Sedation Failure Research Articles

Effects of Sleep Deprivation on the Sedation of Pediatric Patients Undergoing MRI Examinations

ABSTRACT Sedation is an essential factor for pediatric magnetic resonance imaging (MRI) procedure. A long-term failure of sedation has a detrimental effect on a 1 day test plan. Given this background, this study examined the effects of sedation using a sleep deprivation method in pediatric patients scheduled to undergo an MRI examination. The current study examined 54 patients (36 boys and 18 girls) with diseases, such as epilepsy, brain tumor, development delay, mental retardation, and cerebral infarction, who were treated at our medical institution from December 2009 to March 2010. The patients were classified into two groups: group A (n = 27) with sleep deprivation, and group B (n = 27) without sleep deprivation. The mean age of these patients was 4.2 years. Comparative analysis of groups A and B was performed to assess the success rate of pediatric sedation, the time elapsed until complete sedation had been achieved, and the frequency at which patients took Pocral syrup (chloral hydrate). In group A, patients were allowed to start sleep 1 hr later and were woken 1 hr earlier than their mean sleep time. According to this pretreatment, the rate of successful sedation, frequency of the administration of Pocral syrup, and the time elapsed until deep sedation had been achieved were measured. In group A, the rate of successful sedation was 100%, the mean time elapsed until deep sedation had been achieved was 23 min, and the mean frequency of Pocral syrup administration was 1.2 times. In addition, the proportions of patients who had achieved successful sedation after one-time use and two-time use of Pocral syrup were 77.8% and 22.2%, respectively. In group B, successful sedation was achieved in 89%, and the mean time elapsed until deep sedation was 39 min. The mean frequency of Pocral syrup administration was 1.5 times. The proportions of patients who had achieved successful sedation after one-time use and two-time use of Pocral syrup were 51.9% and 48.12%, respectively. The statistical significance was tested using a nonparametric analysis, Mann–Whitney U Test (p < 0.05). Other studies have reported that sleep deprivation had no significant effects. An actual comparison of the sleep-deprived and other patients showed that sleep deprivation affected the rate of successful sedation, the frequency of Pocral syrup administration, and the time elapsed until the patients were sedated. The rate of successful sedation was significantly higher in group A than in group B. The time elapsed until deep sedation had been achieved was also significantly shorter in group A than in group B. In addition, the frequency of Pocral syrup administration (administration dose) was significantly lower in group A than in group B. In conclusion, sleep deprivation increases the effectiveness of pediatric sedation in an MRI examination of pediatric patients and might assist in performing an MRI examination more efficiently in pediatric patients.

Life-threatening critical respiratory events: a retrospective study of postoperative patients found unresponsive during analgesic therapy

Study Objective To identify risk factors for life-threatening critical respiratory events occurring during parenteral analgesic therapy for acute postoperative pain. Design Retrospective, observational, cohort study. Setting University hospital. Measurements The electronic records of patients with sudden-onset, life-threatening critical respiratory events during analgesic therapy for postoperative pain were studied. Critical respiratory event data were identified from the hospital risk management database between 8/1/2000 and 7/31//2007. Patients required rescue treatment with naloxone, endototracheal intubation, or cardiopulmonary resusucitation. Pediatric patients were excluded from the study. In addition to the event description (type of analgesia, opioid dose, patient monitoring data, time of day, and time from surgery), each patient's record was reviewed to extract co-morbidities and outcome data. Main Results Over the 6-year period, 32 patients experienced a postoperative critical respiratory event. Twenty-six events and three deaths occurred within the first 24 hours of opioid therapy. Four of 32 patients died. Congestive heart failure, postoperative acute renal failure, obstructive sleep apnea, cardiac dysrhythmia, diabetes mellitus, coronary artery disease, and hypertension were significant associations in adult patients. Conclusions The first 24 hours after commencing opioid-based analgesic therapy represents a high risk period. Obstructive sleep apnea, deep levels of sedation, nocturnal presentation, and postoperative acute renal failure were seen in patients who died as a result of these critical respiratory events.

