Short-Term Chloral Hydrate Administration and Cancer in Humans

Risk factors for chloral hydrate sedation failure in pediatric patients: a retrospective analysis

BACKGROUND

This study aimed to investigate the risk factors for chloral hydrate sedation failure and complications in a tertiary children's hospital in South Korea.

METHODS

A retrospective analysis of pediatric procedural sedation with chloral hydrate between January 1, 2021, and March 30, 2022, was performed. The collected data included patient characteristics, sedation history, and procedure. Multivariable regression analysis was performed to identify the risk factors for procedural sedation failure and complications.

RESULTS

A total of 6,691 procedural sedation were included in the analysis; sedation failure following chloral hydrate (50 mg/kg) occurred in 1,457 patients (21.8%) and was associated with a higher rate of overall complications compared to those with successful sedation (17.5% [225/1457] vs. 6.2% [322/5234]; P < 0.001, odds ratio: 3.236). In the multivariable regression analysis, the following factors were associated with increased risk of sedation failure: general ward or intensive care unit inpatient (compared with outpatient); congenital syndrome; oxygen dependency; history of sedation failure or complications with chloral hydrate; procedure more than 60 min; and magnetic resonance imaging, radiotherapy, or procedures with painful or intense stimuli (all P values < 0.05). Factors contributing to the complications included general ward inpatient, congenital syndromes, congenital heart disease, preterm birth, oxygen dependency, history of complications with chloral hydrate, and current sedation failure with chloral hydrate (all P values < 0.05).

CONCLUSIONS

To achieve successful sedation with chloral hydrate, the patient's sedation history, risk factors, and the type and duration of the procedure should be considered.

Comparison of intranasal dexmedetomidine alone and dexmedetomidine-chloral hydrate combination sedation for electroencephalography in children: A large retrospective cohort study and propensity score-matched analysis

Aim

To compare the safety and efficacy of intranasal high-dose dexmedetomidine (DEX) versus a combination of intranasal low-dose dexmedetomidine and oral chloral hydrate (DEX-CH) sedation during electroencephalography (EEG) in children.

Methods

Unadjusted analysis, 1:1 propensity score matching (PSM), and inverse probability of treatment weighting (IPTW) were used to compare the sedation success rate, adverse effects, onset time, and recovery time of these two sedation methods for 6967 children who underwent EEG.

Results

A total of 6967 children were enrolled in this study, of whom 846 (12.1 %) underwent DEX intranasal sedation while 6121 (87.9 %) received DEX-CH sedation. No significant differences were observed in the sedation success rate with the first dose between the two groups [824 (97.4 %) for DEX vs. 5971 (97.6 %) for DEX-CH; RR 0.99; 95 % CI, 0.98-1.01; P = 0.79]. Similarly, there were no notable disparities in the incidence of adverse events [16 (1.9 %) for DEX vs. 101 (1.7 %) for DEX-CH; RR 1.15; 95 % CI, 0.68-1.93; P = 0.32]. However, intranasal DEX sedation compared with DEX-CH sedation was associated with lower vomiting [0 vs. 95(1.6 %); RR 0.04; 95 % CI, 0.02-0.6; P = 0.02] or more bradycardia [13(1.5 %) vs. 2(0.03 %); RR 47.03; 95 % CI, 10.63-208.04; P < 0.001]. Multivariate analysis using PSM and IPTW analysis yielded similar results.

Conclusion

Both methods for EEG had high sedation success rate and low incidence of adverse events. High-dose intranasal DEX was more likely to induce bradycardia and had a shorter recovery time than the DEX-CH sedation, which was more likely to induce vomiting.

Intranasal dexmedetomidine for sedation in ABR testing in children: No pain, big gain!

OBJECTIVES

Obtaining perfect immobility or sleep in children undergoing ABR auditory brainstem response) testing can be challenging. We examined the effectiveness and safety of intranasal dexmedetomidine for sedation of children undergoing ABR testing.

MATERIAL AND METHODS

We included prospectively all patients aged from 1 to 15 years for whom sedation for ABR testing was required, between July 2018 and November 2021. We administered an initial dose of 2.5 μg/kg intranasal dexmedetomidine with a repeat dose of 1 μg/kg if needed 30 min later. Collected data included success rate of sedation, sedation onset and recovery times and incidence of side effects.

RESULTS

ABR testing was undertaken successfully in 57 of the 59 patients, giving a total success rate of 96,6 %. (95 % confidence interval 88.5 %-99.1 %). The median time to onset of sleep was 32 ± 18.3 min. The median duration of sedation recovery time was 48 ± 24.7 min. We recorded the adverse effects. Thirty-one patients experienced bradycardia and 28 patients experienced hypotension, all of which resolved without intervention.

CONCLUSION

Intranasal dexmedetomidine is an effective, safe, simple of use and noninvasive method for sedation in children. It could have a major role in auditory brainstem response testing, specially in the case of non-cooperative children.

REGISTRATION NUMBER OF THE TRIAL

NCT03530371.

Melatonin vs. dexmedetomidine for sleep induction in children before electroencephalography

Background and objectives

In children requiring electroencephalography (EEG), sleep recording can provide crucial information. As EEG recordings during spontaneous sleep are not always possible, pharmacological sleep-inducing agents are sometimes required. The aim of the study was to evaluate safety and efficacy of melatonin (Mel) and dexmedetomidine (Dex; intranasal and sublingual application) for sleep induction prior to EEG.

Methods

In this prospective randomized study, 156 consecutive patients aged 1-19 years were enrolled and randomized by draw into melatonin group (Mel; n = 54; dose: 0.1 mg/kg), dexmedetomidine (Dex) sublingual group (DexL; n = 51; dose: 3 mcg/kg) or dexmedetomidine intranasal group (DexN; n = 51; dose: 3 mcg/kg). We compared the groups in several parameters regarding efficacy and safety and also carried out a separate analysis for a subgroup of patients with complex behavioral problems.

Results

Sleep was achieved in 93.6% of participants after the first application of the drug and in 99.4% after the application of another if needed. Mel was effective as the first drug in 83.3% and Dex in 99.0% (p < 0.001); in the subgroup of patients with complex developmental problems Mel was effective in 73.4% and Dex in 100% (p < 0.001). The patients fell asleep faster after intranasal application of Dex than after sublingual application (p = 0.006). None of the patients had respiratory depression, bradycardia, desaturation, or hypotension.

Conclusions

Mel and Dex are both safe for sleep induction prior to EEG recording in children. Dex is more effective compared to Mel in inducing sleep, also in the subgroup of children with complex behavioral problems.

Clinical Trial Registration

Dexmedetomidine and Melatonin for Sleep Induction for EEG in Children, NCT04665453.

Efficacy and safety of chloral hydrate in auditory brainstem response test: A systematic review and single-arm meta-analysis

OBJECTIVES

To evaluate the safety and efficacy of chloral hydrate in auditory brainstem response (ABR) tests.

