Midazolam and myoclonus in neonate

Intravenous midazolam infusion for sedation of infants in the neonatal intensive care unit

BACKGROUND

Proper sedation for neonates undergoing uncomfortable procedures may reduce stress and avoid complications. Midazolam is a short-acting benzodiazepine that is used increasingly in neonatal intensive care units (NICUs). However, its effectiveness as a sedative in neonates has not been systematically evaluated.

OBJECTIVES

Primary objeciveTo assess the effectiveness of intravenous midazolam infusion for sedation, as evaluated by behavioural and/or physiological measurements of sedation levels, in critically ill neonates in the NICU. Secondary objectivesTo assess effects of intravenous midazolam infusion for sedation on complications including the following.1. Incidence of intraventricular haemorrhage (IVH)/periventricular leukomalacia (PVL).2. Mortality.3. Occurrence of adverse effects associated with the use of midazolam (hypotension, neurological abnormalities).4. Days of ventilation.5. Days of supplemental oxygen.6. Incidence of pneumothorax.7. Length of NICU stay (days).8. Long-term neurodevelopmental outcomes.

SELECTION CRITERIA

We selected for review randomised and quasi-randomised controlled trials of intravenous midazolam infusion for sedation in infants aged 28 days or younger.

DATA COLLECTION AND ANALYSIS

We abstracted data regarding the primary outcome of level of sedation. We assessed secondary outcomes such as intraventricular haemorrhage, periventricular leukomalacia, death, length of NICU stay and adverse effects associated with midazolam. When appropriate, we performed meta-analyses using risk ratios (RRs) and risk differences (RDs), and if the RD was statistically significant, we calculated the number needed to treat for an additional beneficial outcome (NNTB) or an additional harmful outcome (NNTH), along with their 95% confidence intervals (95% CIs) for categorical variables, and weighted mean differences (WMDs) for continuous variables. We assessed heterogeneity by performing the I-squared (I2) test.

MAIN RESULTS

We included in the review three trials enrolling 148 neonates. We identified no new trials for this update. Using different sedation scales, each study showed a statistically significantly higher sedation level in the midazolam group compared with the placebo group. However, none of the sedation scales used have been validated in preterm infants; therefore, we could not ascertain the effectiveness of midazolam in this population. Duration of NICU stay was significantly longer in the midazolam group than in the placebo group (WMD 5.4 days, 95% CI 0.40 to 10.5; I2 = 0%; two studies, 89 infants). One study (43 infants) reported significantly lower Premature Infant Pain Profile (PIPP) scores during midazolam infusion than during dextrose (placebo) infusion (MD -3.80, 95% CI -5.93 to -1.67). Another study (46 infants) observed a higher incidence of adverse neurological events at 28 days' postnatal age (death, grade III or IV IVH or PVL) in the midazolam group compared with the morphine group (RR 7.64, 95% CI 1.02 to 57.21; RD 0.28, 95% CI 0.07 to 0.49; NNTH 4, 95% CI 2 to 14) (tests for heterogeneity not applicable). We considered these trials to be of moderate quality according to GRADE assessment based on the following outcomes: mortality during hospital stay, length of NICU stay, adequacy of analgesia according to PIPP scores and poor neurological outcomes by 28 days' postnatal age.

AUTHORS' CONCLUSIONS

Data are insufficient to promote the use of intravenous midazolam infusion as a sedative for neonates undergoing intensive care. This review raises concerns about the safety of midazolam in neonates. Further research on the effectiveness and safety of midazolam in neonates is needed.

The clinical heterogeneity of drug-induced myoclonus: an illustrated review

A wide variety of drugs can cause myoclonus. To illustrate this, we first discuss two personally observed cases, one presenting with generalized, but facial-predominant, myoclonus that was induced by amantadine; and the other presenting with propriospinal myoclonus triggered by an antibiotic. We then review the literature on drugs that may cause myoclonus, extracting the corresponding clinical phenotype and suggested underlying pathophysiology. The most frequently reported classes of drugs causing myoclonus include opiates, antidepressants, antipsychotics, and antibiotics. The distribution of myoclonus ranges from focal to generalized, even amongst patients using the same drug, which suggests various neuro-anatomical generators. Possible underlying pathophysiological alterations involve serotonin, dopamine, GABA, and glutamate-related processes at various levels of the neuraxis. The high number of cases of drug-induced myoclonus, together with their reported heterogeneous clinical characteristics, underscores the importance of considering drugs as a possible cause of myoclonus, regardless of its clinical characteristics.

