Treatment of Persistent Pulmonary Hypertension of the Newborn: Use of Pulmonary Vasodilators in Term Neonates

Persistent pulmonary hypertension of the newborn (PPHN) represents a challenging condition associated with significant morbidity. A successful transition from intrauterine to extrauterine life is contingent on adequate pulmonary vasodilation. Several pathophysiologies contribute to the failure of this cascade and may result in life-threatening hypoxia and acidosis in the newborn. Management includes optimal respiratory support, adequate sedation and analgesia, and support of vascular tone and cardiac function. Pulmonary vasodilation has the potential to overcome the cycle of hypoxia and acidosis, improving outcome in these infants. Oxygen and inhaled nitric oxide represent the foundation of therapy. Tertiary pulmonary vasodilators represent a greater challenge, selecting between therapies that include prostanoids, sildenafil, and milrinone. Variable levels of evidence exist for each agent. Thorough review of available data informing efficacy and adverse effects contributes to the development of an informed approach to neonates with refractory PPHN.

Perioperative Nesiritide Versus Milrinone in High-Risk Coronary Artery Bypass Graft Patients

Background:

Patients with left-ventricular dysfunction have an increased risk of developing heart failure after coronary artery bypass graft (CABG) surgery. Therapies to maintain cardiac output in such patients warrant investigation. Nesiritide is unique among intravenous medications used to manage heart failure. It mediates natriuresis and vasodilation and suppresses the renin–angiotensin'aldosterone axis. Nesiritide may attenuate the body's neurohormonal response to myocardial stretch after CABG and provide clinical benefit in the immediate postoperative period.

Objective:

To determine whether perioperative infusion of nesiritide improves clinical outcomes compared with milrinone therapy.

Methods:

A prospective, open-label, randomized controlled trial was conducted in 40 consecutive hemodynamically stable patients with ejection fractions 35% or less undergoing CABG surgery. Patients were randomized to receive either an intraoperative bolus of nesiritide or milrinone followed by a 24 hour infusion of each agent. Length of postoperative intensive care unit stay was the primary outcome variable evaluated. Incidence of postoperative heart failure, 30 day readmission rates, mortality, and other clinical parameters were also compared.

Results:

Patients receiving nesiritide had a mean ± SD postoperative intensive care unit stay of 50.6 ± 46.8 hours compared with 44.1 ± 23.5 hours in those receiving milrinone (p = 0.578). Incidence of postoperative heart failure was also not significantly different between the drugs (p = 0.259). Thirty day follow-up confirmed no difference in hospital readmission rates between nesiritide and milrinone (p = 0.661). No differences in mortality were observed during hospitalization or 30 days of follow-up.

Conclusions:

Nesiritide does not decrease postoperative intensive care unit stay or other clinical parameters compared with milrinone in high-risk patients with hemodynamically stable left-ventricular function undergoing CABG surgery.

Nesiritide Compared with Milrinone for Cardiac Surgery

Management of patients with low cardiac output syndromes is difficult. Current therapies (ie, inotropes) have associated adverse effects and have not been shown to impact clinical outcomes such as decreased mortality or length of stay. Patients unable to recover from low cardiac output states have end organ damage, increased lengths of stay, increased hospital costs, and readmissions. Nesiritide has been suggested as an alternative or adjunct medication to treat cardiac surgery patients. Recent trials have provided information on the effects of some of these agents on clinical outcomes including respiratory failure, length of stay, and mortality.

Effect of Levosimendan and Milrinone on Regional Myocardial Ischemia/Reperfusion-Induced Arrhythmias in Dogs

Phosphodiesterase inhibitors as inodilators in heart failure are associated with promotion of arrhythmias. Calcium sensitizers have been proposed for the treatment of severe decompensated heart failure. The effect of levosimendan, a calcium sensitizer, and milrinone, a phosphodiesterase inhibitor, on ventricular arrhythmias was compared in a model of acute regional myocardial ischemia and reperfusion. The left anterior descending coronary artery in dogs was occluded for 25 minutes, followed by reperfusion. The 2 drugs were administered in a hemodynamically equieffective dose (0.1 μmol/kg) 10 minutes before coronary occlusion. Levosimendan, but not milrinone, significantly attenuated the pronounced increase in the number of ventricular premature beats (-63%), tachycardia (-50%), fibrillation (-70%), and inhomogeneity of ventricular electrical activation. Levosimendan significantly improved the overall survival rate. Levosimendan has a more beneficial profile than milrinone regarding the development of ventricular arrhythmias during and after regional myocardial ischemia

Crossed Pulmonary Arteries in a Patient With Persistent Truncus Arteriosus

We report a 14-month-old child with persistent truncus arteriosus and crossed pulmonary arteries. The potential advantage of crossed pulmonary artery arrangement in achieving surgical correction is discussed.