SETTING AND DESIGN

In this study, the authors systematically searched both English (Embase, PubMed, and Web of Science) and Chinese (Chinese National Knowledge Infrastructure, Wanfang Data, and VIP Chinese Science) databases. Two authors independently performed data extraction and quality assessment. The pooled sedation failure rate and the pooled incidence of adverse events were calculated via a random-effects model. Sensitivity and subgroup analyses were performed to explore the sources of heterogeneity, and the PRISMA guideline was followed.

PARTICIPANTS

Patients with ABR tests receiving chloral hydrate sedation.

MAIN OUTCOME MEASURES

The pooled sedation failure rate and the pooled incidence of adverse events.

RESULTS

A total of 23 clinical studies were included in the final analysis. The pooled sedation failure rate of patients who received chloral hydrate sedation before ABR examination was 10.0% [95% confidence interval (CI) (6.7%, 15.0%), I2 = 95%, p < .01]. There were significant differences in the prevalence of sedation failure between sample sizes greater than 200 and those less than or equal to 200 (5.6% vs. 19.6%, p < .01) and between the studies that reported sleep deprivation and those that did not report sleep deprivation (7.1% vs. 18.9%, p < .01). The pooled incidence of adverse events was 10.32% [95% CI (5.83%, 14.82%), I2 = 98.1%, p < .01].

CONCLUSIONS

Chloral hydrate has a high rate of sedation failure, adverse events, and potential carcinogenicity. Therefore, replacing its use in ABR tests with safer and more effective sedatives is warranted.

French survey of sedation practices for pediatric magnetic resonance and computed tomography imaging

BACKGROUND

Pediatric magnetic resonance imaging (MRI) and computed tompgraphy (CT) require patient immobility and therefore often require sedation or general anesthesia of patients. Consensus on these procedures is lacking in France.

OBJECTIVE

Thus, the aim of this study was to describe the current sedation practices for pediatric MRI and CT in France.

MATERIAL AND METHODS

From January 2019 to December 2019, an online questionnaire was delivered by electronic mail to a representative radiologist in 60 pediatric radiology centers registered by the French-speaking pediatric and prenatal imaging society. Questions included protocols, drugs used, monitoring and side effects.

RESULTS

Representatives of 40 of the 60 (67%) radiology centers responded to the survey. Among them, 31 performed sedation including 17 (55%) centers where radiologists performed sedation without anesthesiologists present during the procedure. The premedication drugs were hydroxyzine (n = 8, 80%) and melatonin (n = 2, 20%), Sedation drugs used for children ages 0 to 6 years old were pentobarbital (n = 9, 60%), midazolam (n = 2, 13%), chloral hydrate (n = 2, 13%), diazepam (n = 1, 6.5%) and chlorpromazine (n = 1, 6.5%). A written sedation protocol was available in 10/17 (59%) centers. In 6/17 (35%) centers, no monitoring was used during the procedures. Blood pressure monitoring and capnography were rarely used (< 10%) and post-sedation monitoring was heterogeneous. No life-threatening adverse effect was reported, but 6 centers reported at least one incident per year.

CONCLUSION

For half of the responding radiology centers, radiologists performed sedation alone in agreement with the local anesthesiology team. Sedation procedures and monitoring were heterogenous among centers. Adjustment and harmonization of the practices according to the capacity of each center may be useful.

Nasal drip of dexmedetomidine for optimal sedation during PICC insertion in pediatric burn care

BACKGROUND

For peripherally inserted central catheter (PICC) inserting, tranquil cooperation of children for an extended period is often required. Therefore, sedation is routinely induced clinically prior to PICC inserting. Chloral hydrate is a commonly used sedative for children. However, its clinical acceptance has remained low. And the sedation effect is non-satisfactory. Previous studies have confirmed the safety and effectiveness of intravenous/oral dosing or nasal dripping for sedation during the examinations of electrocardiography and computed tomography. Yet few studies have assessed the sedating efficacy of dexmedetomidine nasal drops for PICC inserting.

METHODS

From a cohort of 40 hospitalized patients scheduled for PICC inserting, 15 children employing a novel sedative mode of dexmedetomidine nasal drops at a dose of 2 ug/kg were assigned into group A while group B included another 25 children sedated routinely via an enema of 10% chloral hydrate at a dose of 0.5 mL/kg. The Ramsay's scoring criteria were utilized for assessing the status of sedation. Two groups were observed with regards to success rate of sedation, onset time of sedation and occurrences of adverse reactions.

RESULTS

Statistical inter-group differences existed in success rate and onset time of sedation. The success rate of group A was higher than that of group B (93.3% vs 64.0%, X2 = 4.302, P = .038 < 0.05). Group A had a faster onset of sedation than group B (14.86 ± 2.57 vs 19.06 ± 3.40 minutes, t = 3.781, P = .001 < 0.05). No inter-group difference of statistical significance existed in occurrence of adverse reactions (P = 1.000 > 0.05). Logistic regression analysis showed that the success rate of sedation in group A was higher than that in group B, and the difference was statistically significant (P = .036 < 0.05).

CONCLUSIONS

For sedating burn children, nasal dripping of dexmedetomidine is both safe and effective during PICC inserting. Without any obvious adverse reaction, it may relieve sufferings and enhance acceptance.

Nurse-driven intranasal dexmedetomidine administration as sedation for non-invasive procedures in children: a single centre audit

The purpose of this study is to audit the efficacy and safety of intranasal dexmedetomidine sedation for non-invasive procedural sedation in children provided by nurses of the procedural sedation (PROSA) team in the University Hospitals Leuven. Efficacy (successful sedation as sole sedative) and safety (cardiorespiratory monitoring, saturation) were assessed. In this audit, prospectively recorded data were extracted from the medical files in 772 patients between 4 weeks to 18 years old, who underwent sedation with intranasal dexmedetomidine (2-4 µg/kg) by the nurse-driven PROSA team, following pre-screening on risk factors. Ninety-one percent of the patients were successfully sedated (single dose, monotherapy), 60 patients (7.8%) needed an additional intervention during sedation, 37 (4.8%) needed an extra dose of intranasal dexmedetomidine, and 14 (1.8%) received an additional other sedative. Successful sedation rates were higher in younger children, and medical imaging was the most common indication. Sedation failed in 12 (1.6%) patients, with 10 of them failed to fall asleep. Adverse events were limited in number (n = 13, 1.7%) and severity: 4 patients had a low heart rate (one received atropine), one had an irregular heart rate, and 7 desaturation events were described. Hypotension was treated with normal saline in one case.

CONCLUSIONS

In this nurse-driven PROSA setting, intranasal dexmedetomidine is effective and safe for non-invasive procedural sedation in an a priori low risk group of paediatric patients.

WHAT IS KNOWN

• Procedural sedation outside the operating theatre or intensive care units is increasingly used, including sedation performed by non-anaesthesiologists or nurses. This resulted in the development of procedural sedation and analgesia (PROSA) teams. • Off-label use of intranasal dexmedetomidine in children is increasing, with a limited number of audits on this practice, its safety and efficacy.