The effects of temperament and behaviour problems on sedation failure in anxious children after midazolam premedication

Midazolam is one of the most frequently used agents for sedation in paediatric dentistry. It is unclear how temperament traits and behaviour problems are related to sedation failure in children. We investigated whether sedation failure after premedication with oral midazolam can be predicted by behaviour problems and temperament traits. Sixty children (aged 4-8 years) referred for dental treatment under sedation (40/60% N2O/O2), who had a Frankl Behaviour Scale score of at least 3, were premedicated with oral midazolam (0.75 mg kg(-1)). The level of sedation was assessed at defined time intervals, according to the Houpt Sedation Rating Scale. Children's sedation success during dental treatment was classified as satisfactory or unsatisfactory. Heart rate and oxygen saturation were evaluated by an oxygen saturation monitor in the sedation period. On the treatment day, parents completed 'The Revised Conners' Parent Rating Scale' and 'Short Temperament Scale for Children' to assess their child's behaviour problems and temperament, respectively. The rates of sedation success were found to be satisfactory in 78.4% and unsatisfactory in 21.6%. Student's t-test demonstrated that in addition to the Short Temperament Scale for Children Inflexibility subscale being significant the Revised Conners' Parent Rating Scale: Long Form Psychosomatic subscale was also found to be a significant predictor of sedation failure. Psychosomatic behaviour problems and an inflexible temperament trait might contribute to sedation failure in children undergoing dental treatment under midazolam premedication and N2O/O2 sedation. Appropriate patient selection based on the evaluation of childhood behavioural problems and temperament characteristics might increase midazolam sedation success in children.

Impact of addition of propofol to ED formulary

Study Objectives Access to propofol remains a challenge for many emergency physicians. This report examines changes in patient care after the introduction of propofol to an emergency department formulary. Methods The Procedural Sedation in the Community Emergency Department registry is a prospective multicentered database of community emergency physician–directed procedural sedation cases. Medication selection and patient outcome were compared at a single Procedural Sedation in the Community Emergency Department registry study site before and after credentialing of emergency physicians for the use of propofol. Analysis was done through analysis of variance and χ 2 test. Results Over a 36-month period, 573 patients were entered into the registry from the single study site, 255 before and 318 after propofol introduction. The percentage of propofol use increased from 26% of procedural sedation cases in the first 3 months of availability to 69% in the final 3 months analyzed. Before propofol use, 46% of cases were completed with a single agent compared with after propofol use, in which 66% were completed with a single agent ( P < .001). Complications decreased from 9% of patients before propofol use to 3% of patients after propofol use ( P < .05), whereas sedation failures decreased from 5.1% to 4.1% ( P < .02). Conclusion Granted access to propofol, emergency physicians will preferentially use this medication over prior procedural sedation agents with fewer procedural sedation complications and greater procedural success.

A Comparison of the Efficacy and Safety of Chloral Hydrate Versus Inhaled Anesthesia for Sedating Infants and Toddlers for Transthoracic Echocardiograms

Pediatric patients may need sedation for a transthoracic echocardiogram. Due to the unpredictability and safety concerns with chloral hydrate, we offered mask anesthesia as an alternate strategy. A retrospective chart review of 507 pediatric patients sedated for transthoracic echocardiography was conducted to compare the use of oral chloral hydrate (n = 297) with the face mask administration of sevoflurane anesthesia (n = 210). Anesthesia had a shorter time from administration of sedation to hospital discharge (112 vs 155 minutes), largely because of a shorter, more predictable, and less variable time to achieve satisfactory study conditions. Using anesthesia, an average 43-minute difference would allow for an additional procedure using the same resources. Anesthesia was not associated with sedation failure (0% vs 6%), and the duration of examination was shorter (40 vs 46 minutes). There were no significant adverse events in either cohort. Anesthesia, although more costly, is balanced by more the efficient use of hospital and parental resources, with greater family and staff satisfaction.

