Clinical Focus

  • Anesthesia
  • Anesthesia, Pediatric

Academic Appointments

Professional Education

  • Medical Education:University of Missouri Kansas City School of Medicine Registrar (1983) MO
  • Residency:George Washington University (1986) DC
  • Internship:George Washington University (1984) DC
  • Board Certification: Anesthesia, American Board of Anesthesiology (1988)
  • Fellowship:Denver Children's Hospital (1987) CO


2018-19 Courses


All Publications

  • Ketamine does not increase pulmonary vascular resistance in children with pulmonary hypertension undergoing sevoflurane anesthesia and spontaneous ventilation ANESTHESIA AND ANALGESIA Williams, G. D., Philip, B. M., Chu, L. F., Boltz, M. G., Kamra, K., Terwey, H., Hammer, G. B., Perry, S. B., Feinstein, J. A., Ramamoorthy, C. 2007; 105 (6): 1578-1584


    The use of ketamine in children with increased pulmonary vascular resistance is controversial. In this prospective, open label study, we evaluated the hemodynamic responses to ketamine in children with pulmonary hypertension (mean pulmonary artery pressure >25 mm Hg).Children aged 3 mo to 18 yr with pulmonary hypertension, who were scheduled for cardiac catheterization with general anesthesia, were studied. Patients were anesthetized with sevoflurane (1 minimum alveolar anesthetic concentration [MAC]) in air while breathing spontaneously via a facemask. After baseline catheterization measurements, sevoflurane was reduced (0.5 MAC) and ketamine (2 mg/kg IV over 5 min) was administered, followed by a ketamine infusion (10 microg x kg(-1) x min(-1)). Catheterization measurements were repeated at 5, 10, and 15 min after completion of ketamine load. Data at various time points were compared (ANOVA, P < 0.05).Fifteen patients (age 147, 108 mo; median, interquartile range) were studied. Diagnoses included idiopathic pulmonary arterial hypertension (5), congenital heart disease (9), and diaphragmatic hernia (1). At baseline, median (interquartile range) baseline pulmonary vascular resistance index was 11.3 (8.2) Wood units; 33% of patients had suprasystemic mean pulmonary artery pressures. Heart rate (99, 94 bpm; P = 0.016) and Pao2 (95, 104 mm Hg; P = 007) changed after ketamine administration (baseline, 15 min after ketamine; P value). There were no significant differences in mean systemic arterial blood pressure, mean pulmonary artery pressure, systemic or pulmonary vascular resistance index, cardiac index, arterial pH, or Paco2.In the presence of sevoflurane, ketamine did not increase pulmonary vascular resistance in spontaneously breathing children with severe pulmonary hypertension.

    View details for DOI 10.1213/01.ane.0000287656.29064.89

    View details for Web of Science ID 000251274400014

    View details for PubMedID 18042853

  • Modified and conventional ultrafiltration during pediatric cardiac surgery: Clinical outcomes compared JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Williams, G. D., Ramamoorthy, C., Chu, L., Hammer, G. B., Kamra, K., Boltz, M. G., Pentcheva, K., McCarthy, J. P., Reddy, V. M. 2006; 132 (6): 1291-1298


    This prospective study compared clinical outcomes after heart surgery between three groups of infants with congenital heart disease. One group received dilutional conventional ultrafiltration (group D), another received modified ultrafiltration (group M), and a third group received both dilutional conventional and modified ultrafiltration (group B). We hypothesized that group B patients would have the best clinical outcome.Children younger than 1 year undergoing heart surgery for biventricular repair by the same surgeon were randomly allocated to one of the three study groups. Patient management was standardized, and intensive care staff were blinded to group allocation. Primary outcome measure was duration of postoperative mechanical ventilation. Other outcome measures recorded included total blood products transfused, duration of chest tube in situ, chest tube output, and stays in intensive care and in the hospital.Sixty infants completed study protocol. Mean age and weight were as follows: group D (n = 19), 61 days, 4.3 kg; group M (n = 20), 64 days, 4.5 kg; and group B (n = 21), 86 days, 4.4 kg. Preoperative and intraoperative characteristics were similar between groups. Ultrafiltrate volumes obtained were 196 +/- 93 mL/kg in group D, 105 +/- 33 mL/kg in group M, and 261 +/- 113 mL/kg in group B. There were no significant differences between groups for any outcome variable. Technical difficulties prevented completion of modified ultrafiltration in 2 of 41 infants.There was no clinical advantage in combining conventional and modified ultrafiltration. Because clinical outcomes were similar across groups, relative risks of the ultrafiltration strategies may influence choice.

    View details for DOI 10.1016/j.jtcvs.2006.05.059

    View details for Web of Science ID 000242626200010

    View details for PubMedID 17140945

  • Postoperative analgesia after spinal blockade in infants and children undergoing cardiac surgery ANESTHESIA AND ANALGESIA Hammer, G. B., Ramamoorthy, C., Cao, H., Williams, G. D., Boltz, M. G., Kamra, K., Drover, D. R. 2005; 100 (5): 1283-1288