WHAT IS NEW

• In an audit on 772 procedures, nurse-driven intranasal dexmedetomidine administration as sedation for non-invasive procedures in children within a structured framework was safe and effective. • Imaging (CT, MRI) was the most common procedural indication in our study, but also nuclear imaging techniques were included.

Efficacy of Liposomal Melatonin in sleep EEG in Childhood: A Double Blind Case Control Study

Electroencephalography (EEG) is pivotal in the clinical assessment of epilepsy, and sleep is known to improve the diagnostic yield of its recording. Sleep-EEG recording is generally reached by either partial deprivation or by administration of sleep-inducing agents, although it is still not achieved in a considerable percentage of patients. We conducted a double-blind placebo-controlled study, involving a hundred patients between 1 and 6 years old, randomized into two groups: Group 1 received liposomal melatonin (melatosome) whereas Group 2 received a placebo. Sleep latency (SL), defined as the time span between the onset of a well-established posterior dominant rhythm, considered as a frequency of 3 to 4 Hz, increasing to 4-5 Hz by the age of 6 months, to 5-7 Hz by 12 months, and finally to 8 Hz by 3 years, and the first EEG sleep figures detected, were measured for each patient. A significant difference in SL was observed (10.8 ± 5 vs. 18.1 ± 13.4 min, p-value = 0.002). Within each group, no differences in sleep latency were detected between genders. Furthermore, no difference in EEG abnormality detection was observed between the two groups. Our study confirmed the efficacy and safety of melatonin administration in sleep induction. Nonetheless, liposomal melatonin presents a greater bioavailability, ensuring a faster effect and allowing lower dosages. Such results, never before reported in the literature, suggest that the routine employment of melatonin might improve clinical practice in neurophysiology, reducing unsuccessful recordings.

Chloral hydrate as a sedating agent for neurodiagnostic procedures in children

BACKGROUND

This is an updated version of a Cochrane Review published in 2017. Paediatric neurodiagnostic investigations, including brain neuroimaging and electroencephalography (EEG), play an important role in the assessment of neurodevelopmental disorders. The use of an appropriate sedative agent is important to ensure the successful completion of the neurodiagnostic procedures, particularly in children, who are usually unable to remain still throughout the procedure.

OBJECTIVES

To assess the effectiveness and adverse effects of chloral hydrate as a sedative agent for non-invasive neurodiagnostic procedures in children.

SEARCH METHODS

We searched the following databases on 14 May 2020, with no language restrictions: the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 12 May 2020). CRS Web includes randomised or quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, the Cochrane Central Register of Controlled Trials (CENTRAL), and the specialised registers of Cochrane Review Groups including Cochrane Epilepsy.

SELECTION CRITERIA

Randomised controlled trials that assessed chloral hydrate agent against other sedative agent(s), non-drug agent(s), or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated studies identified by the search for their eligibility, extracted data, and assessed risk of bias. Results were expressed in terms of risk ratio (RR) for dichotomous data and mean difference (MD) for continuous data, with 95% confidence intervals (CIs).

MAIN RESULTS

We included 16 studies with a total of 2922 children. The methodological quality of the included studies was mixed. Blinding of the participants and personnel was not achieved in most of the included studies, and three of the 16 studies were at high risk of bias for selective reporting. Evaluation of the efficacy of the sedative agents was also underpowered, with all the comparisons performed in small studies. Fewer children who received oral chloral hydrate had sedation failure compared with oral promethazine (RR 0.11, 95% CI 0.01 to 0.82; 1 study; moderate-certainty evidence). More children who received oral chloral hydrate had sedation failure after one dose compared to intravenous pentobarbital (RR 4.33, 95% CI 1.35 to 13.89; 1 study; low-certainty evidence), but there was no clear difference after two doses (RR 3.00, 95% CI 0.33 to 27.46; 1 study; very low-certainty evidence). Children with oral chloral hydrate had more sedation failure compared with rectal sodium thiopental (RR 1.33, 95% CI 0.60 to 2.96; 1 study; moderate-certainty evidence) and music therapy (RR 17.00, 95% CI 2.37 to 122.14; 1 study; very low-certainty evidence). Sedation failure rates were similar between groups for comparisons with oral dexmedetomidine, oral hydroxyzine hydrochloride, oral midazolam and oral clonidine. Children who received oral chloral hydrate had a shorter time to adequate sedation compared with those who received oral dexmedetomidine (MD -3.86, 95% CI -5.12 to -2.6; 1 study), oral hydroxyzine hydrochloride (MD -7.5, 95% CI -7.85 to -7.15; 1 study), oral promethazine (MD -12.11, 95% CI -18.48 to -5.74; 1 study) (moderate-certainty evidence for three aforementioned outcomes), rectal midazolam (MD -95.70, 95% CI -114.51 to -76.89; 1 study), and oral clonidine (MD -37.48, 95% CI -55.97 to -18.99; 1 study) (low-certainty evidence for two aforementioned outcomes). However, children with oral chloral hydrate took longer to achieve adequate sedation when compared with intravenous pentobarbital (MD 19, 95% CI 16.61 to 21.39; 1 study; low-certainty evidence), intranasal midazolam (MD 12.83, 95% CI 7.22 to 18.44; 1 study; moderate-certainty evidence), and intranasal dexmedetomidine (MD 2.80, 95% CI 0.77 to 4.83; 1 study, moderate-certainty evidence). Children who received oral chloral hydrate appeared significantly less likely to complete neurodiagnostic procedure with child awakening when compared with rectal sodium thiopental (RR 0.95, 95% CI 0.83 to 1.09; 1 study; moderate-certainty evidence). Chloral hydrate was associated with a higher risk of the following adverse events: desaturation versus rectal sodium thiopental (RR 5.00, 95% 0.24 to 102.30; 1 study), unsteadiness versus intranasal dexmedetomidine (MD 10.21, 95% CI 0.58 to 178.52; 1 study), vomiting versus intranasal dexmedetomidine (MD 10.59, 95% CI 0.61 to 185.45; 1 study) (low-certainty evidence for aforementioned three outcomes), and crying during administration of sedation versus intranasal dexmedetomidine (MD 1.39, 95% CI 1.08 to 1.80; 1 study, moderate-certainty evidence). Chloral hydrate was associated with a lower risk of the following: diarrhoea compared with rectal sodium thiopental (RR 0.04, 95% CI 0.00 to 0.72; 1 study), lower mean diastolic blood pressure compared with sodium thiopental (MD 7.40, 95% CI 5.11 to 9.69; 1 study), drowsiness compared with oral clonidine (RR 0.44, 95% CI 0.30 to 0.64; 1 study), vertigo compared with oral clonidine (RR 0.15, 95% CI 0.01 to 2.79; 1 study) (moderate-certainty evidence for aforementioned four outcomes), and bradycardia compared with intranasal dexmedetomidine (MD 0.17, 95% CI 0.05 to 0.59; 1 study; high-certainty evidence). No other adverse events were significantly associated with chloral hydrate, although there was an increased risk of combined adverse events overall (RR 7.66, 95% CI 1.78 to 32.91; 1 study; low-certainty evidence).