Sleep deprivation for radiological procedures in children

Sir, Radioimaging procedures in children often require sedation. Many centers, including ours, lack a dedicated team to provide sedation due to constraints of resources and time. Any innovation to decrease sedation requirement is welcome. Sleep deprivation had been tried routinely at some centers prior to radiological procedures [1]. We implemented the same and retrospectively analyzed the results and present our experience. Medication used for children (n=41) requiring sedation for noninvasive radioimaging was reviewed. These children were divided into two groups: 18 were sleep-deprived prior to procedure and 23 were not sleep-deprived. The dosages of drugs used and the adverse events documented were analyzed. We included only inpatients in this study. Sleep deprivation was defined as <5 h of night sleep. Parents were instructed to wake the child after 5 h of sleep. Usually the child would be woken up at 3 A.M. and engaged in play. The duty nurses or residents would ensure that the child was awake. In the case of infants the parents were encouraged to keep the infant awake for at least 4 h before the procedure. The two groups were comparable in terms of age, gender, imaging procedure and the duration of procedure. The most common primary sedation used was oral chloral hydrate with a mean dosage of 66.87±29.05 mg/kg for the sleep-deprived group and 61.89±38.93 mg/kg for the nonsleep-deprived group. Non-sleep-deprived patients required an additional 0.19 mg/kg of diazepam IV compared to the sleep-deprived group (P<0.05). None of the sleep-deprived patients required rescue medicines (IV promethazine, IV pentazocine), except one child who required extension of sedation beyond 3 h (for combined CT head and MRI spine). Two children with hyperactivity who had failed sedation earlier were managed with oral sedation alone after sleep deprivation. There was no serious adverse event in either of the two groups. We concluded that pre-procedural sleep deprivation decreases the need for IV sedation and lowers sedation failure rates. Even though this study included only inpatients, we think the same finding can apply to outpatients. For outpatients, parents/guardians of children are directed to wake the child after 5 h of sleep and encouraged to prevent napping during the journey to the hospital. On the negative side, sleep deprivation for a child means sleep deprivation for parents! However, the need for less sedative medication allays parental anxiety and ensures cooperation. We now recommend sleep deprivation before planned imaging procedures more often at our centre.

Head CT is of limited diagnostic value in critically ill patients who remain unresponsive after discontinuation of sedation

BackgroundProlonged sedation is common in mechanically ventilated patients and is associated with increased morbidity and mortality. We sought to determine the diagnostic value of head computed tomography (CT) in mechanically ventilated patients who remain unresponsive after discontinuation of sedation.MethodsA retrospective review of adult (age >18 years of age) patients consecutively admitted to the medical intensive care unit of a tertiary care medical center. Patients requiring mechanical ventilation for management of respiratory failure for longer than 72 hours were included in the study group. A group that did not have difficulty with awakening was included as a control.ResultsThe median time after sedation was discontinued until a head CT was performed was 2 days (interquartile range 1.375–2 days). Majority (80%) of patients underwent head CT evaluation within the first 48 hours after discontinuation of sedation. Head CT was non-diagnostic in all but one patient who had a small subarachnoid hemorrhage. Twenty-five patients (60%) had a normal head CT. Head CT findings did not alter the management of any of the patients. The control group was similar to the experimental group with respect to demographics, etiology of respiratory failure and type of sedation used. However, while 37% of subjects in the control group had daily interruption of sedation, only 19% in the patient group had daily interruption of sedation (p < 0.05).ConclusionIn patients on mechanical ventilation for at least 72 hours and who remain unresponsive after sedative discontinuation and with a non-focal neurologic examination, head CT is performed early and is of very limited diagnostic utility. Routine use of daily interruption of sedation is used in a minority of patients outside of a clinical trial setting though it may decrease the frequency of unresponsiveness from prolonged sedation and the need for head CT in patients mechanically ventilated for a prolonged period.

Propofol-based sedation regimen for infants and children undergoing ambulatory magnetic resonance imaging

BackgroundPropofol is widely used for infants and children requiring sedation for magnetic resonance imaging. However, increased doses of propofol may quickly lead to an unintended deep sedation and respiratory depression. Thus, an appropriate low dosage, which nevertheless ensures sufficient sleep for successful magnetic resonance imaging (MRI) completion, would probably minimize respiratory adverse events. We investigated the safety and efficacy of a low-dose propofol-based sedation regimen in a broad age range of children. MethodsWe investigated 500 infants and children, prospectively. Premedication consisted of i.v. midazolam 0.1 mg kg−1. Sedation was induced with i.v. nalbuphine 0.1 mg kg−1 and propofol 1 mg kg−1, and maintained with propofol 5 mg kg−1 h−1. Outcome measures were induction time, sedation time, recovery time, need for additional sedation, respiratory events, cardiovascular events, paradoxical reactions, and sedation failure. ResultsData were obtained from 53 infants and 447 children. Median (IQR) age was 5.3 (4.5, 6.1) yr and body weight was 19.3 (16.5, 24.7) kg. The induction time was 2 (1, 2) min, sedation time 55 (45, 65) min, and recovery time 8 (8, 9) min. Additional sedation was necessary in 11 patients (2.2%), mild respiratory events occurred in five patients (1%). All MRI examinations could be completed without paradoxical reaction or sedation failure. ConclusionThis sedation regimen provides the shortest induction time so far described, a rare demand for additional sedation, a low incidence of respiratory events, and a rapid recovery.

