Management of well appearing infants born to afebrile mothers with inadequate GBS prophylaxis: A retrospective comparison of the three approaches recommended by the COFN.

BACKGROUND: There are three different approaches set forth by the Committee on the Fetus and Newborn (COFN) for managing asymptomatic neonates born to mothers with inadequate intrapartum antibiotic prophylaxis (IAP) for early-onset Group B Strep (GBS) infection. The first approach is that of categorical risk factor assessments, and recommends that asymptomatic infants born to afebrile mothers with inadequate IAP for GBS be monitored with clinical observation for 36-48 hours. The second approach recommends serial physical examinations and vital signs for 36-48 hours to closely monitor changes in clinical condition for all patients. The Kaiser Permanente EOS risk calculator (SRC) is an example of the third approach, a multivariate risk assessment, and it takes into consideration several perinatal risk factors. This multivariate risk assessment then provides recommendations for reassessment and management based on presume risk of the infant developing or having Early Onset Sepsis (EOS). The aim of our study was to compare these three recently published recommendations from the COFN for the management of asymptomatic neonates born to afebrile mothers with inadequate IAP for GBS. STUDY DESIGN: This is a retrospective study of asymptomatic neonates with gestational age ≥35 weeks born to afebrile mothers with indicated inadequate IAP for GBS between April 2017 and July 2020. Management recommendations of the SRC were compared to the recommendations of categorical risk assessment and risk assessment based on clinical condition. RESULTS: A total of 7,396 infants were born during the study period, 394 (5.3%. to mothers with inadequate IAP. Recommendations for these infants according to both the categorical risk factor guideline and the clinical condition guideline include extended, close observation. However, the SRC recommended routine newborn care for 99.7%.f these infants. None of the infants developed EOS. CONCLUSION: The SRC recommend routine neonatal care without enhanced and prolonged observation for nearly all asymptomatic infants born to afebrile mothers with inadequate IAP. As none of the infants in this cohort had EOS, further studies in a larger cohort are needed to establish the safety of SRC in neonates born to mothers with inadequate IAP.

Setting roller pump occlusion with the transonic HT109 flowmeter.

Setting the occlusion of a roller pump may be facilitated using the TRansonic HT109 Ultrasonic Flowmeter (Transonic Systems, Inc. Ithaca, NY) with non-invasive transducer. The process addresses the need to set occlusion quickly and accurately before initiation of extracorporeal membrane oxygenation (ECMO). This can be performed with the circuit tubing before blood prime and does not require opening the fluid filled ECMO apparatus to air. The principle is based on the fact that fluid flow through the tubing will change with roller occlusion. Using the Transonic flowmeter, a pre determined (partially occlusive) setting can be achieved by first determining the point of total occlusion, then decreasing occlusion a small percentage from this maximum (i.e., total) occlusion. Clinical application in 35 neonatal ECMO cases has shown the practice to be safe, reliable, and efficient.

Pulmonary sequelae in infants treated with extracorporeal membrane oxygenation.

The decision to place an infant on extracorporeal membrane oxygenation (ECMO) is based on predictions of expected morbidity and mortality. One unknown factor is the relationship between pre-ECMO pulmonary dysfunction and on barotrauma and post-ECMO pulmonary sequelae. To determine whether placement of infants on extracorporeal membrane oxygenation (ECMO) early is associated with less subsequent pulmonary dysfunction than placing infants on EMCO later, we evaluated pulmonary function in 25 neonates prior to ECMO, when the infants had come off EMCO, and at the time of nursery discharge. Pulmonary resistance (R) and compliance (CL) were determined by a pneumotachograph and esophageal manometry, and functional residual capacity (FRC) was determined by a helium dilution method. Maximal expiratory flow (VmaxFRC) was determined by thoracic compression at the time of discharge. Infants were assigned to an early ECMO group (< 36 hours of age, n = 12), or a late ECMO group (> 36 hours of age, n = 13). When first evaluated, the early group had a higher oxygenation index than the late group (mean value, 63 versus 48), but initial pulmonary function measurements were not different between the two groups. In the early group mean CL increase from 0.20 to 0.36 ml/cmH2O/kg, FRC increased from 7 to 20 ml/kg, and mean R decreased from 107 to 61 cmH2O/L/sec between the initial study and immediately after ECMO. In the late group, only FRC increased from a mean of 8 to 20 ml/kg. CL and FRC increased from post-ECMO to discharge in both groups (mean CL from 0.36 to 0.76 ml/cmH2O/kg in the early group, and from 0.30 to 0.79 in the late group). Mean FRC increased from 20 to 26 ml/kg in the early group, and from 20 to 25 ml/kg in the late group. VmaxFRC was lower in the late than the early group at discharge (mean, 1.14 versus 1.58 L/sec; P < 0.05). While both groups of infants had minimal pulmonary dysfunction at discharge, the infants placed on ECMO early had evidence of slightly less airway dysfunction despite a higher initial oxygenation index than the infants placed on ECMO late.

The use of tapered plastic luer connectors in neonatal extracorporeal membrane oxygenation.

Tapered luer connectors can split, crack, and leak under certain clinical conditions. The purpose of this study was to analyze the causes of these failures and suggest methods of managing the problem. Experience is related to the use of plastic luers in neonatal extracorporeal membrane oxygenation; however, the guidelines suggested may have some application in the general intensive care population.

Investigation of fatigue failure of S-65-HL "Super Tygon" roller pump tubing.

A failure analysis was performed on Norton S-65-HL Tygon tubing. Fatigue testing was performed on four sizes of this tubing, and essentially showed how the tubing wears out. A dynamic "life hours to failure" test, which was performed on the 3/8" internal diameter (ID) size, quantified when the tubing ruptured. Based on results of laboratory testing and the institution's clinical extracorporeal membrane oxygenation (ECMO) experience, a reasonable life expectancy for the 3/8" S-65-HL Tygon size was determined for use in this institution's neonatal ECMO system. An understanding of the expected performance of roller pump tubing-an integral component of the ECMO system-is imperative to providing safe, effective extracorporeal life support.

Bypass cannulas utilized in extracorporeal membrane oxygenation in neonates: radiographic findings.

ECMO, as applied to neonates with severe respiratory failure, involves either a single or dual cannula system for removal of desaturated blood from and return of oxygenated blood to the patient. ECMO cannulas have undergone considerable change and improvement since the early 1980s, and a variety of cannulas are now available commercially for neonatal ECMO. All ECMO cannulas have a characteristic appearance on the chest radiograph, which is important in the assessment of cannula position and some cannula complications. We report the physical characteristics, advantages, disadvantages, and radiographic appearance of the most widely utilized neonatal ECMO cannulas.