Severe withdrawal syndrome possibly associated with cessation of a midazolam and fentanyl infusion

The role of systematic reviews in pharmacovigilance planning and Clinical Trials Authorisation application: example from the SLEEPS trial

BACKGROUND

Adequate sedation is crucial to the management of children requiring assisted ventilation on Paediatric Intensive Care Units (PICU). The evidence-base of randomised controlled trials (RCTs) in this area is small and a trial was planned to compare midazolam and clonidine, two sedatives widely used within PICUs neither of which being licensed for that use. The application to obtain a Clinical Trials Authorisation from the Medicines and Healthcare products Regulatory Agency (MHRA) required a dossier summarising the safety profiles of each drug and the pharmacovigilance plan for the trial needed to be determined by this information. A systematic review was undertaken to identify reports relating to the safety of each drug.

METHODOLOGY/PRINCIPAL FINDINGS

The Summary of Product Characteristics (SmPC) were obtained for each sedative. The MHRA were requested to provide reports relating to the use of each drug as a sedative in children under the age of 16. Medline was searched to identify RCTs, controlled clinical trials, observational studies, case reports and series. 288 abstracts were identified for midazolam and 16 for clonidine with full texts obtained for 80 and 6 articles respectively. Thirty-three studies provided data for midazolam and two for clonidine. The majority of data has come from observational studies and case reports. The MHRA provided details of 10 and 3 reports of suspected adverse drug reactions.

CONCLUSIONS/SIGNIFICANCE

No adverse reactions were identified in addition to those specified within the SmPC for the licensed use of the drugs. Based on this information and the wide spread use of both sedatives in routine practice the pharmacovigilance plan was restricted to adverse reactions. The Clinical Trials Authorisation was granted based on the data presented in the SmPC and the pharmacovigilance plan within the clinical trial protocol restricting collection and reporting to adverse reactions.

Opioid and benzodiazepine withdrawal syndromes in the paediatric intensive care unit: a review of recent literature

AIMS AND OBJECTIVES

This paper aims to critically review and analyse available literature to inform and advance patient care.

BACKGROUND

Withdrawal syndromes related to the routine administration of sedation and analgesia in paediatric intensive care unit (PICU) have been recognized since the 1990 s. Common symptoms include tremors, agitation, inconsolable crying and sleeplessness.

SEARCH STRATEGIES

A critical review was undertaken to assess developments in this area. Four databases were searched using Ovid Online. These were Ovid Medline, CINAHL, BNI and Embase. Key terms included were 'Paediatric', 'Sedation', 'Withdrawal' and 'Intensive care'.

INCLUSION AND EXCLUSION CRITERIA

Articles from 1980 onwards were reviewed for their relevance to paediatric iatrogenic withdrawal. Additionally, seminal work from the 1970s was included. Because of the scarcity of literature, relevant editorials and opinion pieces were included.

RESULTS

A total of 2,232,586 papers resulted from keyword searches. Use of Boolean operators to combine terms reduced the number of results to 62. Exclusion criteria reduced the number of suitable papers to 20. Tracking reference lists yielded a further 18 papers. In total, 38 papers were retrieved examining 1375 patients. Four papers surveyed drug usage on PICU, 14 listed withdrawal symptoms, 4 described the frequency of withdrawal in the PICU population, 9 described risk factors, 4 presented or validated clinical tools and 14 describe treatment strategies.

CONCLUSIONS

Withdrawal syndromes may affect 20% of exposed children and are related to infusion duration and total dose. Fifty-one symptoms are described in the literature. Future studies need accurate, validated clinical tools to be effective. Risk factors, signs and symptoms have been identified, and validation studies must now take place.

RELEVANCE TO CLINICAL PRACTICE

Withdrawal syndromes continue to be widespread and difficult to diagnose. Awareness of their causes and treatments should influence clinical decisions at the bedside.

Orofacial automatisms induced by acute withdrawal from high-dose midazolam mimicking nonconvulsive status epilepticus in a child

Nonconvulsive Status Epilepticus (NCSE) is not uncommon in children, and can be challenging to diagnose and treat. Etiologies vary widely and include infection, trauma and acute withdrawal from medications such as anticonvulsants. We report a child who experienced orofacial dyskinesias concerning for NCSE after withdrawal from high dose benzodiazepines andopiates. Automonic signs typically associated with sedative withdrawal were absent and treatment with benzodiazepines did not improve his symptoms. Diagnostic testing was negative, including electroencephalogram, and resolution was complete within five days. Our case demonstrates the orofacial dyskinesias that may occur during sedative medication withdrawal, and highlights potential confusion with non-convulsive status epilepticus.

Sequential use of midazolam and propofol for long-term sedation in postoperative mechanically ventilated patients

Acute withdrawal syndromes, including agitation and a long weaning time, are common adverse effects after long-term sedation with midazolam. We performed this study to determine whether the sequential use of midazolam and propofol could reduce adverse effects as compared with midazolam alone. We studied 26 patients receiving mechanical ventilation for three or more days after surgery. Patients were randomly assigned to two groups. In Group M, patients were sedated with midazolam alone. In Group M-P, midazolam was switched to propofol approximately 24 h before the expected stopping of sedation. The level of sedation was maintained at 4 or 5 on the Ramsay sedation scale. The sedation agitation scale was evaluated for 24 h after extubation. The recovery time from stopping of sedation to extubation was significantly shorter in Group M-P (1.3 +/- 0.4 h) compared with Group M (4.0 +/- 2.4 h). The incidence of agitation in Group M-P (8%) was significantly less frequent than that in Group M (54%). The results indicate that sequential use of midazolam and propofol for long-term sedation could reduce the incidence of agitation compared with midazolam alone.

IMPLICATIONS

Our study indicates that sequential use of midazolam and propofol could reduce the incidence of agitation compared with midazolam alone.

Opioid and Benzodiazepine Withdrawal Syndrome in Adult Burn Patients

The prolonged use of continuous intravenous sedation [benzodiazepines (BZDs)] and pain medication [opioids (OPs)] is now common in intensive care units. Few studies have evaluated the characteristics that may lead to an acute withdrawal syndrome when these long-term medications are withdrawn. Those studies that have made recommendations for weaning rates to prevent withdrawal have given these recommendations with minimal data to support their recommendations. The purpose of this study was to retrospectively review the records of adult burn patients for the presence of acute BZD or OP withdrawal syndrome and to characterize whether patterns of BZD or OP administration or weaning rates contribute to the development of acute withdrawal syndrome. We found no relation of acute withdrawal syndrome to peak dose, total dose, or duration of dose of BZD/OP before the terminal withdrawal phase. There was a significant relationship between the rate of BZD/OP weaning in the terminal drug withdrawal phase and the percentage of days that patients experienced withdrawal symptoms ( P < 0.005). Those patients who underwent a prolonged terminal weaning from these medications experienced fewer symptoms. The optimal rate of weaning that would allow decreased ventilator and intensive care unit length of stay without development of acute withdrawal symptoms is yet to be determined.

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.

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.