High dose dexmedetomidine as the sole sedative for pediatric MRI

This large-scale retrospective review evaluates the sedation profile of dexmedetomidine. To determine the hemodynamic responses, efficacy and adverse events associated with the use of high dose dexmedetomidine as the sole sedative for magnetic resonance imaging (MRI) studies. Dexmedetomidine has been used at our institution since 2005 to provide sedation for pediatric radiological imaging studies. Over time, an effective protocol utilizing high dose dexmedetomidine as the sole sedative agent has evolved. As part of the ongoing Quality Assurance process, data on all sedations are reviewed monthly and protocols modified as needed. Data were analyzed from all 747 consecutive patients who received dexmedetomidine for MRI sedation from April 2005 to April 2007. Since 2005, the 10-min loading dose of our dexmedetomidine protocol increased from 2 to 3 microg.kg(-1), and the infusion rate increased from 1 to 1.5 to 2 microg.kg(-1).h(-1). The current sedation protocol progressively increased the rate of successful sedation (able to complete the imaging study) when using dexmedetomidine alone from 91.8% to 97.6% (P = 0.009), reducing the requirement for adjuvant pentobarbital in the event of sedation failure with dexmedetomidine alone and decreased the mean recovery time by 10 min (P < 0.001). Although dexmedetomidine sedation was associated with a 16% incidence of bradycardia, all concomitant mean arterial blood pressures were within 20% of age-adjusted normal range and oxygen saturations were 95% or higher. Dexmedetomidine in high doses provides adequate sedation for pediatric MRI studies. While use of high dose dexmedetomidine is associated with decreases in heart rate and blood pressure outside the established 'awake' norms, this deviation is generally within 20% of norms, and is not associated with adverse sequelae. Dexmedetomidine is useful as the sole sedative for pediatric MRI.

Comparison of Propofol With Pentobarbital/Midazolam/Fentanyl Sedation for Magnetic Resonance Imaging of the Brain in Children

Propofol and pentobarbital, alone or combined with other agents, are frequently used to induce deep sedation in children for MRI. However, we are unaware of a previous comparison of these 2 agents as part of a randomized, controlled trial. We compared the recovery time of children after deep sedation with single-agent propofol with a pentobarbital-based regimen for MRI and considered additional variables of safety and efficacy. This prospective, randomized trial at a tertiary children's hospital enrolled 60 patients 1 to 17 years old who required intravenous sedation for elective cranial MRI. Patients were assigned randomly to receive a loading dose of propofol followed by continuous intravenous infusion of propofol or to receive sequential doses of midazolam, pentobarbital, and fentanyl until a modified Ramsay score of >4 was attained. A nurse who was blind to group assignment assessed discharge readiness (Aldrete score > 8) and administered a follow-up questionnaire. We compared recovery time, time to induction of sedation, total sedation time, quality of imaging, number of repeat-image sequences, adverse events, caregiver satisfaction, and time to return to presedation functional status. The groups were similar in age, gender, race, American Society of Anesthesiology physical status class, and frequency of cognitive impairment. No sedation failure or significant adverse events were observed. Propofol offered significantly shorter sedation induction time, recovery time, total sedation time, and time to return to baseline functional status. Caregiver satisfaction scores were also significantly higher in the patients in the propofol group. Propofol permits faster onset and recovery than, and comparable efficacy to, a pentobarbital/midazolam/fentanyl regimen for sedation of children for MRI.

The use of a pediatric emergency medicine–staffed sedation service during imaging: a retrospective analysis

Hypothesis A sedation service staffed by pediatric emergency medicine (PEM) physicians can sedate children during imaging, with a low adverse event risk and minimal sedation failures. Design/Methods We reviewed 1042 PEM-administered sedations during a 12-month period, collecting data regarding demographics, presedation evaluation, medications used, sedation length, adverse events, corrective measures, and postsedation disposition. Successful image completion without patient awakening defined effective sedation. Minor adverse events included hypoxia (<93%), malaligned airway, self-resolving transient bradycardia, and atypical reactions to sedation agents. Cardiorespiratory incidents requiring resuscitation were considered major events. Results Of 923 sedation episodes, 92 (10.0%) experienced adverse events; 7 (0.76%) were major. Sedation failed in 17 (1.8%). No sedation resulted in an increased level of care or permanent injury. Conclusions A PEM-staffed sedation service provided sedation to children undergoing imaging with a low adverse event risk, minimal failures, and no residual morbidity. However, all sedating clinicians should possess critical airway skills.

