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Biomedical subjects

R E Schumacher

Publications and source records attributed to R E Schumacher.

At least 19 recordsLinked to original sources

Are newborns receiving premedication before elective intubation?

AIMS: To determine the extent and type of premedication used for elective endotracheal intubation in neonatal intensive care units (NICUs). METHODS: A pretested questionnaire was distributed via e-mail to the program directors of the neonatology divisions with accredited fellowship programs in Neonatal-Perinatal Medicine in the United States. RESULTS: Of the 100 individuals contacted, 78 (78%) participated in the survey. Only 34 of the 78 respondents (43.6%) always use any premedication for elective intubation. Nineteen respondents (24.4%) reported to have a written policy regarding premedication. Morphine or fentanyl was used most commonly (57.1%), with a combination of opioids and midazolam or other benzodiazepines used less frequently. Fourteen respondents (25%) also use muscle relaxants with sedation for premedication, but only nine respondents combined paralysis with atropine and sedation. CONCLUSION: Most neonatology fellowship program directors do not report always using premedication for newborns before elective endotracheal intubation despite strong evidence of physiologic and practical benefits. Only a minority of the NICUs has written guidelines for sedation, which may preclude effective auditing of this practice. Educational interventions may be necessary to ensure changes in clinical practice.

Analgesics, Opioid↗

Extracorporeal membrane oxygenation 2001. The odyssey continues.

Extracorporeal membrane oxygenation was established as a standard of care by demonstrating its ability to save lives in moribund infants. The designs of early studies provided no living cohorts of similarly ill patients by which to measure accurately other (and perhaps to many more important) outcomes of interest: long-term neurodevelopmental outcomes or cost. Prospective cohort studies of neurodevelopmental outcomes post-ECMO demonstrate: (1) because ECMO, as used, saves lives, there will be an increase in the absolute number of handicapped children surviving; (2) there is little evidence that ECMO creates a relative increase in the percent of handicapped children surviving severe respiratory failure. The high direct costs of an ECMO program are measured and well publicized. When such costs are compared with similar therapies in other fields (in such terms as cost per survivor), the cost of ECMO does not seem to be an outlier. Trials of newer therapies, such as iNO, show the capacity to decrease the use of ECMO but have failed to demonstrate either cost-effectiveness or better long-term outcomes. It has not been shown that either society or individual patients have benefited from the decreased need for ECMO.

Administration, Inhalation↗

Lack of vancomycin-associated nephrotoxicity in newborn infants: a case-control study.

OBJECTIVE: The purpose of this study was to compare the incidence of nephrotoxicity, defined as doubling of baseline serum creatinine concentration, in newborn infants with peak vancomycin serum concentrations </=40 microg/mL at steady state to infants with peak vancomycin serum concentrations >40 microg/mL. A secondary objective was to correlate concomitant disease states and potentially nephrotoxic drug therapy with rises in serum creatinine in vancomycin recipients. METHODS: Newborn infants with culture-proven Staphylococcus aureus or coagulase-negative staphylococcal septicemia who received vancomycin therapy for >3 days between 1985 and 1995 were identified from an existing database and a review of medical record. All 69 patients included in the study had serial serum creatinine determinations, including a baseline value within 48 hours of starting treatment with vancomycin, and serum vancomycin concentrations determined after at least three doses, with peak and trough concentrations determined 1 hour after a 60-minute infusion and 15 to 30 minutes before a dose, respectively. Infants with congenital renal or cardiac anomalies were excluded. Demographic characteristics, vancomycin dosing regimen, serum vancomycin concentrations and sample times, concomitant drug therapy, and disease states were recorded. Patients were divided into group A (peak vancomycin concentration </=40 microg/mL) and group B (peak vancomycin concentration >40 microg/mL). The change in serum creatinine concentration between the start and end of vancomycin therapy was determined. Nephrotoxicity was identified if serum creatinine doubled at any time from the start to the end of vancomycin therapy. Alternative definitions of nephrotoxicity (any rise in serum creatinine to >0.6 mg/dL or new abnormalities of urine sediment) were used in additional analyses. RESULTS: A total of 69 evaluable patients (gestational age, 28.9 +/- 3.0 weeks; birth weight, 1219 +/- 516 g) were identified, 61 in group A and 8 in group B. Six patients in group A underwent doubling of serum creatinine concentration during vancomycin therapy, whereas none in group B did so. Serum creatinine doubled to >0.6 mg/dL in only 3 infants (all in group A). Any increase in serum creatinine to >0.6 mg/dL was seen in 10 infants, 9 of whom were in group A. No confounding variable, including previous or concomitant underlying disease states associated with renal dysfunction or treatment with other potentially nephrotoxic agents, were associated with a significant rise in serum creatinine. CONCLUSION: Vancomycin-associated nephrotoxicity is rare in neonates, even with serum peak concentrations >40 microg/mL.

Anti-Bacterial Agents↗

Treatment of parenteral nutrition-associated cholestasis with cholecystokinin-octapeptide.