AUTHORS' CONCLUSIONS

The certainty of evidence for the comparisons of oral chloral hydrate against several other methods of sedation was variable. Oral chloral hydrate appears to have a lower sedation failure rate when compared with oral promethazine. Sedation failure was similar between groups for other comparisons such as oral dexmedetomidine, oral hydroxyzine hydrochloride, and oral midazolam. Oral chloral hydrate had a higher sedation failure rate when compared with intravenous pentobarbital, rectal sodium thiopental, and music therapy. Chloral hydrate appeared to be associated with higher rates of adverse events than intranasal dexmedetomidine. However, the evidence for the outcomes for oral chloral hydrate versus intravenous pentobarbital, rectal sodium thiopental, intranasal dexmedetomidine, and music therapy was mostly of low certainty, therefore the findings should be interpreted with caution. Further research should determine the effects of oral chloral hydrate on major clinical outcomes such as successful completion of procedures, requirements for an additional sedative agent, and degree of sedation measured using validated scales, which were rarely assessed in the studies included in this review. The safety profile of chloral hydrate should be studied further, especially for major adverse effects such as oxygen desaturation.

Factors affecting successful use of intranasal dexmedetomidine: a cohort study from a national paediatrics tertiary centre

BACKGROUND

Use of intranasal (IN) dexmedetomidine for procedural sedation has been reported in recent years. Good patient selection is important to ensure high success rates. We aimed to identify factors that influence the successful use of IN dexmedetomidine in non-invasive investigations.

METHODS

All paediatric patients who received IN dexmedetomidine for investigations between 01 July 2019 to 01 July 2020 were included. Baseline demographics, time to reach adequate sedation level, duration of sedation, dose, indications for sedation and need for rescue sedatives were recorded. Procedures were classified into "long" or "short" according to completion time. Successful sedation was defined by completion of investigations by IN dexmedetomidine alone.

RESULTS

Of 105 patients included, median age was 20.0 months, and median weight 11.0 kg. Magnetic resonance imaging (56, 53.3%) was the most common indication. Sixty (57.1%) were successfully sedated using IN dexmedetomidine alone. Automated auditory brainstem response, computerised tomography and mercaptoacetyltriglycine-3 renogram scans had the highest success rate (83.3%, 83.3%, and 100% respectively). On multivariate analysis, short procedures had an adjusted odds ratio of 5.30 (95% CI: 1.69-16.61; P=0.004) compared to long procedures.

CONCLUSIONS

IN dexmedetomidine is effective for procedural sedation for paediatric patients. The most important predictor for sedation success was indication of sedation and duration of procedures.

Systematic review and meta-analysis found that intranasal dexmedetomidine was a safe and effective sedative drug during paediatric procedural sedation

AIM

This systematic review and meta-analysis evaluated the effectiveness of intranasal dexmedetomidine as a sole sedative during paediatric procedural sedation outside the operating room.

METHODS

Relevant literature identified by PubMed, Scopus, ClinicalTrials.gov, ScienceDirect and Cochrane Library up to 31 December 2019 was systematically reviewed. Randomised controlled trials that compared intranasal dexmedetomidine with another sedative or placebo during paediatric procedural sedation were included. Trials that studied intranasal dexmedetomidine as a premedication before anaesthesia were excluded. The primary outcome was the success of the planned procedure.

RESULTS

We analysed seven randomised controlled trials of 730 patients: four trials with 570 patients compared dexmedetomidine with chloral hydrate and three trials with 160 patients compared dexmedetomidine with midazolam. The incidence of successfully completing the procedure did not differ between dexmedetomidine and chloral hydrate, but dexmedetomidine had a higher success rate than midazolam. The incidence of hypotension, bradycardia or respiratory complications did not differ between the sedatives used. Nausea and vomiting were more common in children treated with chloral hydrate than in those treated with other sedatives.

CONCLUSION

Intranasal dexmedetomidine was a safe and effective sedative for minor paediatric procedures.

Intramuscular dexmedetomidine and oral chloral hydrate for pediatric sedation for electroencephalography: A propensity score-matched analysis

BACKGROUND

Intramuscular dexmedetomidine can be used for pediatric sedation without requiring intravenous access and has advantages for electroencephalography by inducing natural sleep pathway, but only a limited number of studies compared the efficacy of intramuscular dexmedetomidine with oral chloral hydrate.

AIMS

To compare the efficacy and safety of intramuscular dexmedetomidine and oral chloral hydrate used for sedation during electroencephalography in pediatric patients.

METHODS

We reviewed the medical records of pediatric patients who underwent sedation for electroencephalography between January 2015 and December 2016. Initial doses of dexmedetomidine and chloral hydrate were 3 mcg/kg and 50 mg/kg, respectively; second doses (1 mcg/kg and 50 mg/kg, respectively) were administered if adequate sedation was not achieved. Demographic data, time of sedative administration, time of sedation and awakening, and time of arrival at recovery room and discharge were analyzed.

RESULTS

Out of a total of 1239 patients, 125 patients had received dexmedetomidine and 1114 had received chloral hydrate. After 1:1 propensity score matching, the dexmedetomidine and chloral hydrate groups each had 118 patients. Testing completion rate with a single dose of medication was higher in the dexmedetomidine group (91.5% vs 71.2%; mean difference [95% CI] 20.3 [10.8-29.9]; P < .0001; Pearson chi-square value = 16.09). Sedation onset time was shorter in the dexmedetomidine group as well (16.6 ± 13.0 minutes vs 41.5 ± 26.8 minutes; mean difference [95% CI] 24.8 [19.1-30.6]; P < .0001; T = 8.27). On the contrary, the duration of recovery was longer in the dexmedetomidine group (35.5 ± 40.2 minutes vs 18.5 ± 30.7 minutes; mean difference [95% CI] 18.6 [8.8-28.5]; P = .0002; T = -2.82). Total residence time was not significantly different between the two groups (125.8 ± 40.6 minutes vs 122.1 ± 42.2 minutes, mean difference [95% CI] 5.21 [6.1-16.5], P = .3665 T = 0.04).

CONCLUSIONS

Intramuscular dexmedetomidine showed higher sedation success rate and shorter time to achieving the desired sedation level compared with oral chloral hydrate and thus may be an effective alternative for oral chloral hydrate in pediatric patients requiring sedation for electroencephalography.

Intranasal dexmedetomidine versus oral chloral hydrate for diagnostic procedures sedation in infants and toddlers: A systematic review and meta-analysis

BACKGROUND

Intranasal dexmedetomidine is a relatively new way to sedate young children undergoing nonpainful diagnostic procedures. We performed a meta-analysis to compare the efficacy and safety of intranasal dexmedetomidine in young children with those of oral chloral hydrate, which has been a commonly used method for decades.

