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.

Validation of a simple tool for anxiety trait screening in children presenting for surgery

Background.

Screening for preoperative anxiety is an important challenge during the preoperative period. The aim of our study was to validate the faces scale used to detect anxiety trait in children.

Methods.

Children aged 8-18 yr were asked to quantify their anxiety trait using the readily available faces scale and to respond to the trait component of the State-Trait Anxiety Inventory (STAI) for children (C) or adults (A) before the anaesthesia consultation. Using receiver operating characteristics analysis, we determined the faces scale optimal value on a construct cohort. A validation cohort was recruited to assess the accuracy of the results.

Results.

The construction cohort comprised 207 patients and the validation cohort 91 patients. The receiver operating characteristics analysis found an area under the curve of 0.75 [95% confidence interval (CI) 0.67, 0.83]. The optimal value for faces scale score was 4, with a sensitivity of 0.61 [95% CI 0.59, 0.62] and a specificity of 0.82 [95% CI 0.81, 0.83]. When this threshold was applied to the construction and validation cohorts, 61.3 and 44.4% of positives were true positives in the construction and validation cohorts, respectively; and 82.1 and 81.3% of negatives were true negatives, respectively.

Conclusions.

Our study determined the performance of a simple faces scale to measure the preoperative anxiety trait in children aged 8-18 yr. This tool is potentially helpful for clinicians aiming to identify patients at risk of preoperative anxiety and to assign them to targeted management.

Performance of CT ASPECTS and Collateral Score in Risk Stratification: Can Target Perfusion Profiles Be Predicted without Perfusion Imaging?

BACKGROUND AND PURPOSE

Endovascular trials suggest that revascularization benefits a subset of acute ischemic stroke patients with large-artery occlusion and small-core infarct volumes. The objective of our study was to identify thresholds of noncontrast CT-ASPECTS and collateral scores on CT angiography that best predict ischemic core volume thresholds quantified by CT perfusion among patients with acute ischemic stroke.

MATERIALS AND METHODS

Fifty-four patients with acute ischemic stroke (<12 hours) and MCA/intracranial ICA occlusion underwent NCCT/CTP during their initial evaluation. CTP analysis was performed on a user-independent platform (RApid processing of PerfusIon and Diffusion), computing core infarct (defined as CBF of <30% normal). A target mismatch profile consisting of infarction core of ≤50 mL was selected to define candidates with acute ischemic stroke likely to benefit from revascularization.

RESULTS

NCCT-ASPECTS of ≥9 with a CTA collateral score of 3 had 100% specificity for identifying patients with a CBF core volume of ≤50 mL. NCCT-ASPECTS of ≤6 had 100% specificity for identifying patients with a CBF core volume of >50 mL. In our cohort, 44 (81%) patients had an NCCT-ASPECTS of ≥9, a CTA collateral score of 3, or an NCCT-ASPECTS of ≤6.

CONCLUSIONS

Using an NCCT-ASPECTS of ≥9 or a CTA collateral score of 3 best predicts CBF core volume infarct of ≤50 mL, while an NCCT-ASPECTS of ≤6 best predicts a CBF core volume infarct of >50 mL. Together these thresholds suggest that a specific population of patients with acute ischemic stroke not meeting such profiles may benefit most from CTP imaging to determine candidacy for revascularization.

Efficacy of intraoperative dexmedetomidine compared with placebo for surgery in adults: a meta-analysis of published studies

Dexmedetomidine (Dex) demonstrates sedative and analgesic effects. We investigated the intraoperative and postoperative effects of intraoperative Dex administration during surgery in adult patients. A search for randomized placebo-controlled trials was conducted in Pubmed and Embase databases to identify randomized controlled clinical trials using intraoperative Dex for surgery in adult population. Outcome assessed were: intraoperative and postoperative opioid consumption, time of recovery from anesthesia, postoperative pain, and postoperative nausea or vomiting (PONV) in the first 24 hours. Data from each trial were combined to calculate pooled odds ratios (OR), mean difference (MD) or standardized mean difference (SMD) and 95% confidence interval (95 % CI). Heterogeneity was measured using I² statistics. Eighteen randomized controlled trials were analyzed. Dex was administered to 815 patients and 410 received placebo. Overall, Dex significantly decreased intraoperative opioid consumption (SMD=-1.58 [-2.98, -0.19], I²=95 %, P<0.00001), but did not decrease time of recovery from anesthesia (SMD=-0.13 [-1.60, 1.34] minutes, I²=95 %, P<0.00001). Dex significantly reduced postoperative opioid consumption (SMD=-1.58 [-2.98, -0.19], I²=95 %, P<0.00001), postoperative pain intensity (SMD=-0.73 [-1.19, -0.27], I²=62 %, P=0.03), and the prevalence of PONV (OR=0.43 [0.27, 0.69], I²=0 %, P=0.46). This meta-analysis shows that intraoperative Dex administration in adult patients reduces intra and postoperative opioid consumption, postoperative pain and PONV. Time of recovery is not affected.

