate variability: protocol for a scoping review

INTRODUCTION

Surgical interventions can elicit neuroendocrine responses and sympathovagal imbalance, ultimately affecting cardiac autonomic function. Cardiac complications account for 30% of postoperative complications and are the leading cause of morbidity and mortality following non-cardiac surgery. One cardiovascular parameter, heart rate variability (HRV), has been found to be predictive of postoperative morbidity and mortality. HRV is defined as variation in time intervals between heartbeats and is affected by cardiac autonomic balance. Furthermore, altered HRV has been shown to predict cardiovascular events in non-surgical settings. In multiple studies, experimentally induced pain in healthy humans leads to reduced HRV suggesting a causal relationship. In a different studies, chronic pain has been associated with altered HRV, however, in the setting of clinical pain conditions, it remains unclear how much HRV impairment is due to pain itself versus autonomic changes related to analgesia. We aim to review the available evidence describing the association between postsurgical pain and HRV alterations in the early postoperative period.

METHODS AND ANALYSIS

We will conduct a scoping review of relevant studies using detailed searches of MEDLINE and EMBASE, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Included studies will involve participants undergoing non-cardiac surgery and investigate outcomes of (1) measures of pain intensity; (2) measures of HRV and (3) statistical assessment of association between #1 and #2. As secondary review outcomes included studies will also be examined for other cardiovascular events and for their attempts to control for analgesic treatment and presurgical HRV differences among treatment groups in the analysis. This work aims to synthesise available evidence to inform future research questions related to postsurgical pain and cardiac complications.

ETHICS AND DISSEMINATION

Ethics review and approval is not required for this review. The results will be submitted for publication in peer-reviewed journals.

The effectiveness of vibratory stimulation in reducing pain in children receiving vaccine injection: A randomized controlled trial

BACKGROUND

Although vaccine injections are important, children experience pain and discomfort upon their administration. BUZZY®, a vibratory stimulation tool with an ice pack, was reported to be an effective tool for reducing the pain caused to children during injection administration; its mechanisms were explained by gate control theory. However, the evidence is inadequate because of insufficient methodology in previous reports. Therefore, we aimed to assess whether the application of vibration would significantly reduce children's pain during vaccine injections.

METHODS

A single-blind randomized controlled trial recruiting children aged ≤6 years who were receiving vaccine injections was conducted between August and December 2019. If the children's parents consented to their participation, BUZZY® was attached to the child's arm prior to vaccination. BUZZY® was switched on before injection in the intervention group but not in the control group. The vaccination procedure was recorded, and researchers and parents assessed each child's pain using validated pain scales. Researchers conducted their assessment using video data to ensure blinding. Parents were administered a questionnaire after the children's vaccination. Data were analyzed using the t-test or chi-square test.

RESULTS

We analyzed 118 children (intervention group = 62, control = 56). No between-group difference was observed according to the researchers' assessment (mean score = 6.98 and 7.63, respectively; p = 0.25); however, a significant difference was found based on the parents' assessment (mean score = 7.39 versus 8.46; p = 0.02). Most responses received to open-ended questions were positive comments for this study.

CONCLUSIONS

We revealed that the effect of vibration is not significant in reducing vaccine injection pain among children. Further studies are needed to examine the other components of BUZZY®, which include its cooling effect, and the effect of BUZZY® itself in terms of whether children will undergo vaccination without resistance and have reduced trauma related to vaccination.

Multiparametric Monitoring of Hypnosis and Nociception-Antinociception Balance during General Anesthesia-A New Era in Patient Safety Standards and Healthcare Management

The development of general anesthesia techniques and anesthetic substances has opened new horizons for the expansion and improvement of surgical techniques. Nevertheless, more complex surgical procedures have brought a higher complexity and longer duration for general anesthesia, which has led to a series of adverse events such as hemodynamic instability, under- or overdosage of anesthetic drugs, and an increased number of post-anesthetic events. In order to adapt the anesthesia according to the particularities of each patient, the multimodal monitoring of these patients is highly recommended. Classically, general anesthesia monitoring consists of the analysis of vital functions and gas exchange. Multimodal monitoring refers to the concomitant monitoring of the degree of hypnosis and the nociceptive-antinociceptive balance. By titrating anesthetic drugs according to these parameters, clinical benefits can be obtained, such as hemodynamic stabilization, the reduction of awakening times, and the reduction of postoperative complications. Another important aspect is the impact on the status of inflammation and the redox balance. By minimizing inflammatory and oxidative impact, a faster recovery can be achieved that increases patient safety. The purpose of this literature review is to present the most modern multimodal monitoring techniques to discuss the particularities of each technique.

