Dexmedetomidine vs midazolam for sedation of critically ill patients: a randomized trial

CONTEXT

Gamma-aminobutyric acid receptor agonist medications are the most commonly used sedatives for intensive care unit (ICU) patients, yet preliminary evidence indicates that the alpha(2) agonist dexmedetomidine may have distinct advantages.

OBJECTIVE

To compare the efficacy and safety of prolonged sedation with dexmedetomidine vs midazolam for mechanically ventilated patients.

DESIGN, SETTING, AND PATIENTS

Prospective, double-blind, randomized trial conducted in 68 centers in 5 countries between March 2005 and August 2007 among 375 medical/surgical ICU patients with expected mechanical ventilation for more than 24 hours. Sedation level and delirium were assessed using the Richmond Agitation-Sedation Scale (RASS) and the Confusion Assessment Method for the ICU.

INTERVENTIONS

Dexmedetomidine (0.2-1.4 microg/kg per hour [n = 244]) or midazolam (0.02-0.1 mg/kg per hour [n = 122]) titrated to achieve light sedation (RASS scores between -2 and +1) from enrollment until extubation or 30 days.

MAIN OUTCOME MEASURES

Percentage of time within target RASS range. Secondary end points included prevalence and duration of delirium, use of fentanyl and open-label midazolam, and nursing assessments. Additional outcomes included duration of mechanical ventilation, ICU length of stay, and adverse events.

RESULTS

There was no difference in percentage of time within the target RASS range (77.3% for dexmedetomidine group vs 75.1% for midazolam group; difference, 2.2% [95% confidence interval {CI}, -3.2% to 7.5%]; P = .18). The prevalence of delirium during treatment was 54% (n = 132/244) in dexmedetomidine-treated patients vs 76.6% (n = 93/122) in midazolam-treated patients (difference, 22.6% [95% CI, 14% to 33%]; P < .001). Median time to extubation was 1.9 days shorter in dexmedetomidine-treated patients (3.7 days [95% CI, 3.1 to 4.0] vs 5.6 days [95% CI, 4.6 to 5.9]; P = .01), and ICU length of stay was similar (5.9 days [95% CI, 5.7 to 7.0] vs 7.6 days [95% CI, 6.7 to 8.6]; P = .24). Dexmedetomidine-treated patients were more likely to develop bradycardia (42.2% [103/244] vs 18.9% [23/122]; P < .001), with a nonsignificant increase in the proportion requiring treatment (4.9% [12/244] vs 0.8% [1/122]; P = .07), but had a lower likelihood of tachycardia (25.4% [62/244] vs 44.3% [54/122]; P < .001) or hypertension requiring treatment (18.9% [46/244] vs 29.5% [36/122]; P = .02).

CONCLUSIONS

There was no difference between dexmedetomidine and midazolam in time at targeted sedation level in mechanically ventilated ICU patients. At comparable sedation levels, dexmedetomidine-treated patients spent less time on the ventilator, experienced less delirium, and developed less tachycardia and hypertension. The most notable adverse effect of dexmedetomidine was bradycardia.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00216190 Published online February 2, 2009 (doi:10.1001/jama.2009.56).

Dexmedetomidine vs midazolam or propofol for sedation during prolonged mechanical ventilation: two randomized controlled trials

CONTEXT

Long-term sedation with midazolam or propofol in intensive care units (ICUs) has serious adverse effects. Dexmedetomidine, an α(2)-agonist available for ICU sedation, may reduce the duration of mechanical ventilation and enhance patient comfort.

OBJECTIVE

To determine the efficacy of dexmedetomidine vs midazolam or propofol (preferred usual care) in maintaining sedation; reducing duration of mechanical ventilation; and improving patients' interaction with nursing care.

DESIGN, SETTING, AND PATIENTS

Two phase 3 multicenter, randomized, double-blind trials carried out from 2007 to 2010. The MIDEX trial compared midazolam with dexmedetomidine in ICUs of 44 centers in 9 European countries; the PRODEX trial compared propofol with dexmedetomidine in 31 centers in 6 European countries and 2 centers in Russia. Included were adult ICU patients receiving mechanical ventilation who needed light to moderate sedation for more than 24 hours (midazolam, n = 251, vs dexmedetomidine, n = 249; propofol, n = 247, vs dexmedetomidine, n = 251).

INTERVENTIONS

Sedation with dexmedetomidine, midazolam, or propofol; daily sedation stops; and spontaneous breathing trials.

MAIN OUTCOME MEASURES

For each trial, we tested whether dexmedetomidine was noninferior to control with respect to proportion of time at target sedation level (measured by Richmond Agitation-Sedation Scale) and superior to control with respect to duration of mechanical ventilation. Secondary end points were patients' ability to communicate pain (measured using a visual analogue scale [VAS]) and length of ICU stay. Time at target sedation was analyzed in per-protocol population (midazolam, n = 233, vs dexmedetomidine, n = 227; propofol, n = 214, vs dexmedetomidine, n = 223).

RESULTS

Dexmedetomidine/midazolam ratio in time at target sedation was 1.07 (95% CI, 0.97-1.18) and dexmedetomidine/propofol, 1.00 (95% CI, 0.92-1.08). Median duration of mechanical ventilation appeared shorter with dexmedetomidine (123 hours [IQR, 67-337]) vs midazolam (164 hours [IQR, 92-380]; P = .03) but not with dexmedetomidine (97 hours [IQR, 45-257]) vs propofol (118 hours [IQR, 48-327]; P = .24). Patients' interaction (measured using VAS) was improved with dexmedetomidine (estimated score difference vs midazolam, 19.7 [95% CI, 15.2-24.2]; P < .001; and vs propofol, 11.2 [95% CI, 6.4-15.9]; P < .001). Length of ICU and hospital stay and mortality were similar. Dexmedetomidine vs midazolam patients had more hypotension (51/247 [20.6%] vs 29/250 [11.6%]; P = .007) and bradycardia (35/247 [14.2%] vs 13/250 [5.2%]; P < .001).

