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Biomedical subjects

J A Menke

Publications and source records attributed to J A Menke.

At least 19 recordsLinked to original sources
PubMed1991

Dopamine pharmacokinetics in critically ill newborn infants.

Dopamine is frequently used in critically ill newborn infants for treatment of shock and cardiac failure, but its pharmacokinetics has not been evaluated using a specific analytical method. Steady-state arterial plasma concentrations of dopamine were measured in 11 seriously ill infants receiving dopamine infusion, 5-20 micrograms.kg-1.min-1, for presumed or proven sepsis and hypotensive shock. Steady-state concentrations of dopamine ranged from 0.013-0.3 microgram/ml. Total body clearance averaged 115 ml.kg-1.min-1. The apparent volume of distribution and elimination half life averaged 1.8 l.kg-1 and 6.9 min, respectively. No relationship was observed between dopamine pharmacokinetics and gestational age, postnatal age or birthweight. Substantial interindividual variation was seen in dopamine pharmacokinetics in seriously ill infants, and plasma concentrations could not be predicted accurately from its infusion rate. Marked variation in clearance explains in part, the wide dose requirements of dopamine needed to elicit clinical response in critically ill newborn infants.

Birth Weight↗
PubMed1991

The use of LIS for blood usage review. Experience in a children's hospital.

To comply with the requirements of the Joint Commission for the Accreditation of Healthcare Organizations (JCAHO) and to facilitate the review process, the authors designed a program to screen for the appropriateness of packed red cell (PRC) and platelet concentrate (PLT) transfusions. The purpose of this report is to describe the methodology of the review process. A quality assurance (QA) monitor was created in the Laboratory Information System (LIS) to screen indicators: hemoglobin for PRCs and platelet count for PLTs. Numerical value limits were defined to determine acceptable ranges. Each week, the LIS compiles a list of all patients who received transfusions and for whom the QA monitor determined that the values of the screened indicators were outside the defined appropriate limits. A detailed transfusion record is generated for each patient identified. During a six-month evaluation of this program, a total of 1,788 PRC and 3,109 PLT units were transfused. Of these, 582 PRC (32.5%) and 2,219 PLT (71.4%) units were within the acceptable guidelines. Lists for the remaining 1,206 PRCs and 890 PLTs were generated. Review of the transfusion record and other laboratory values from the LIS established the appropriateness of 1,052 PRC and 782 PLT transfusions. At the conclusion of the six-month period, the medical charts for 181 (11%) PRC and 108 (4.5%) PLT transfusions required chart review. This method provided major reduction in time of the transfusion review process. Similar guidelines may be used to monitor other transfusion products such as fresh frozen plasma.

Blood Transfusion↗
PubMed1990

Perinatal grief and mourning.

The grief and mourning that parents experience following a perinatal loss is as devastating as the loss of an older loved one. The pattern of mourning can be anticipated and interventions can be implemented. With proper help, the parents can pass through this catastrophic time in their lives with a minimum of scars. If the physician stops, reaches out, listens, and supports the parents, he or she can have a dramatic effect on the lives of these parents. In the same manner in which we started this paper, we close with a quotation from another parent who suffered a loss: Daughters may die, But why? For even daughters can't live with half a heart. Three days isn't much a life. But long enough to remember thin blue lips, uneven gasps in incubators, Racking breaths that cause a pain to those who watched. Long enough to remember I never held her Or felt her softness Or counted her toes. I didn't even know the color of her eyes. Dead paled hands not quite covered by the gown she Was to go home in. Moist earth smell. One small casket. And the tears. You see, I hold in my hand but souvenirs of an occasion. A sheet of paper filled with statistics, A certificate with smudged footprints, A tiny bracelet engraved "Girl, Smith." You say that you are sorry That you know how I feel. But you can't know because I don't feel. Not yet.

Bereavement↗
PubMed1989

Prognostic significance of cystic intracranial lesions in neonates.