Canadian Palliative Community Milrinone Infusions: A Case Series

Abstract Symptom managementfor end-of-life heartfailure (HF) patients is a significant concern. Currently, Canadian practice does not support community milrinone therapy in end-of-life HF patients. Two patients had severe HF that was unresponsive to optimal medications. Further optimization and furosemide infusions were ineffective for symptom management. Both patients' symptoms were better controlled with optimal medication, furosemide, and milrinone infusions. A tailored discharge plan was developed to assist with community milrinone infusions. We discuss the challenges and successes of transitioning two patients to the community. By providing symptom management and meaningful patient and family experience, both patients were able to die in a setting of their choosing. Milrinone infusions as a bridge to end of life may improve symptoms and quality of life. Select patients may benefit from milrinone infusions with resources put in place; these end-of-life HF patients can be supported in the community.

Prophylactic milrinone for the prevention of low cardiac output syndrome and mortality in children undergoing surgery for congenital heart disease

BACKGROUND

Children with congenital heart disease often undergo heart surgery at a young age. They are at risk for postoperative low cardiac output syndrome (LCOS) or death. Milrinone may be used to provide inotropic and vasodilatory support during the immediate postoperative period.

OBJECTIVES

This review examines the effectiveness of prophylactic postoperative use of milrinone to prevent LCOS or death in children having undergone surgery for congenital heart disease.

SEARCH METHODS

Electronic and manual literature searches were performed to identify randomised controlled trials. We searched CENTRAL, MEDLINE, EMBASE and Web of Science in February 2014 and conducted a top-up search in September 2014 as well as clinical trial registries and reference lists of published studies. We did not apply any language restrictions.

SELECTION CRITERIA

Only randomised controlled trials were selected for analysis. We considered studies with newborn infants, infants, toddlers, and children up to 12 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data according to a pre-defined protocol. We obtained additional information from all study authors.

MAIN RESULTS

Three of the five included studies compared milrinone versus levosimendan, one study compared milrinone with placebo, and one compared milrinone verus dobutamine, with 101, 242, and 50 participants, respectively. Three trials were at low risk of bias while two were at higher risk of bias. The number and definitions of outcomes were non-uniform as well. In one study comparing two doses of milrinone and placebo, there was some evidence in an overall comparison of milrinone versus placebo that milrinone lowered risk for LCOS (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.28 to 0.96; 227 participants). The results from two small studies do not provide enough information to determine whether milrinone increases the risk of LCOS when compared to levosimendan (RR 1.22, 95% CI 0.32 to 4.65; 59 participants). Mortality rates in the studies were low, and there was insufficient evidence to draw conclusions on the effect of milrinone compared to placebo or levosimendan or dobutamine regarding mortality, the duration of intensive care stay, hospital stay, mechanical ventilation, or maximum inotrope score (where available). Numbers of patients requiring mechanical cardiac support were also low and did not allow a comparison between studies, and none of the participants of any study received a heart transplantation up to the end of the respective follow-up period. Time to death within three months was not reported in any of the included studies. A number of adverse events was examined, but differences between the treatment groups could not be proven for hypotension, intraventricular haemorrhage, hypokalaemia, bronchospasm, elevated serum levels of liver enzymes, or a reduced left ventricular ejection fraction < 50% or reduced left ventricular fraction of shortening < 28%. Our analysis did not prove an increased risk of arrhythmias in patients treated prophylactically with milrinone compared with placebo (RR 3.59, 95% CI 0.83 to 15.42; 238 participants), a decreased risk of pleural effusions (RR 1.78, 95% CI 0.92 to 3.42; 231 participants), or a difference in risk of thrombocytopenia on milrinone compared with placebo (RR 0.86, 95% CI 0.39 to 1.88; 238 participants). Comparisons of milrinone with levosimendan or with dobutamine, respectively, did not clarify the risk of arrhythmia and were not possible for pleural effusions or thrombocytopenia.

