Steven E. Lucking

Dependence of oxygen consumption on oxygen delivery in children with hyperdynamic septic shock and low oxygen extraction.

We studied the effect of increasing systemic oxygen delivery (&U1E0A;o2) by packed RBC (PRBC) transfusion on oxygen consumption (&OV0312;o2) in children with hyperdynamic septic shock. After routine resuscitation with volume loading and pharmacologic support, patients were studied if they had significant derangements of oxygen transport variables defined as: baseline &OV0312;o2 <180 ml/min·m2 and oxygen extraction (O2 extr) <24%. Eight studies were performed. PRBC transfusion increased &U1E0A;o2 from 636 ± 167 to 828 ± 266 ml/min·m2 (p < .01) without increasing cardiac index (5.2 ± 1.3 vs. 5.0 ± 1.4 L/min·m2). &OV0312;o2 increased from 112 ± 36 to 157 ± 60 ml/min·m2 (p < .01) while O2 extr was unchanged (18 ± 3% vs. 19 ± 6%). Despite initial low O2 extr, &OV0312;o2 can be increased in pediatric septic shock by a further increase in &U1E0A;o2. Since &OV0312;o2 correlates with survival, one should consider enhancing &U1E0A;o2 further despite initial low O2 extr and high &U1E0A;o2. Effects on morbidity and mortality require further study.

Decreasing unplanned extubations: utilization of the Penn State Children's Hospital Sedation Algorithm.

Objective To determine whether institution of a standardized algorithm of goal-directed sedation impacted the incidence of unplanned extubations in critically ill pediatric patients. Design Prospective, observational study with historical controls. Setting Pediatric intensive care unit (PICU) in a tertiary care university-based children’s hospital. Patients All mechanically ventilated children admitted to the PICU during a 10-yr period. Interventions After examining the data pertaining to unplanned extubations, the Penn State Children’s Hospital Sedation Algorithm (PSCHSA) was instituted as an absolute requirement for all mechanically ventilated children. Physician orders for the goal sedation level and the appropriate medications to achieve that goal were obligatory for every ventilated patient. Data were then collected for 5 yrs after institution of the PSCHSA. Measurements and Main Results Before utilization of the PSCHSA, unplanned extubation rates ranged between 0.44 and 0.63 per 100 intubated patient days. In the 4 yrs after mandatory use of the PSCHSA for management of all ventilated patients, unplanned extubation rates were between 0 and 0.19 per 100 intubated patient days, demonstrating a significant decrease (p < .001). Throughout the entire study period, no changes were made in the model of patient care that would alter the rate of unplanned extubations. Despite a higher percentage of PICU patients that were intubated, length of stay in the PICU did not increase, suggesting that oversedation did not led to increased ventilator days. Conclusions Utilization of the PSCHSA resulted in a decreased number of unplanned extubations without increasing the length of PICU stay. Implementation of the PSCHSA is needed in other PICUs to validate these findings.

Shock following generalized hypoxic-ischemic injury in previously healthy infants and children.

Eighteen previously healthy patients with hypoxic-ischemic shock were observed longitudinally by means of data measured or derived from systemic arterial and pulmonary artery catheters. Shock was characterized by low cardiac index, elevated right and left heart filling pressures, elevated systemic and pulmonary vascular resistances, decreased oxygen consumption, and elevated oxygen extraction indices. Oxygen consumption was significantly correlated with oxygen delivery (r=0.74, P

High-frequency ventilation versus conventional ventilation in dogs with right ventricular dysfunction

A randomized crossover protocol was used to compare conventional mechanical ventilation (CMV) and high-frequency ventilation (HFV) in mongrel dogs experiencing right ventricular dysfunction after right ventriculotomy. When inspired oxygen, pH, Pco2, core temperature, and preload were held constant, cardiac output increased significantly (p < .05) from 1.16 ± 0.24 to 1.38 ± 0.25 L/min and pulmonary vascular resistance decreased significantly (p < .05) from 734 ± 257 to 554 ± 169 dyne sec/cm5 during HFV relative to CMV. We also noted a significant (p < .05) increase in mean arterial pressure from 116 ± 27 to 124 ± 23 mm Hg and a significant (p < .05) increase in left ventricular stroke work from 10.2 ± 3.5 to 12.3 ± 2.6 gm during HFV. During the inspiratory phase of CMV there were increases in CVP, pulmonary artery pressure, and systemic arterial pressure, and decreases in pulmonary artery flow which did not occur during HFV. HFV may be preferable to CMV in the presence of right ventricular dysfunction.