Thirty-five infants with cystic parenchymal lesions detected by ultrasonography during the neonatal period were evaluated via periodic neurologic and developmental assessments. Long-term neurologic status (abnormal, normal, and isolated motor deficit) was assigned at 2 years of age. Abnormal neurologic status was strongly associated with bilateral cystic lesions as well as hydrocephalus during the neonatal period. Microcephaly at 6-8 months of age also correlated with abnormal status at 2 years of age. The neurologic exam at discharge and at 6-8 months of age added further negative predictive value for the infants with isolated motor delays. A literature review was conducted to determine the incidence of motor and mental delays in a large series of infants with cystic intracranial lesions.

Brain Diseases↗
PubMed1987

Intestinal blood flow and oxygen uptake in the neonatal piglet during reduced perfusion pressure.

The effect of reduced perfusion pressure on neonatal intestinal blood flow, vascular resistance, arterio-venous oxygen content (a-v O2), and oxygen uptake was studied in nine fasted newborn piglets, aged 5-6 days. Successive reductions of intestinal perfusion pressure were achieved by a clamp on the thoracic aorta. Intestinal blood flow decreased after each reduction of perfusion pressure. Intestinal vascular resistance increased and Gf, a measure of flow control, was negative after all but the final, most severe reduction of perfusion pressure. However, intestinal a-v O2 increased after each pressure reduction and intestinal oxygen uptake was thus maintained at greater than or equal to 95% of its baseline value until perfusion pressure was reduced to less than or equal to 70% of its base-line value. The neonatal intestine maintains tissue oxygen uptake during moderate hypotension, and this is accomplished by regulation of a-v O2, rather than by regulation of blood flow.

Animals↗
PubMed1987

Relationships of five Doppler measures with flow in an in vitro model and clinical findings in newborn infants.

This report compares six Doppler ultrasound measures of blood flow: Pourcelot's pulsatility index, Gosling's pulsatility index, area under the curve, systolic amplitude, diastolic amplitude, and mean amplitude. Recordings from an in vitro arterial model and from the anterior cerebral arteries in 33 newborn infants with asphyxia, intraventricular hemorrhage, or normal state were analyzed. In the model, all measures had excellent correlation with flow. Neonates were correctly classified according to diagnosis by the Doppler measures as follows: Pourcelot's pulsatility index (100%), Gosling's pulsatility index (97%), diastolic amplitude (94%), mean amplitude (76%), area under the curve (70%), and systolic amplitude (58%). The best accuracy was obtained with the pulsatility indices.

Asphyxia Neonatorum↗
PubMed1986

Intestinal blood flow and O2 uptake during hypoxemia in the newborn piglet.

Previous work has indicated that the neonatal intestinal circulation responds to hypoxemia with vasoconstriction and subsequent intestinal ischemia. This work was carried out in newborn lambs, a ruminant species, and may not be representative of all newborns. Therefore, we measured intestinal blood flow, vascular resistance, tissue O2 uptake, and cardiac output during normoxemia and varying degrees of hypoxemia in newborn piglets, a nonruminant species. Hypoxemia was induced by adding N2 gas to the inspired gas mixture, and measurements were obtained over a wide range of arterial O2 contents (2.2-15.6 ml O2 X dl-1). Intestinal blood flow increased in response to moderate hypoxemia and decreased in response to severe hypoxemia. The changes in intestinal blood flow were primarily due to change in intestinal vascular resistance, not cardiac output. Intestinal O2 was independent of arterial O2 content until the latter decreased below approximately 6.5 ml O2 X dl-1. These data indicate that the response of the neonatal intestinal circulation to hypoxemia is species specific and that the nonruminant neonatal intestine is capable of vasodilation in response to moderate hypoxemia.

Animals↗
PubMed1986

Alterations in cerebral blood flow and oxygen consumption during prolonged hypocarbia.