Validation of the UNESP-Botucatu pig composite acute pain scale (UPAPS)

The creation of species-specific valid tools for pain assessment is essential to recognize pain and determine the requirement and efficacy of analgesic treatments. This study aimed to assess behaviour and investigate the validity and reliability of an acute pain scale in pigs undergoing orchiectomy. Forty-five pigs aged 38±3 days were castrated under local anaesthesia. Behaviour was video-recorded 30 minutes before and intermittently up to 24 hours after castration. Edited footage (before surgery, after surgery before and after rescue analgesia, and 24 hours postoperatively) was analysed twice (one month apart) by one observer who was present during video-recording (in-person researcher) and three blinded observers. Statistical analysis was performed using R software and differences were considered significant when p<0.05. Intra and inter-observer agreement, based on intra-class correlation coefficient, was good or very good between most observers (>0.60), except between observers 1 and 3 (moderate agreement 0.57). The scale was unidimensional according to principal component analysis. The scale showed acceptable item-total Spearman correlation, excellent predictive and concurrent criterion validity (Spearman correlation ≥ 0.85 between the proposed scale versus visual analogue, numerical rating, and simple descriptive scales), internal consistency (Cronbach's α coefficient >0.80 for all items), responsiveness (the pain scores of all items of the scale increased after castration and decreased after intervention analgesia according to Friedman test), and specificity (> 95%). Sensitivity was good or excellent for most of the items. The optimal cut-off point for rescue analgesia was ≥ 6 of 18. Discriminatory ability was excellent for all observers according to the area under the curve (>0.95). The proposed scale is a reliable and valid instrument and may be used clinically and experimentally to assess postoperative acute pain in pigs. The well-defined cut-off point supports the evaluator´s decision to provide or not analgesia.

High-Frequency Heart Rate Variability Index: A Prospective, Observational Trial Assessing Utility as a Marker for the Balance Between Analgesia and Nociception Under General Anesthesia

BACKGROUND

Maintaining a balance between nociception and analgesia perioperatively reduces morbidity and improves outcomes. Current intraoperative analgesic strategies are based on subjective and nonspecific parameters. The high-frequency heart rate (HR) variability index is purported to assess the balance between nociception and analgesia in patients under general anesthesia. This prospective observational study investigated whether intraoperative changes in the high-frequency HR variability index correlate with clinically relevant nociceptive stimulation and the addition of analgesics.

METHODS

Instantaneous and mean high-frequency HR variability indexes were measured continuously in 79 adult subjects undergoing general anesthesia for laparoscopic cholecystectomy. The indexes were compared just before and 2 minutes after direct laryngoscopy, orogastric tube placement, first skin incision, and abdominal insufflation and just before and 6 minutes after the administration of IV hydromorphone.

RESULTS

Data from 65 subjects were included in the final analysis. The instantaneous index decreased after skin incision ([SEM], 58.7 [2.0] vs 47.5 [2.0]; P < .001) and abdominal insufflation (54.0 [2.0] vs 46.3 [2.0]; P = .002). There was no change in the instantaneous index after laryngoscopy (47.2 [2.2] vs 40.3 [2.3]; P = .026) and orogastric tube placement (49.8 [2.3] vs 45.4 [2.0]; P = .109). The instantaneous index increased after hydromorphone administration (58.2 [1.9] vs 64.8 [1.8]; P = .003).

CONCLUSIONS

In adult subjects under general anesthesia for laparoscopic cholecystectomy, changes in the high-frequency HR variability index reflect alterations in the balance between nociception and analgesia. This index might be used intraoperatively to titrate analgesia for individual patients. Further testing is necessary to determine whether the intraoperative use of the index affects patient outcomes.

