Robert G. Locke, D.O, MPH, FACOP, FAAP

Director, Neonatal Research, Neonatal Medical Group

Publications

Adjustment of high flow nasal cannula rates using real-time work of breathing indices in premature infants with respiratory insufficiency
Adjustment of high flow nasal cannula rates using real-time work of breathing indices in premature infants with respiratory insufficiency
Kovatis KZ, Locke RG, Mackley AB, Subedi K, Shaffer TH

J Perinatol 2021 07;41(7):1711-1717

PMID: 33664469

Abstract

OBJECTIVE">To assess the feasibility of real-time monitoring of work of breathing (WOB) indices and the impact of adjusting HFNC flow on breathing synchrony and oxygen stability in premature infants.</Abstr: To assess the feasibility of real-time monitoring of work of breathing (WOB) indices and the impact of adjusting HFNC flow on breathing synchrony and oxygen stability in premature infants.

STUDY DESIGN">A prospective, observational study of infants stable on HFNC. The flow adjusted per predetermined algorithm. Respiratory inductive plethysmography (RIP) noninvasively measured WOB. A high-resolution pulse oximeter collected oxygen saturation and heart rate data. Summary statistics and mixed linear models were used.</Abstr: A prospective, observational study of infants stable on HFNC. The flow adjusted per predetermined algorithm. Respiratory inductive plethysmography (RIP) noninvasively measured WOB. A high-resolution pulse oximeter collected oxygen saturation and heart rate data. Summary statistics and mixed linear models were used.

RESULTS">Baseline data for 32 infants, final analysis of 21 infants. Eighty-one percent with abnormal WOB. Sixty-two percent demonstrated 20% improvement in WOB. For infants with gestational age <28 weeks, an incremental increase in HFNC flow rate decreased WOB (p < 0.001) and improved oxygen saturation and stability (p < 0.01).</Abstr: Baseline data for 32 infants, final analysis of 21 infants. Eighty-one percent with abnormal WOB. Sixty-two percent demonstrated 20% improvement in WOB. For infants with gestational age <28 weeks, an incremental increase in HFNC flow rate decreased WOB (p < 0.001) and improved oxygen saturation and stability (p < 0.01).

CONCLUSIONS">Premature infants do not receive optimal support on HFNC. The use of a real-time feedback system to adjust HFNC is feasible and improves WOB, oxygen saturation, and oxygen stability. This technology may improve the utility of HFNC in premature infants.© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc. part of Springer Nature.</CopyrightInfo: Premature infants do not receive optimal support on HFNC. The use of a real-time feedback system to adjust HFNC is feasible and improves WOB, oxygen saturation, and oxygen stability. This technology may improve the utility of HFNC in premature infants.

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Variation in NICU Admission Rates Without Identifiable Cause
Variation in NICU Admission Rates Without Identifiable Cause
Ziegler KA, Paul DA, Hoffman M, Locke R

Hosp Pediatr 2016 May;6(5):255-60

PMID: 27117951

Abstract

OBJECTIVES: Admission to the NICU is influenced by physiologic compromise and by hospital care protocols. Providing appropriate care must be balanced with adverse consequences of NICU admission, such as interrupting maternal-infant bonding and unnecessary interventions. This study aims to determine the variation in NICU admissions in term and late preterm infants among 19 hospitals.
METHODS: We used the Consortium on Safe Labor (CSL) database to determine NICU admission rates. This database includes data from 217 442 infants aged 35 to 42 weeks within 19 US maternal delivery hospitals from 2002 to 2008. NICU admission rates were evaluated for absolute factors including, but not limited to, sepsis, asphyxia, respiratory distress, and intracranial hemorrhage, as well as relative factors, such as maternal drug use, chorioamnionitis, and infant birth weight ≤ 2500 g.
RESULTS: Percentage of infants 35 to 42 weeks' gestation admitted to the NICU without an identifiable absolute or relative cause for intensive care services ranged from 0% to 59.4% (mean, 10.8%; P < .001). Among infants 35 to 42 weeks' gestation and ≥ 2500 g, infants without absolute or relative identified cause accounted for 9.1% of total NICU days and had lower length of stays (-2.7 days; 95% confidence interval -3.4; -2.1) compared to those with an identified reason.
CONCLUSIONS: There is significant variation in admission rates among NICUs that cannot be explained by infant health conditions. Further analysis is needed to determine the cause of between-site variation and potential opportunities to refine protocols and optimize use of NICU services.
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Time Series Analysis for Forecasting Hospital Census: Application to the Neonatal Intensive Care Unit
Time Series Analysis for Forecasting Hospital Census: Application to the Neonatal Intensive Care Unit
Capan M, Hoover S, Jackson EV, Paul D, Locke R