METHODS

We searched PubMed, Embase, and the Cochrane Library for all randomized controlled trials that compared intranasal dexmedetomidine with oral chloral hydrate in children undergoing diagnostic procedures. Data on success rate of sedation, onset time, recovery time, and adverse effects were extracted and respectively analyzed.

RESULTS

Five studies with a total of 720 patients met the inclusion criteria. Intranasal dexmedetomidine provided significant higher success rate of sedation (relative risk [RR], 1.12; 95% confidence interval [CI], 1.02 to 1.24; P = .02; I = 74%) than oral chloral hydrate. Furthermore, it experienced significantly shorter onset time (weight mean difference [WMD], -1.79; 95% CI, -3.23 to -0.34; P = .02; I = 69%). Nevertheless, there were no statistically differences in recovery time (WMD, -10.53; 95% CI, -24.17 to 3.11; P = .13; I = 92%) and the proportion of patients back to normal activities (RR, 1.11; 95% CI, 0.77-1.60; P = .57; I = 0%). Intranasal dexmedetomidine was associated with a significantly lower incidence of nausea and vomiting (RR, 0.05; 95% CI, 0.01-0.22; P < .0001; I = 0%) than oral chloral hydrate. Although adverse events such as bradycardia, hypotension and hypoxia were not synthetized due to lack of data, no clinical interventions except oxygen supplementation were required in any patients.

CONCLUSION

Our meta-analysis revealed that intranasal dexmedetomidine is possibly a more effective and acceptable sedation method for infants and toddlers undergoing diagnostic procedures than oral chloral hydrate. Additionally, it shows similar safety profile and could be a potential alternative to oral chloral hydrate.

Safety and effectiveness of chloral hydrate in outpatient paediatric sedation for objective hearing tests

OBJECTIVES

Chloral hydrate is a sedative that has been used for many years in clinical practice and, under proper conditions, gives a deep and long enough sleep to allow performance of objective hearing tests in young children. The reluctance to use this substance stems from side effects reported over time that can vary, depending on dose, procedure settings and immediate life supporting intervention when needed. Our study adds to those that have appeared in recent years, showing that chloral hydrate is an effective and safe substance when is used in proper conditions.

METHODS

The study included 322 children who needed sedation for objective hearing tests, from April 2014 to March 2018. Parents were instructed to bring the child tired and fasted for at least 2 h before sedation. The sedative was administered by trained staff in the hospital, and the child was monitored until awaking.

RESULTS

In our study group, over half of the children were in the age 1-4 years group, and only 15% were older than 4 years. The dose of chloral hydrate ranged between 50 and 83 mg/kg body weight, with an average of 75 mg. Successful sedation occurred in 94.1% of children; 0.9% of children awoke during testing and required supplemental sedation or rescheduling of the testing. The most common side effects were vomiting, agitation, prolonged sleep, and failure to fall asleep.

CONCLUSIONS

Comparing the side effects of chloral hydrate in our study with those from other studies, ours were similar to those described in the literature. In our study chloral hydrate was effective and had only limited adverse effects. The use of chloral hydrate under hospital conditions with proper monitoring could be a practical and safe solution for outpatients or those with short-term hospitalisation.

Median Effective Dose of Intranasal Dexmedetomidine for Transthoracic Echocardiography in Children with Kawasaki Disease Who Have a History of Repeated Sedation

Background

The aim of this study was to investigate the median effective dose (ED50) of intranasal dexmedetomidine for echocardiography in children with Kawasaki disease who had a history of repeated sedation.

Material/Methods

There were 73 pediatric Kawasaki disease patients aged 1 to 36 months enrolled in this study who had American Society of Anesthesiologists (ASA) I–II, were scheduled to undergo echocardiography under sedation. They were assigned to 2 groups (group A: age 1–18 months, and group B: age 19–36 months). Intranasal dexmedetomidine was administered before echocardiography. The dose of intranasal dexmedetomidine was determined with the up-down sequential allocation, and the initial dose was 2 μg/kg with an increment/decrement of 0.2 μg/kg. The ED50 of intranasal dexmedetomidine for sedation was determined with the up-and-down method of Dixon and Massey and probit regression. The time to effective sedation, time to regaining consciousness, vital signs, oxygen saturation, echocardiographic examination time, clinical side-effects, and characteristics of regaining consciousness were recorded and compared.

Results

The ED50 of intranasal dexmedetomidine for sedation was 2.184 μg/kg (95% CI, 1.587–2.785) in group A and 2.313 μg/kg (95% CI, 1.799–3.426) in group B. There were no significant differences in the time to sedation and time to regaining consciousness between groups. Additionally, change in hemodynamic and hypoxemia were not noted in both groups.

Conclusions

The ED50 of intranasal dexmedetomidine was determined in children with Kawasaki disease who had a history of repeated sedation to be appropriate for repeated-routine sedation of echocardiographic examination in pediatric patients. The ED50 of intranasal dexmedetomidine for echocardiography in this circumstance is similar to that in children receiving initial sedation.

Chloral hydrate as a sedating agent for neurodiagnostic procedures in children

BACKGROUND

Paediatric neurodiagnostic investigations, including brain neuroimaging and electroencephalography (EEG), play an important role in the assessment of neurodevelopmental disorders. The use of an appropriate sedative agent is important to ensure the successful completion of the neurodiagnostic procedures, particularly in children, who are usually unable to remain still throughout the procedure.

OBJECTIVES

To assess the effectiveness and adverse effects of chloral hydrate as a sedative agent for non-invasive neurodiagnostic procedures in children.

SEARCH METHODS

We used the standard search strategy of the Cochrane Epilepsy Group. We searched MEDLINE (OVID SP) (1950 to July 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 7, 2017), Embase (1980 to July 2017), and the Cochrane Epilepsy Group Specialized Register (via CENTRAL) using a combination of keywords and MeSH headings.

SELECTION CRITERIA

We included randomised controlled trials that assessed chloral hydrate agent against other sedative agent(s), non-drug agent(s), or placebo for children undergoing non-invasive neurodiagnostic procedures.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for their eligibility, extracted data, and assessed risk of bias. Results were expressed in terms of risk ratio (RR) for dichotomous data, mean difference (MD) for continuous data, with 95% confidence intervals (CIs).