Usefulness of ANI (analgesia nociception index) monitoring for outpatient saphenectomy surgery outcomes: an observational study

The Analgesia Nociception Index (ANI), derived from heart rate variability is a proposed guide to obtain an adequate control of the analgesic component during anaesthesia. This single blind observational study was designed to evaluate the relationship between intraoperative ANI values and length of stay in Day Surgery Units (DSU) in patients undergoing varicose vein intervention. 131 patients (ASA I-II) scheduled for elective varicose vein surgery were studied. A propofol closed-loop TCI was used to maintain a specific level of BIS. To control analgesia, a remifentanil TCI was used, modifying the target according to hemodynamic changes. Patients were included in the ANI > 50 sub-group or in the ANI < 50 sub-group depending on whether the ANI value was greater than 50 for at least 60% of the anaesthesia maintenance period (AMP) or not. The primary endpoint was the length of stay in DSU. Other variables studied were ANI values, duration of the AMP, remifentanil TCI target average, postoperative pain, rescue-analgesia needs and postoperative nausea and vomiting (PONV) were analysed. Statistical analysis of length of stay in DSU was performed with Mann-Whitney test. ANI > 50 sub-group showed a lower length of stay in the DSU [165 min (118-212) vs 186.5 min (119-254), p = 0.0425]. Discharge timing from DSU was statistically different among study sub-groups (p = 0.005). An adequate nociception level measured by ANI during varicose vein surgery might reduce the length of stay at DSU. Further studies are needed to assess the usefulness of ANI in other anaesthesia conditions.

Can postoperative pain be predicted? New parameter: analgesia nociception index

Background/aim

The Analgesia Nociception Index (ANI) is a new method of identifying nociception-analgesia balance. In this study, we investigate the correlation between the ANI and numeric rating scale (NRS) values immediately before and after extubation. The NRS values were recorded in the postanesthesia care unit, in a group of patients who underwent laparoscopic cholecystectomy, with the aim of evaluating the potential use of ANI values in the prediction of postoperative pain levels.

Materials and methods

The ANI and NRS values, heartbeat rate (HR), systolic and diastolic arterial pressure (SAP/DAP), and oxygen saturation (SpO2) values of the patients were recorded into three groups based on the initial NRS values recorded in the postanesthesia care unit (group I: NRS ≤ 3, group II: NRS 4–6, group III: NRS ≥ 7). Patients whose ANI values were lower than 47, considered as the pain threshold, and the groups to which these patients belonged were also recorded.

Results

Statistically significant increases were noted in HR, SAP, and DAP after extubation, while there was no significant change in ANI values. A weak correlation was identified between the ANI and NRS values of all patient groups.

Conclusion

We failed to identify a correlation between ANI and NRS values before and after extubation. Previous studies suggested that the ANI provides more valuable information in anesthetized patients, whereas our findings show that it is ineffective in the prediction of potential postoperative pain.

Painapple®. Validation and evaluation of an electronic application for the management of acute pain in pediatric patients

INTRODUCTION

The digital version of the assessment scales recommended for the pediatric patient could contribute to its improvement and to implement the quality indicators described for the management of acute pain.

MATERIAL AND METHODS

Psychometric validation (validity and reliability) of pain assessment and treatment side effects scales incorporated in the electronic application PainAPPle. For this, both formats (paper and electronic) of all the scales were applied in two measurements with 30minutes of difference in 44 patients from 4 to 18years of the Acute Pain Unit in the immediate postoperative period. In addition, the data collected by PainAPPle was evaluated by retrospectively applying the quality indicators described for the management of acute postoperative pain.

RESULTS

Reliability was studied analyzing the high correlation (Spearman greater than 0.5, P<.001) that we obtained for the values of each scale in two moments with 30minutes of difference, in the same patients. For validity, the high correlation (Spearman greater than 0.5, P<.001) between the values of the paper scales (gold rule) and PainAPPle at both minute 0 and 30 was analyzed. Concordance obtained taking into account the cut-off point of the scales that would force a treatment were also statistically significant (P<.005).

