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Bio

Clinical Focus

  • Pediatric Critical Care Medicine
  • Pediatric Cardiac Critical Care

Academic Appointments

Professional Education

  • Board Certification: American Board of Pediatrics, Pediatrics (2012)
  • Fellowship: Boston Children's Hospital (2015) MA
  • Board Certification: American Board of Pediatrics, Pediatric Critical Care Medicine (2014)
  • Fellowship: Boston Children's Hospital (2014) MA
  • Residency: Boston Children's Hospital (2011) MA
  • Medical Education: University of Massachusetts Medical School (2008) MA

Contact

  • Pediatric Cardiology 750 Welch Rd Ste 321 Palo Alto, CA 94304
    • Tel: (650) 724-5554
    Fax: (650) 725-8343

Publications

All Publications

  • Mid-Term Outcomes After Unifocalization Guided by Intraoperative Pulmonary Flow Study. World journal for pediatric & congenital heart surgery Goodman, A., Ma, M., Zhang, Y., Ryan, K. R., Jahadi, O., Wise-Faberowski, L., Hanley, F. L., McElhinney, D. B. 2021; 12 (1): 76?83

    Abstract

    BACKGROUND: Repair of tetralogy of Fallot (TOF) with major aortopulmonary collateral arteries (MAPCAs) requires unifocalization of pulmonary circulation, intracardiac repair with the closure of the ventricular septal defect, and placement of a right ventricle (RV) to pulmonary artery (PA) conduit. The decision to perform complete repair is sometimes aided by an intraoperative flow study to estimate the total resistance of the reconstructed pulmonary circulation.METHODS: We reviewed patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs to evaluate acute and mid-term outcomes after repair with and without flow studies and to characterize the relationship between PA pressure during the flow study and postrepair RV pressure.RESULTS: Among 579 patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs, 99 (17%) had an intraoperative flow study during one (n = 91) or more (n = 8) operations to determine the suitability for a complete repair. There was a reasonably good correlation between mean PA pressure at 3 L/min/m2 during the flow study and postrepair RV pressure and RV:aortic pressure ratio. Acute and mid-term outcomes (median: 3.8 years) after complete repair in the flow study patients (n = 78) did not differ significantly from those in whom the flow study was not performed (n = 444). Furthermore, prior failed flow study was not associated with differences in outcome after subsequent intracardiac repair.CONCLUSIONS: The intraoperative flow study remains a useful adjunct for determining the suitability for complete repair in a subset of patients undergoing surgery for TOF/MAPCAs, as it is reasonably accurate for estimating postoperative PA pressure and serves as a reliable guide for the feasibility of single-stage complete repair.

    View details for DOI 10.1177/2150135120964427

    View details for PubMedID 33407027

  • Continuous EEG for Seizure Detection in Neonates after Cardiac Bypass without Deep Hypothermic Cardiac Arrest Levy, R., Karamian, A., Mayne, E., Iqbal, M., Purington, N., Ryan, K., Wusthoff, C. LIPPINCOTT WILLIAMS & WILKINS. 2020

    View details for Web of Science ID 000536058004299

  • The Use of Clevidipine for Hypertension in Pediatric Patients Receiving Mechanical Circulatory Support. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies Wu, M., Ryan, K. R., Rosenthal, D. N., Jahadi, O., Moss, J., Kwiatkowski, D. M. 2020

    Abstract

    Limited data exist regarding the management of hypertension in pediatric patients on mechanical circulatory support. Hypertension is a known risk factor for stroke and low cardiac output in patients requiring mechanical circulatory support and a narrow therapeutic window of blood pressure is often targeted. Traditional short-acting infusions to treat hypertension, such as sodium nitroprusside, may lead to accumulation of toxic metabolites in patients with renal dysfunction. Our primary objective was to describe use of clevidipine, a continuous short-acting calcium channel blocking medication, for blood pressure control in pediatric patients on mechanical circulatory support.Single-center retrospective cohort study.A 26-bed quaternary cardiovascular ICU in a university-based pediatric hospital in California.Mechanical circulatory support patients admitted to cardiovascular ICU who received clevidipine infusions between October 1, 2016, and March 31, 2019.Clevidipine infusion.Data from a cohort of 38 patients who received a total of 45 clevidipine infusions were reviewed. The cohort had a median age of 2.7 years and included neonates. No patient had record of hypotensive events, code events, or received low-dose epinephrine or code-dosed epinephrine related to a clevidipine infusion. Median duration of clevidipine infusion was 4.1 days (1.5-9.2 d). Eleven patients transitioned from clevidipine to enteral antihypertensive agents, and 26 clevidipine infusions were administered as a single agent without sodium nitroprusside. Seven patients were switched from sodium nitroprusside to clevidipine to avoid cyanide toxicity, a majority of whom had elevated serum creatinine.In this pediatric cardiac cohort, clevidipine infusions were effective at hypertension management and were not associated with hypotensive or code events. This report details the largest cohort and longest duration of clevidipine administration within a pediatric population and did not demonstrate hypotensive events, even among neonatal populations. Clevidipine may be a reasonable cost-effective alternative antihypertensive medication compared to traditional short-acting agents.