Prospective randomized trial evaluating ketamine for advanced endoscopic procedures in difficult to sedate patients

Adequate patient sedation is mandatory for advanced endoscopic procedures such as ERCP and EUS. To evaluate the effectiveness and safety of ketamine in difficult to sedate patients undergoing advanced endoscopic procedures. This was a prospective, randomized trial of all patients undergoing ERCP or EUS who were not adequately sedated despite administration of meperidine 50 mg, midazolam 5 mg and diazepam 5 mg. Patients during endoscopy were then randomized to receive either intravenous ketamine (20 mg) every 5 min or continue to receive standard sedation using meperidine and diazepam. Of 175 patients, 82 were randomized to receive ketamine and 93 standard sedatives. Compared with standard sedation, qualitative physician rating (P < 0.0001) and depth of sedation (P < 0.001) were superior in the ketamine group with shorter recovery times (P < 0.0001). Both patient discomfort and sedation-related technical difficulty were significantly less among patients randomized to receive ketamine (P < 0.0001). More patients in the standard sedation group were crossed-over to the ketamine group due to sedation failure (35.5 vs. 3.7%, P < 0.0001). Nine patients who received ketamine, developed adverse events that were managed conservatively. Ketamine is a useful adjunct to conscious sedation in patients who are difficult to sedate. Its use Results in better quality and depth of sedation with shorter recovery times than patients sedated using benzodiazepines and meperidine alone. Further prospective studies evaluating the effectiveness and safety of ketamine for endoscopic sedation are needed.

Evaluation of Sedation Failure in the Outpatient Oral and Maxillofacial Surgery Clinic

Our goal was to report on the incidence of sedation failures in our outpatient oral surgery clinic. Sedation failure is the inability to complete a procedure under intravenous sedation. There is very little in the oral surgery literature on this subject. Proper Institutional Review Board approval was obtained from the appropriate governing body for this project. The medical records of 539 intravenous sedation patients treated at the Oral and Maxillofacial Surgery Clinic at our institution were retrospectively evaluated to determine the incidence of failed sedation. Patients sedated with midazolam and fentanyl were placed in group A. There were 323 patients in group A. We placed patients sedated with midazolam, fentanyl and methohexital into group B. There were 216 patients in group B. The gender, medical history, type of procedure being performed, amount of drug given, and the patient's vital signs throughout the procedure were recorded. There were 9 failed sedations with a rate of 1.6% (9/539); 3 in group B (1%) and 6 in group A (2%). Five of our failures were undergoing multiple tooth extractions. Two of the failures were undergoing surgical removal of impacted third molars. Two patients underwent mandibular fracture reduction. Failure was attributed to increased agitation and combativeness, uncontrolled hypertension, tachycardia and desaturation. The mandible fracture population and multiple teeth extraction patients had higher rates of failure than other groups. This may be the result of procedure length, type of procedure, or a preoperative anxiety and attitude toward treatment expressed by the patient making sedation unpredictable. Level of training and experience of the practitioner may contribute to sedation failure. These results allow us to develop a prospective study protocol of outpatient sedation and to quantify more detailed information about preoperative anxiety, medical status, and social history than we had available during our chart review. More specific conclusions may help us determine if certain patient populations are at a higher risk for failed sedations.

Failure of Intravenous Sedation due to Significant Hypertension: A Case Report

Failure of Intravenous Sedation due to Significant Hypertension: A Case Report

Sedation and Anesthesia Protocols Used for Magnetic Resonance Imaging Studies in Infants: Provider and Pharmacologic Considerations