CONCLUSIONS

PainAPPle is a validated instrument for the management of acute pain in pediatric patients. The collected data allow to apply the quality indicators described for the management of acute postoperative pain.

Postoperative Pain Management in Pediatric Patients Undergoing Cardiac Surgery: Where Are We Heading?

OBJECTIVES

Adequate postoperative pain management is crucial in pediatric patients undergoing cardiac surgery because pain can lead to devastating short- and long-term consequences. This review discusses the limitations of current postoperative pain assessment and management in children after cardiac surgery, the obstacles to providing optimal treatment, and concepts to consider that may overcome these barriers.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

Effective pain management in infants and young children undergoing cardiac surgery continues to evolve with innovative methods of both assessment and therapy using newer drugs or novel routes of administration. Artificial intelligence- and machine learning-based pain assessment and patient-tailored management in both pain measurement and prevention are already being integrated into the routine of current practice.

Objective monitoring of nociception: a review of current commercial solutions

Nociception, in contrast to pain, is not a subjective feeling, but the physiological encoding and processing of nociceptive stimuli. However, monitoring nociception remains a challenge in attempts to lower the incidence of acute postoperative pain and the move towards a more automated approach to analgesia and anaesthesia. To date, several commercialised devices promise a more accurate reflection of nociception than the traditionally used vital signs, blood pressure and heart rate. This narrative review presents an overview of existing technologies and commercially available devices, and offers a perspective for future research. Although firm conclusions about individual methods may be premature, none currently appears to offer a sufficiently broad applicability. Furthermore, there is currently no firm evidence for any clinically relevant influence of such devices on patient outcome. However, the available monitors have significantly aided the understanding of underlying mechanisms and identification of potential pitfalls.

Impact of CYP3A4*1G Polymorphism on Fentanyl Analgesia Assessed by Analgesia Nociception Index in Chinese Patients Undergoing Hysteroscopy

Background:

The clinical efficacy of fentanyl for pain control differs greatly across individuals. The purpose of this study was to investigate the impact of CYP3A4*1G polymorphism including wild-type homozygote (CYP3A4*1/*1, GG), mutant heterozygote (CYP3A4*1/*1G, GA), and mutant homozygote (CYP3A4*1G/*1G, AA) on fentanyl analgesia in Chinese patients undergoing hysteroscopy by the assessment of analgesia nociception index (ANI).

Methods:

A total of 200 gynecologic patients scheduled for elective hysteroscopy under general anesthesia at Peking University People's Hospital from May to December in 2017 were enrolled in this study. Venous blood was withdrawn for genotyping of CYP3A4*1G before operation. Fentanyl 1 μg/kg was administered preoperatively followed by target-controlled infusion of propofol for induction and maintenance. Intraoperative analgesic efficacy of fentanyl was assessed by ANI monitoring at T0 (entering room), T1 (cervical dilation), T2 (start of cervical aspiration), and T3 (end of cervical aspiration) time points. The duration of propofol infusion and total dosage of propofol were recorded as well.

Results:

The patients were divided into three groups according to CYP3A4*1G polymorphism, including 143 in GG group, 47 in GA group, and 10 in AA group. There was no significant difference in clinical demographics among three groups. The frequency of CYP3A4*1G variant alleles accounted for 16.8% and the distribution of variant alleles was consistent with Hardy–Weinberg equilibrium. Using a multilevel model, ANI values at T1 (63.81 ± 19.61), T2 (63.63 ± 17.82), and T3 (65.68 ± 17.79) were significantly lower than that at T0 (77.16 ± 12.93) in the study population (F = 23.50, P < 0.001), suggesting that higher levels of pain at T1, T2, and T3 than T0. Patients with GG genotype showed significantly lower ANI than those with GA or AA genotypes during hysteroscopy under the same dose of fentanyl.

Conclusion:

CYP3A4*1G polymorphism associated with the analgesic efficacy of intraoperative fentanyl in the patients undergoing hysteroscopy under general anesthesia.

