Purpose Built Catheters for Minimally Invasive Surfactant Therapy: Experience from a Canadian Tertiary Level Neonatal Intensive Care Unit

Background

Minimally invasive surfactant therapy (MIST), a method of surfactant delivery via a thin catheter during spontaneous breathing, is an increasingly popular alternative to intubation and surfactant administration. Recently, purpose-built catheters for MIST received regulatory approval in Canada and became available for use. However, procedural success and user experience with such catheters have not been described.

Methods

This retrospective cohort study included neonates who received MIST using purpose-built catheters between January 1, 2021, and March 31, 2022. Two types of purpose-built catheters were used in this period - SurfCath™ and BLEScath™. Procedural success, number of attempts, and adverse events in neonates receiving MIST via the two catheters were compared using chi-square or Fisher's tests. User experience was described using an ease-of-use scale.

Results

Thirty-seven neonates met eligibility criteria; 22 received MIST via SurfCath™, whereas 15 received MIST via BLEScath™. Success rates were 91% in SurfCath™ and 93% in BLEScath™ (P> 0.994). Failed attempts were lower in SurfCath™ (23%) in comparison to BLEScath™ (33%), but the difference was not statistically significant (P=0.708). Among operators, 90% found SurfCath™ very easy/relatively easy to use compared to 43% of users reflecting the same degree of use with BLEScath™ (P=.021). There was no difference in adverse events.

Conclusion

This is the first study in Canada to report MIST with purpose-built catheters. Overall, the success rate was equally high with both catheters. Users subjectively reported higher ease of use with SurfCath™. Commercially available purpose-built catheters should facilitate universal adaptation of the MIST method.

13 Impact of Catheter Choice on Procedural Success of Minimally Invasive Surfactant Therapy

Primary Subject area

Neonatal-Perinatal Medicine

Background

Surfactant delivery via a thin endotracheal catheter during spontaneous breathing, a technique called minimally invasive surfactant therapy (MIST), is an alternative to intubation and surfactant administration. Procedural details among different centres vary, with marked differences in the choice of catheter to instill surfactant. Studies report use of feeding catheters, multi-access catheters, vascular catheters and, recently, custom-designed catheters for this purpose. The impact of choice of catheter on procedural success and adverse effects has not been reported.

Objectives

The objective of the present study was to compare the procedural success and adverse effects of MIST, using a semi-rigid vascular catheter (16G Angiocath-Hobart Method) versus a flexible multi-access catheter (MAC).

Design/Methods

This was a retrospective review of prospectively collected data at a tertiary care neonatal intensive care unit in southwestern Ontario. All neonates who received surfactant via MIST between May 1, 2016 and September 30, 2020 were included in the study. Relevant baseline characteristics, data on procedural details (premedication, type of catheter) were collected. The procedural success, number of attempts, and adverse effects between neonates who received MIST via MAC and 16G Angiocath were compared using a Chi Square test or Fisher’s test, as appropriate. A P value of less than 0.05 was considered significant.

Results

A total of 139 neonates received surfactant via MIST method during the study period. 93 neonates received the surfactant via MAC, while 46 received it via Angiocath. The baseline demographic characteristics in the two groups were similar (Table 1). A higher proportion of neonates in the Angiocath group received atropine (100% vs. 76%, P =.002] and fentanyl (98% vs. 36%; p<0.001) than the MAC group.

The procedural success was 91% in the Angiocath group and 89% in the MAC group (p >.99). Multiple attempts were needed in 24% of neonates in the Angiocath group, and 37% in the MAC group (p=0.158). More episodes of desaturations were noted in the Angiocath group (89%) than the MAC group (69%) (P=0.012). Other rates of common adverse effects were similar between the two groups (Table 2).

Conclusion

The overall procedural success of MIST was similar in both catheter groups. The proportion of neonates requiring multiple attempts was lower with Angiocath use, though this difference was not statistically significant. Desaturation episodes were seen more frequently in the Angiocath group, possibly related to higher use of procedural sedation in this group.

Effect of maternal depression and anxiety on use of health services for infants

OBJECTIVE

To evaluate the association between postpartum maternal depressive symptoms or maternal anxiety and health services utilization (HSU) for infants.

DESIGN

Telephone survey.

SETTING

London-Middlesex region of Ontario.

