Clinical Focus

  • Pediatric Anesthesia
  • Pediatric cardiac anesthesia
  • Anesthesia

Academic Appointments

Professional Education

  • Residency:South East Scotland School of Anaesthesia (2007) Scotland
  • Fellowship:Westmead Children's Hospital (2006) Australia
  • Residency:South East Scotland School of Anaesthesia (2001) Scotland
  • Residency:South Manchester NHS Trust (1999) UK
  • Residency:Trafford General Hospital (1999) UK
  • Residency:St John's Hospital at Howden (1998) UK
  • Internship:South Manchester NHS Trust (1997) UK
  • Medical Education:Edinburgh University (1997) UK


All Publications

  • LVOT-VTI is a Useful Indicator of Low Ventricular Function in Young Patients. Pediatric cardiology Navaratnam, M., Punn, R., Ramamoorthy, C., Tacy, T. A. 2017


    Left ventricular outflow tract velocity time integral (LVOT-VTI), a Doppler-derived measure of stroke distance, is used as a surrogate marker of cardiac function in adults. LVOT-VTI is easily obtained, independent of ventricular geometry and wall motion abnormalities. We investigated the relationship between LVOT-VTI and conventional measures of function in young patients by comparing controls to children with dilated cardiomyopathy (DCM). Sixty-two healthy and 52 DCM patients over 1 year were studied retrospectively. The average pulsed (PW) and continuous wave (CW) LVOT-VTIs from apical views were measured from three cycles. Body surface area (BSA) and Ejection fraction (EF) were obtained. We compared LVOT-VTIs between study and control groups and assessed BSA's impact on LVOT-VTI. The entire cohort was classified into three levels of LV function which were compared. We determined LVOT-VTI cutoff values that indicated an EF <50%. The mean PW-LVOT-VTI in the DCM group was significantly lower than that of the normal group (0.15 vs. 0.18 m; p < 0.0012). The mean CW-LVOT-VTI was significantly lower in DCM (0.20 vs. 0.24 m; p < 0.0001). There was no impact of BSA on LVOT-VTI except when comparing BSA and CW-LVOT-VTI in the normal group. There was a positive relationship between LVOT-VTI and EF for PW (Rs = 0.29, p = 0.0022) and CW (Rs = 0.22, p = 0.0364) and a difference in mean LVOT-VTI between EF groups (p < 0.0001). ROC analysis demonstrated that PW-LVOT-VTI <0.17 m (AUC = 0.73; p < 0.0001) and CW-LVOT-VTI <0.22 m (AUC = 0.76; p < 0.0001) was associated with EF <50%. This study indicates that LVOT-VTI can be a useful alternative measure of LV performance in children over 1 year.

    View details for DOI 10.1007/s00246-017-1630-9

    View details for PubMedID 28534242

  • Perioperative management of pediatric en-bloc combined heart-liver transplants: a case series review. Paediatric anaesthesia Navaratnam, M., Ng, A., Williams, G. D., Maeda, K., Mendoza, J. M., Concepcion, W., Hollander, S. A., Ramamoorthy, C. 2016; 26 (10): 976-986