CONCLUSIONS

Among ICU patients receiving prolonged mechanical ventilation, dexmedetomidine was not inferior to midazolam and propofol in maintaining light to moderate sedation. Dexmedetomidine reduced duration of mechanical ventilation compared with midazolam and improved patients' ability to communicate pain compared with midazolam and propofol. More adverse effects were associated with dexmedetomidine.

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: NCT00481312, NCT00479661.

Intramuscular versus intravenous therapy for prehospital status epilepticus

BACKGROUND

Early termination of prolonged seizures with intravenous administration of benzodiazepines improves outcomes. For faster and more reliable administration, paramedics increasingly use an intramuscular route.

METHODS

This double-blind, randomized, noninferiority trial compared the efficacy of intramuscular midazolam with that of intravenous lorazepam for children and adults in status epilepticus treated by paramedics. Subjects whose convulsions had persisted for more than 5 minutes and who were still convulsing after paramedics arrived were given the study medication by either intramuscular autoinjector or intravenous infusion. The primary outcome was absence of seizures at the time of arrival in the emergency department without the need for rescue therapy. Secondary outcomes included endotracheal intubation, recurrent seizures, and timing of treatment relative to the cessation of convulsive seizures. This trial tested the hypothesis that intramuscular midazolam was noninferior to intravenous lorazepam by a margin of 10 percentage points.

RESULTS

At the time of arrival in the emergency department, seizures were absent without rescue therapy in 329 of 448 subjects (73.4%) in the intramuscular-midazolam group and in 282 of 445 (63.4%) in the intravenous-lorazepam group (absolute difference, 10 percentage points; 95% confidence interval, 4.0 to 16.1; P<0.001 for both noninferiority and superiority). The two treatment groups were similar with respect to need for endotracheal intubation (14.1% of subjects with intramuscular midazolam and 14.4% with intravenous lorazepam) and recurrence of seizures (11.4% and 10.6%, respectively). Among subjects whose seizures ceased before arrival in the emergency department, the median times to active treatment were 1.2 minutes in the intramuscular-midazolam group and 4.8 minutes in the intravenous-lorazepam group, with corresponding median times from active treatment to cessation of convulsions of 3.3 minutes and 1.6 minutes. Adverse-event rates were similar in the two groups.

CONCLUSIONS

For subjects in status epilepticus, intramuscular midazolam is at least as safe and effective as intravenous lorazepam for prehospital seizure cessation. (Funded by the National Institute of Neurological Disorders and Stroke and others; ClinicalTrials.gov number, ClinicalTrials.gov NCT00809146.).

Frequent hypoxemia and apnea after sedation with midazolam and fentanyl

More than 80 deaths have occurred after the use of midazolam (Versed), often in combination with opioids, to sedate patients undergoing various medical and surgical procedures. We investigated the respiratory effects of midazolam (0.05 mg.kg-1) and fentanyl (2.0 micrograms.kg-1) in volunteers. The incidence of hypoxemia (oxyhemoglobin saturation less than 90%) and apnea (no spontaneous respiratory effort for 15 s) and the ventilatory response to carbon dioxide were evaluated. Midazolam alone produced no significant respiratory effects. Fentanyl alone produced hypoxemia in half of the subjects and significant depression of the ventilatory response to CO2, but did not produce apnea. Midazolam and fentanyl in combination significantly increased the incidence of hypoxemia (11 of 12 subjects) and apnea (6 of 12 subjects), but did not depress the ventilatory response to CO2 more than did fentanyl alone. Adverse reactions linked to midazolam and reported to the Department of Health and Human Services highlight apnea- and hypoxia-related problems as among the most frequent adverse reactions. Seventy-eight per cent of the deaths associated with midazolam were respiratory in nature, and in 57% an opioid had also been administered. All but three of the deaths associated with the use of midazolam occurred in patients unattended by anesthesia personnel. We conclude that combining midazolam with fentanyl or other opioids produces a potent drug interaction that places patients at a high risk for hypoxemia and apnea. Adequate precautions, including monitoring of patient oxygenation with pulse oximetry, the administration of supplemental oxygen, and the availability of persons skilled in airway management are recommended when benzodiazepines are administered in combination with opioids.

Results from the American Society for Gastrointestinal Endoscopy/U.S. Food and Drug Administration collaborative study on complication rates and drug use during gastrointestinal endoscopy

We used data from the American Society for Gastrointestinal Endoscopy's computer-based management system to compare the rates of serious cardiorespiratory complications and death associated with the use of midazolam and diazepam. Data were analyzed from 21,011 procedures. Midazolam was used in 15,061 of these procedures, diazepam in 4,302, and neither in 1,648. We assessed benzodiazepine dose, concomitant drug administration, type of procedure, and selected patient characteristics in each of these three groups. No significant difference between these three groups were noted other than the fact that certain clinical centers tended to exclusively use midazolam, whereas others used both benzodiazepines. Reports of serious cardiorespiratory complications and death were uncommon, occurring in 5.4 and 0.3 per thousand procedures, respectively. Midazolam did not seem to place patients in this sample at greater risk for cardiorespiratory complications than diazepam. Concomitant use of narcotics and urgent and emergent procedures, however, did increase the risk of serious cardiorespiratory events.

Neural bases for addictive properties of benzodiazepines

Benzodiazepines are widely used in clinics and for recreational purposes, but will lead to addiction in vulnerable individuals. Addictive drugs increase the levels of dopamine and also trigger long-lasting synaptic adaptations in the mesolimbic reward system that ultimately may induce the pathological behaviour. The neural basis for the addictive nature of benzodiazepines, however, remains elusive. Here we show that benzodiazepines increase firing of dopamine neurons of the ventral tegmental area through the positive modulation of GABA(A) (gamma-aminobutyric acid type A) receptors in nearby interneurons. Such disinhibition, which relies on alpha1-containing GABA(A) receptors expressed in these cells, triggers drug-evoked synaptic plasticity in excitatory afferents onto dopamine neurons and underlies drug reinforcement. Taken together, our data provide evidence that benzodiazepines share defining pharmacological features of addictive drugs through cell-type-specific expression of alpha1-containing GABA(A) receptors in the ventral tegmental area. The data also indicate that subunit-selective benzodiazepines sparing alpha1 may be devoid of addiction liability.

