Invasive Mechanical Ventilation in Premature Infants: Where do we Stand Today?

Abstract

Respiratory support is an essential part of care during clinical course of premature infants. Despite the wide-spread use of non-invasive modes of ventilation today the most vulnerable extremely premature infants are still likely to require invasive mechanical ventilation. Multiple studies have been published addressing advantages and disadvantages of various modes of ventilation in neonates. In this review we critically evaluate data supporting use of different modalities of invasive mechanical ventilation in premature infants. Specific attention is paid to aspects of synchronizedand patient-triggered ventilation, comparison of volume-targeted, pressure-limited modes of ventilation and high frequency ventilation. As a separate subject we assess the use of multiple techniques to shorten the length of invasive mechanical ventilation including modes of ventilation, post-extubation support, permissive hypercapnea and targeting lower oxygen saturation. *Corresponding author: Sergei Roumiantsev,Attending Physician, Massachusetts General Hospital for Children, Newborn Services,55 Fruit Street, FND 526A, Boston, MA 02114, USA, Tel: 617-724-9040; Fax: 617-724-9346; E-mail: sroumiantsev@partners.org Received December 12, 2012; Accepted February 28, 2013; Published March 04, 2013 Citation: Roumiantsev S (2013) Invasive Mechanical Ventilation in Premature Infants: Where do we Stand Today? J Pulmon Resp Med S13: 002. doi:10.4172/2161-105X.S13-002 Copyright: © 2013 Roumiantsev S. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction On August 9, 1963 the entire world was shocked to learn that Patrick Bouvier Kennedy, newborn son of the beloved American president died at the age of 2 days. He was born in Otis Air Force Base Hospital at 34 weeks of gestation with birth weight of 4 pounds and 10.5 ounces. He was transported to Children’s Hospital Boston with the diagnosis of hyaline membrane disease, now called neonatal Respiratory Distress Syndrome (RDS). As newspapers reported in his obituary very little treatment was available besides observation and blood chemistry. This event brought to public view and raised awareness of how little medical care is available for the smallest patients. It was a pivotal point to accelerate the development of dedicated specialized Neonatal Intensive Care Units (NICUs) across the country. Development of mechanical ventilation and other new therapies for neonates in general and premature babies in particular has resulted in dramatic improvements in survival of premature infants as well as the ability to rescue extremely premature infants at lower gestational than was imaginable in the 1960s. The last two decades were marked by improved survival of extremely premature infants [1,2]. Infant mortality due to RDS in the United States has decreased dramatically from 268 in 100,000 live birth in 1971 [3] to 14.7 per 100,000 live births in 2008 [4]. While multiple factors contributed to this statistic, an understanding of pathophysiology of RDS and development of mechanical ventilation for infants was a key element of this success. One of the early studies showing a beneficial effect of mechanical ventilation on survival compared mechanical ventilation (negative pressure ventilation, pressure limited positive pressure and volume limited positive pressure ventilation) vs. no ventilation in premature infants with RDS was published in early 1970 [5]. This study was especially interesting historically, as 40 years later we continue to debate the efficacy of various ventilator strategies and non-invasive ventilator support. Since the introduction of invasive mechanical ventilation of neonates we have been faced with complications of chronic lung disease in premature infants. Northway described the chronic pulmonary syndrome associated with intermittent positive-pressure ventilation and high oxygen concentration, Broncho Pulmonary Dysplasia(BPD) [6]. At the same time Gregory introduced Continuous Positive Pressure Ventilation (CPAP) as an alternative to invasive mechanical ventilation [7]. The 1970s and 1980s were marked by the development and use of neonatal Time Cycled Pressure Limited (TCPL) ventilators [8,9] and high frequency ventilators [10,11]. Despite the availability of more sophisticated neonatal ventilators, invasive mechanical ventilation remained the major risk factor for development of BPD. Centers that used less invasive ventilation had lower rates of Chronic Lung Disease (CLD) [12,13]. These studies have shifted the discussion and the interest in neonatal mechanical ventilation towards how we can use less of mechanical ventilation, with the hope of reducing BPD. Current approaches to CPAP and Noninvasive Positive Pressure Ventilation (NIPPV) is reviewed elsewhere in the current issue of the Journal. Although recent data suggest that the use of CPAP and NIPPV may be beneficial, a majority of the most vulnerable infants still require intubation and invasive mechanical ventilation. Several large studies such as SUPPORT [14] and COIN [15] trials show that over 50% of infants with gestational age 24-28 weeks require intubation and mechanical ventilation during their hospital stay, even with careful selection of the patients enrolled into a CPAP arm. Smaller randomized trials show that NIPPV reduced the need for intubation and invasive mechanical ventilation, but exclude the most vulnerable infants less than 26 weeks of gestation [16,17]. The prevalence of moderate to severe BPD among infants less than 26 weeks remains >60% [18]. The goal of this review is to discuss commonly used approaches in invasive mechanical ventilation of neonates and the benefits of novel modalities. Challenges of Neonatal Ventilation Mechanical ventilation of small neonates poses multiple technological challenges, resulting in substantial delays in the Citation: Roumiantsev S (2013) Invasive Mechanical Ventilation in Premature Infants: Where do we Stand Today? J Pulmon Resp Med S13: 002. doi:10.4172/2161-105X.S13-002