Intravenous midazolam infusion for sedation of infants in the neonatal intensive care unit

BACKGROUND

Proper sedation for neonates undergoing uncomfortable procedures may reduce stress and avoid complications. Midazolam is a short-acting benzodiazepine that is increasingly used in neonatal intensive care units (NICU). However, its effectiveness as a sedative in neonates has not been systematically evaluated.

OBJECTIVES

To determine whether intravenous midazolam infusion is an effective sedative, as evaluated by behavioural or physiological measurements, or both, for critically ill neonates undergoing intensive care and to assess clinically significant short- and long-term adverse effects associated with its use.

SEARCH METHODS

We performed a literature search according to the Cochrane Neonatal Review Group search strategy. Randomised and quasi-randomised controlled trials of intravenous midazolam use in neonates were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2012), MEDLINE (1985 to 2012), EMBASE (1980 to 2012), CINAHL (1981 to 2012), reference lists of published studies, personal files, and abstracts published in The Pediatric Academic Societies Meeting Abstract Archives from 1990 to 2011.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of intravenous midazolam infusion in infants aged 28 days or less for sedation were selected for review.

DATA COLLECTION AND ANALYSIS

Data regarding the primary outcome of level of sedation were abstracted. Secondary outcomes such as intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), death, length of NICU stay, and adverse effects associated with midazolam were assessed. When appropriate, meta-analyses were performed using risk ratio (RR), risk difference (RD), along with their 95% confidence intervals (95% CI) for categorical variables and weighted mean difference (WMD) for continuous variables.

MAIN RESULTS

Three trials were included in the review. Using different sedation scales, each study showed a statistically significantly higher sedation level in the midazolam group compared to the placebo group. However, since none of the sedation scales used have been validated in preterm infants, the effectiveness of midazolam in this population could not be ascertained. One study showed a statistically significant higher incidence of adverse neurological events (death, grade III or IV IVH, PVL), and meta-analysis of data from two studies showed a statistically significant longer duration of NICU stay in the midazolam group compared to the placebo group.

AUTHORS' CONCLUSIONS

There are insufficient data to promote the use of intravenous midazolam infusion as a sedative for neonates undergoing intensive care. This review raises concerns about the safety of midazolam in neonates. Further research on the effectiveness and safety of midazolam in neonates is needed.

Nonepileptic motor phenomena in the neonate

The newborn infant is prone to clinical motor phenomena that are not epileptic in nature. These include tremors, jitteriness, various forms of myoclonus and brainstem release phenomena. They are frequently misdiagnosed as seizures, resulting in unnecessary investigations and treatment with anticonvulsants, which have potentially harmful side effects. Unfortunately, there is a paucity of literature about many of these phenomena in the newborn, and some of the major textbooks refer to these events as nonepileptic seizures, leading to further confusion for the practitioner. The present paper aims to review these phenomena with special emphasis on differentiating them from epileptic seizures, and offers information on treatment and prognosis wherever possible.

Do ventilated neonates require pain management?

Mechanical ventilation is a stressful experience in neonates resulting in changes in neuroendocrine parameters, pain scores, and physiologic responses. Assisted ventilation in neonates is presumed to be associated with chronic repetitive pain, which in turn is associated with adverse long-term sequelae. Reasons to routinely sedate ventilated neonates include improved ventilator synchrony, improved pulmonary function, and decreased neuroendocrine responses, including cortisol, beta-endorphine, and catecholamines. Reasons not to treat include the well-known adverse side effects of pain medication, especially the opiates, including hypotension from morphine, chest wall rigidity from fentanyl, and tolerance, dependence, and withdrawal from both opiates and benzodiazepines. Additionally, adverse effects such as death and IVH are not improved with preemptive treatment. Chronic pain assessment is poorly validated and difficult to assess in this population, and most studies have evaluated only acute pain scores. If patients are treated, opiates are the most common class of drugs, with morphine the most well studied. Fentanyl may be advantageous in hypotensive, younger neonates because it has fewer cardiovascular effects. The benzodiazepines, midazolam and lorazepam, have been used in ventilated neonates, but midazolam has been associated with adverse effects in one small study so concern remains regarding its use. Significant gaps in our knowledge exist, especially in regard to long-term effects of treatment, or lack thereof, and in the assessment of the chronic pain associated with assisted ventilation.