Most studies report the efficacy of only a single drug to achieve sedation in a broad age range of children. In clinical practice, a variety of sedative and anesthetic regimes are monitored by nurses and physicians. In this study we report the efficacy of a tiered approach to monitoring and sedation in infants. Two-hundred-fifty-eight infants who required magnetic resonance imaging (MRI) studies received either oral chloral hydrate (n = 102) or bolus doses of IV pentobarbital (n = 67) monitored by nurses or IV propofol infusion (n = 68) titrated by physicians. Fewer cardiorespiratory events were observed in the chloral hydrate group (2.9%) compared to pentobarbital (13.4%) and propofol groups (13.6%); P < 0.05, propofol versus chloral hydrate. Infants who received propofol were ready to begin MRI scanning earlier (mean 9.1 +/- 6.7 min) than infants who received oral chloral hydrate (mean 23.5 +/- 13.4 min; P < 0.05). The time to discharge was longest in the pentobarbital (mean 80.3 +/- 39.2 min) and shortest in the propofol group (mean 53.9 +/- 30.1 min; P < 0.05). Infants in the chloral hydrate group moved more frequently (22.5%) during MRI scanning (with four sedation failures of 102) compared to 12.2% in the pentobarbital group and 1.4% in the propofol group (P < 0.001).

The effect of melatonin on sedation of children undergoing magnetic resonance imaging

Melatonin may induce a natural sleepiness and improve predictability of sedation drugs. We have investigated its clinical value in children sedated for magnetic resonance imaging. In a stratified randomized double-blind study, 98 children received either melatonin or placebo 10 min before they were sedated with a standard oral regimen. Children >5 and <15 kg received chloral hydrate and those >or=15 and <40 kg had a combination of temazepam with droperidol (T&D). The doses of melatonin were 3 and 6 mg, respectively. One observer recorded the time taken to reach criteria for deep sedation, sedation failure and other sedation-related events. In the chloral hydrate group (n=50) 50% were deeply sedated by 31 min after melatonin and 40 min after placebo (P=0.57). There were zero and 1 failures, respectively. The geometric mean time taken to reach deep sedation was 39 min in both subgroups. In the T&D group (n=48) 50% were deeply sedated by 70 min in both subgroups (two failures in each); geometric mean times were 68 and 71 min, respectively (P=0.58). Children closed their eyes slightly earlier after melatonin (respective geometric means 42 vs 48, P=0.17), and took slightly longer to achieve discharge criteria (146 vs 135, P=0.47). In these doses and clinical conditions, melatonin did not contribute to sedation of children.

Prospective Randomized Trial Evaluating Ketamine for Advanced Endoscopic Procedures in Difficult to Sedate Patients

SUMMARY Background Adequate patient sedation is mandatory for advanced endoscopic procedures such as ERCP and EUS. Aim To evaluate the effectiveness and safety of ketamine in difficult to sedate patients undergoing advanced endoscopic procedures. Methods This was a prospective, randomized trial of all patients undergoing ERCP or EUS who were not adequately sedated despite administration of meperidine 50 mg, midazolam 5 mg and diazepam 5 mg. Patients during endoscopy were then randomized to receive either intravenous ketamine (20 mg) every 5 min or continue to receive standard sedation using meperidine and diazepam. Results Of 175 patients, 82 were randomized to receive ketamine and 93 standard sedatives. Compared with standard sedation, qualitative physician rating (P < 0.0001) and depth of sedation (P < 0.001) were superior in the ketamine group with shorter recovery times (P < 0.0001). Both patient discomfort and sedation-related technical difficulty were significantly less among patients randomized to receive ketamine (P < 0.0001). More patients in the standard sedation group were crossed-over to the ketamine group due to sedation failure (35.5 vs. 3.7%, P < 0.0001). Nine patients who received ketamine, developed adverse events that were managed conservatively. Conclusions Ketamine is a useful adjunct to conscious sedation in patients who are difficult to sedate. Its use results in better quality and depth of sedation with shorter recovery times than patients sedated using benzodiazepines and meperidine alone. Further prospective studies evaluating the effectiveness and safety of ketamine for endoscopic sedation are needed.