Postoperative decrease in plasma sodium concentration after infusion of hypotonic intravenous solutions in neonatal surgery

BACKGROUND

Hypotonic i.v. solutions can cause hyponatraemia in the context of paediatric surgery. However, this has not been demonstrated in neonatal surgery. The goal of this study was to define the relationship between infused perioperative free water and plasma sodium in neonates.

METHODS

Newborns up to 7 days old undergoing abdominal or thoracic surgery were included in this prospective, observational study. Collected data included type and duration of surgery, calculated i.v. free water intake, and pre- and postoperative plasma sodium. Statistical analyses were performed using the Pearson correlation, Mann-Whitney test, and receiver operating characteristic analysis with a 1000 time bootstrap procedure.

RESULTS

Thirty-four subjects were included. Postoperative hyponatraemia occurred in four subjects (11.9%). The difference between preoperative and postoperative plasma sodium measurements (ΔNaP) correlated with calculated free water intake during surgery (r=0.37, P=0.03), but not with preoperative free water intake. Calculated operative free water intake exceeding 6.5 ml kg(-1) h(-1) was associated with ΔNaP≥4 mM with a sensitivity and specificity [median (95% confidence interval)] of 0.7 (0.9-1) and 0.5 (0.3-0.7), respectively.

CONCLUSIONS

Hypotonic solutions and i.v. free water intake of more than 6.5 ml kg(-1) h(-1) are associated with reductions in postoperative plasma sodium measurements ≥4 mM. In the context of neonatal surgery, close monitoring of plasma sodium is mandatory. Routine use of hypotonic i.v. solutions during neonatal surgery should be questioned as they are likely to reduce plasma sodium.

[Opioid-sparing effect of ketamine during tonsillectomy in children]

INTRODUCTION

In the adult population, Ketamine is currently used as an antihyperalgesic and opioid-sparing agent during the perioperative period. However, for doses of ketamine up to 0.5mg/kg, these effects have not been found in pediatric population. The aim of the present study was to evaluate the efficacy of a preoperative bolus of 1mg/kg of ketamine on postoperative pain intensity and morphine consumption in children undergoing tonsillectomy.

METHODS

We have undertaken a retrospective comparison of 60 consecutive children operated for tonsillectomy in our institution before (first 30 patients) and after (last 30 patients) the introduction of a preoperative bolus of 1mg/kg of ketamine. Data collected were: age, ASA score, dose of intraoperative sufentanil, OPS score during PACU stay and the first postoperative day, morphine consumption during PACU stay and the first postoperative day, psychodysleptic manifestations, pain at first solid oral intake and postoperative respiratory complications or haemorrhage.

RESULTS

No difference was found between the two groups in terms of demographic characteristics. Perioperative doses of sufentanil, postoperative opioid consumption or pain score in PACU or during 24hours were similar between the two groups. The two groups did not differ in terms of pain at first oral intake, or other adverse effects.

CONCLUSION

These results suggest that 1mg/kg of ketamine administered right after anaesthesia induction in children undergoing tonsillectomy did not result in an opioid sparing effect.

Deviation from a preoperative surgical and anaesthetic care plan is associated with increased risk of adverse intraoperative events in major abdominal surgery

BACKGROUND

Perioperative coordination facilitates team communication and planning. The aim of this study was to determine how often deviation from predicted surgical conditions and a pre-established anaesthetic care plan in major abdominal surgery occurred, and whether this was associated with an increase in adverse clinical events.

METHODS

In this prospective observational study, weekly preoperative interdisciplinary team meetings were conducted according to a joint care plan checklist in a tertiary care centre in France. Any discordance with preoperative predictions and deviation from the care plan were noted. A link to the incidence of predetermined adverse intraoperative events was investigated.

RESULTS

Intraoperative adverse clinical events (ACEs) occurred in 15 % of all cases and were associated with postoperative complications [relative risk (RR) = 1.5; 95 % confidence interval (1.1; 2.2)]. Quality of prediction of surgical procedural items was modest, with one in five to six items not correctly predicted. Discordant surgical prediction was associated with an increased incidence of ACE. Deviation from the anaesthetic care plan occurred in around 13 %, which was more frequent when surgical prediction was inaccurate (RR > 3) and independently associated with ACE (odds ratio 6).