PARTICIPANTS

Mothers of infants 2 to 12 months of age between 2004 and 2005 (N = 655). This sample was drawn from a larger longitudinal cohort of mothers recruited during pregnancy.

MAIN OUTCOME MEASURES

Maternal depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Anxiety was measured using the State-Trait Anxiety Inventory. Infant HSU outcomes included number of primary care provider (PCP) visits for infants < 6 months of age, number of PCP visits for infants 6 to 12 months of age, emergency department (ED) use, and walk-in clinic (WIC) use.

RESULTS

Multivariable regression methods were used to compare HSU for infants. After adjustment for confounders, no significant associations were observed between postpartum maternal depressive symptoms and PCP visits, ED use, or WIC use. Similarly, no significant associations were observed for maternal anxiety and PCP visits, ED use, or WIC use.

CONCLUSION

In contrast to some previous studies, this study found no association between postpartum maternal depressive symptoms or anxiety and HSU for infants.

Preterm histologic chorioamnionitis: impact on cord gas and pH values and neonatal outcome

OBJECTIVE

The purpose of this study was to further delineate the impact of preterm chorioamnionitis on a spectrum of neonatal outcomes using a large tertiary hospital population.

STUDY DESIGN

The perinatal/neonatal and placental pathology databases of St. Joseph's Health Care, London, Ontario, Canada, were used to obtain the umbilical cord gas and pH values, incidence of adverse neonatal outcomes, patient demographics, and placental pathology reports for all preterm (25 to 34 weeks of gestation), singleton, liveborn infants with no major anomalies who were delivered with spontaneous onset of labor or for suspected chorioamnionitis between November 1, 1995, and October 31, 2003. Patient groupings on the basis of placental inflammation and clinical chorioamnionitis were studied by a comparison of mean values and incidences for those neonatal outcomes that were available from the database with the use of linear and logistic regression analysis and controlling for potentially confounding variables.

RESULTS

There were 660 infants who met the inclusion criteria and had placental pathology available of whom 368 (56%) had no placental inflammation, 114 (17%) had placental chorioamnionitis, and 178 (27%) had placental funisitis. Umbilical cord partial pressure oxygen and base excess values were generally higher in the placental inflammation/clinical chorioamnionitis groups, in keeping with enhanced oxygen delivery and an overall decrease in the metabolic contribution to acidosis attributed to altered lactate metabolism in these infants. After adjusting for confounders (primarily differences in gestational age), the incidence of respiratory distress syndrome was significantly decreased in the placental inflammation/clinical chorioamnionitis groups, in keeping with cytokine-induced synthesis of surfactant proteins in these infants. Although the incidence of bronchopulmonary dysplasia, intraventricular hemorrhage, and periventricular leukomalacia was generally unchanged among the groups studied, that for intraventricular hemorrhage and periventricular leukomalacia was lowest in the placental inflammation/no clinical chorioamnionitis patients and highest in the placental inflammation/clinical chorioamnionitis patients, suggesting a differential effect of clinical chorioamnionitis for these outcomes.

CONCLUSION

Overall, infants born preterm with intrauterine infection were better oxygenated and showed less metabolic acidosis at birth and had incidences of respiratory distress syndrome and intraventricular hemorrhage, which were variably lower. Although there are likely threshold levels of inflammatory cytokines that do give rise to adverse outcome, a minimal level of cytokines may also be beneficial for the transition at birth from intrauterine to extrauterine existence when preterm pending the circumstances (ie, exposure to antenatal steroids) and emphasizing the complex relationship among preterm birth, infection, and adverse neonatal outcome.

The impact of labor at term on measures of neonatal outcome

OBJECTIVE

The purpose of this study was to determine risk assessments for a spectrum of neonatal outcomes with elective cesarean delivery versus a trial of labor for previous cesarean section and otherwise healthy patients who deliver at term.

STUDY DESIGN

The perinatal/neonatal database of St. Joseph's Health Care, London, Ontario, Canada, was used to obtain the umbilical cord pH and base excess values, incidence of adverse neonatal outcomes, and patient demographics for all term (> or =37 weeks of gestation), singleton, liveborn, or intrapartum demise infants with no major anomalies who were delivered between January 1992 and March 2002 (n = 33,709 infants). Patient groupings (all patient, patient with previous cesarean delivery, and low-risk patient) with no labor versus labor were studied by a comparison of mean values/incidences for those neonatal outcomes that were available from the database with the use of linear and logistic regression analysis and controlling for potentially confounding variables.