The effect of prolonged (2 h) hypocarbia on cerebral blood flow, oxygen delivery, extraction, and consumption was studied in eight, 1- to 4-day-old piglets. Hyperventilation to PaCO2 less than 20 mm Hg acutely (30 min) decreased cerebral blood flow and oxygen consumption. Cerebral oxygen consumption was subsequently restored via increases in cerebral blood flow and thus, cerebral oxygen delivery. Cerebral oxygen extraction rose from a normocarbic baseline of 50 to 75% with acute hypocarbia and was maintained at this level. The percent decrease in blood flow to the cerebrum was greater than that to other brain regions during hypocarbia.

Animals↗
PubMed1986

The effect of naloxone on the hemodynamics of the newborn piglet with septic shock.

Naloxone has been shown to reverse the hemodynamic sequelae of experimental septic shock in adult animal models. Its effectiveness in the newborn has not been studied. To further investigate the efficacy of naloxone, we instrumented 18 piglets for continuous measurement of mean arterial pressure, mean pulmonary arterial pressure, central venous pressure, heart rate, left ventricular pressure, contractility, cardiac output, and O2. Oxygen consumption, systemic vascular resistance, and pulmonary vascular resistance were calculated. Following a stabilization period, group B beta-hemolytic Streptococci were infused over 30 min. Following the infusion, naloxone (1 mg/kg) was given followed by a continuous infusion of 1 mg/kg/h in nine treatment animals. Nine control animals were given an equal volume of saline. Both groups developed significant increases in mean pulmonary arterial pressure followed by a return to baseline. Oxygen consumption, cardiac output, contractility and mean arterial pressure decreased in both groups. Treatment with naloxone was associated with a cessation in the fall in the mean arterial pressure and the contractility. The difference in mean arterial pressure and contractility between groups was significant. The naloxone group had significantly improved 5-h survival. We speculate that naloxone may reverse some of the hemodynamic sequelae and improve survival in newborns with septic shock.

Animals↗
PubMed1985

A microcomputer-based tutorial program for computer-based training and patient care.

This program provides the nonprogrammer a tool to develop easily modified computer assisted tutorials, tests, and simulations with a word processor. In addition, by using the branching and query features of this program, one can easily develop text files that provide rapid access to information related to patient care such as neonatal formularies and patient care algorithms.

Computer-Assisted Instruction↗
PubMed1979

Group B beta hemolytic streptococcal sepsis and the idiopathic respiratory distress syndrome: a comparison.

The clinical features of 27 patients with early onset group B beta hemolytic streptococcus sepsis were reviewed. Fifteen presented with a clinical pattern indistinguishable from the idiopathic respiratory distress syndrome and were compared with 15 patients with IRDS. Rupture of membranes for greater than 12 hours prior to delivery occurred more often in patients with GBS (33%) than in the patients with IRDS (16%). Hypotension was more commonly seen in the patients with GBS (56%) than in the patients with IRDS (36%). There was no difference in the incidence of apnea or the respirator peak inspiratory pressure requirements between the two groups of patients, but there was a tendency for a decline in the total white blood cell count in the first 24 hours of life in those patients with GBS sepsis.

Diagnosis, Differential↗
PubMed1977

"Acquired" lobar emphysema: a complication of respiratory distress in premature infants.

Ten premature infants with respiratory distress developed a type of pulmonary lobar emphysema that is clinically and histologically distinct from interstitial or congenital lobar emphysema. In eight patients emphysema was noted in the right lower lobe, while in two the left upper lobe was affected. Five infants exhibited nonresolution of the emphysema and an inability to be weaned from ventilator support. Lung scans in these five infants showed absent or markedly decreased perfusion of the involved lobe. Lobectomy was necessary. Postoperatively, their respiratory status improved and they were successfully weaned from the ventilator. Five premature infants with identical radiographic emphysematous changes had normal lung scans. These infants did not require lobectomy and were also successfully weaned from the ventilator. Radiographic changes of lobar emphysema in these five infants completely resolved. Pathologic changes in the excised lobes were characteristic of bronchopulmonary dysplasia and obstructive intraalveolar emphysema. The long-term effects of positive pressure ventilation, oxygen, and suctioning techniques directed toward the right lower lobe may play an important role in the etiology of "acquired" lobar emphysema.

Female↗