Milrinone Acts as a Vasodilator But Not an Inotrope in Children After Cardiac Surgery—Insights From Wave Intensity Analysis

Abstract

Objectives: Milrinone is an inodilator widely used in the postoperative management of children undergoing cardiac surgery. The literature supporting its inotropic effect is sparse. We sought to study the effect of milrinone on the vasculature and its effects on the ventricular function using wave intensity analysis. We also intended to evaluate the feasibility of using wave intensity analysis by the bedside. Design: prospective single-center observational study. Setting: PICU of a tertiary children’s hospital. Patients: Children (< 18 yr) admitted to PICU following cardiac surgery who required to be commenced on a milrinone infusion. Interventions: Echocardiography and Doppler ultrasound assessments for wave intensity analysis were performed prior to commencing milrinone and 4–6 hours after milrinone infusion. Measurements and Main Results: Wave intensity analysis was successfully performed and analyzed in 15 of 16 patients (94%). We identified three waves—a forward compression wave, backward compression wave, and forward decompression wave. The waves were described with their cumulative intensity and wave-related pressure change. There was a 26% reduction in backward compression wave cumulative intensity following the introduction of milrinone. Other variables (backward compression wave cumulative intensity/forward compression wave cumulative intensity ratio, backward compression wave wave-related pressure change, backward compression wave wave-related pressure change/forward compression wave wave-related pressure change ratio) consistent with vasodilation also decreased after milrinone. It also decreased the vascular wavespeed by 7.1% and increased the distensibility of the vessels by 14.6%. However, it did not increase forward compression wave cumulative intensity, a variable indicating the systolic force generated by the ventricle. Forward decompression wave cumulative intensity indicating ventricular early diastolic relaxation also did not change. Conclusions: In a cohort of children recovering in PICU after having undergone cardiac surgery, we found that milrinone acted as a vasodilator but did not demonstrate an improvement in the contractility or an improved relaxation of the left ventricle as assessed by wave intensity analysis. We were able to demonstrate the feasibility and utility of wave intensity analysis to further understand ventriculo-vascular interactions in an intensive care setting.

Clinical approach to vasoplegia in the transplant patient from the Pediatric Heart Transplant Society

“…For patients at risk for vasoplegia, delay in the initiation of milrinone should be considered (e.g., for 12–24 h), especially if urine output is decreased. When there is clinical evidence of vasoplegia, discontinuation of milrinone should be strongly considered 18–22 Vasopressin: Vasopressin can be used effectively to counter a vasoplegic state.…”

“…When there is clinical evidence of vasoplegia, discontinuation of milrinone should be strongly considered. [18][19][20][21][22] 3. Vasopressin: Vasopressin can be used effectively to counter a vasoplegic state.…”

Pathogenesis, Prognosis and Outcomes of Multiple Organ Failure in Newborns (Review)

“…Милринон -ингибитор фосфодиэстеразы-3, обладает положительным инотропным, периферическим вазодилатирующим и лузитропным эффектом [117]. В последнее десятилетие милринон в неонатологии назначается для лечения сердечно-легочной дисфункции в контексте легочной гипертензии и низкого уровня сердечного выброса при аномалиях развития сердечно-сосудистой и дыхательной системы, асфиксии, периоперационном периоде при кардиохирургических вмешательствах и врожденных диафрагмальных грыжах [118]. В то же время авторы Кокрейновского обзора (2015 год, 8 РКИ) подчеркивают необходимость исследований более хорошего качества, так как имеющихся данных недостаточно, чтобы выявить преимущества милринона по сравнению с плацебо, левосименданом или добутамином в отношении летальности, продолжительности пребывания в отделении интенсивной терапии, пребывания в больнице, искусственной вентиляции легких [119].…”

Comparison of the Efficacy of Inhaled Versus Infused Milrinone in the Management of Persistent Pulmonary Hypertension in Infants in Resource-Limited Settings A Randomized Clinical Trial

“…Milrinone is a phosphodiesterase III inhibitor that has been shown to reduce lling pressure and reduce systemic and pulmonary arterial pressure by a mechanism of vasodilation and is among the drugs used in the absence of iNO (7) . Milrinone is part of Iran's Pharmacopoeia and is produced in the country by different pharmaceutical companies with the same quality and effectiveness and approved by the Food and Drug Administration.…”