    The aim of this prospective, randomized, controlled clinical trial was to define the opioid analgesic requirement after a remifentanil (REMI)-based anesthetic with spinal anesthetic blockade (SAB+REMI) or without (REMI) spinal blockade for open-heart surgery in children. We enrolled 45 patients who were candidates for tracheal extubation in the operating room after cardiac surgery. Exclusion criteria included age <3 mo and >6 yr, pulmonary hypertension, congestive heart failure, contraindication to SAB, and failure to obtain informed consent. All patients had an inhaled induction with sevoflurane and maintenance of anesthesia with REMI and isoflurane (0.3% end-tidal). In addition, patients assigned to the SAB+REMI group received SAB with tetracaine (0.5-2.0 mg/kg) and morphine (7 mug/kg). After tracheal extubation in the operating room, patients received fentanyl 0.3 mug/kg IV every 10 min by patient-controlled analgesia for pain score = 4. Pain scores and fentanyl doses were recorded every hour for 24 h or until the patient was ready for discharge from the intensive care unit. Patients in the SAB+REMI group had significantly lower pain scores (P = 0.046 for the first 8 h; P =0.05 for 24 h) and received less IV fentanyl (P = 0.003 for the first 8 h; P = 0.004 for 24 h) than those in the REMI group. There were no intergroup differences in adverse effects, including hypotension, bradycardia, highest PaCO(2), lowest pH, episodes of oxygen desaturation, pruritus, and vomiting.

    View details for DOI 10.1213/01.ANE.0000148698.84881.10

    View details for Web of Science ID 000228755400013

    View details for PubMedID 15845670

  • The effect of baricity of intrathecal morphine in children receiving tetracaine spinal anaesthesia for cardiac surgery: a preliminary report PAEDIATRIC ANAESTHESIA Finkel, J. C., Boltz, M. G., Conran, A. M. 2002; 12 (4): 327-331


    This prospective, randomized study examined the effect of baricity of intrathecal preservative-free morphine on the duration of postoperative analgesia and incidence of side-effects in infants and children receiving high spinal anaesthesia with hyperbaric tetracaine in combination with a light general anaesthetic.Fourteen infants and children, aged 7-91 months, undergoing repair of either uncomplicated atrial or ventricular septal defects, were randomized to receive either 10 microg x kg(-1) of intrathecal morphine in combination with 0.5% tetracaine D10 (hyperbaric morphine group) or intrathecal morphine mixed with saline and injected sequentially after the administration of 0.5% tetracaine D10 (hypobaric morphine group). After spinal injection, patients were positioned in 30 degrees of Trendelenburg for a minimum of 10 min. Postoperatively, patients were monitored for a minimum of 12 h. Pain scores and the incidence and severity of side-effects were recorded every 1 h.All patients were extubated at the conclusion of surgery without any incidence of respiratory depression. There was a decreased incidence of vomiting in the hypobaric morphine group and no significant difference in the duration of analgesia.When intrathecal morphine is administered in conjunction with a hyperbaric tetracaine spinal to paediatric cardiac patients in the head down position, sequential administration of the hypobaric solution may mitigate side-effects.

    View details for Web of Science ID 000175654600008

    View details for PubMedID 11982840

  • Anesthesia for outpatient repair of patent ductus arteriosus JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA Uezono, S., Hammer, G. B., Wellis, V., Boltz, M. G., Pike, N. A., Black, M. D. 2001; 15 (6): 750-752

    View details for DOI 10.1053/jcan.2001.28322

    View details for Web of Science ID 000172868600017

    View details for PubMedID 11748526

  • Combined regional and light general anesthesia: are the risks increased or minimized? Current opinion in anaesthesiology Boltz, M. G., Krane, E. J. 1999; 12 (3): 321-323


    Regional anesthesia during general anesthesia has become increasingly popular in recent years. Most pediatric anesthesiologists are proponents of this practice, and believe that surgical morbidity is reduced, but controversy remains regarding safety. Neuraxial anesthesia during general anesthesia is especially controversial. Unfortunately, outcome studies are lacking but the literature reflects an absence of reported serious morbidity or mortality.

    View details for PubMedID 17013331

  • Outcomes after single injection caudal epidural versus continuous infusion epidural via caudal approach for postoperative analgesia in infants and children undergoing patent ductus arteriosus ligation PAEDIATRIC ANAESTHESIA Lin, Y. C., Sentivany-Collins, S. K., Peterson, K. L., Boltz, M. G., Krane, E. J. 1999; 9 (2): 139-143


    Adequate postoperative analgesia enhances deep breathing and minimizes respiratory complications after thoracotomy. This study compares postoperative outcomes after single injection caudal epidural vs continuous infusion epidural via caudal approach for postoperative analgesia in infants and children undergoing thoracotomy for patent ductus arteriosus (PDA) ligation. A retrospective chart review was performed for 27 children who had undergone PDA ligation. The children were divided into three groups. We compared patient demographics, surgical duration, anaesthesia duration, length of ICU stay, incidence of emesis requiring treatment, time required to establish regular oral intake, requirement for supplemental intravenous opioids during the first postoperative day, and length of hospital stay. For paediatric patients undergoing PDA ligation, postoperative analgesia with continuous infusion epidural via caudal approach produced shorter ICU stay, less occurrence of postoperative emesis, earlier oral intake, elimination of intravenous opioid supplementation, and shorter hospital stay compared with single injection caudal epidural techniques.

    View details for Web of Science ID 000079182200009

    View details for PubMedID 10189655

  • Post-transplant lymphoproliferative disease may present with severe airway obstruction ANESTHESIOLOGY Hammer, G. B., Cao, S., Boltz, M. G., Messner, A. 1998; 89 (1): 263-265

    View details for Web of Science ID 000074710800035

    View details for PubMedID 9667319