AUTHORS' CONCLUSIONS

There is insufficient evidence of the effectiveness of prophylactic milrinone in preventing death or low cardiac output syndrome in children undergoing surgery for congenital heart disease, compared to placebo. So far, no differences have been shown between milrinone and other inodilators, such as levosimendan or dobutamine, in the immediate postoperative period, in reducing the risk of LCOS or death. The existing data on the prophylactic use of milrinone has to be viewed cautiously due to the small number of small trials and their risk of bias.

Milrinone attenuates arteriolar vasoconstriction and capillary perfusion deficits on endotoxemic hamsters

Background and Objective

Apart from its inotropic property, milrinone has vasodilator, anti-inflammatory and antithrombotic effects that could assist in the reversal of septic microcirculatory changes. This paper investigates the effects of milrinone on endotoxemia-related microcirculatory changes and compares them to those observed with the use of norepinephrine.

Materials and Methods

After skinfold chamber implantation procedures and endotoxemia induction by intravenous Escherichia coli lipopolysaccharide administration (2 mg.kg-1), male golden Syrian hamsters were treated with two regimens of intravenous milrinone (0.25 or 0.5 μg.kg-1.min-1). Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables. Macro-hemodynamic, biochemical, and hematological parameters and survival rate were also analyzed. Endotoxemic non-treated animals, endotoxemic animals treated with norepinephrine (0.2 μg.kg-1.min-1), and non-endotoxemic hamsters served as controls.

Results

Milrinone (0.5 μg.kg-1.min-1) was effective in reducing lipopolysaccharide-induced arteriolar vasoconstriction, capillary perfusion deficits, and inflammatory response, and in increasing survival. Norepinephrine treated animals showed the best mean arterial pressure levels but the worst functional capillary density values among all endotoxemic groups.

Conclusion

Our data suggests that milrinone yielded protective effects on endotoxemic animals’ microcirculation, showed anti-inflammatory properties, and improved survival. Norepinephrine did not recruit the microcirculation nor demonstrated anti-inflammatory effects.

[BRONCHOPULMONARY DYSPLASIA--WHAT DO WE KNOW TODAY?]

The survival of great number of extremely premature newborn babies is associated with increased risk of damage of the newborn lung and development of chronic lung disease/Broncopulmonary dysplasia. The lower the gestational age and weight, the greater the frequency of BPD. The disease leads to impairment of the normal alveolization and vascularization of the premature lung. There are new theories for the pathogenesis of BPD and new staging of the disease. These changes lead to new therapeutic strategies.

Milrinone ameliorates cardiac mechanical dysfunction after hypothermia in an intact rat model

BACKGROUND

Rewarming from hypothermia is often complicated by cardiac dysfunction, characterized by substantial reduction in stroke volume. Previously we have reported that inotropic agents, working via cardiac β-receptor agonism may exert serious side effects when applied to treat cardiac contractile dysfunction during rewarming. In this study we tested whether Milrinone, a phosphodiesterase III inhibitor, is able to ameliorate such dysfunction when given during rewarming.

METHODS

A rat model designed for circulatory studies during experimental hypothermia with cooling to a core temperature of 15°C, stable hypothermia at this temperature for 3h and subsequent rewarming was used, with a total of 3 groups: (1) a normothermic group receiving Milrinone, (2) a hypothermic group receiving Milrinone the last hour of hypothermia and during rewarming, and (3) a hypothermic saline control group. Hemodynamic function was monitored using a conductance catheter introduced to the left ventricle.

RESULTS

After rewarming from 15°C, stroke volume and cardiac output returned to within baseline values in Milrinone treated animals, while these variables were significantly reduced in saline controls.

CONCLUSIONS

Milrinone ameliorated cardiac dysfunction during rewarming from 15°C. The present results suggest that at low core temperatures and during rewarming from such temperatures, pharmacologic efforts to support cardiovascular function is better achieved by substances preventing cyclic AMP breakdown rather than increasing its formation via β-receptor stimulation.

The effect of milrinone on induced hypotension in elderly patients during spinal surgery: a randomized controlled trial

BACKGROUND CONTEXT

Induced hypotension is widely used intraoperatively to reduce blood loss and to improve the surgical field during spinal surgery.

PURPOSE

To determine the effect of milrinone on induced hypotension during spinal surgery in elderly patients.

STUDY DESIGN/SETTING

Prospective randomized clinical trial.

PATIENT SAMPLE

Forty patients, 60 to 70 years old, ASA I-II, who underwent elective lumbar fusion surgery.