MAIN RESULTS

We included 13 studies with a total of 2390 children. The studies were all conducted in hospitals that provided neurodiagnostic services. Most studies assessed the proportion of sedation failure during the neurodiagnostic procedure, time for adequate sedation, and potential adverse effects associated with the sedative agent.The methodological quality of the included studies was mixed, as reflected by a wide variation in their 'Risk of bias' profiles. Blinding of the participants and personnel was not achieved in most of the included studies, and three of the 13 studies had high risk of bias for selective reporting. Evaluation of the efficacy of the sedative agents was also underpowered, with all the comparisons performed in single small studies.Children who received oral chloral hydrate had lower sedation failure when compared with oral promethazine (RR 0.11, 95% CI 0.01 to 0.82; 1 study, moderate-quality evidence). Children who received oral chloral hydrate had a higher risk of sedation failure after one dose compared to those who received intravenous pentobarbital (RR 4.33, 95% CI 1.35 to 13.89; 1 study, low-quality evidence), but after two doses there was no evidence of a significant difference between the two groups (RR 3.00, 95% CI 0.33 to 27.46; 1 study, very low-quality evidence). Children who received oral chloral hydrate appeared to have more sedation failure when compared with music therapy, but the quality of evidence was very low for this outcome (RR 17.00, 95% CI 2.37 to 122.14; 1 study). Sedation failure rates were similar between oral chloral hydrate, oral dexmedetomidine, oral hydroxyzine hydrochloride, and oral midazolam.Children who received oral chloral hydrate had a shorter time to achieve adequate sedation when compared with those who received oral dexmedetomidine (MD -3.86, 95% CI -5.12 to -2.6; 1 study, moderate-quality evidence), oral hydroxyzine hydrochloride (MD -7.5, 95% CI -7.85 to -7.15; 1 study, moderate-quality evidence), oral promethazine (MD -12.11, 95% CI -18.48 to -5.74; 1 study, moderate-quality evidence), and rectal midazolam (MD -95.70, 95% CI -114.51 to -76.89; 1 study). However, children with oral chloral hydrate took longer to achieve adequate sedation when compared with intravenous pentobarbital (MD 19, 95% CI 16.61 to 21.39; 1 study, low-quality evidence) and intranasal midazolam (MD 12.83, 95% CI 7.22 to 18.44; 1 study, moderate-quality evidence).No data were available to assess the proportion of children with successful completion of neurodiagnostic procedure without interruption by the child awakening. Most trials did not assess adequate sedation as measured by specific validated scales, except in the comparison of chloral hydrate versus intranasal midazolam and oral promethazine.Compared to dexmedetomidine, chloral hydrate was associated with a higher risk of nausea and vomiting (RR 12.04 95% CI 1.58 to 91.96). No other adverse events were significantly associated with chloral hydrate (including behavioural change, oxygen desaturation) although there was an increased risk of adverse events overall (RR 7.66, 95% CI 1.78 to 32.91; 1 study, low-quality evidence).

AUTHORS' CONCLUSIONS

The quality of evidence for the comparisons of oral chloral hydrate against several other methods of sedation was very variable. Oral chloral hydrate appears to have a lower sedation failure rate when compared with oral promethazine for children undergoing paediatric neurodiagnostic procedures. The sedation failure was similar for other comparisons such as oral dexmedetomidine, oral hydroxyzine hydrochloride, and oral midazolam. When compared with intravenous pentobarbital and music therapy, oral chloral hydrate had a higher sedation failure rate. However, it must be noted that the evidence for the outcomes for the comparisons of oral chloral hydrate against intravenous pentobarbital and music therapy was of very low to low quality, therefore the corresponding findings should be interpreted with caution.Further research should determine the effects of oral chloral hydrate on major clinical outcomes such as successful completion of procedures, requirements for additional sedative agent, and degree of sedation measured using validated scales, which were rarely assessed in the studies included in this review. The safety profile of chloral hydrate should be studied further, especially the risk of major adverse effects such as bradycardia, hypotension, and oxygen desaturation.

Early follow-up of lung disease in infants with cystic fibrosis using the raised volume rapid thoracic compression technique and computed tomography during quiet breathing

BACKGROUND

Among the different techniques used to monitor lung disease progression in infants with CF diagnosed by Newborn screening (NBS), raised volume-rapid thoracic compression (RVRTC) remains a promising tool. However, the need of sedation and positive pressure ventilation considerably limits its clinical use. We recently described a semi-quantitative method to evaluate air trapping by chest tomography during quite breathing without sedation (CTqb score). This parameter is the radiological sign of airway obstruction and could be also used for lung disease follow-up in infants with CF. However, its discriminative power compared with RVRTC and correlation with lung function parameters are not known.

OBJECTIVES

To compare the discriminative powers of the CTqb score and RVRTC parameters and to determine their correlation during the first year of life of infants with CF.

METHODS

In this multicenter longitudinal study, infants with CF diagnosed by NBS underwent RVRTC and CT during quite breathing at 10 ± 4 weeks (n = 30) and then at 13 ± 1 months of age (n = 28).

RESULTS

All RVRTC parameters and the CTqb score remained stable between evaluations. The CTqb score showed a higher discriminative power than forced expiratory volume in 0.5 s (FEV_0.5 ; the main RVRTC parameter) at both visits (66% and 50% of abnormal values vs 30% and 28%, respectively). No correlation was found between CTqb score and_, the different RVRTC parameters or the plethysmographic functional residual capacity, indicating that they evaluate different aspect of CF lung disease.

Intranasal Dexmedetomidine for Procedural Sedation in Children, a Suitable Alternative to Chloral Hydrate

Sedation is often required for children undergoing diagnostic procedures. Chloral hydrate has been one of the sedative drugs most used in children over the last 3 decades, with supporting evidence for its efficacy and safety. Recently, chloral hydrate was banned in Italy and France, in consideration of evidence of its carcinogenicity and genotoxicity. Dexmedetomidine is a sedative with unique properties that has been increasingly used for procedural sedation in children. Several studies demonstrated its efficacy and safety for sedation in non-painful diagnostic procedures. Dexmedetomidine's impact on respiratory drive and airway patency and tone is much less when compared to the majority of other sedative agents. Administration via the intranasal route allows satisfactory procedural success rates. Studies that specifically compared intranasal dexmedetomidine and chloral hydrate for children undergoing non-painful procedures showed that dexmedetomidine was as effective as and safer than chloral hydrate. For these reasons, we suggest that intranasal dexmedetomidine could be a suitable alternative to chloral hydrate.

Conscious Sedation: Emerging Trends in Pediatric Dentistry

Dental fear and anxiety is a common problem in pediatric patients. There is considerable variation in techniques used to manage them. Various sedation techniques using many different anesthetic agents have gained considerable popularity over the past few years. Children are not little adults; they differ physically, psychologically, and emotionally. The purpose of this review is to survey recent trends and concerning issues in the rapidly changing field of pediatric sedation. We will study the topic from the perspective of an anesthesiologist. It will also provide information to practitioners on the practice of conscious sedation in dentistry and will also outline the route of administration, pharmacokinetics, and pharmacodynamics of various drugs used.

Comparison of rescue techniques for failed chloral hydrate sedation for magnetic resonance imaging scans--additional chloral hydrate vs intranasal dexmedetomidine

BACKGROUND

Chloral hydrate, a commonly used sedative in children during noninvasive diagnostic procedures, is associated with side effects like prolonged sedation, paradoxical excitement, delirium, and unpleasant taste. Dexmedetomidine, a highly selective α-2 agonist, has better pharmacokinetic properties than chloral hydrate. We conducted this prospective, double-blind, randomized controlled trial to evaluate efficacy of intranasal dexmedetomidine with that of a second oral dose of chloral hydrate for rescue sedation during magnetic resonance imaging (MRI) studies in infants.