CONCLUSION

Surgery was more difficult than expected in up to one out of five cases. In a similar proportion, disagreement between preoperative care plans and observed clinical management was independently associated with an increased risk of adverse clinical events.

Lessons learnt from two pediatric motor vehicle accidents resulting in anal canal, rectal and gluteal muscle wrenching

Ano-rectal trauma is common in motor vehicle accidents involving children. Inadequate initial assessment of the extent of lesions may be life threatening. We describe two cases where children were struck by buses that subsequently rolled over them in the prone position, resulting in ano-rectal and gluteal muscle wrenching. The first patient was inadequately assessed. Initial management did not include a diverting stoma, leading to life-threatening necrosis and septic shock. The second benefitted from our previous experience and recovery was uneventful. The distinctive mechanism of trauma in true gluteal muscle and anal canal wrenching is discussed. Gluteal muscle, anal canal and rectal wrenching as a result of rolling force from a motor vehicle is a very serious condition requiring immediate intestinal diversion with a stoma. Immediate repair may be attempted at the same time as stoma creation if the patient is stable. Broad-spectrum antibiotics and close wound monitoring are necessary to avoid muscle necrosis and serious complications.

Premedication with clonidine is superior to benzodiazepines. A meta analysis of published studies

BACKGROUND

Premedication is considered important in pediatric anesthesia. Benzodiazepines are the most commonly used premedication agents. Clonidine, an alpha2 adrenoceptor agonist, is gaining popularity among anesthesiologists. The goal of the present study was to perform a meta-analysis of studies comparing premedication with clonidine to Benzodiazepines.

METHODS

A comprehensive literature search was conducted to identify clinical trials focusing on the comparison of clonidine and Benzodiazepines for premedication in children. Six reviewers independently assessed each study to meet the inclusion criteria and extracted data. Original data from each trial were combined to calculate the pooled odds ratio (OR) or the mean differences (MD), 95% confidence intervals [95% CI] and statistical heterogeneity were accessed.

RESULTS

Ten publications fulfilling the inclusion criteria were found. Premedication with clonidine, in comparison with midazolam, exhibited a superior effect on sedation at induction (OR=0.49 [0.27, 0.89]), decreased the incidence of emergence agitation (OR=0.25 [0.11, 0.58]) and produced a more effective early post-operative analgesia (OR=0.33 [0.21, 0.58]). Compared with diazepam, clonidine was superior in preventing post-operative nausea and vomiting (PONV).

DISCUSSION

Premedication with clonidine is superior to midazolam in producing sedation, decreasing post-operative pain and emergence agitation. However, the superiority of clonidine for PONV prevention remains unclear while other factors such as nausea prevention might interfere with this result.

Pharmacological prevention of sevoflurane- and desflurane-related emergence agitation in children: a meta-analysis of published studies

BACKGROUND

Emergence agitation (EA) in children is increased after sevoflurane anaesthesia. The efficacy of prophylactic treatment is controversial. The aim of this study was to provide a meta-analysis of the studies of the pharmacological prevention of EA in children.

METHODS

A comprehensive literature search was conducted to identify clinical trials that focused on the prevention of EA in children anaesthetized with sevoflurane, desflurane, or both. The data from each trial were combined using the Mantel-Haenszel model to calculate the pooled odds ratio (OR) and 95% confidence interval. I(2) statistics were used to assess statistics heterogeneity and the funnel plot and the Begg-Mazumdar test to assess bias.

RESULTS

Thirty-seven articles were found which included a total of 1695 patients in the intervention groups and 1477 in the control ones. Midazolam and 5HT(3) inhibitors were not found to have a protective effect against EA [OR=0.88 (0.44, 1.76); OR=0.39 (0.12, 1.31), respectively], whereas propofol [OR=0.21 (0.16, 0.28)], ketamine [OR=0.28 (0.13, 0.60)], alpha(2)-adrenoceptors [OR=0.23 (0.17, 0.33)], fentanyl [OR=0.31 (0.18, 0.56)], and peroperative analgesia [OR=0.15 (0.07, 0.34)] were all found to have a preventive effect. Subgroup analysis according to the peroperative analgesia given does not affect the results.

CONCLUSIONS

This meta-analysis found that propofol, ketamine, fentanyl, and preoperative analgesia had a prophylactic effect in preventing EA. The analgesic properties of these drugs do not seem to have a role in this effect.

Could nutritional rehabilitation at home complement or replace centre-based therapeutic feeding programmes for severe malnutrition?