Observational study of newborn infant parasympathetic evaluation as a comfort system in awake patients admitted to a pediatric intensive care unit

To compare the newborn infant parasympathetic evaluation system (NIPE) scores with a validated clinical scale using two different nebulizers in children with bronchiolitis admitted to a PICU. Comfort was evaluated using the COMFORT-behavior scale (CBS) before (T1), during (T2) and after (T3) each nebulization. In order to compare NIPE and CBS values during the whole T1 to T3 period, the variable Dif-CBS was defined as the difference between maximal and minimal CBS scores, and Dif-NIPE as the difference between 75th and 25th percentile NIPE values. Analyses were carried out, firstly for the total of nebulizations and secondly comparing two different nebulization systems: a jet nebulizer (JN) and a nebulizer integrated in high flow nasal cannulas (NHF). 84 nebulizations were recorded on 14 patients with a median [25th–75th percentile] age of 6 months (3.1–9.5). A Dif-CBS of 4 points (2–7), as well as changes in CBS scores between T1 and T2, defined the nebulization as a discomfort stimulus. The NIPE system, represented as the Dif-NIPE, showed a median variation of 9 points (7–10), and was poorly correlated to Dif-CBS [r_s 0.162 (P = 0.142)]. Discomfort during nebulization, assessed by CBS was greater with the JN system compared to NHF: 17 (13–22) vs 13 (9–15) (P = 0.001). NIPE monitoring detected no significant differences between both nebulization systems (P = 0.706). NIPE monitoring showed a variation in comfort during nebulization in the patient with bronchiolitis, though correlation with CBS was poor. Further research is required before NIPE can be suggested as a comfort monitoring system for the awake infant.

Heart rate variability: implications for perioperative anesthesia care

PURPOSE OF REVIEW

Heart rate variability (HRV) is a measure of the balance between both the parasympathetic and sympathetic nervous system and may provide useful information for anesthesia care providers. HRV may offer predictive information about critically ill and operative patients. Further, HRV collection provides real-time information of patient autonomic nervous system status and may allow tailoring of the analgesia for patients in the ICU and operating room.

RECENT FINDINGS

Reduced and abnormal resting HRV predict sudden and nonsudden cardiac death. Recent evidence shows that decreased HRV correlates with worsened outcomes in both trauma patients and patients with sepsis, as well as the risk of developing hypotension after induction of general anesthesia and placement of intrathecal local anesthesia. In addition, HRV appears to provide an accurate assessment of the nociception-analgesia balance in deeply sedated ICU patients and those under general anesthesia.

SUMMARY

No study has assessed the prognostic value of preoperative HRV in patients presenting for surgery. Use of HRV for patient risk stratification and intraoperative analgesia management may allow tailored perioperative care and improved outcomes. If intraoperative HRV data leads to decreased perioperative opioid use, opioid-related adverse events, a serious perioperative issue, may be decreased.

CLINICAL TRIALS REGISTRATION

Not applicable.

Evaluation of the analgesia nociception index for monitoring intraoperative analgesia in children

BACKGROUND

Intraoperative analgesia is still administered without guidance. Anaesthetists decide upon dosing on the basis of mean population opioid pharmacological studies and in response to variations in haemodynamic status. However, those techniques have been shown to be imprecise. We assessed the diagnostic value of monitoring the analgesia nociception index (ANI) to detect surgical stimulation in children.

METHODS

This was an observational study of 2- to 12-yr-old patients 5 min before and after surgical incision. Hypnosis was maintained with sevoflurane and guided by bispectral index. Intraoperative analgesia was administered as a remifentanil infusion titrated to variations in haemodynamic parameters, and ANI monitor values were recorded. ANI parameters assessed included instantaneous ANI (ANIi), mean ANI (ANIm), and the relative change of ANIi to ANIm (DeltaANI=ANIi-ANIm/ANIm). Statistical analyses were performed using receiver-operating-characteristic analysis with determination of the area under the receiver operating characteristic (AUROC) curve and the grey zone.