METHODS

One hundred and fifty infants (age group: 1-6 months), who were not adequately sedated after initial oral dose of 50 mg · kg(-1) chloral hydrate, were randomly divided into three groups with the following protocol for each group. Group C: second oral dose chloral hydrate 25 mg · kg(-1); Group L and Group H: intranasal dexmedetomidine in a dosage of 1 and 2 mcg · kg(-1), respectively. Status of sedation, induction time, time to wake up, vital signs, oxygen saturation, and recovery characteristics were recorded.

RESULTS

Successful rescue sedation in Groups C, L, and H were achieved in 40 (80%), 47 (94%), and 49 (98%) of infants, respectively, on an intention to treat analysis, and the proportion of infants successfully sedated in Group H was more than that of Group L (P ˂ 0.01). There were no significant differences in sedation induction time; however, the time to wake up was significantly shorter in Group L as compared to that in Group C or H (P < 0.01). No significant adverse hemodynamic or hypoxemic effects were observed in the study.

CONCLUSION

Intranasal dexmedetomidine induced satisfactory rescue sedation in 1- to 6-month-old infants during MRI study, and appears to cause sedation in a dose-dependent manner.

Comparison of Effects of Different Dexmedetomidine and Chloral Hydrate Doses Used in Sedation on Electroencephalography in Pediatric Patients

The aim of this study was to compare the efficacy and safety of different oral chloral hydrate and dexmedetomidine doses used for sedation during electroencephalography (EEG) in children. One hundred sixty children aged 1 to 9 years with American Society of Anesthesiologists physical status I-II who were uncooperative during EEG recording or who were referred to our electrodiagnostic unit for sleep EEG were included to the study. The patients were randomly assigned into 4 groups. In groups D1 and D2, patients received oral dexmedetomidine doses of 2 and 3 µg/kg, respectively. In group C1 and C2, patients received oral chloral hydrate doses of 50 and 100 mg/kg, respectively. The induction time was significantly shorter in group C2 compared with other groups (P = .000). The rate of adverse effects was significantly higher in group C2 compared with the dexmedetomidine groups (D1 and D2; P = .004). In conclusion, dexmedetomidine can be used safely for sedation during EEG in children.

Chemical contaminants in swimming pools: Occurrence, implications and control

A range of trace chemical contaminants have been reported to occur in swimming pools. Current disinfection practices and monitoring of swimming pool water quality are aimed at preventing the spread of microbial infections and diseases. However, disinfection by-products (DBPs) are formed when the disinfectants used react with organic and inorganic matter in the pool. Additional chemicals may be present in swimming pools originating from anthropogenic sources (bodily excretions, lotions, cosmetics, etc.) or from the source water used where trace chemicals may already be present. DBPs have been the most widely investigated trace chemical contaminants, including trihalomethanes (THMs), haloacetic acids (HAAs), halobenzoquinones (HBQs), haloacetonitriles (HANs), halonitromethanes (HNMs), N-nitrosamines, nitrite, nitrates and chloramines. The presence and concentrations of these chemical contaminants are dependent upon several factors including the types of pools, types of disinfectants used, disinfectant dosages, bather loads, temperature and pH of swimming pool waters. Chemical constituents of personal care products (PCPs) such as parabens and ultraviolet (UV) filters from sunscreens have also been reported. By-products from reactions of these chemicals with disinfectants and UV irradiation have been reported and some may be more toxic than their parent compounds. There is evidence to suggest that exposure to some of these chemicals may lead to health risks. This paper provides a detailed review of various chemical contaminants reported in swimming pools. The concentrations of chemicals present in swimming pools may also provide an alternative indicator to swimming pool water quality, providing insights to contamination sources. Alternative treatment methods such as activated carbon filtration and advanced oxidation processes may be beneficial in improving swimming pool water quality.

Chloral hydrate, chloral hydrate--promethazine and chloral hydrate -hydroxyzine efficacy in electroencephalography sedation

OBJECTIVE

To compare efficacy and safety of chloral hydrate (CH), chloral hydrate and promethazine (CH + P) and chloral hydrate and hydroxyzine (CH + H) in electroencephalography (EEG) sedation.

METHODS

In a parallel single-blinded randomized clinical trial, ninety 1-7 y-old uncooperative kids who were referred to Pediatric Neurology Clinic of Shahid Sadoughi University, Yazd, Iran from April through August 2012, were randomly assigned to receive 40 mg/kg of chloral hydrate or 40 mg/kg of chloral hydrate and 1 mg/kg of promethazine or 40 mg/kg of chloral hydrate and 2 mg/kg of hydroxyzine. The primary endpoint was efficacy in sufficient sedation (obtaining four Ramsay sedation score) and successful completion of EEG. Secondary endpoint was clinical adverse events.

RESULTS

Thirty nine girls (43.3 %) and 51 boys (56.7 %) with mean age of 3.34 ± 1.47 y were assessed. Sufficient sedation and completion of EEG were achieved in 70 % (N = 21) of chloral hydrate group, in 83.3 % (N = 25) of CH + H group and in 96.7 % (N = 29) of CH + P group (p = 0.02). Mild clinical adverse events including vomiting [16.7 % (N = 5) in CH, 6.7 % (N = 2) in CH + P, 6.7 % (N = 2) in CH + H], agitation in 3.3 % of CH + P (N = 1) group and mild transient hypotension in 3.3 % of CH + H (N = 1) group occurred. Safety of these three sedation regimens was not statistically significant different (p = 0.14).

CONCLUSIONS

Combination of chloral hydrate-antihistamines can be used as the most effective and safe sedation regimen in drug induced sleep electroencephalography of kids.

Prospective clinical audit of chloral hydrate administration practices in a neonatal unit

AIM

Chloral hydrate is generally considered a safe and effective single dosing procedural sedative for neonates in the clinical setting. However, its safety profile as a repetitive dosing maintenance sedative is largely unknown. This study aimed to document current administration practices of chloral hydrate in the Neonatal Unit, Royal Children's Hospital, Melbourne, Australia, over a 6-month period.

METHODS

Patients who had been prescribed chloral hydrate during the specified audit period were recruited into the study and prospectively followed for a period of 28 days, or until they were discharged from the unit. Demographic data were collected on recruitment, and daily documentation of chloral hydrate administration was recorded.

RESULTS

A total of 238 doses of chloral hydrate were administered to a cohort of 32 patients during the study period. The majority of the audited doses (84%) were ordered as repeating doses. Doses were more likely to be given at night than during the day, and the median dosage for repetitive dosing was found to be above the study site's recommended dosing range. Pre-dose and/or post-dose assessment of distress/agitation accompanied dosage approximately half of the time. The audit did not reveal any recognisable pattern of sedation maintenance or weaning process for patients who received multiple doses.

CONCLUSIONS

Health-care professionals caring for hospitalised infants should be made aware of the potential risks of chloral hydrate as a repetitive dosing sedative, and of the importance of systematically evaluating the appropriateness and effectiveness of utilising such pharmacological intervention for managing and treating distress.