[Pathological patterns in neonatal EEG before 30 weeks of gestational age]

Pathological features on very premature EEG concern background abnormalities and abnormal patterns. Positive rolandic sharp waves keep an important place regarding diagnosis and prognosis. Background abnormalities give essential complementary informations. Unusual patterns (abnormal localisation or morphological aspect, high amplitude) remain early markers of cerebral lesions. Analysis of these pathological features must always take into account treatment given to the baby, which can by itself modify the EEG.

Sédation–analgésie avant intubation trachéale en réanimation néonatale et en salle de naissance: pratiques en France métropolitaine

Tracheal intubation is a painful procedure commonly used in the neonatal intensive care units and in the delivery rooms. It can be complicated by changes in vital signs.

OBJECTIVE

To ascertain the use of sedatives and/or analgesics before tracheal intubation in French neonatal intensive care units and delivery rooms.

METHODS

A survey by questionnaire sent to 58 neonatal intensive care units and 58 maternities.

RESULTS

We obtained 46 responses (79,3%) from the neonatal intensive care units and 38 (65,5%) from the delivery rooms. In neonatal intensive care units, 74% of the newborns received a sedative and/or an analgesic before being intubated, and 60% of the units had specific written guidelines. Opioïds and benzodiazepines were the main drugs used. In the delivery rooms, sedatives or analgesics were only used in 21% of the centres.

CONCLUSION

The use of sedation-analgesia seems to improve in neonatology but is still insufficient in the delivery rooms. The development of specific guidelines and a best learning about the different drugs are necessary.

Drug-induced myoclonus: frequency, mechanisms and management

Myoclonus is a sudden, abrupt, brief, 'shock-like' involuntary movement caused by muscular contractions ('positive myoclonus') or a sudden brief lapse of muscle contraction in active postural muscles ('negative myoclonus' or 'asterixis'). Various disorders can cause myoclonus including neurodegenerative and systemic metabolic disorders and CNS infections. In addition, myoclonus has been described as an adverse effect of some drugs. Level II evidence is available to indicate that levodopa, cyclic antidepressants and bismuth salts can cause myoclonus, while there is less robust evidence to associate numerous other drugs with the induction of myoclonus. The pharmacological mechanisms responsible for this adverse effect are not well established, although increased serotonergic transmission may be involved in the induction of myoclonus by several drugs. Drug-induced myoclonus usually resolves after withdrawal of the offending drug, but in some cases specific treatments are needed.

Sleeping beauties: the impact of sedation on neonatal development

Sedatives are frequently administered in neonatal intensive care to induce sleep for diagnostic and radiology procedures, calm irritable infants, manage pain-related agitation, and enhance ventilation. The pharmacology and side effects of sedatives commonly used with neonates will be reviewed and placed within the context of their potential effect on neonatal development. Alternative caregiving strategies to minimize or eliminate the need for sedation will be discussed.

Intravenous midazolam infusion for sedation of infants in the neonatal intensive care unit

BACKGROUND

The need for sedation for neonates undergoing uncomfortable procedures in the neonatal intensive care unit (NICU) has often been overlooked. Proper sedation may reduce stress and avoid complications during procedures such as mechanical ventilation. Midazolam is a short acting benzodiazepine that has been increasingly used in the NICU. However, the effectiveness of intravenous midazolam as a sedative in neonates has not been systematically evaluated.

OBJECTIVES

To determine whether intravenous midazolam infusion is an effective sedative, as evaluated by behavioural and/or physiologic measurements, for critically ill neonates undergoing intensive care, and to assess clinically significant short and long term adverse effects associated with its use.

SEARCH STRATEGY

Literature search according to the Cochrane Neonatal Review Group search strategy. Randomized and quasi-randomized controlled trials of intravenous midazolam use in neonates were identified by searching the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002), MEDLINE (1985-2002), EMBASE (1980-2002), reference lists of published studies, personal files, and abstracts published in Pediatric Research from 1990-2002.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials of intravenous midazolam infusion in infants </= 28 days of age for sedation during mechanical ventilation or radiologic investigations were selected for review. Studies on midazolam use as an anesthetic or an anticonvulsant were excluded. Studies involving neonates and older infants and children were excluded if data for neonates could not be extracted.