Cost-effectiveness of exogenous surfactant therapy in pediatric patients with acute hypoxemic respiratory failure.

Objective: To determine whether the use of exogenous surfactant (Infasurf) in pediatric acute hypoxemic respiratory failure is cost-effective. Design: Deterministic cost-effectiveness analysis based on a Markov model. The model was calibrated using outcomes and resource utilization observed in a multiple-centered, prospective, randomized, controlled unblinded trial of Infasurf in pediatric acute hypoxemic respiratory failure. Costs were short-run direct costs estimated from the perspective of the hospital as provider. Primary outcomes were expected costs, expected survival rates, and incremental cost per life saved. Setting: Patients in the trial were treated in one of eight pediatric intensive care units of tertiary medical centers. Patients: Forty-two children with acute hypoxemic respiratory failure who were randomized to receive either standard therapy or exogenous surfactant in addition to standard therapy. Measurements and Main Results: Our baseline analysis suggests that for a 10-kg child, the Infasurf strategy is both less costly (

The use of the Beck Airway Airflow Monitor for verifying intratracheal endotracheal tube placement in patients in the pediatric emergency department and intensive care unit.

62,922 vs.

Trending of impedance-monitored cardiac variables: method and statistical power analysis of 100 control studies in a pediatric intensive care unit.

74,006) and more effective (survival: 90.3% vs. 85.1%) and therefore dominates standard treatment. Cost savings were realized in the model because patients in the surfactant group were more likely to leave the pediatric intensive care unit sooner. The Infasurf strategy continues to dominate for children up to 60 kg. At 70 kg, the cost to save an additional life using the Infasurf strategy is

Safety and efficacy of sedation with propofol for transoesophageal echocardiography in children in an outpatient setting

79,805, which is still cost-effective if the provider is willing to make this tradeoff. Conclusions: For the majority of pediatric patients with acute hypoxemic respiratory failure, exogenous surfactant is cost-effective. If the use of this medication becomes standard care, a greater variety of packaging sizes could lead to decreased acquisition costs and increase the number of patients for whom this treatment is cost-effective.

A prospective assessment of the effect of aminophylline therapy on urine output and inflammation in critically ill children.

Traditional methods of confirming that the endotracheal tube is in the trachea are often unavailable or difficult to perform in some clinical situations, such as Intel-facility transport or other times outside the neonatal intensive care unit We evaluated the Beck Airway Airflow Monitor (BAAM), through which airflow makes a whistling sound, for its safety and efficacy hi neonates. We studied 46 neonates ranging hi weight from 0.6 to 3.7 kg. We found that the BAAM consistently produced the desired whistling sound signaling intratracheal placement of the endotracheal tube in all infants weighing above 1.5 kg. No adverse effects or complications were noted. The results support the safety and efficacy of the BAAM hi confirming intratracheal endotracheal tube position in neonates.

Organ blood flow and cardiovascular effects of high-frequency oscillation versus conventional ventilation in dogs with right heart failure

The NCCOM3-R6 monitor continuously monitors cardiac output and five other cardiovascular variables from the thoracic electrical bioimpedance signal. We averaged data over 5-min intervals for 130 min in 100 control studies in 40 pediatric ICU patients, age 0.04 to 20.39 yr (median 1.39) and weighing 2.0 to 59.5 kg (median 8.8). For individual studies, 99% of the 5-min averages of cardiac output fell within +/- 44% of the baseline cardiac output for that study. Normal ranges were somewhat narrower for the other five variables. When we averaged data for 100 studies, 5-min interval observations for each variable did not deviate from baseline over a 2-h period (p greater than .70). With a sample size of 100 studies, we could detect a change in cardiac output of +/- 5% at the p less than .005 level with a power of 0.95. We conclude that with a sufficiently large sample size, studies employing the NCCOM3 can detect clinically significant cardiovascular changes due to pharmacologic or procedural stressors.