OUTCOME MEASURES

Intraoperative hemodynamics, blood loss, hourly urine output, and grade of surgical field.

METHODS

All patients were randomized to group M or N. The study drug was infused after perivertebral muscle retraction until complete interbody fusion. In group M, 50 μg/kg/min of milrinone was infused over 10 minutes as a loading dose followed by 0.6 μg/kg/min of milrinone as a continuous dose. In group N, an identical volume of normal saline was infused in the same fashion. This study was not funded by commercial or other sponsorship and the authors confirm no conflicts of interest, financial or otherwise.

RESULTS

During infusion of the study drug, the systolic and mean blood pressures were maintained within adequate limits of induced hypotension in group M. Intraoperative blood loss was 445.0±226.5 mL in group M and 765.0±339.2 mL in group N (p=.001). Hourly urine output was 1.4±0.6 mL in group M and 0.8±0.2 mL in group N (p<.001). The grade of the surgical field was better in group M than in group N (p=.004).

CONCLUSIONS

We conclude that milrinone is useful for induced hypotension in elderly patients during spinal surgery.

A neonate with critical congenital heart disease

Critical congenital heart disease (CCHD) is defined as a ductal-dependent congenital heart defect requiring surgical or percutaneous intervention via cardiac catheterization before 1 year of age. Most cases of CCHD can be diagnosed with prenatal ultrasound or fetal echocardiogram. If not prenatally diagnosed, CCHD can be stable in the newborn nursery due to persistent ductal patency, and the patient may only be diagnosed after ductal closure and development of cardiac symptoms at home. In this case, a 6-day-old female presented to the emergency department (ED) floppy with agonal respirations, poor capillary refill, and absent femoral pulses. On the day of presentation, the patient became increasingly fussy, refused feeding, and began to gasp. The patient was transported to the ED for evaluation, where a bedside echocardiogram revealed interrupted aortic arch (IAA), ventricular septal defect, minimal flow through a thread-like ductus arteriosus, and severely depressed cardiac function. IAA is very rare, with an incidence of three cases per 1 million live births. Patients require neonatal supportive care, continuous prostaglandin E1 infusion, and urgent referral for neonatal surgical repair in the first days to weeks of life. To reduce the volume of undiagnosed CCHD in the immediate newborn period, the U.S. Department of Health and Human Services Secretary's Advisory Committee on Heritable Diseases in Newborns and Children (SACHDNC) recommended that CCHD screening via pulse oximetry be added to the recommended uniform screening panel. A positive screen results in an immediate referral for an echocardiogram. Fetal diagnosis, newborn screening, and/or careful clinical examination may have resulted in detection of IAA in our patient prior to ductal closure.

Diagnosis and treatment of pulmonary hypertension in infancy

Normal pulmonary vascular development in infancy requires maintenance of low pulmonary vascular resistance after birth, and is necessary for normal lung function and growth. The developing lung is subject to multiple genetic, pathological and/or environmental influences that can adversely affect lung adaptation, development, and growth, leading to pulmonary hypertension. New classifications of pulmonary hypertension are beginning to account for these diverse phenotypes, and or pulmonary hypertension in infants due to PPHN, congenital diaphragmatic hernia, and bronchopulmonary dysplasia (BPD). The most effective pharmacotherapeutic strategies for infants with PPHN are directed at selective reduction of PVR, and take advantage of a rapidly advancing understanding of the altered signaling pathways in the remodeled vasculature.

Effect of milrinone on short term outcome of patients with myocardial dysfunction undergoing off-pump coronary artery bypass graft: a randomized clinical trial

Myocardial dysfunction is a major complication in cardiac surgery that needs inotropic support. This study evaluates the effect of milrinone on patients with low ventricular ejection fraction undergoing off- pump coronary artery bypass graft (OPCAB). The present study is designed to evaluate the effect of milrinone on myocardial dysfunction. Eighty patients with low ventricular ejection fraction (<35%), candidate for elective OPCAB, were enrolled in this study. They were randomly assigned to two groups. One group received milrinone (50 μg/kg) intravenously and another group received a saline as placebo followed by 24 hours infusion of each agent (0.5 μg/kg/min). Short outcome of patients such as hemodynamic parameters and left ventricular ejection fraction were variables evaluated. Serum levels of creatine phosphokinase, the MB isoenzyme of creatine kinase, occurrence of arrhythmias and mean duration of mechanical ventilation were significantly lower in milrinone group (P&lt;0.05). The mean post operative left ventricular ejection fraction was significantly higher in milrinone group (P=0.031). There were no statistical significant differences between the two groups in terms of intra-aortic balloon pump, inotropic support requirement, myocardial ischemia, myocardial infarction, duration of inotropic support, duration of intensive care unit stay, mortality and morbidity rate. Administration of milrinone in patients undergoing OPCAB with low ventricular ejection fraction is useful and effective.