DATA COLLECTION AND ANALYSIS

Data regarding the primary outcome of level of sedation (as evaluated by behavioural scales or physiologic parameters) were abstracted. Secondary outcomes including intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), death within 28 days of age, adverse effects associated with midazolam (hemodynamic and neurologic), days of ventilation, days of supplemental oxygen use, pneumothorax, length of NICU stay, and long term neurodevelopmental outcome were assessed. When appropriate, meta-analyses were performed using relative risk (RR), risk difference (RD), along with their 95% confidence intervals (95% CI) for categorical variables and weighted mean difference (WMD) for continuous variables.

MAIN RESULTS

Three trials were eligible for inclusion in the review. Data on level of sedation from the three trials could not be combined for meta-analysis because of differences in tools used to measure sedation levels. Two studies (Jacqz-Aigrain 1994, Arya 2001) showed a statistically significantly higher level of sedation in the midazolam group compared to the placebo group. The third study (Anand 1999) comparing midazolam to morphine and placebo found no statistically significant difference in sedation level among the three groups, but a statistically significantly higher level of sedation was found in the midazolam group compared with the placebo group during the treatment infusion. However, since the sedation scales used in all three studies have not been validated in preterm infants, the effectiveness of midazolam as a sedative in this population could not be ascertained. In the study by Jacqz-Aigrain et al (Jacqz-Aigrain 1994), blood pressure was statistically significantly lower in the midazolam group than in the placebo group on days one and two, although there was no statistically significant difference in the incidence of hypotension requiring albumin or vasoactive drugs between groups. The study by Anand et al (Anand 1999) showed a statistically significant higher incidence of adverse neurologic events (death, grade III-IV IVH, PVL) in the midazolam group compared with the other groups. In addition, meta-analysis of available data from two studies (Jacqz-Aigrain 1994, Anand 1999) showed a statistically significantly longer duration of NICU stay in the midazolam group compared to the placebo group (WMD 5.4 days, 95%CI 0.4, 10.5). Meta-analyses of other secondary outcomes showed no statistically significant differences between the midazolam and placebo groups.

REVIEWER'S CONCLUSIONS

There are insufficient data to promote the use of intravenous midazolam infusion as a sedative for neonates undergoing intensive care. This review raises concerns about the safety of midazolam in neonates. Further research on the effectiveness and safety of midazolam in neonates is needed.

Safety of benzodiazepines in newborns

BACKGROUND

Benzodiazepines are being used in neonatal intensive care units for sedation and control of seizures. However, anecdotal reports suggest that their use in infants may be associated with serious adverse effects (AEs).

OBJECTIVE

To determine the incidence of AEs from benzodiazepine use in preterm and full-term infants.

METHODS

Retrospective chart review of 63 infants who received benzodiazepines as a sedative or anticonvulsant over a 16-month period.

RESULTS

Mean +/- SD gestational age of the infants was 33.1 +/- 6.2 weeks, and birth weight was 2.3 +/- 1.2 kg. Median (range) postnatal age at commencement of drug administration was 19 (5-54) days. Forty-one infants received lorazepam, 8 received midazolam, and 14 received both. Ten (16%) of the infants had 14 documented adverse events: seizures (n = 6), hypotension (n = 5), and respiratory depression (n = 3). Using a validated adverse drug reaction probability scale, a probable association with benzodiazepine use was demonstrated in 12 of the AEs. Due to the retrospective nature of the data, a score for definite association was not attainable. Anticonvulsant administration was required for 4 of 6 infants and, in all cases of respiratory depression, ventilatory support was initiated or increased. Two cases of significant hypotension were treated with inotropes. There was no statistically significant correlation between AEs and benzodiazepine dose or concomitant use of inotropes or analgesics (morphine), although most infants had underlying medical conditions or received multiple drugs that may have predisposed them to experience AEs.

CONCLUSIONS

Administration of benzodiazepines was frequently associated with AEs in full-term and preterm infants. It is possible that underlying illnesses and concomitant drug use predisposed these effects. Until the benefit-to-risk ratio is determined by further studies, judicious use of benzodiazepines is recommended in this vulnerable population.