RESULTS

Overall, 49 subjects were included in this study. The AUROC was 0.755 (0.738-0.772), 0.771 (0.755-0.787), and 0.756 (0.738-0.774) for ANIi, ANIm, and DeltaANI, respectively. The threshold of ANI parameters indicating the presence of noxious surgical stimuli was ≤53%, ≤56%, and ≤-13.3% for ANIi, ANIm, and DeltaANI, respectively. The percentage of subjects in the inconclusive zone was 41%, 51%, and 33% for ANIi, ANIm, and DeltaANI, respectively.

CONCLUSIONS

ANI has diagnostic value for detecting surgical stimuli in children.

Postoperative pain management in the postanesthesia care unit: an update

Acute postoperative pain remains a major problem, resulting in multiple undesirable outcomes if inadequately controlled. Most surgical patients spend their immediate postoperative period in the postanesthesia care unit (PACU), where pain management, being unsatisfactory and requiring improvements, affects further recovery. Recent studies on postoperative pain management in the PACU were reviewed for the advances in assessments and treatments. More objective assessments of pain being independent of patients' participation may be potentially appropriate in the PACU, including photoplethysmography-derived parameters, analgesia nociception index, skin conductance, and pupillometry, although further studies are needed to confirm their utilities. Multimodal analgesia with different analgesics and techniques has been widely used. With theoretical basis of preventing central sensitization, preventive analgesia is increasingly common. New opioids are being developed with minimization of adverse effects of traditional opioids. More intravenous nonopioid analgesics and adjuncts (such as dexmedetomidine and dexamethasone) are introduced for their opioid-sparing effects. Current evidence suggests that regional analgesic techniques are effective in the reduction of pain and stay in the PACU. Being available alternatives to epidural analgesia, perineural techniques and infiltrative techniques including wound infiltration, transversus abdominis plane block, local infiltration analgesia, and intraperitoneal administration have played a more important role for their effectiveness and safety.

Analgesia nociception index (ani) monitoring in patients with thoracic paravertebral block: a randomized controlled study

The goal of the study was to evaluate the effectiveness of analgesia nociception index (ANI) monitoring during intraoperative period for patients with thoracic paravertebral block (TPVB) undergoing breast surgery under general anesthesia. This prospective randomized trial was performed after receiving ethics committee approval in 44 patients who were scheduled to undergo breast surgery under general anesthesia. TPVB was performed in the preoperative period using 20 mL of bupivacaine 0.25% at T4 level. Anesthesia maintenance was provided with sevoflurane in O₂: air mixture and remifentanil infusion. Intraoperative concentration of sevoflurane was adjusted according to BIS monitoring keeping the values between 40-60. In a randomized manner patients were divided into two groups. In Group control (n:22) intraoperative remifentanil infusion rate was regulated according to hemodynamic parameters, in Group ANI (n:22) remifentanil infusion rate was titrated to keep ANI monitoring values between 50-70. Total remifentanil consumption was recorded as micrograms. Demographic data, anesthesia and surgery time, intraoperative hemodynamic parameters, post-anesthesia recovery time and requirement of additional analgesic in the recovery drug were recorded. There were no significant difference in demographic data, intraoperative hemodynamic parameters, post-anesthesia recovery time and requirement of additional analgesic drug. There was a statistically significant difference between groups in total remifentanil consumption (Group ANI: 629.6 ± 422.4 mcg, Group control: 965.2 ± 543.6 mcg) (p = 0.027). In patients under general anesthesia ANI monitorisation can help optimisation of opioid consumption and provide data about nociception/antinociception intraoperatively but further experimental and clinical trials in a large scale are needed.

Evaluation of the Parasympathetic Tone Activity (PTA) index to assess the analgesia/nociception balance in anaesthetised dogs

