Shock and Hypotension in the Newborn Medication
- Author: Samir Gupta, DM, MRCP, MD, FRCPCH, FRCPI; Chief Editor: Ted Rosenkrantz, MD more...
In premature infants younger than 30 weeks' gestation, poor cardiac contractility is most common; patients benefit from early institution of dobutamine.
Patients with septic shock benefit from dopamine as first-line management; it has been found to be more effective than dobutamine and albumin in correcting blood pressure for short-term treatment in these situations; however, the effect of these drugs on long-term outcome is unknown.
Although adrenaline is used for cardiovascular compromise, its effect on mortality and morbidity has not yet been evaluated.
No evidence suggests that milrinone is beneficial in prevention of low systemic blood flow in ill, very-preterm neonates during the first postnatal day.
Alpha/Beta Adrenergic Agonists
Cardiovascular performance deteriorates and cardiac output falls if effective therapy is not administered. Adrenergic antagonists improve the patient’s hemodynamic status by increasing myocardial contractility and heart rate, resulting in increased cardiac output. They also increase peripheral resistance by causing vasoconstriction. Increased cardiac output and increased peripheral resistance lead to increased blood pressure.
Dopamine stimulates adrenergic and dopaminergic receptors. Its hemodynamic effect is dependent on the dose. Lower doses predominantly stimulate dopaminergic receptors that, in turn, produce renal and mesenteric vasodilation. Cardiac stimulation and peripheral vasoconstriction is produced by higher doses.
Dobutamine produces vasodilation and increases the inotropic state. At higher dosages, it may cause increased heart rate, exacerbating myocardial ischemia.
Epinephrine elicits alpha-agonist effects that include increased peripheral vascular resistance, reversed peripheral vasodilatation, systemic hypotension, and vascular permeability. The drug's beta-agonist effects include bronchodilatation, chronotropic cardiac activity, and positive inotropic effects.
Isoproterenol possesses beta1- and beta2-adrenergic receptor activity. It binds to beta receptors of the heart, smooth muscle of the bronchi, skeletal muscle, vasculature, and alimentary tract. Isoproterenol elicits positive inotropic and chronotropic actions.
Norepinephrine is used to treat protracted hypotension following adequate fluid-volume replacement. It stimulates beta1- and alpha-adrenergic receptors, increasing cardiac muscle contractility and heart rate, as well as vasoconstriction; this results in systemic blood pressure and coronary blood flow increases. After obtaining a response, the rate of flow should be adjusted and maintained at a low-normal blood pressure, such as 80-100mm Hg systolic, sufficient to perfuse vital organs.
Preload reduction with vasodilators is thought to be helpful in acute decompensated heart failure by reducing congestion and minimizing cardiac oxygen demand. Afterload reduction is also thought to be helpful in some patients with acute decompensated heart failure by decreasing myocardial oxygen demand and improving forward flow.
Hydralazine decreases systemic resistance through direct vasodilation of arterioles.
Nitroprusside produces vasodilation and increases inotropic activity of the heart. At higher dosages, it may exacerbate myocardial ischemia by increasing heart rate.
Inotropic agents increase cardiac contractility and may reduce vascular tone by vasodilatation.
Phentolamine has positive inotropic and chronotropic effects on the heart. Phentolamine is an alpha1- and alpha2-adrenergic blocking agent that blocks circulating epinephrine and norepinephrine action, reducing hypertension resulting from catecholamine effects on alpha receptors.
Milrinone is a bi-pyridine positive inotrope and vasodilator with little chronotropic activity. Its mode of actions differs from that of digitalis glycosides and catecholamines. Milrinone selectively inhibits phosphodiesterase type III (PDE III) in cardiac and smooth vascular muscle, resulting in reduced afterload and preload and increased inotropy.
The use of crystalloid or colloid solutions is appropriate, unless the source of hypovolemia is hemorrhage, in which case whole or reconstituted blood is more appropriate.
Isotonic sodium chloride solution is a low-cost alternative that is readily available.
Albumin is useful for plasma volume expansion and the maintenance of cardiac output.
Lactated Ringer solution with isotonic sodium chloride
Each fluid is essentially isotonic and has equivalent volume restorative properties. Although some differences between metabolic changes are observed with the administration of large quantities of either fluid, for practical purposes and in most situations, the differences are clinically irrelevant. Importantly, there is no demonstrable difference in hemodynamic effect, morbidity, or mortality with resuscitation.
In early onset neonatal sepsis, ampicillin and either gentamicin or cefotaxime are the antimicrobials of choice until a specific infectious agent is identified.