Safety and efficacy of buccal midazolam versus rectal diazepam for emergency treatment of seizures in children: a randomised controlled trial

BACKGROUND

Rectal diazepam and buccal midazolam are used for emergency treatment of acute febrile and afebrile (epileptic) seizures in children. We aimed to compare the safety and efficacy of these drugs.

METHODS

A multicentre, randomised controlled trial was undertaken to compare buccal midazolam with rectal diazepam for emergency-room treatment of children aged 6 months and older presenting to hospital with active seizures and without intravenous access. The dose varied according to age from 2.5 to 10 mg. The primary endpoint was therapeutic success: cessation of seizures within 10 min and for at least 1 hour, without respiratory depression requiring intervention. Analysis was per protocol.

FINDINGS

Consent was obtained for 219 separate episodes involving 177 patients, who had a median age of 3 years (IQR 1-5) at initial episode. Therapeutic success was 56% (61 of 109) for buccal midazolam and 27% (30 of 110) for rectal diazepam (percentage difference 29%, 95% CI 16-41). Analysing only initial episodes revealed a similar result. The rate of respiratory depression did not differ between groups. When centre, age, known diagnosis of epilepsy, use of antiepileptic drugs, prior treatment, and length of seizure before treatment were adjusted for with logistic regression, buccal midazolam was more effective than rectal diazepam.

INTERPRETATION

Buccal midazolam was more effective than rectal diazepam for children presenting to hospital with acute seizures and was not associated with an increased incidence of respiratory depression.

Buccal midazolam and rectal diazepam for treatment of prolonged seizures in childhood and adolescence: a randomised trial

BACKGROUND

Convulsive status epilepticus is the most common neurological medical emergency and has high morbidity and mortality. Early treatment before admission to hospital is best with an effective medication that can be administered safely. We aimed to find out whether there are differences in efficacy and adverse events between buccal administration of liquid midazolam and rectal administration of liquid diazepam in the acute treatment of seizures.

METHODS

At a residential school with on-site medical facilities 42 young people with severe epilepsy were enrolled. Continuous seizures of more than 5 min duration were randomly treated with buccal midazolam or rectal diazepam. If the seizure did not stop within 10 min additional medication chosen by the attending physician was administered. We monitored oxygen saturation and blood pressure for 30 min after treatment. The main outcome measures were efficacy, time from arrival of the nurse to drug administration, time from drug administration to end of seizure, and incidence of adverse cardiorespiratory events.

FINDINGS

Buccal midazolam was used to treat 40 seizures in 14 students, and rectal diazepam 39 seizures in 14 students. Midazolam stopped 30 (75%) of 40 seizures and diazepam 23 (59%) of 39 (p=0.16). The median time from arrival of the nurse to administration of medication was 2 min. Time from administration to end of seizure did not differ significantly between the two treatments. No clinically important adverse cardiorespiratory events were identified in the two groups. Buccal midazolam was universally acceptable to the nursing and care staff.

INTERPRETATION

Buccal midazolam is at least as effective as rectal diazepam in the acute treatment of seizures. Administration via the mouth is more socially acceptable and convenient and may become the preferred treatment for long seizures that occur outside hospital.

Propofol versus midazolam/meperidine for outpatient colonoscopy: administration by nurses supervised by endoscopists

BACKGROUND

Propofol is under evaluation as a sedative for endoscopic procedures.

METHODS

Eighty outpatients (ASA Class I or II) undergoing colonoscopy were randomized to receive either propofol or midazolam plus meperidine, administered by a nurse and supervised by an endoscopist. Endpoints were patient satisfaction, procedure and recovery times, neuropsychological function, and complications.

RESULTS

The mean dose of propofol administered was 218 mg; mean doses of midazolam and meperidine were, respectively, 4.7 mg and 89.7 mg. Mean time to sedation was faster in the propofol patients (2.1 min vs. 7.0 min; p < 0.0001), and depth of sedation was greater (p < 0.0001). On average, after the procedure, the propofol patients could stand at the bedside sooner (14.2 vs. 30.2 min), reached full recovery faster (14.4 vs. 33.0 min), and were discharged sooner (40.5 vs. 71.1 min) (all p < 0.0001). Patients who received propofol also expressed greater overall mean satisfaction on a 10-point visual analog scale (9.3 vs. 8.6; p < 0.05). At discharge, the propofol group had better scores on tests reflective of learning, memory, working memory span, and mental speed. Four patients in the midazolam/meperidine group developed minor complications (1 hypotension and bradycardia, 2 hypotension alone, and 1 tachycardia) and 1 patient in the propofol group had oxygen desaturation develop during an episode of epistaxis.

CONCLUSION

For outpatient colonoscopy, propofol administered by nurses and supervised by endoscopists has several advantages over midazolam plus meperidine and deserves additional investigation.

Prolonged sedation due to accumulation of conjugated metabolites of midazolam

Midazolam is a short-acting benzodiazepine routinely used in intensive-care medicine. Conjugates of its main metabolite, alpha-hydroxymidazolam, have been shown to accumulate in renal failure but have not previously been related to the prolonged sedative effects commonly observed in critically ill patients. We report five patients with severe renal failure who had prolonged sedation after administration of midazolam. In all five patients, the comatose state was immediately reversed by the benzodiazepine-receptor antagonist flumazenil. Serum concentration monitoring showed high concentrations of conjugated alpha-hydroxymidazolam when concentrations of the unconjugated metabolite and the parent drug were below the therapeutic range. In-vitro binding studies showed that the affinity of binding to the cerebral benzodiazepine receptor of glucuronidated alpha-hydroxymidazolam was only about ten times weaker (affinity constant 16 nmol/L) than that of midazolam (1.4 nmol/L) or unconjugated alpha-hydroxymidazolam (2.2 nmol/L). Conjugated metabolites of midazolam have substantial pharmacological activity. Physicians should be aware that these metabolites can accumulate in patients with renal failure.