    View details for DOI 10.1097/PCC.0000000000002562

    View details for PubMedID 32796396

  • Developments in Pediatric Ventricular Assist Device Support. World journal for pediatric & congenital heart surgery Tume, S. C., Conway, J., Ryan, K. R., Philip, J., Fortkiewicz, J. M., Murray, J. 2019: 2150135119880890

    Abstract

    Mechanical support devices have revolutionized the management of circulatory failure. This has been met by a dramatic increase in ventricular assist device (VAD) utilization in children over the last two decades. Previous wide gaps in experience and knowledge have significantly narrowed in the recent years. As we continue to gain experience with this technology, we face new challenges such as complex congenital circulations and small patient size. The emergence of new pharmacologic therapies and device technology offers more opportunities and requires constant adjustment in practice. As we continue to embark on this journey, constant insight is needed to refine patient selection criteria, minimize complications, and continue to push the field for safer smaller devices to accommodate these complex patient populations. In this review focused at inpatient critical care environment, we discuss the recent field developments and focus on challenging patient populations, the emergence of temporary support, management of anticoagulation, and diagnostic approach to stroke in the setting of VAD support.

    View details for DOI 10.1177/2150135119880890

    View details for PubMedID 31663841

  • Neurodevelopmental Outcomes Among Children With Congenital Heart Disease: At-Risk Populations and Modifiable Risk Factors. World journal for pediatric & congenital heart surgery Ryan, K. R., Jones, M. B., Allen, K. Y., Marino, B. S., Casey, F., Wernovsky, G., Lisanti, A. J. 2019: 2150135119878702

    Abstract

    As survivable outcomes among patients with complex congenital heart disease (cCHD) have continued to improve over the last several decades, more attention is being dedicated to interventions that impact not just survival but quality of life among patients with cCHD. In particular, patients with cCHD are at risk for impaired neurodevelopmental outcomes. In this review summarizing select presentations given at the 14th Annual Pediatric Cardiac Intensive Care Society's Annual Meeting in 2019, we discuss the neurodevelopmental phenotype of patients with cCHD, patients at greatest risk of impaired development, and three specific modifiable risk factors impacting development.

    View details for DOI 10.1177/2150135119878702

    View details for PubMedID 31658880

  • Vasoplegia after pediatric cardiac transplantation in patients supported with a continuous flow ventricular assist device JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sacks, L. D., Hollander, S. A., Zhang, Y., Ryan, K. R., Ford, M. A., Maeda, K., Murray, J. M., Almond, C. S., Kwiatkowski, D. M. 2019; 157 (6): 2433?40

    View details for DOI 10.1016/j.jtcvs.2019.01.100

    View details for Web of Science ID 000468116200105

  • Vasoplegia after pediatric cardiac transplantation in patients supported with a continuous flow ventricular assist device. The Journal of thoracic and cardiovascular surgery Sacks, L. D., Hollander, S. A., Zhang, Y., Ryan, K. R., Ford, M. A., Maeda, K., Murray, J. M., Almond, C. S., Kwiatkowski, D. M. 2019

    Abstract

    OBJECTIVE: To determine the association between continuous flow ventricular assist devices and the incidence of vasoplegia following orthotopic heart transplant in children. Moreover, to propose a novel clinical definition of vasoplegia for use in pediatric populations.METHODS: This is a single-center, retrospective cohort study set in the cardiovascular intensive care unit of a tertiary children's hospital. All patients aged 3years and older who underwent orthotopic heart transplant at Stanford Universitybetween April 1, 2014, and July 31, 2017, were included. Vasoplegia was defined by the use of vasoconstrictive medication, diastolic hypotension, preserved systolic heart function, and absence of infection or right atrial pressure or central venous pressure <5mm Hg.RESULTS: Of 44 eligible patients, 21 were supported using a continuous flow ventricular assist device. Following heart transplant, 14 patients (32%) developed vasoplegia by the study definition. Development of vasoplegia was associated with pretransplant use of a continuous flow ventricular assist device (52% vs 13%) with a relative risk of 4.02 (95% confidence interval, 1.30-12.45; P=.009). No other variables were predictive of vasoplegia in univariable analysis. Presence of vasoplegia was not associated with adverse outcomes, although there were trends towards higher incidence of acute kidney injury and increased length of hospital stays.CONCLUSIONS: Children receiving continuous flow ventricular assist device support are at increased risk for vasoplegia following orthotopic heart transplant, using a novel definition of vasoplegia. Anticipation of this complication will allow for prompt intervention, thereby minimizing hemodynamic instability and impact on patient outcomes.

    View details for PubMedID 30929985

  • An alternative cannulation approach for venovenous extracorporeal membrane oxygenation in children for long-term ambulatory support. The Journal of thoracic and cardiovascular surgery Maeda, K., Ryan, K., Conrad, C. K., Yarlagadda, V. V. 2018

    View details for PubMedID 29685584

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