Flumazenil's Reversal of Myoclonic-like Movements Associated with Midazolam in Term Newborns

Sedation is an important aspect of care for critically ill newborns. Proper sedation reduces stress during procedures such as mechanical ventilation. Midazolam, a short-acting benzodiazepine, is widely administered as a sedative in newborn intensive care units but is not without side effects. Three term newborns developed myoclonic-like abnormal movements after receiving midazolam. In one, flumazenil controlled the abnormal movements. Flumazenil is a potent benzodiazepine antagonist that competitively blocks the central effects of benzodiazepines. It can reverse the sedative effects of benzodiazepines occurring after diagnostic or therapeutic procedures or after benzodiazepine overdose. Flumazenil may be considered in cases of abnormal movements associated with midazolam. However, further studies are needed to provide guidelines for the administration of this drug in newborns.

Treatment of pain in the neonatal intensive care unit

Pain is a disruptive influence on infants in the NICU. The most obvious and effective strategy to decrease infant pain in the NICU is to stringently limit the frequency of painful procedures, especially those that are most commonly reported (i.e., heel lances and endotracheal suctioning), and have these performed on infants that are most unstable or critically ill by the most experienced person available. Organizational concerns over the cost of NICU care have forced a re-evaluation of the necessity of certain diagnostic and care procedures and a limiting of procedures to those that can be documented to positively affect clinical outcome. Pharmacologic and nonpharmacologic strategies are essential to the prevention and management of neonatal pain, and these should be considered for complementary use for every infant. Research has shown the safety and effectiveness of some of the strategies in reducing mild pain caused by brief invasive procedures; however, many of the studies had methodologic limitations. Therefore, more research is required to determine the comparative efficacy of the various strategies and to document additive or synergistic effects when combined.

Premedication before intubation in UK neonatal units

AIMS

To establish the extent and type of premedication used before intubation in neonatal units in the United Kingdom.

METHODS

A structured telephone survey was conducted of 241 eligible units. Units were subdivided into those that routinely intubated and ventilated babies (routine group) and those that transferred intubated and ventilated babies (transfer group).

RESULTS

Of the units contacted, 239 (99%) participated. Only 88/239 (37%) gave any sedation before intubating on the unit and only 34/239 (14%) had a written policy covering this. Morphine was used most commonly (66%), with other opioids and benzodiazepines used less frequently. Of the 88 units using sedation, 19 (22%) also used paralysis. Suxamethonium was given by 10/19 (53%) but only half of these combined it with atropine. Drug doses varied by factors of up to 200, even for commonly used drugs.

CONCLUSION

Most UK neonatal units do not sedate babies before intubating, despite evidence of physiological and practical benefits. Only a minority have written guidelines, which prohibits auditing of practice.

Prevention and management of pain and stress in the neonate

This statement is intended for health care professionals caring for neonates (preterm to one month of age). The objectives of this statement are to: increase awareness that neonates experience pain; provide a physiological basis for neonatal pain and stress assessment and management by health care professionals; make recommendations for reduced exposure of the neonate to noxious stimuli and to minimize associated adverse outcomes; and recommend effective and safe interventions that relieve pain and stress.

Haemodynamic responses and population pharmacokinetics of midazolam following administration to ventilated, preterm neonates

OBJECTIVE

To evaluate the effects of intravenous midazolam on haemodynamic variables and cerebral blood flow velocity (CBFV) and to determine the pharmacokinetics using a population approach in very low birthweight (VLBW) ventilated infants.

METHODOLOGY

Physiological variables were measured at predetermined times in 10 infants with birthweight < or = 1500 g following a bolus dose of intravenous midazolam (0.1 mg/kg). Heart rate, mean arterial blood pressure (MAP) and transcutaneous CO2 (TcPCO2) were recorded and CBFV was assessed by Doppler ultrasound. Midazolam concentrations were also measured and pharmacokinetic parameters determined using a population modelling package.

RESULTS

No change in heart rate occurred during the study period, while the MAP decreased by 3 mmHg 5 min after midazolam administration compared to baseline values. A non-significant fall in TcPCO2 was seen at 20 min. Mean CBFV decreased from the baseline by 12% at 5 min, then returning to predose values. Midazolam concentrations were in the range shown to be effective in sedation of paediatric intensive care infants with the elimination being delayed in comparison to older children.

CONCLUSIONS

As only minor cerebral and haemodynamic effects were found with the use of midazolam in stable ventilated preterm infants, it appears to be a safe, short-term sedative agent.