Propofol vs midazolam in short-, medium-, and long-term sedation of critically ill patients. A cost-benefit analysis

The purpose of this study was to evaluate and compare the clinical effects, safety, and economic cost of propofol and midazolam in the sedation of patients undergoing mechanical ventilation in the ICU. Eighty-eight critically ill patients were studied and randomly allocated to receive short-term (less than 24 h), medium-term (24 h to 7 days), and prolonged (more than 7 days) continuous sedation with propofol (n = 46) or midazolam (n = 42). Mean doses required were 2.36 mg/kg/h for propofol and 0.17 mg/kg/h for midazolam. Patients in the group receiving propofol showed a percentage of hours of sedation at the desired level (grade 2, 3, 4, or 5 on the Ramsay scale) of 93 percent, compared with 82 percent (p < 0.05) in the group receiving midazolam. Both agents were considered safe with respect to the induction of adverse reactions during their use in prolonged sedation. Recovery after interrupting sedation was significantly faster in patients treated with propofol than in those sedated with midazolam (p < 0.05). Recovery of total consciousness was predictable according to sedation time in propofol-treated subgroups (r = 0.98, 0.88, and 0.92, respectively), while this correlation was not observed in the midazolam-treated group. In the subgroup with sedation of less than 24 h, propofol provided a cost savings of approximately 2,000 pesetas (pts) per patient, due to shorter stays in the ICU. We conclude that propofol is a sedative agent with the same safety, higher clinical effectiveness, and a better cost-benefit ratio than midazolam in the continuous sedation of critically ill patients.

Sedative use in the last week of life and the implications for end-of-life decision making

BACKGROUND

The use of sedation at the end of life has aroused ethical controversy, attracting accusations of hastening death by gradually increasing sedative doses. The doctrine of double effect has been introduced as an ethical defense. This study aimed to determine how sedative doses change at the end of life and how often the doctrine of double effect might be relevant.

METHODS

Case note review was performed of 237 consecutive patients who died in a specialist palliative care unit. Sedative dose changes during the last week of life were noted and survival from admission was compared between groups of patients receiving no sedation, sedation for 7 days, or a commencement of sedation in the last 48 hours of life. There was detailed review of notes from patients who received a marked increase in sedative dose to explore the applicability of the doctrine of double effect.

RESULTS

Sedation was given to 48% of patients. Of these, 13% received sedatives for 7 days or more, while 56% commenced sedative use only in the last 48 hours of life. The groups receiving no sedation or sedation for less than 48 hours had the shortest survival from admission (mean, 14.3 and 14.2 days), whereas the 7-day sedation group survived for a mean of 36.6 days (P<.001). Sedative use and dose increased toward the end of life, but the detailed case note review disclosed only 2 cases where the doctrine of double effect may have been implicated.

CONCLUSION

Sedative dose increases in the last hours of life were not associated with shortened survival overall, suggesting that the doctrine of double effect rarely has to be invoked to excuse sedative prescribing in end-stage care.

Propofol versus traditional sedative agents for gastrointestinal endoscopy: a meta-analysis

BACKGROUND & AIMS

Even though propofol has better recovery profile than traditional agents, its use is limited because of the perception of increased complication rates. Because an adequately powered trial comparing risk of propofol with traditional agents is lacking, we performed a meta-analysis of the current literature.

METHODS

We searched Medline (1966-October 2004), EMBASE (1980-October 2004), and Cochrane controlled trials registry. The following 4 cardiopulmonary complications were assessed: hypoxia, hypotension, arrhythmias, and apnea. Procedures were divided into 3 groups: esophagogastroduodenoscopy group, colonoscopy group, and endoscopic retrograde cholangiopancreatography/endoscopic ultrasonography group. Pooled odds ratios for complications were calculated for all the procedures combined and then separately for the 3 groups. Random effects models were used for 2-proportion comparisons.

RESULTS

Of the 90 citations identified, 12 original studies qualified for this meta-analysis and included 1161 patients. Of these, 634 received propofol, and 527 received midazolam, meperidine, and/or fentanyl. Most of the included studies were randomized trials of moderate quality and nonsignificant heterogeneity (Cochran Q = 4.81, P = .90). Compared with traditional sedative agents, the pooled odds ratio with the use of propofol for developing hypoxia or hypotension for all the procedures combined was 0.74 (95% confidence interval [CI], 0.44-1.24); for EGD, 0.85 (95% CI, 0.33-2.17); for colonoscopy, 0.4 (95% CI, 0.2-0.79); and for ERCP/EUS, 1.07 (95% CI, 0.38-3.01).

CONCLUSIONS

Propofol sedation during colonoscopy appears to have lower odds of cardiopulmonary complications compared with traditional agents, but for other procedures, the risk of complications is similar.

Premedication of children with oral midazolam

In a randomized, double-blind, placebo-controlled study, the safety, efficacy and feasibility of oral midazolam premedication in children were evaluated in an ambulatory surgery unit. Eighty unmedicated children (ASA PS I or II, ages 1-6 yr) were randomly assigned to one of four groups receiving midazolam 0.5, 0.75, or 1.0 mg.kg-1 or a placebo 30 min before separation from parents. Heart rate, systolic blood pressure, arterial oxygen saturation, respiratory rate, sedation and anxiolysis scores were recorded before premedication, every five minutes for 30 min and then during induction of anaesthesia and recovery. We found that heart rate, systolic blood pressure, arterial oxygen saturation and respiratory rate were unchanged during the study. Sedation and anxiolysis scores in the midazolam-treated groups were greater than those in the placebo group and that anxiolysis at the time of separation from the parents was judged excellent in 80-90% of the children who received midazolam. However, sedation and anxiolysis did not differ among the three midazolam groups. Mean times to discharge from hospital were similar for all four groups. The side effects, loss of balance and head control, blurred vision and dysphoric reactions were observed only in the 0.75 and 1.0 mg.kg-1 midazolam groups. We conclude that oral midazolam 0.5 mg.kg-1 is a safe and effective premedication and that 0.75 and 1 mg.kg-1 while offering no additional benefit, may cause more side effects.