The Parasympathetic Tone Activity (PTA) is an index based on the analysis of heart rate variability that has been recently developed to assess the analgesia/nociception balance in anaesthetised animals. The present study aimed to evaluate its performance in dogs undergoing surgery. Thirty dogs admitted for elective surgeries, were anaesthetised with a standardised protocol. PTA, heart rate (HR), systolic blood pressure (SBP) and HDR (defined as an increase by >20% in HR and/or SBP within 5min) were assessed at the following predefined time-points: T_StSt (steady-state, after induction of anaesthesia and before start of surgery), T_Clamp (clamping of surgical drapes on the skin), T_Cut (cutaneous incision), T_PrePTA (retrospectively assessed 1min before a PTA decline of at least 20%) and T_EndIso (isoflurane discontinuation). The dynamic variation of PTA over 1min (∆PTA) was calculated at each predefined time-points and its performance to predict HDR was assessed by building Receiver Operating Characteristics (ROC) curves. A significant decrease of PTA (p<0.002) was detected 1min after T_Clamp, T_Cut and T_PrePTA followed by a significant increase in HR and/or SBP within 5min after the time points (p<0.01). The ΔPTA was associated with the following performance in predicting HDR: AUC ROC [95% CI]=0.80 [0.71 to 0.88] (p<0.05), with a sensitivity of 77% and a specificity of 72% for a threshold value of -18%. Although encouraging, the performance of the PTA index and its dynamic variation needs to be further evaluated, particularly in different clinical contexts.

Monitoring of nociception, reality or fiction?

There are currently various projects underway that attempt to monitor the nociceptive responses caused by surgical stress and ensure patients the best analgesic conditions. The systemic response to surgical stress has repercussions in the postoperative period, such as worse pain control, delayed recovery, greater complications, longer stay in resuscitation and hospital units, and increased healthcare costs. However, treatment with higher doses of opioids than necessary may lead to slower awakening, increased drowsiness and adverse effects, as well as situations of postoperative opioid-induced hyperalgesia. There are 2 large groups of nociceptive monitoring according to the origin of the theoretical objective of monitoring response to the stimulus, that may derive from changes in the electroencephalogram or the response of the autonomic nervous system.

Efficacy of using Zaontz urethral stent in hypospadias repair by the Face, Legs, Activity, Cry, Consolability (FLACC) scale: A prospective study

INTRODUCTION

The developments in hypospadias surgical techniques and materials are intended to improve surgery outcomes and patient comfort. The aim of this study is to determine the effect of the Zaontz urethral stent (ZUS) (Cook Medical) on patient comfort and surgical success rates in children undergoing hypospadias surgery.

METHODS

A feeding tube was used to repair 46 cases of primary distal hypospadias, and ZUS (6F, 8F, and 10F in diameter) was used to repair to 31 cases of primary distal hypospadias between December 2009 and June 2011 in our clinic. ZUS was compared with the feeding tube in terms of surgical success rates and patient comfort in assessments made during postoperative periods.

RESULTS

The patients with ZUS were followed with a stent for seven days postoperatively, as were the patients with the feeding tube. There was no statistical difference between the two groups in terms of fistula formation (p>0.05). Patient comfort was evaluated by the Face, Legs, Activity, Cry, Consolability (FLACC) scale on the first and third postoperative days, and a statistically significant difference was observed in favour of ZUS on the third postoperative day (p<0.05).

CONCLUSIONS

Compared with a feeding tube in hypospadias repair, ZUS does not make any contribution to the urinary fistula rates. However, ZUS may have an advantage in terms of patient comfort in the postoperative followup. On the other hand, the small number of patients and the high price of the ZUS were the most important limitations. Prospective, randomized trials are needed to assess efficacy and cost.

Paracetamol and morphine for infant and neonatal pain; still a long way to go?

INTRODUCTION

Pharmacologic pain management in newborns and infants is often based on limited scientific data. To close the knowledge gap, drug-related research in this population is increasingly supported by the authorities, but remains very challenging. This review summarizes the challenges of analgesic studies in newborns and infants on morphine and paracetamol (acetaminophen). Areas covered: Aspects such as the definition and multimodal character of pain are reflected to newborn infants. Specific problems addressed include defining pharmacodynamic endpoints, performing clinical trials in this population and assessing developmental changes in both pharmacokinetics and pharmacodynamics. Expert commentary: Neonatal and infant pain management research faces two major challenges: lack of clear biomarkers and very heterogeneous pharmacokinetics and pharmacodynamics of analgesics. There is a clear call for integral research addressing the multimodality of pain in this population and further developing population pharmacokinetic models towards physiology-based models.