To measure the success rate of three different strategies used in Médecins Sans Frontières large-scale therapeutic nutritional rehabilitation programme in Niger, we analysed three cohorts of severely malnourished patients in terms of daily weight gain, length of stay, recovery, case fatality and defaulting. A total of 1937 children aged 6-59 months were followed prospectively from 15 August 2002 to 21 October 2003. For the three cohorts, 660 children were maintained in the therapeutic feeding centre (TFC) during the entire treatment, 937 children were initially treated at the TFC and completed treatment at home and 340 children were exclusively treated at home. For all cohorts, average time in the programme and average weight gain met the international standards (30-40 days, >8 g/kg/day). Default rates were 28.1, 16.8 and 5.6% for TFC only, TFC plus home-based and home-based alone strategies, respectively. The overall case fatality rate for the entire programme was 6.8%. Case fatality rates were 18.9% for TFC only and 1.7% for home-based alone. No deaths were recorded in children transferred to rehabilitation at home. This study suggests that satisfactory results for the treatment of severe malnutrition can be achieved using a combination of home and hospital-based strategies.

Case management of a multidrug-resistant Shigella dysenteriae serotype 1 outbreak in a crisis context in Sierra Leone, 1999-2000

From December 1999 to the end of February 2000, 4218 cases of dysentery were reported in Kenema district, southeastern Sierra Leone, by a Médecins Sans Frontières team operating in this region. Shigella dysenteriae serotype 1 was isolated from the early cases. The overall attack rate was 7.5% but higher among children under 5 years (11.2%) compared to the rest of the population (6.8%) (RR = 1.6; 95% CI 1.5-1.8). The case fatality ratio was 3.1%, and higher for children under 5 years (6.1% vs. 2.1%) (RR = 2.9; 95% CI 2.1-4.1). A case management strategy based on stratification of affected cases was chosen in this resource-poor setting. Patients considered at higher risk of death were treated with a 5 day ciprofloxacin regimen in isolation centres. Five hundred and eighty-three cases were treated with a case fatality ratio of 0.9%. Patients who did not have signs of severity when seen by health workers were given hygiene advice and oral rehydration salts. This strategy was effective in this complex emergency.

Locomotor activity in depressed children and adolescents: I. Circadian dysregulation

OBJECTIVE

To determine whether circadian activity rhythms were altered in pediatric patients with depression. Evidence was sought for a shift in the timing of the rhythm, blunting of circadian amplitude, or emergence of noncircadian periodicities.

METHOD

Locomotor activity was quantified in 57 patients with major depressive mood disorders (mean age 12.4 years) and 16 normal controls (9.9 years). Activity was measured in 5-minute epochs during 72 hours using belt-worn electronic activity monitors.

RESULTS

Patients with mood disorders displayed a 15% decrease in the amplitude of their circadian rhythm, and a 52% increase in the magnitude of their twice-daily (hemicircadian) rhythm. No significant difference emerged in the timing of the circadian rhythm. Depressed inpatients and outpatients displayed comparable disturbances, which were most marked in adolescents.

CONCLUSIONS

Circadian activity rhythms were dysregulated in pediatric patients with major depression. These findings may have etiological and diagnostic significance.

The hemolytic-uremic syndrome

Our experience with 61 episodes of the hemolytic-uremic syndrome in 60 patients showed a mean patient age of 3 years and a higher incidence of the disease during the summer months. Diarrhea, often bloody, preceded the other features of the illness in 93 percent of the cases. Hemolytic anemia, hematuria and proteinuria occurred in all of the patients. Thrombocytopenia and severe azotemia (blood urea nitrogen greater than 100 mg per dl) occurred in 74 percent and 72 percent of the children, respectively. Blood transfusions were necessary in 64 percent and dialysis was required in 54 percent of the cases. Mortality was low (5 percent) and 85 percent of the children had a complete recovery.

CNS manifestations of the hemolytic-uremic syndrome. Relationship to metabolic alterations and prognosis

To define the CNS manifestations of the hemolytic-uremic syndrome (HUS), the records of 61 consecutive episodes of HUS in 60 patients were reviewed. Major CNS signs (seizures and/or coma) occurred in 30 of the 61 episodes. Twenty-four children had seizures. Analysis of blood pressure and metabolic parameters or admission to the hospital did not predict which child would exhibit CNS signs. However, during the subsequent course of the illness, children with CNS dysfunction had lower minimum serum sodium concentrations and more severe azotemia and were more likely to require dialysis than children without CNS signs. Of the 61 episodes, there were three deaths, and three children suffered major CNS sequelae. Coma at the time of admission and elevated CSF protein levels were features associated with poor outcome.