RESULTS

Labor was associated with a small drop in umbilical artery pH from approximately 7.27 to 7.25 and base excess from approximately -3.1 to -5.4 mmol/L, but this was generally well tolerated, with no difference in the incidence of 5-minute Apgar scores of <7 for any of the patient population groupings. Neonatal respiratory morbidity was increased generally in the group of elective cesarean delivery patients, which resulted in increased neonatal intensive care unit triage/admission even out to 7 days; some of this risk was likely to persist even with a policy of elective cesarean delivery after 39 weeks of gestation. Although we found no significant difference in the incidence of pathologic acidemia at birth with an umbilical artery pH <7.00, there was a risk for intrapartum/neonatal death that could be attributed to labor events per se that ranged from 1 of 882 for the patients with previous cesarean delivery to 1 of 3406 for the low-risk patients.

CONCLUSION

For otherwise healthy patients at term, the risk of adverse neonatal outcomes is low, with the choice between elective cesarean delivery and trial of labor in general balancing the low risk of increased respiratory morbidity and thereby neonatal intensive care unit triage/admission against the extremely low risk of labor-related infant death and severe morbidity. However, this balance for the patients with previous cesarean delivery appears shifted, with less benefit from a trial of labor in terms of reduced respiratory morbidity and neonatal intensive care unit triage/admission and with increased labor-related severe morbidity/death, albeit with all of these still at a low level.

The risks of spontaneous preterm delivery and perinatal mortality in relation to size at birth according to fetal versus neonatal growth standards

OBJECTIVE

The aim of this study was to test the null hypothesis that size at birth relative to fetal or neonatal growth standards is not a significant variable related to the risk of spontaneous preterm delivery.

STUDY DESIGN

This was a hospital-based cohort study of consecutive births at a tertiary care perinatal center from January 1, 1985, to December 31, 1996. A total of 37,377 pregnancies met the following inclusion criteria: (1) singleton gestation, (2) 25 to 40 weeks' gestation, and (3) no anomalies. Neonates were divided into 5 birth weight categories according to either fetal (uncorrected for sex) or neonatal (corrected for sex) growth standards, as follows: (1) intrauterine growth restriction, birth weight <3rd percentile; (2) borderline intrauterine growth restriction, birth weight > or = 3rd percentile and <10th percentile; (3) appropriate for gestational age, birth weight from 10th percentile through 90th percentile; (4) borderline large for gestational age, birth weight >90th percentile but < or = 97th percentile, and (5) large for gestational age, birth weight >97th percentile. Logistic regression analysis was used to estimate the independent effect of birth weight category on the risk of preterm delivery after spontaneous onset of labor, with the appropriate-for-gestational-age group serving as a reference.

RESULTS

When fetal growth standards were applied, there was a significant increase in the risk of spontaneous preterm delivery when birth weight was outside the appropriate-for-gestational-age range (odds ratios of 2.5, 1.4, 1.2, and 1.9 for intrauterine growth restriction, borderline intrauterine growth restriction, borderline large-for-gestational age, and large-for-gestational-age groups, respectively). In contrast, when neonatal growth standards were applied, the risks of spontaneous preterm delivery in intrauterine growth restriction, borderline intrauterine growth restriction, and large-for-gestational-age groups were significantly lower (odds ratios of 0.5, 0.7, and 0.7 for intrauterine growth restriction, borderline intrauterine growth restriction, and large-for-gestational-age groups, respectively) because of an underestimation in the number of fetuses with abnormal size at birth delivered prematurely. With both fetal and neonatal growth standards there was a 5-to 6-fold greater risk of perinatal death for both preterm and term fetuses with intrauterine growth restriction.

CONCLUSION

Fetal growth standards are more appropriate in predicting the impact of birth weight category on the risk of spontaneous preterm delivery than are neonatal growth standards. When fetal standards are applied, the risks of preterm birth in both extreme abnormal birth weight categories (intrauterine growth restriction and large for gestational age) are 2- to 3-fold greater than the risk among appropriate-for-gestational-age infants.