[Characteristics of circulatory disturbance and the treatment of severe hand-foot-and-mouth disease]

OBJECTIVE

To investigate the characteristics of circulatory disturbance and treatment of severe hand-foot-and-mouth disease (HFMD).

METHOD

The clinical characteristics, laboratory findings, therapy and outcome of 22 severe HFMD patients were retrospectively analyzed.

RESULT

All the 22 severe HFMD patients came from the countryside. All these patients had encephalitis. Fifteen cases had myocardial injury. All had symptoms of sympathetic excitation and 17 cases had hypertension [(128 ± 16)/(81 ± 14) mm Hg (1 mm Hg = 0.133 kPa)]. Fourteen cases had exacerbation with rapid decline of blood pressure [(61 ± 12)/(33 ± 12) mm Hg]. In cardiorespiratory failure stage, 13 patients had neurogenic pulmonary edema accompanied by circulatory failure and 12 cases had a lower glasgow scores (less than 7). Myocardial injury and ECG change were found in some cases. Inotropic and pressor drugs were given in patients with circulatory collapse. Five cases received fluid resuscitation due to refractoriness to inotropic drugs. Nine patients received blood purification. Seventeen survived and 5 cases died due to circulatory failure.

CONCLUSION

Circulation failure of severe HFMD is the main cause of death. Early and appropriate circulation support is very important to reduce mortality.

Preoperative inhalation of milrinone attenuates inflammation in patients undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVES

The purpose of this study was to evaluate the effect of preoperative inhalation of milrinone on cardiopulmonary bypass (CPB)-related inflammation.

SUBJECTS AND METHODS

A total of 30 patients undergoing cardiac surgery were recruited and randomized for preoperative inhalation of milrinone (Mil group) or normal saline (NS group), respectively. Each group had 15 patients. Their hemodynamic parameters were measured and blood samples were obtained longitudinally. The levels of serum interleukin (IL-6), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase (MMP)-9 were determined by ELISA.

RESULTS

The levels of serum IL-6, TNF-α, and MMP-9 significantly increased at the end of cardiac surgery and remained high for 24 h in both groups of patients. However, the levels of proinflammatory cytokines at the end of cardiac surgery in the Mil group of patients were significantly lower than those of the NS group of patients.

CONCLUSIONS

Our data indicated that preoperative inhalation of milrinone significantly mitigated CPB-related inflammation.

Relation of milrinone after surgery for congenital heart disease to significant postoperative tachyarrhythmias

Milrinone reduces the risk of low cardiac output syndrome for some pediatric patients after congenital heart surgery. Data from adults undergoing cardiac surgery suggest an association between milrinone and an increased risk of postoperative arrhythmias. We tested the hypothesis that milrinone is an independent risk factor for tachyarrhythmias after congenital heart surgery. Subjects undergoing congenital heart surgery at our institution were consecutively enrolled for 38 months, through September 2010. The data were prospectively collected, including a review of full-disclosure telemetry and the medical records. Within 38 months, 603 enrolled subjects underwent 724 operative procedures. The median age was 5.5 months (range 0.0 to 426), the median weight was 6.0 kg (range 0.7 to 108), and the cohort was 45% female. The overall arrhythmia incidence was 50%, most commonly monomorphic ventricular tachycardia (n = 85, 12%), junctional ectopic tachycardia (n = 69, 10%), accelerated junctional rhythm (n = 58, 8%), and atrial tachyarrhythmias (including atrial fibrillation, atrial flutter, and ectopic or chaotic atrial tachycardia, n = 58, 8%). Multivariate logistic regression analysis demonstrated that independent of age <1 month, the use of cardiopulmonary bypass, the duration of cardiopulmonary bypass, Risk Adjusted classification for Congenital Heart Surgery, version 1, score >3, and the use of epinephrine or dopamine, milrinone use on admission to the cardiac intensive care unit remained independently associated with an increase in the odds of postoperative tachyarrhythmia resulting in an intervention (odds ratio 2.8, 95% confidence interval 1.3 to 6.0, p = 0.007). In conclusion, milrinone use is an independent risk factor for clinically significant tachyarrhythmias in the early postoperative period after congenital heart surgery.