Appl Clin Inform 2016;7(2):275-89

PMID: 27437040

Abstract

BACKGROUND: Accurate prediction of future patient census in hospital units is essential for patient safety, health outcomes, and resource planning. Forecasting census in the Neonatal Intensive Care Unit (NICU) is particularly challenging due to limited ability to control the census and clinical trajectories. The fixed average census approach, using average census from previous year, is a forecasting alternative used in clinical practice, but has limitations due to census variations.
OBJECTIVE: Our objectives are to: (i) analyze the daily NICU census at a single health care facility and develop census forecasting models, (ii) explore models with and without patient data characteristics obtained at the time of admission, and (iii) evaluate accuracy of the models compared with the fixed average census approach.
METHODS: We used five years of retrospective daily NICU census data for model development (January 2008 - December 2012, N=1827 observations) and one year of data for validation (January - December 2013, N=365 observations). Best-fitting models of ARIMA and linear regression were applied to various 7-day prediction periods and compared using error statistics.
RESULTS: The census showed a slightly increasing linear trend. Best fitting models included a non-seasonal model, ARIMA(1,0,0), seasonal ARIMA models, ARIMA(1,0,0)x(1,1,2)7 and ARIMA(2,1,4)x(1,1,2)14, as well as a seasonal linear regression model. Proposed forecasting models resulted on average in 36.49% improvement in forecasting accuracy compared with the fixed average census approach.
CONCLUSIONS: Time series models provide higher prediction accuracy under different census conditions compared with the fixed average census approach. Presented methodology is easily applicable in clinical practice, can be generalized to other care settings, support short- and long-term census forecasting, and inform staff resource planning.
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Prolonged early antibiotic use and bronchopulmonary dysplasia in very low birth weight infants
Prolonged early antibiotic use and bronchopulmonary dysplasia in very low birth weight infants
Novitsky A, Tuttle D, Locke RG, Saiman L, Mackley A, Paul DA

Am J Perinatol 2015 Jan;32(1):43-8

PMID: 24792766

Abstract

OBJECTIVE: The objective of the article is to determine if > 48 hours of antibiotic treatment during the 1st week of life is associated with subsequent isolation of bacteria from the endotracheal tube (ETT), and an increased risk of bronchopulmonary dysplasia (BPD).
STUDY DESIGN: Retrospective cohort study of very low birth weight infants. Routine weekly surveillance ETT cultures were obtained to monitor bacterial colonization in all intubated infants. Risk factors for BPD were assessed using unadjusted and multivariable analyses.
RESULTS: In the study sample (n = 906), infants with BPD (n = 182) were more likely to have received > 48 hours antibiotic treatment (31 vs. 14%, p 48 hours of antibiotics remained associated with BPD (adjusted odds ratio, 2.2; 95% confidence interval, 1.4-3.5) after controlling for confounding variables.
CONCLUSIONS: Antibiotic duration > 48 hours in the 1st week of life was associated with subsequent BPD and the presence of resistant bacteria in routine ETT cultures.
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Complementary and Alternative Medicine use in women during pregnancy: do their healthcare providers know?
Complementary and Alternative Medicine use in women during pregnancy: do their healthcare providers know?
Strouss L, Mackley A, Guillen U, Paul DA, Locke R

BMC Complement Altern Med 2014;14:85

PMID: 24592860

Abstract

BACKGROUND: The National Institutes of Health reported in 2007 that approximately 38% of United States adults have used at least one type of Complementary and Alternative Medicine (CAM). There are no studies available that assess general CAM use in US pregnant women.The objectives of our study were to determine the prevalence and type of CAM use during pregnancy at one medical center; understand who is using CAM and why they are using it; and assess the state of patients' CAM use disclosure to their obstetrical providers.
METHODS: A cross-sectional survey study of post-partum women was done to assess self-reported CAM use during pregnancy. Results of this survey were compared to results from a previous survey performed by this research team in 2006. Data were analyzed using binary logistic regression.
RESULTS: In 2013, 153 women completed the survey, yielding a response rate of 74.3%. Seventy-two percent and 68.5% of participants reported CAM use during their pregnancies in 2006 and 2013 respectively. The percentage of participants who reported discussing CAM use with their obstetrical providers was less than 1% in 2006 and 50% in 2013. Increased use of different CAM therapies was associated with increased maternal age, primagravida, being US-born, and having a college education (p ≤ 0.05). However, these factors were poor predictors of CAM use.
CONCLUSIONS: Given the frequency of CAM use and the difficulty in predicting who is using it, obstetrical providers should consider being informed about CAM and incorporating discussions about its use into routine patient assessments.
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