    Combined heart and liver transplantation (CHLT) in the pediatric population involves a complex group of patients, many of whom have palliated congenital heart disease (CHD) involving single ventricle physiology.The purpose of this study was to describe the perioperative management of pediatric patients undergoing CHLT at a single institution and to identify management strategies that may be used to optimize perioperative care.We did a retrospective database review of all patients receiving CHLT at a children's hospital between 2006 and 2014. Information collected included preoperative characteristics, intraoperative management, blood transfusions, and postoperative morbidity and mortality.Five pediatric CHLTs were performed over an 8-year period. All patients had a history of complex CHD with multiple sternotomies, three of whom had failing Fontan physiology. Patient age ranged from 7 to 23 years and weight from 29.5 to 68.5 kg. All CHLTs were performed using an en-bloc technique where both the donor heart and liver were implanted together on cardiopulmonary bypass (CPB). The median operating room time was 14.25 h, median CPB time was 3.58 h, and median donor ischemia time was 4.13 h. Patients separated from CPB on dopamine, epinephrine, and milrinone infusions and two required inhaled nitric oxide. All patients received a massive intraoperative blood transfusion post CPB with amounts ranging from one to three times the patient's estimated blood volume. The patient who required the most transfusions was in decompensated heart and liver failure preoperatively. Four of the five patients received an antifibrinolytic agent as well as a procoagulant (prothrombin complex concentrate or recombinant activated Factor VII) to assist with hemostasis. There were no 30-day thromboembolic events detected. Postoperatively the median length of mechanical ventilation, ICU stay and stay to hospital discharge was 4, 8, and 37 days, respectively. All patients are alive and free from allograft rejection at this time.Combined heart and liver transplantation in the pediatric population involves a complex group of patients with unique perioperative challenges. Successful management starts with thorough preoperative planning and communication and involves strategies to deal with massive intraoperative hemorrhage and coagulopathy in addition to protecting and supporting the transplanted heart and liver and meticulous surgical technique. An integrated multidisciplinary team approach is the cornerstone for successful outcomes.

    View details for DOI 10.1111/pan.12950

    View details for PubMedID 27402424

  • Surgical Reconstruction of Tracheal Stenosis in Conjunction With Congenital Heart Defects Basic Science Forum of the 58th Annual Meeting of the Southern-Thoracic-Surgical-Association Mainwaring, R. D., Shillingford, M., Davies, R., Koltai, P., Navaratnam, M., Reddy, V. M., Hanley, F. L. ELSEVIER SCIENCE INC. 2012: 1266–73


    Surgical reconstruction is the primary method of treating airway obstruction in children. Tracheal stenosis is frequently associated with congenital heart defects, which may further complicate the overall management strategy. The purpose of this study was to review our experience with surgical reconstruction of airway obstruction in conjunction with congenital heart defects.This was a retrospective review of our surgical experience with tracheal stenosis from February 2003 to August 2011. Twenty-seven patients were identified in our database. Six patients had isolated, congenital tracheal stenosis, and 21 had tracheal stenosis in association with congenital heart defects. There were two identifiable subgroups. Thirteen patients had airway stenoses identified concurrently with congenital heart defects and underwent combined repair. The second group comprised 8 patients who had previous correction of their congenital heart defects and experienced delayed presentation of tracheal (n = 6) or bronchial (n = 2) obstruction.The median age at surgery was 9 months. There were 2 postoperative deaths, both in children with single ventricle. The median duration of follow-up for the entire cohort of 25 surviving patients was 4 years. None of the patients have required reoperations on the trachea; 5 have had minor reinterventions.The data demonstrate that tracheal obstruction is frequently found in conjunction with congenital heart defects. Nearly one third of our patients had delayed presentation of airway obstruction that was identified subsequent to previous congenital heart defect repair. Tracheal reconstructive techniques were effective regardless of the cause of the airway obstruction.

    View details for DOI 10.1016/j.athoracsur.2011.12.063

    View details for Web of Science ID 000302120200049

    View details for PubMedID 22381444

  • Pediatric pacemakers and ICDs: how to optimize perioperative care PEDIATRIC ANESTHESIA Navaratnam, M., Dubin, A. 2011; 21 (5): 512-521


    An increasing number of pediatric patients with permanent pacemakers and implantable cardioverter defibrillators (ICDs) require cardiac and noncardiac surgery. It is critical that the anesthesiologist caring for these patients understands the management of the device and the underlying heart disease. Children with these devices are more vulnerable to lead failure and inappropriate shocks compared with the adult population. Preoperative assessment and appropriate reprogramming of the device, in addition to minimizing sources of electromagnetic interference, are keystones in the perioperative care of these patients. Prior consultation with qualified programmers is recommended to enable timely optimization of the device. Magnets may be used in emergency situations but it is important to appreciate the limitations of magnet use on different models of pacemakers and ICDs. Safe and successful perioperative care is dependent upon a well-organized and coordinated multidisciplinary team approach.

    View details for DOI 10.1111/j.1460-9592.2011.03562.x

    View details for Web of Science ID 000289469500006

    View details for PubMedID 21481077