[Effect of inhaling specific phosphodiesterase inhibitor on lung injury induced by cardiopulmonary bypass]

OBJECTIVE

To evaluate the effect of pretreatment by inhaling specific phosphodiesterase inhibitor on lung injury induced by cardiopulmonary bypass (CPB).

METHODS

From April 2010 to November 2010, 30 patients were divided randomly into two groups: control group (n = 15) and milrinone group (n = 15). In milrinone group, 5 mg milrinone diluted by 5ml normal saline was inhaled per 8 h two days pre-operation. In control group, only 10 ml normal saline was inhaled. Blood samples were drawn from ulnar vein and radial artery pre-operation (T(0)), 30 min post-aortic unclamping (T(1)), at the end of operation (T(2)), 24 h, 72 h and 7 d post-operation (T(3)-T(5)). The following parameters were determined: TNF-α (tumor necrosis factor-alpha), IL-6 (interleukin-6), HSCRP (high-sensitivity C-reactive protein), MDA (malondialdehyde), MPO (myeloperoxidase) level and leucocyte count ratio of venous and arterial blood. And the values of pulmonary vascular resistance (PVR) and oxygenation index (OI) were measured through a Swan-Ganz catheter at the first 5 time points.

RESULTS

PVR rose while OI declined at post-operation. But the range of above-mentioned indices in milrinone group was significantly smaller than that in control group. And the indices recovered much earlier in milrinone group. The levels of TNF-α, IL-6, HSCRP, MDA, MPO and leucocyte count ratio were not significantly different at T(0) between two groups and increased significantly after CPB in both groups. But the level of TNF-α (ng/L) was significantly lower at T(2), T(4), T(5) in milrinone group than that in control group (60 ± 5 vs 79 ± 7, 29 ± 6 vs 40 ± 8, 18 ± 5 vs 28 ± 7, all P < 0.05). The levels of IL-6 and MDA were significantly lower at T(1)-T(4) in milrinone group. The level of HSCRP became elevated post-operatively in both groups and reached its peak at 24 h post-operation, especially in control group. The level of MPO (µg/L) was significantly lower at T(2), T(3) and T(5) (134 ± 20 vs 190 ± 23, 142 ± 28 vs 178 ± 20, 65 ± 9 vs 75 ± 11, all P < 0.05). And the V/A ratio was significantly lower at T(1)-T(3) in milrinone group than in control group (1.12 ± 0.11 vs 1.37 ± 0.09, 1.07 ± 0.07 vs 1.25 ± 0.07, both P < 0.01).

CONCLUSION

Inhaled milrinone may protect the lungs from acute injury induced by CPB. Inhaling milrinone is safe and feasible for the prevention of acute CPB-induced injury.

Milrinone for persistent pulmonary hypertension of the newborn

BACKGROUND

Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome characterized by suboptimal oxygenation as a result of sustained elevation in pulmonary vascular resistance after birth. Currently, the therapeutic mainstay for PPHN is optimal lung inflation and selective vasodilatation with inhaled nitric oxide (iNO). However, iNO is not available in all countries and not all infants will respond to iNO. Milrinone is a phosphodiesterase III inhibitor which induces pulmonary vasodilatation by its actions through a cyclic adenylate monophosphate mediated signaling pathway.

OBJECTIVES

To assess efficacy and safety in infants with PPHN either treated with: milrinone compared with placebo or no treatment; milrinone compared with iNO; milrinone as an adjunct to iNO compared with iNO alone; milrinone compared with potential treatments for PPHN other than iNO.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2010), MEDLINE and EMBASE databases from their inception until January 2010. We searched the reference lists of potentially relevant studies without any language restriction.

SELECTION CRITERIA

Fully published randomized controlled trials (RCTs) and quasi-RCTs comparing milrinone with placebo, iNO or potential treatments other than iNO in neonates with PPHN were included if trials reported any clinical outcome.

DATA COLLECTION AND ANALYSIS

We found no studies meeting the criteria for inclusion in this review.

MAIN RESULTS

We found no studies meeting the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy and safety of milrinone in the treatment of PPHN are not known and its use should be restricted within the context of RCTs. Such studies should address a comparison of milrinone with placebo (in clinical situations where iNO is not available) or, in well resourced countries, should compare milrinone with iNO or as an adjunct to iNO compared with iNO alone.