Complications of sedation with midazolam in the intensive care unit and a comparison with other sedative regimens

OBJECTIVE

To describe the various complications that have been reported with use of midazolam for sedation in the intensive care unit (ICU).

DATA SOURCES

Publications in scientific literature.

DATA EXTRACTION

Computer search of the literature.

SYNTHESIS

Sedation is required in the ICU in order for patients to tolerate noxious stimuli, particularly mechanical ventilation. Under- and oversedation can lead to complications. To sedate patients in the ICU, midazolam is commonly administered via titrated, continuous infusions. Cardiorespiratory effects tend to be minimal; however, hypotension can occur in hypovolemic patients. Prolonged sedation after cessation of the midazolam infusion may be caused by altered kinetics of the drug in critically ill patients or by accumulation of active metabolites. In addition, paradoxical and psychotic reactions have been rarely reported. Tolerance and tachyphylaxis may occur, particularly with longer-term infusions (> or = 3 days). Benzodiazepine withdrawal syndrome has also been associated with high dose/long-term midazolam infusions. Compared with propofol infusions, midazolam infusions have been associated with a decreased occurrence of hypotension but a more variable time course for recovery of function after the cessation of the infusion. Lorazepam is a more cost-effective choice for long-term (> 24 hrs) sedation.

CONCLUSION

Continuous infusion midazolam provides effective sedation in the ICU with few complications overall, especially when the dose is titrated.

Propofol versus midazolam and meperidine for conscious sedation in GI endoscopy

OBJECTIVE

Propofol (2,6-diisopropyl phenol) is a relatively new intravenous sedative hypnotic with an ideal pharmacokinetic profile for conscious sedation. In this study, we compared the safety and efficacy of propofol versus the conventional regimen of midazolam and meperidine for conscious sedation in GI endoscopy.

METHODS

In this prospective study, 274 patients that included many elderly patients with multiple comorbid conditions underwent GI endoscopic procedures at our hospital. A total of 150 patients received propofol (20-120 mg) and fentanyl (0.25-1.5 mg). The control group of 124 patients was given midazolam (2-6 mg) and meperidine (25-75 mg). The dose of medication was titrated according to patient need and the duration of the procedure. A "comfort score" on a scale of 1-4 assessed the efficacy of the drugs based on pain or discomfort to the patient and ease of endoscopy. A "sedation score" was used to assess the degree of sedation on a scale of 1-5. The Aldrete score was used to measure recovery from anesthesia at 5 and 10 min after the procedure.

RESULTS

After controlling for age, American Society of Anesthesiologists' Physical Status Classification (ASA grade), and type and duration of procedure, logistic regression analysis determined that propofol resulted in 2.04 times better patient comfort (p = 0.033, 95% CI = 1.058-3.923). Propofol was 1.84 times more likely to produce deeper sedation than the regimen of midazolam and meperidine (p = 0.027, 95% CI = 1.071-3.083). The recovery from sedation was faster in patients receiving propofol, although this did not reach statistical significance. The safety parameters between the two groups were comparable.

CONCLUSION

Propofol was associated with a statistically significant improvement in comfort and sedation score when compared to midazolam and meperidine.

Does midazolam alter the clinical effects of intravenous ketamine sedation in children? A double-blind, randomized, controlled, emergency department trial

STUDY OBJECTIVE

This study was conducted to investigate the frequency and severity of adverse effects, specifically emergence phenomena, experienced by patients receiving intravenous ketamine with or without midazolam for sedation in a pediatric emergency department.

METHODS

Patients aged 4.5 months to 16 years receiving ketamine sedation were prospectively enrolled in a double-blind, randomized, controlled study at a university-affiliated children's hospital-pediatric ED. All patients received ketamine (1 mg/kg) and glycopyrrolate (5 microgram/kg) intravenously. Patients were randomly assigned to receive midazolam (0.1 mg/kg) intravenously or no midazolam. Total time of sedation, sedation efficacy, and adverse effects were recorded. Adverse effects were compared between patients receiving ketamine versus those who received ketamine and midazolam. Additional comparisons were made based on age and number of ketamine doses administered.

RESULTS

Two hundred sixty-six patients were studied; 129 received ketamine and 137 patients received ketamine and midazolam. Time of sedation and efficacy of sedation were equivalent between groups. Overall, adverse effects with ketamine sedation included respiratory events (12 [4.5%]), vomiting (50 [18.7%]), emergence phenomena in the pediatric ED (71 [26.7%]), and emergence phenomena at home (60 [22.4%]). Significant emergence phenomena in the pediatric ED (ie, nightmares, hallucinations, and severe agitation) occurred in 7.1% of the ketamine group and in 6.2% of the ketamine-midazolam group, a rate difference of 0.8 (95% confidence interval [CI] -5.3 to 7.0). The addition of midazolam led to an increased incidence of oxygen desaturation events (ketamine 1.6% versus ketamine-midazolam 7.3%; rate difference -5.7, 95% CI -10.6 to -0.9) but a decreased incidence of vomiting (ketamine 19.4%, ketamine-midazolam 9.6%, rate difference 9.8, 95% CI 1.4 to 18.2). The incidence of emergence phenomena and significant emergence phenomena was not affected by the addition of midazolam. However, the addition of midazolam was associated with more agitation in the pediatric ED in children 10 years or older (ketamine 5.7% versus ketamine-midazolam 35.7%; rate difference -30.0, 95% CI -10.7 to -49.3). Age breakdown further showed 6.3% (95% CI 0.9 to 11.6) more episodes of oxygen desaturation in the ketamine-midazolam group in children younger than 10 years, and 12.1% (95% CI 1.5 to 22.6) more vomiting episodes in the ketamine group in children younger than 10 years.