Update of carcinogenicity studies in animals and humans of 535 marketed pharmaceuticals

This survey is a compendium of information retrieved on carcinogenicity in animals and humans of 535 marketed pharmaceuticals whose expected clinical use is continuous for at least 6 months or intermittent over an extended period of time. Of the 535 drugs, 530 have the result of at least one carcinogenicity assay in animals, and 279 (52.1%) of them gave a positive response in at least one assay. Only 186 drugs (34.8%) have retrievable information on carcinogenicity in humans, and 104 of them gave to a variable extent evidence of a potential carcinogenic activity. Concerning the correlation between results obtained in animals and epidemiological findings, 58 drugs gave at least one positive result in carcinogenicity assays performed in animals and to a variable extent displayed evidence of carcinogenicity in humans, but 97 drugs tested positive in animals and were noncarcinogenic in humans or vice versa. Our findings, which are in agreement with previous studies, indicate that the evaluation of the benefit/carcinogenic risk ratio should be always made in prescribing a drug.

Oral chloral hydrate vs. intranasal midazolam for sedation during computerized tomography

We conducted this single blind randomized clinical trial to compare the efficacy and safety of oral chloral hydrate and intranasal midazolam for induction of sedation for computerized tomography scan of brain in children. Participants aged 1-10 years (n=60) were randomized to receive 100 mg/kg chloral hydrate orally with intra nasal normal saline OR intranasal midazolam 0.2 mg/kg with oral normal saline. Adequate sedation (Ramsay sedation score of four) was obtained and CT scan completed successfully in 76.7% of chloral hydrate group and in 40% of midazolam group (P=0.004). No significant difference was seen for side effects frequency between the two drugs (10% in chloral hydrate, 3.3% in midazolam group; P=0.34). We conclude that oral chloral hydrate can be considered as a safe and effective drug for sedation in children undergoing CT scan of brain.

Chloral hydrate sedation in radiology: retrospective audit of reduced dose

BACKGROUND

Chloral hydrate (CH) is safe and effective for sedation of suitable children.

OBJECTIVE

The purpose of this study was to assess whether adequate sedation is achieved with reduced CH doses.

MATERIALS AND METHODS

We retrospectively recorded outpatient CH sedations over 1 year. We defined standard doses of CH as 50 mg/kg (infants) and 75 mg/kg (children >1 year). A reduced dose was defined as at least 20% lower than the standard dose.

RESULTS

In total, 653 children received CH sedation (age, 1 month-3 years 10 months), 42% were given a reduced initial dose. Augmentation dose was required in 10.9% of all children, and in a higher proportion of children >1 year (15.7%) compared to infants (5.7%; P < 0.001). Sedation was successful in 96.7%, and more frequently successful in infants (98.3%) than children >1 year (95.3%; P = 0.03). A reduced initial dose had no negative effect on outcome (P = 0.19) or time to sedation. No significant complications were seen.

CONCLUSION

We advocate sedation with reduced CH doses (40 mg/kg for infants; 60 mg/kg for children >1 year of age) for outpatient imaging procedures when the child is judged to be quiet or sleepy on arrival.

Reactivity of mucohalic acids in water

One group of disinfection byproducts of increasing interest are the halogenated furanones, which are formed in the chlorination of drinking water. Among these halofuranones is mucochloric acid (MCA, 3,4-dichloro-5-hydroxyfuran-2(5H)-one), and mucobromic acid (MBA, 3,4-dibromo-5-hydroxyfuran-2(5H)-one). Both mucohalic acids (MXA) are direct genotoxins and potential carcinogens, with the capacity to alkylate the DNA bases guanosine, adenosine and cytosine, and they have been measured in concentrations ranging up to 700 ng/l in tap water. MCA and MBA react in basic aqueous medium to form mucoxyhalic acids (4-halo-3,5-hydroxyfuran-2(5H)-one). Since: i) this reaction may represent the first step in the abiotic decomposition of mucohalic acids, ii) mucoxyhalic acids have been proposed as possible intermediates in the reaction of MXA with DNA, a kinetic study of the reaction mechanism is of interest. Here, the following conclusions were drawn: a) At moderately basic pH, the reaction of mucohalic acids with OH(-) to form mucoxyhalic acids is kinetically significant. b) The nucleophilic attack of hydroxide ions on MXA occurs through a combination of two paths: one of them is first-order in hydroxide whereas the other is second-order and are proposed to occur through the deprotonation of the hydrate of MXA. c) The hydration constants of mucohalic acids -0.23 and 0.17 for MCA and MBA respectively - corresponds to the very significant hydrate concentrations. Since hydrates are not electrophilic, these values imply a decrease in the alkylating capacity of mucohalic acids.

Trichloroethylene risk assessment: a review and commentary

Trichloroethylene (TCE) is a widespread environmental contaminant that is carcinogenic when given in high, chronic doses to certain strains of mice and rats. The capacity of TCE to cause cancer in humans is less clear. The current maximum contaminant level (MCL) of 5 ppb (microg/L) is based on an US Environment Protection Agency (USEPA) policy decision rather than the underlying science. In view of major advances in understanding the etiology and mechanisms of chemically induced cancer, USEPA began in the late 1990s to revise its guidelines for cancer risk assessment. TCE was chosen as the pilot chemical. The USEPA (2005) final guidelines emphasized a "weight-of-evidence" approach with consideration of dose-response relationships, modes of action, and metabolic/toxicokinetic processes. Where adequate data are available to support reversible binding of the carcinogenic moiety to biological receptors as the initiating event (i.e., a threshold exists), a nonlinear approach is to be used. Otherwise, the default assumption of a linear (i.e., nonthreshold) dose-response is utilized. When validated physiologically based pharmacokinetic (PBPK) models are available, they are to be used to predict internal dosimetry as the basis for species and dose extrapolations. The present article reviews pertinent literature and discusses areas where research may resolve some outstanding issues and facilitate the reassessment process. Key research needs are proposed, including role of dichloroacetic acid (DCA) in TCE-induced liver tumorigenesis in humans; extension of current PBPK models to predict target organ deposition of trichloroacetic acid (TCA) and DCA in humans ingesting TCE in drinking water; use of human hepatocytes to ascertain metabolic rate constants for use in PBPK models that incorporate variability in metabolism of TCE by potentially sensitive subpopulations; measurement of the efficiency of first-pass elimination of trace levels of TCE in drinking water; and assessment of exogenous factors' (e.g., alcohol, drugs) ability to alter metabolic activation and risks at such low-level exposure.

Efficient sampling approaches to address confounding in database studies

Administrative and other population-based databases are widely used in pharmacoepidemiology to study the unintended effects of medications. They allow investigators to study large case series, and they document prescription medication exposure without having to contact individuals or medical charts, or rely on human recall. However, such databases often lack information on potentially important confounding variables. This review describes some of the sampling approaches and accompanying data-analysis methods that can be used to assess, and deal efficiently with, such confounding.