Ampicillin has bactericidal activity against susceptible organisms.
Cefotaxime is a third-generation cephalosporin that possesses antimicrobial effects on a predominantly gram-negative spectrum. Its efficacy against gram-positive organisms is lower.
Gentamicin is an aminoglycoside antibiotic for gram-negative coverage. It is used in combination with an agent against gram-positive organisms and one that covers anaerobes. Dosing regimens are numerous; adjust the dose based on creatinine clearance (CrCl) and changes in the volume of distribution. The drug may be administered intravenously or intramuscularly.
Follow each regimen by at least a trough level drawn on the third dose (0.5h before dosing). Peak levels may be drawn 0.5 hour after a 30-minute infusion. If the trough level is greater than 2mg/L, increase the dosing interval.
Schmaltz C. Hypotension and shock in the preterm neonate. Adv Neonatal Care. 2009 Aug. 9(4):156-62. [Medline].
Al-Aweel I, Pursley DM, Rubin LP, et al. Variations in prevalence of hypotension, hypertension, and vasopressor use in NICUs. J Perinatol. 2001 Jul-Aug. 21(5):272-8. [Medline].
Northern Neonatal Nursing Initiative. Systolic blood pressure in babies of less than 32 weeks gestation in the first year of life. Arch Dis Child Fetal Neonatal Ed. 1999 Jan. 80(1):F38-42. [Medline].
Gupta S, Wyllie J. Correlation of Non-invasive Systolic and Mean Blood pressure (BP) Measurements with Echocardiographic Haemodynamic Assessment. Third Congress of the European Academy of Paediatric Societies (EAPS). Copenhagen, Denmark. October 23-26, 2010.
Laughon M, Bose C, Allred E, et al. Factors associated with treatment for hypotension in extremely low gestational age newborns during the first postnatal week. Pediatrics. 2007 Feb. 119(2):273-80. [Medline].
[Guideline] Dellinger RP, Levy MM, Carlet JM, et al. Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock: 2008. Intensive Care Med. 2008 Jan. 34(1):17-60. [Medline].
Wahab Mohamed WA, Saeed MA. Mannose-binding lectin serum levels in neonatal sepsis and septic shock. J Matern Fetal Neonatal Med. 2011 Jun 1. [Medline].
Kluckow M, Evans N. Superior vena cava flow in newborn infants: a novel marker of systemic blood flow. Arch Dis Child Fetal Neonatal Ed. 2000 May. 82(3):F182-7. [Medline].
Osborn DA, Evans N, Kluckow M, et al. Low superior vena cava flow and effect of inotropes on neurodevelopment to 3 years in preterm infants. Pediatrics. 2007 Aug. 120(2):372-80. [Medline].
Skinner JR, Milligan DW, Hunter S, et al. Central venous pressure in the ventilated neonate. Arch Dis Child. 1992 Apr. 67(4 Spec No):374-7. [Medline].
|Agent Type||Agent||Initial Dosage||Additional Factors|
|Volume expanders||Isotonic sodium chloride solution||10-20 mL/kg intravenous (IV)||Inexpensive, available|
|Albumin (5%)||10-20 mL/kg IV||Expensive|
|Plasma||10-20 mL/kg IV||Expensive|
|Lactated ringer solution||10-20 mL/kg IV||Inexpensive, available|
|Isotonic glucose||10-20 mL/kg IV||Inexpensive, available|
|Whole blood products||10-20 mL/kg IV||Limited availability|
|Reconstituted blood products||10-20 mL/kg IV||Use type
|Vasoactive drugs||Dopamine||5-20 mcg/kg/min IV||Never administer intra-arterially|
|Dobutamine||5-20 mcg/kg/min IV||Never administer intra-arterially|
|Epinephrine||0.05-1 mcg/kg/min IV||Never administer intra-arterially|
|Hydralazine||0.1-0.5 mg/kg IV every 3-6 h||Afterload reducer|
|Isoproterenol||0.05-0.5 mcg/kg/min IV||Never administer intra-arterially|
|Nitroprusside||0.5-8 mcg/kg/min IV||Afterload reducer|
|Norepinephrine||0.05-1 mcg/kg/min IV||Never administer intra-arterially|
|Phentolamine||1-20 mcg/kg/min IV||Afterload reducer|
|Milrinone||22.5-45 mcg/kg/h continuous IV infusion (ie, 0.375-0.75 mcg/kg/min)||Afterload reducer in cardiac dysfunction; decrease dose with renal impairment|