CONCLUSION

Ketamine and combined ketamine and midazolam provided equally effective sedation. The addition of midazolam did not alter the incidence of emergence phenomena. Vomiting occurred more frequently in the ketamine only group, whereas oxygen desaturation occurred more frequently in the ketamine-midazolam group. These findings were more pronounced in patients younger than 10 years. Parental and physician satisfaction remained high for all patients receiving intravenous ketamine sedation.

Prolonged recovery and delayed side effects of sedation for diagnostic imaging studies in children

OBJECTIVE

Although sedation-related adverse events in children in the hospital setting have been extensively reported, limited data are available regarding adverse events after discharge home. Despite nationally recommended discharge criteria, in busy outpatient settings, children may be sent home into the care of their parents after a brief recovery from sedation, placing them at risk for adverse events in an unmonitored setting. Previous studies have not addressed issues such as requirement for escalation of care after discharge (ie, emergency department visits or hospitalization), or parental satisfaction with their child's sedation experience. This study was undertaken to evaluate the recovery and delayed adverse events after discharge of children who received sedation for magnetic resonance imaging or computed tomography.

METHODS

With approval from the institutional review board and written informed consent from a parent, children (<18 years old) sedated for magnetic resonance imaging or computerized tomography were studied. Sedative drugs were ordered at the discretion of the radiologist responsible for the procedure in accordance with institutional sedation guidelines and in consideration of the child's health status. Pediatric nurses in the diagnostic areas administered the sedative agent(s) and monitored children according to preestablished institutional guidelines. Demographics, sedative(s) administered, and adverse events including hypoxemia (decrease in SpO(2) by >/=10% of baseline) and sedation events such as inadequate, failed, or excessive sedation, were documented on the institutional quality assurance tool. Children were discharged from the hospital when they met the following preestablished discharge criteria: return to baseline vital signs, level of consciousness close to baseline, and the ability to maintain a patent airway. The following day, parents were telephoned and questioned regarding the child's alertness, side effects, and whether medical follow-up had been sought. Parents also rated their overall satisfaction with the sedation experience.

RESULTS

Three hundred seventy six children comprised the sample. Eighty nine percent of children received chloral hydrate (CH; 64 +/- 13 mg/kg), and 11% midazolam (.15 +/-.13 mg/kg) as the primary sedative. There was an 8% incidence of failed sedation, and a 1.6% incidence of hypoxemia during the procedure. Three children required prolonged monitoring in the postanesthesia care unit before discharge; 1 child attributable to an allergic reaction, a second attributable to wheezing and oxygen desaturation, and the third attributable to prolonged sedation from CH and midazolam. These children were discharged home from the postanesthesia care unit without additional sequelae. Side effects after discharge included: motor imbalance (31%), gastrointestinal effects (23%), agitation (19%), and restlessness (14%). Agitation and restlessness lasted greater than 6 hours in more than one third of children who experienced these effects. CH was more commonly associated with imbalance compared with midazolam, and restlessness and prolonged imbalance were associated with younger age. Medical advice was sought after discharge for 15 (4%) children, 3 of whom required a visit to the emergency department for excessive or prolonged sedation. Each of these children had received CH as a sole sedative in recommended doses (61-77 mg/kg). In 1 of these cases, the procedure had been aborted because of inadequate sedation in the hospital, yet the child became difficult to arouse at home. Only 48% of children returned to baseline activity and behavior within 8 hours of the procedure; however, 89% were back to baseline status within 24 hours. Notably, 5% of all children did not return to baseline activity until the second day after the procedure. Although not statistically significant, infants <12 months old experienced delayed recovery (ie, >/=24 hours) more frequently compared with older c

Long-term sedation in intensive care unit: a randomized comparison between inhaled sevoflurane and intravenous propofol or midazolam

PURPOSE

To evaluate efficacy and adverse events related to inhaled sevoflurane for long-term sedation compared with standard intravenous (i.v.) sedation with propofol or midazolam.

METHODS

Randomized controlled trial. Sixty intensive care unit (ICU) patients expected to require more than 24 h sedation were randomly assigned to one of three groups: group S, inhaled sevoflurane; group P, i.v. propofol; group M, i.v. midazolam. All patients also received i.v. remifentanil for goal-directed sedation (Ramsay scale and pain score) until extubation or for a maximum of 96 h. Primary end points were wake-up times and extubation delay from termination of sedative administration. Proportion of time within Ramsay score 3-4, i.v. morphine consumption at 24 h post extubation, hallucination episodes after end of sedation, adverse events, inorganic fluoride plasma levels, and ambient sevoflurane concentrations were recorded.

RESULTS

Forty-seven patients were analyzed. Wake-up time and extubation delay were significantly (P<0.01) shorter in group S (18.6 ± 11.8 and 33.6 ± 13.1 min) than in group P (91.3 ± 35.2 and 326.11 ± 360.2 min) or M (260.2 ± 150.2 and 599.6 ± 586.6 min). Proportion of time within desired interval of sedation score was comparable between groups. Morphine consumption during the 24 h following extubation was lower in group S than in groups P and M. Four hallucination episodes were reported in group P, five in group M, and none in group S (P=0.04). No hepatic or renal adverse events were reported. Mean plasma fluoride value was 82 μmol l(-1) (range 12-220 μmol l(-1)), and mean ambient sevoflurane concentration was 0.3 ± 0.1 ppm.

CONCLUSIONS

Long-term inhaled sevoflurane sedation seems to be a safe and effective alternative to i.v. propofol or midazolam. It decreases wake-up and extubation times, and post extubation morphine consumption, and increases awakening quality.