Sedation Using Dexmedetomidine in Pediatric Burn Patients

Maintaining appropriate sedation and analgesia in pediatric burn patients can be quite challenging and often requires high doses of analgesics and anxiolytics because tolerance quickly develops. Escalating doses of opioids and benzodiazepines provide little additional benefit while increasing the incidence of side effects. Dexmedetomidine (DEX) is a novel alpha2-adrenergic agonist that provides sedation, anxiolysis, and analgesia with much less respiratory depression than other sedatives. In addition, DEX stimulation of alpha2 receptors on pancreatic beta cells may inhibit insulin secretion. Hyperglycemia has not been studied specifically in patients receiving DEX. Therefore, we hypothesized that DEX would improve sedation compared with our standard sedation regimen. In addition, we studied the effects of DEX on blood glucose levels. We performed a retrospective chart review of 65 pediatric burn patients (42 boys, 23 girls) in the intensive care unit admitted between 2001 and 2004 who received DEX infusion because of failure to achieve adequate sedation with our standard regimen of opioids and benzodiazepines. We recorded age, TBSA burn size, weight, dose and duration of infusion, adequacy of sedation before and after initiation of DEX, blood glucose levels before and after DEX, and the presence or absence of mechanical ventilation. The mean age was 5 years (range, 0.6-17), burn size was 36% TBSA (range, 3-94), and weight was 26 kg (range, 8-100). All patients were rated "inadequately sedate" before DEX infusion was initiated at 0.2 mug/kg/hr and titrated to effect. Twenty-six patients received a loading dose of 1 mug/kg. The average duration of DEX infusion was 11 days (range, 2-50), and no tachyphylaxis was noted. The mean dose was 0.5 mug/kg/hr (range, 0.1-2). Infusions were weaned over the course of 12 to 24 hours without evidence of rebound hypertension or withdrawal. With DEX titration, all patients were rated "adequately sedate," even though all were sedation failures with opioids and benzodiazepines. Eleven of 42 patients receiving ventilatory support were extubated while on DEX infusion, and no patient showed evidence of DEX induced respiratory depression. Patient's blood glucose levels averaged 121.2 +/- 8.9 mg/dl while on DEX infusion and 117.1 +/- 12.1 mg/dl while off, a nonsignificant difference.

Oral sedation with midazolam and diphenhydramine compared with midazolam alone in children undergoing magnetic resonance imaging

The purpose of this study was to compare the safety and efficacy of oral midazolam and midazolam-diphenhydramine combination to sedate children undergoing magnetic resonance imaging (MRI). We performed a prospective randomized double-blind study in 96 children who were randomly allocated into two groups. Group D received oral diphenhydramine (1.25 mg x kg(-1)) with midazolam (0.5 mg x kg(-1)), and Group P received oral placebo with midazolam (0.5 mg x kg(-1)) alone. Sedation scores, onset and duration of sleep were evaluated. Adverse effects, including hypoxemia, failed sedation, and the return of baseline activity, were documented. Diphenhydramine facilitated an earlier onset of midazolam sedation (P < 0.01), and higher sedation scores (P < 0.01). In children who received midazolam alone, 20 (41%) were inadequately sedated, compared with 9 (18%) children who received midazolam and diphenhydramine combination (P < 0.01). Time to complete recovery was not significantly different between the two groups. Our study indicates that the combination of oral diphenhydramine with oral midazolam resulted in safe and effective sedation for children undergoing MRI. The use of this combination might be more advantageous compared with midazolam alone, resulting in less sedation failure during MRI.

Prospective evaluation of dexmedetomidine for noninvasive procedural sedation in children*

Children often require sedation for lengthy noninvasive procedures. Conventional agents such as chloral hydrate, benzodiazepines, or barbiturates have been associated with sedation failure, respiratory depression, and paradoxic agitation. Dexmedetomidine is a newer alpha(2)-adrenergic receptor agonist with sedative properties and minimal respiratory depression. We hypothesized that it would be an effective agent for these procedures. Prospective case series. Tertiary care children's hospital. Children undergoing noninvasive procedures. Children were sedated with dexmedetomidine given as a bolus of 0.5-1.0 microg/kg over 5-10 mins followed by an infusion of 0.5-1.0 microg/kg/hr. Vital signs, sedative effectiveness, recovery patterns, and complications were prospectively recorded. Forty-eight patients, aged 6.9 +/- 3.7 yrs, were sedated. Fifteen received dexmedetomidine after failing sedation with chloral hydrate and/or midazolam. Sedation was induced with 0.92 +/- 0.36 microg/kg over 10.3 +/- 4.7 mins and maintained with an infusion of 0.69 +/- 0.32 microg/kg/hr. All procedures were completed. Heart rate, blood pressure, and respiratory rate decreased (p < .0001) but remained within normal limits for age. End-tidal CO(2) exceeded 50 mm Hg in seven of 404 measurements (1.7%). Mean recovery time was 84 +/- 42 mins and was significantly longer in the rescue (117 +/- 41 mins) vs. primary (69 +/- 34 mins) group (p < .0001). No patient developed agitation during recovery. Dexmedetomidine provided effective sedation in children undergoing noninvasive procedures and represents an alternative sedative choice for this population.