Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter to the Editor
  • Published:

Treating hypotension in the preterm infant: when and with what: a critical and systematic review

Journal of Perinatology volume 28, page 167 (2008)Cite this article

This comprehensive review by Dempsey and Barrington1 is a foray into an area of sufficient equipoise wherein the management protocols are driven by experience and personal preference rather than sound outcome-based evidence. While we await this evidence, we believe that cerebral autoregulation deserves a more important place in this debate. While available data suggest that hypotensive preterm infants are at risk of neurological injury (IVH/PVL),2, 3 they may lack autoregulation or be below the autoregulatory threshold due to immaturity of blood–brain barrier. If the cerebral circulation is really pressure passive, increased pressure may be of paramount importance even if it is at the expense of reduced flow in other vascular beds. It is also essential to consider the characteristics of immature myocardium. It is known that pressure is the product of flow and resistance. A rise in resistance should normally result in a rise in pressure but might be having a deleterious impact on myocardial contractility as a consequence of increase in afterload. In case of a newly born premature baby with sudden loss of a low vascular resistance circuit (placenta), the immature myocardium, which till now has been contracting against a low afterload, suddenly has to adapt to contract against a raised vascular resistance. A decision to administer cardiotropic drugs, which increase the blood pressure by increasing peripheral vascular resistance, may be open to question. Effectively, this could increase myocardial workload and/or myocardial oxygen consumption. It has been clear for many years that the unique structural and functional limitations of the neonatal (especially preterm) myocardium make it extremely susceptible to increase in afterload4 and maturational alterations in contractility occur with birth and continue throughout infancy.

Assessment of ventricular contractility in the newborn infant using standard echocardiographic indices can result in error due to the unique physiologic state that exists in the neonatal period and shortening fraction may underestimate ventricular function in the newborn. Studies focusing on echocardiographic parameters for assessment of rapidly evolving hemodynamic state in preterm newborns must use load-independent markers to derive meaningful conclusions. The stress–velocity relationship, which describes the relationship between afterload and myocardial contractility (as measured by the mean rate-corrected velocity of circumferential fiber shortening (mVCFc)) has been studied previously in neonates and children.5 This relation was used as a load-independent estimate of contractility. An inverse linear relation between mVCFc and end systolic wall stress (ESWS) was found in both age groups. Evidently, myocardial performance is more sensitive to afterload in the immature heart, and in the face of rising ESWS (surrogate marker of after load), myocardial contractility could decline.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

References

  1. Dempsey EM, Barrington KJ . Treating hypotension in the preterm patient: when and with what: a critical and systematic review. J Perinatol 2007; 27: 469–478.

    Article  CAS  Google Scholar 

  2. Bada HS, Korones SB, Perry EH, Arheart KL, Ray JD, Pourcyrous M et al. Mean arterial blood pressure changes in premature infants and those at risk for intraventricular haemorrhage. J Pediatr 1990; 117 (4): 607–614.

    Article  CAS  Google Scholar 

  3. Miall-Allen VM, De Vries LS, Whitelaw AL . Mean arterial blood pressure and neonatal cerebral lesions. Arch Dis Child 1987; 62: 1068–1069.

    Article  CAS  Google Scholar 

  4. Hawkins J, Van Hare GF, Schmidt KG, Rudolph AM . Effects of increasing after load on left ventricular output in foetal lambs. Circ Res 1989; 65: 127–134.

    Article  CAS  Google Scholar 

  5. Rowland DG, Gutgesell HP . Non-invasive assessment of myocardial contractility, preload, and after load in healthy newborn infants. Am J Cardiol 1995; 75 (12): 818–821.

    Article  CAS  Google Scholar 

  6. Teixeira L, Shivananda S, Arsdell GV, James A, McNamara P . PDA ligation causes postoperative myocardial dysfunction in premature infants. Paediatric Academic Societies Annual Meeting, 2006, abstract 2863. 238.

  7. Sehgal A, McNamara P . Coronary artery perfusion is associated with impaired diastolic dysfunction in preterm infants after PDA ligation. Paediatric Academic Societies Annual Meeting, 2007, Abstract 5896.15.

Download references

Author information

Authors and Affiliations

  1. Division of Neonatology and Cardiovascular Research, The Hospital for Sick Children, Toronto, Ontario, Canada

    A Sehgal

  2. Newborn Services, Monash Medical Centre, Melbourne, Victoria, Australia

    A Ramsden

Authors
  1. A Sehgal
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A Ramsden
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Sehgal, A., Ramsden, A. Treating hypotension in the preterm infant: when and with what: a critical and systematic review. J Perinatol 28, 167 (2008). https://doi.org/10.1038/sj.jp.7211883

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/sj.jp.7211883

Search

Advanced search

Quick links