Biomedical subjects

J A Paschall

Publications and source records attributed to J A Paschall.

3 recordsLinked to original sources

PubMed1998

Hemodynamic support in fluid-refractory pediatric septic shock.

OBJECTIVE: Assess outcome in children treated with inotrope, vasopressor, and/or vasodilator therapy for reversal of fluid-refractory and persistent septic shock. DESIGN: Survey; case series. SETTING: Three pediatric hospitals. PATIENTS: Fifty consecutive patients with fluid-refractory septic shock with a pulmonary artery catheter within 6 hours of resuscitation. INTERVENTIONS: Patients were categorized according to hemodynamic state and use of inotrope, vasopressor, and/or vasodilator therapy to maintain cardiac index (CI) >3.3 L/min/m2 and systemic vascular resistance >800 dyne-sec/cm/m to reverse shock. OUTCOME MEASURES: Hemodynamic state, response to class of cardiovascular therapy, and mortality. RESULTS: After fluid resuscitation, 58% of the children had a low CI and responded to inotropic therapy with or without a vasodilator (group I), 20% had a high CI and low systemic vascular resistance and responded to vasopressor therapy alone (group II), and 22% had both vascular and cardiac dysfunction and responded to combined vasopressor and inotropic therapy (group III). Shock persisted in 36% of the children. Of the children in group I, 50% needed the addition of a vasodilator, and in group II, 50% of children needed the addition of an inotrope for evolving myocardial dysfunction. Four children showed a complete change in hemodynamic state and responded to a switch from inotrope to vasopressor therapy or vice versa. The overall 28-day survival rate was 80% (group I, 72%; group II, 90%; group III, 91%). CONCLUSIONS: Unlike adults, children with fluid-refractory shock are frequently hypodynamic and respond to inotrope and vasodilator therapy. Because hemodynamic states are heterogeneous and change with time, an incorrect cardiovascular therapeutic regimen should be suspected in any child with persistent shock. Outcome can be improved compared with historical literature.

Adolescent↗

PubMed1991

Amrinone during porcine intraperitoneal sepsis.

Seven Yucatan minipigs with chronic, severe intraperitoneal sepsis were given amrinone i.v. (loading dose of 0.75 mg/kg, followed by continuous infusion of 10, 20, 40, and 80 micrograms/kg/min) during the hyperdynamic phase of sepsis. Hemodynamic variables and oxygen utilization, delivery, and extraction were recorded throughout the study. Pulmonary capillary wedge pressure was kept constant to ensure a fixed ventricular filling pressure. Intravenous amrinone modestly augmented cardiac index without altering heart rate. Mean systemic and pulmonary arterial pressures decreased. Systemic and pulmonary vascular resistance fell significantly (P less than 0.05). Amrinone did not significantly alter oxygen utilization or oxygen extraction, although oxygen delivery increased (P less than .05). During the hyperdynamic phase of sepsis in this animal model, amrinone elicits vasodilatation with a modest improvement in stroke volume index. Consequently, cardiac output and oxygen delivery increased modestly. Because of its vasodilating properties and small salutary effects, amrinone is not an optimal first-line medication for hemodynamic stabilization during hyperdynamic sepsis.

Amrinone↗

PubMed1991

Awake porcine model of intraperitoneal sepsis and altered oxygen utilization.

We have characterized an awake swine model of septic shock. Hemodynamic, serum chemistry, and oxygen metabolism parameters were compared between eight septic and five sham animals. Eight male Yucatan miniature swine, weighing 20-28 kg, were anesthetized and catheters were placed in the pulmonary artery, external jugular, and the carotid artery. On day 2, 1.1-4.0 x 10(10) cfu Escherichia coli/kg were administered via an intraperitoneal catheter. Hemodynamic parameters were monitored hourly for 6 hours in awake animals. The animals were then placed back into the animal holding facility for clinical observation until the 24 hour post infusion measurements were taken. Septic animals were initially hypodynamic, with a decrease in cardiac index (CI) from a baseline value of 152.8 +/- 24.8 to 87.9 +/- 17.8 ml/kg/min (P less than .05) and an increased systemic vascular resistance index (SVRI) from a control value of 48.1 +/- 9.5 to 65.0 +/- 16.7 dynes*sec*cm-5/kg. At 24 hours post infusion, the animals were hyperdynamic with the CI increased to 211.0 +/- 27.2 ml/kg/min (P less than .05) and a decreased SVRI to 30.64 +/- 3.9 dynes*sec*cm-5/kg (P less than .05). Oxygen utilization (VO2) increased during sepsis from 6.6 +/- 0.8 to 8.1 +/- 0.8 ml/kg/min at 6 hours (P less than .05) and remained elevated at 24 hours at 7.7 +/- 0.4 (P less than .05). Increased oxygen consumption was attained with an increase in oxygen extraction (O2 ext) from 0.34 +/- 0.03 to 0.56 +/- 0.07 (P less than .05) during the first 6 hours of sepsis. At 24 hours, increased oxygen utilization was maintained by high oxygen delivery state. Significant alterations in serum chemistries in conjunction with post mortem evidence of multiple organ system failure were observed. Mortality on or before 4 days post infusion was 50% and positive blood cultures were obtained in 38% of the animals studied. This awake swine model serves as an excellent model to study metabolic pathophysiology and the treatment of septic shock.

Animals↗