Sedation with propofol for routine ERCP in high-risk octogenarians: a randomized, controlled study

OBJECTIVES

Adequate patient sedation is mandatory for diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP). In this respect it is known that the short-acting anesthetic propofol offers certain potential advantages for sedation during ERCP, but there are no controlled studies concerning the feasibility and safety of propofol sedation in elderly, high-risk patients.

METHODS

One hundred and fifty consecutive patients aged >or=80 yr with high comorbidity (ASA score >or=III: 91 %), randomly received midazolam plus meperidine (n = 75) or propofol alone (n = 75) for sedation during ERCP. Vital signs were continuously monitored and procedure-related parameters, recovery time, and quality as well as patients' cooperation and tolerance of the procedure were assessed.

RESULTS

Clinically relevant changes in vital signs were observed at comparable frequencies with a temporary oxygen desaturation (<90%) occurring in eight patients in the propofol-group and seven patients receiving midazolam/meperidine (n.s.). Hypotension was documented in two patients in the propofol group and one patient receiving midazolam/meperidine. Propofol provided a significantly better patient cooperation than midazolam/meperidine (p < 0.01), but the procedure tolerability was rated nearly the same by both groups. Mean recovery time was significantly shorter in the propofol group (22 +/- 7 min vs 31 +/- 8 min for midazolam/meperidine (p < 0.01)) while the recovery score was significantly higher under propofol (8.3 +/- 1.2 vs 6.1 +/- 1.1(p < 0.01)). During recovery a significant lower number of desaturation events (<90%) were observed in the propofol group (12%) than in the midazolam/meperidine group (26%, p < 0.01).

CONCLUSION

Under careful monitoring the use of propofol for sedation during ERCP is superior to midazolam/meperidine even in high-risk octogenarians.

Comparison of propofol/fentanyl versus ketamine/midazolam for brief orthopedic procedural sedation in a pediatric emergency department

PURPOSE

To compare the effectiveness of 2 medication regimens, propofol/fentanyl (P/F) and ketamine/midazolam (K/M), for brief orthopedic emergency department procedural sedation. This study was powered to compare recovery times (RT) and procedural distress as measured by the Observational Score of Behavioral Distress-revised (OSBD-r; range: 0-23.5 with 23.5 representing maximal distress).

METHODS

We conducted a prospective, partially-blinded controlled comparative trial comparing intravenous P/F with K/M in a convenience sample of 113 patients aged 3 to 18 years old undergoing orthopedic procedural sedation. All medications were administered by the intermittent intravenous bolus method. An independent sedation nurse recorded total sedation time and RT. Effectiveness was measured using 6 parameters: 1) patient distress as assessed by independent blinded observers after videotape review using the OSBD-r; 2) orthopedic satisfaction score (Likert scale 1-5); 3) sedation nurse satisfaction score (Likert 1-5); 4) parental perception of procedural pain using a 0 to 100 mm Visual Analog Scale with the upper limit being "most pain"; 5) patient recall of the procedure; and 6) 1 to 3 week follow-up.

RESULTS

RT and total sedation time were significantly less in the P/F group than in the K/M group (33.4 minutes vs 23.2 minutes). The mean OSBD-r scores during manipulation were 0.084 and 0.278 for the K/M and P/F groups, respectively. Although this difference was statistically significant (95% confidence interval for the mean difference -0.34 to -0.048), both regimens were successful in keeping the scores low. There was no statistical difference between the groups in the other measures of effectiveness. There was a statistically significant difference between the groups in the occurrence of desaturation and late side effects.

CONCLUSIONS

RT with P/F is shorter than with K/M. P/F is comparable to K/M in reducing procedural distress associated with painful orthopedic procedures in the pediatric emergency department. Although propofol has a greater potential of respiratory depression and airway obstruction as compared with ketamine, it offers some unique advantages including a quicker offset and smoother recovery profile.

Continuous EEG monitoring and midazolam infusion for refractory nonconvulsive status epilepticus

BACKGROUND

Although cIV-MDZ has emerged as a popular alternative to barbiturate therapy for refractory status epilepticus (RSE), experience with its use for this indication is limited.

OBJECTIVE

- To evaluate the efficacy of continuous intravenous midazolam (cIV-MDZ) for attaining sustained seizure control in patients with RSE.

METHODS

The authors reviewed 33 episodes of RSE treated with cIV-MDZ in their neurologic intensive care unit over 6 years. All patients were monitored with continuous EEG (cEEG). MDZ infusion rates were titrated to eliminate clinical and EEG seizure activity; cIV-MDZ was discontinued once patients were seizure-free for 24 hours. Acute treatment failures (seizures 1 to 6 hours after starting cIV-MDZ), breakthrough seizures (after 6 hours of therapy), post-treatment seizures (within 48 hours of discontinuing therapy), and ultimate treatment failure (frequent seizures that led to treatment with pentobarbital or propofol) were identified.

RESULTS

All patients were in nonconvulsive SE at the time cIV-MDZ was started; the mean duration of SE before treatment was 3.9 days (range 0 to 17 days). In addition to benzodiazepines, 94% of patients had received at least two antiepileptic drugs (AED) before starting cIV-MDZ. The mean loading dose was 0.19 mg/kg, the mean maximal infusion rate was 0.22 mg/kg/h, and the mean duration of cIV-MDZ therapy was 4.2 days (range 1 to 14 days). Acute treatment failure occurred in 18% (6/33) of episodes, breakthrough seizures in 56% (18/32), post-treatment seizures in 68% (19/28), and ultimate treatment failure in 18% (6/33). Breakthrough seizures were clinically subtle or purely electrographic in 89% (16/18) of cases and were associated with an increased risk of developing post-treatment seizures (p = 0.01).

CONCLUSIONS

Although most patients with RSE initially responded to cIV-MDZ, over half developed subsequent breakthrough seizures, which were predictive of post-treatment seizures and were often detectable only with cEEG. Titrating cIV-MDZ to burst suppression, more aggressive treatment with concurrent AED, or a longer period of initial treatment may reduce the high proportion of patients with RSE who relapse after cIV-MDZ is discontinued.

Adverse cardiovascular and respiratory events during sedation of pediatric patients for imaging examinations

PURPOSE

To retrospectively identify factors associated with an increased risk of adverse cardiovascular or respiratory events during sedation of pediatric patients for imaging examinations.

MATERIALS AND METHODS

This HIPAA-compliant study was institutional review board approved; the requirement for informed consent was waived. All sedation information--including patient demographics, medications (doses and routes of administration), time required to sedate and before discharge, American Society of Anesthesiologists physical status classification, adverse events, and failed sedations--was maintained in a computerized database. A review of the data on all patients sedated between 1997 and 2003 for magnetic resonance imaging, computed tomography, and interventional radiology revealed associated adverse respiratory events in 70 patients. Adverse respiratory event was defined as oxygen desaturation of at least 5%, pulmonary aspiration, and need for airway resuscitation. Adverse cardiovascular events were defined as cardiac arrest and hemodynamic changes requiring medical therapy. Adverse events were compared between sedation regimens--which included fentanyl, chloral hydrate, pentobarbital, and midazolam hydrochloride--by using the Fisher exact test. Multiple logistic regression analysis was applied to identify potential predictors of adverse events.

RESULTS

Among 16,467 sedations performed, 70 (0.4%) were associated with adverse respiratory events: 58 cases of oxygen desaturation, two pulmonary aspirations, 10 cases of airway resuscitation, and no cardiovascular events. Nearly 30% (n = 20) of the 70 patients who had an adverse event had a history of serious respiratory illness. Logistic regression analysis revealed that neither patient age, weight, or sex nor type of imaging procedure was associated with an increased risk of an adverse event. Use of a single sedation agent was associated with lower adverse event risk than was use of multiple agents (P < .001).

CONCLUSION

Consideration should be given to using single agents, avoiding the use of multidrug sedation regimens, and recognizing that a history of pulmonary disease could be associated with an increased risk of adverse respiratory events despite a currently stable respiratory state.

Safety and efficacy of analgesia-based sedation with remifentanil versus standard hypnotic-based regimens in intensive care unit patients with brain injuries: a randomised, controlled trial [ISRCTN50308308]

Introduction

This randomised, open-label, observational, multicentre, parallel group study assessed the safety and efficacy of analgesia-based sedation using remifentanil in the neuro-intensive care unit.

Methods

Patients aged 18–80 years admitted to the intensive care unit within the previous 24 hours, with acute brain injury or after neurosurgery, intubated, expected to require mechanical ventilation for 1–5 days and requiring daily downward titration of sedation for assessment of neurological function were studied. Patients received one of two treatment regimens. Regimen one consisted of analgesia-based sedation, in which remifentanil (initial rate 9 μg kg^-1 h^-1) was titrated before the addition of a hypnotic agent (propofol [0.5 mg kg^-1 h^-1] during days 1–3, midazolam [0.03 mg kg^-1 h^-1] during days 4 and 5) (n = 84). Regimen two consisted of hypnotic-based sedation: hypnotic agent (propofol days 1–3; midazolam days 4 and 5) and fentanyl (n = 37) or morphine (n = 40) according to routine clinical practice. For each regimen, agents were titrated to achieve optimal sedation (Sedation–Agitation Scale score 1–3) and analgesia (Pain Intensity score 1–2).

Results

Overall, between-patient variability around the time of neurological assessment was statistically significantly smaller when using remifentanil (remifentanil 0.44 versus fentanyl 0.86 [P = 0.024] versus morphine 0.98 [P = 0.006]. Overall, mean neurological assessment times were significantly shorter when using remifentanil (remifentanil 0.41 hour versus fentanyl 0.71 hour [P = 0.001] versus morphine 0.82 hour [P < 0.001]). Patients receiving the remifentanil-based regimen were extubated significantly faster than those treated with morphine (1.0 hour versus 1.93 hour, P = 0.001) but there was no difference between remifentanil and fentanyl. Remifentanil was effective, well tolerated and provided comparable haemodynamic stability to that of the hypnotic-based regimen. Over three times as many users rated analgesia-based sedation with remifentanil as very good or excellent in facilitating assessment of neurological function compared with the hypnotic-based regimen.

Conclusions

Analgesia-based sedation with remifentanil permitted significantly faster and more predictable awakening for neurological assessment. Analgesia-based sedation with remifentanil was very effective, well tolerated and had a similar adverse event and haemodynamic profile to those of hypnotic-based regimens when used in critically ill neuro-intensive care unit patients for up to 5 days.

Occurrence of withdrawal in critically ill sedated children

OBJECTIVES

To record the number of children with withdrawal symptoms after the administration of sedatives for mechanical ventilation, and to discuss the possible connection with the administration of midazolam.

DESIGN

Retrospective data collection from case records and charts.

SETTING

Medical and surgical intensive care unit (ICU) in a university hospital.

PATIENTS

Children 6 months to 14 yrs of age who required sedation for mechanical ventilation (n = 40).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Kind and amount of sedatives and analgesics, duration of administration, and occurrence of withdrawal symptoms. The frequency of withdrawal symptoms was 35% (14/40) of the sedated children. A total dose of midazolam of >60 mg/kg was strongly significantly associated with occurrence of withdrawal. Statistical analysis to determine the occurrence of withdrawal associated with the administration of morphine was not possible.

CONCLUSIONS

Signs and symptoms of a withdrawal reaction were observed in several children. The occurrence of withdrawal was statistically related to high doses of midazolam, but it was not possible to determine the influence of morphine. If large doses of midazolam and opioids have been administered, there may be justification for reducing the dose gradually instead of abruptly, or using longer-acting benzodiazepines or opioids on discontinuation of sedation.