The authors investigated whether parenteral nutrition-associated cholestasis (PNAC) in surgical neonates could be alleviated by the administration of cholecystokinin-octapeptide (CCK). Two groups of infants were studied, after major abdominal or cardiac surgery in the newborn period. The low-dose group consisted of three infants with PNAC who received cholecystokinin-octapeptide (Sincalide) at a dose of 0.02 micrograms/kg intravenously (IV), twice daily. The high-dose group comprised eight infants with PNAC who received an initial dose of 0.02 micrograms/kg IV or intramuscularly, three times daily on the first day, followed by a daily doubling of the dose up to as high as 0.32 micrograms/kg. In the low-dose group, direct bilirubin levels declined a mean of 50.2 +/- 14.5%. In the high-dose group, direct bilirubin levels declined a mean of 23.4 +/- 14.3%. In three patients in the high-dose group, no decline occurred. All three had clinical signs of overt liver failure and died of liver failure within 2 months after treatment with CCK. By excluding these patients from the high-dose group, the decline in bilirubin levels increased to 49.6 +/- 10.9%. Side effects from CCK occurred in two patients and consisted of abdominal pain and feeding intolerance. Treatment with CCK appears to be associated with a decline in direct bilirubin levels, provided overt liver failure has not developed.

Abdomen↗

Extracorporeal life support for neonatal respiratory failure. A 20-year experience.

OBJECTIVE: The authors reviewed their experience with extracorporeal life support (ECLS) in neonatal respiratory failure; they define changes in patient population, technique, and outcomes. SUMMARY BACKGROUND DATA: Extracorporeal life support has progressed from laboratory research to initial clinical trials in 1972. Following a decade of clinical research, ECLS is now standard treatment for neonatal respiratory failure refractory to conventional pulmonary support techniques. Our group has the longest and largest experience with this technique. METHODS: Between 1973 and 1993, 460 neonates with severe respiratory failure were treated using ECLS. The records of all patients were reviewed. RESULTS: Overall survival was 87%. Primary diagnoses were meconium aspiration syndrome (MAS; 169 cases [96% survival]), respiratory distress syndrome/hyaline membrane disease (91 cases [88% survival]), persistent pulmonary hypertension of the newborn (37 cases [92%]), pneumonia/sepsis (75 cases [84% survival]), congenital diaphragmatic hernia (CDH; 67 cases [67% survival]), and other diagnoses (21 cases [71% survival]). Common mechanical complications included clots in the circuit (136; 85% survival); air in the circuit (67; 82% survival); cannula problems (65; 83% survival) and oxygenator failure (34; 65% survival). Patient-related complications included intracranial infarct or bleed (54 cases; 61% survival), major bleeding (48 cases; 81% survival), seizures (88 cases; 76% survival), metabolic abnormalities (158 cases; 71% survival) and infection (21 cases; 48% survival). Since 1989, treatment groups have been expanded to include premature infants (13 cases; 62% survival), infants with grade I intracranial hemorrhage (28 cases; 54% survival) and "non-honeymoon" CDH patients (15 cases; 27% survival). Since 1990, single-catheter venovenous access has been used in 131 patients (97% survival) and currently is the preferred mode of access. Follow-up ranges from 1 to 19 years; 80% of patients are growing and developing normally. CONCLUSIONS: Extracorporeal life support has become standard treatment for severe neonatal respiratory failure in our center (460 cases; 87% survival), and worldwide (8913 cases; 81% survival). The availability of ECLS makes the evaluation of other innovative methods of treatment, such as late elective repair of diaphragmatic hernia and new pulmonary vasodilators, possible. The application of ECLS is now being extended to premature and low-birth weight infants as well as older children and adults.

Extracorporeal Membrane Oxygenation↗

The efficacy of extracorporeal life support in premature and low birth weight newborns.

Based on data obtained early in the development of neonatal extracorporeal life support (ECLS), contraindications to the use of ECLS have included low estimated gestational age (EGA) and low birth weight (BW). However, multiple improvements in the technical and management aspects of neonatal ECLS have been implemented since those early data were evaluated. The purpose of this study, therefore, is to assess in the "modern era" the efficacy of prolonged extracorporeal support in premature and low birth weight newborns. Examination of the Extracorporeal Life Support Organization (ELSO) Registry showed that between 1988 and 1991 ECLS was utilized in 158 premature (PREM, EGA < or = 34 weeks), 4,128 full-term (FT, EGA > or = 35 weeks), 26 low birth weight (LBW, BW < 2.0 kg), and 4,333 normal birth weight (NBW, BW > or = 2.0 kg) patients with respiratory failure. Data were evaluated for variables thought to be associated with a decrease in survival or an increase in the incidence of intracranial hemorrhage (ICH). A logistic regression model was developed to evaluate the ability of EGA and BW to predict survival. The incidence of survival (SURV) was decreased (63% v 84%) and ICH increased (37% v 14%) significantly in PREM when compared with FT newborns (P < .001). However, respectable survival rates in PREM patients with EGA > 32 weeks were documented. In addition, both survival and ICH in PREM patients have improved substantially when compared with past reports (Past: SURV = 25% and ICH = 100%; current: SURV = 63% and ICH = 37%; ICH P < .001; SURV P = .056). Survival was significantly decreased in LBW when compared to NBW neonates (65% v 83%, P < .05), but there was no significant difference in ICH.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗

Extracorporeal membrane oxygenation. Will this therapy continue to be as efficacious in the future?

The efficacy of ECMO has been discussed. If only a dichotomous live/die outcome is used as a measure of utility, ECMO is efficacious for infants with a greater than 20% mortality rate. Using a Bayesian approach and neonatal follow-up data, one concludes that ECMO, as used at present, is effective. Future measures of efficacy will vary depending on utility measures used, the populations studied, and the relative efficacy of alternative therapies.

Extracorporeal Membrane Oxygenation↗

Gentamicin pharmacokinetics in term neonates receiving extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) may affect the pharmacokinetics of certain drugs. The objectives of this study were to determine (1) the pharmacokinetics of gentamicin in neonates on ECMO and compare them to reported values for a similar patient population not on ECMO, (2) if the pharmacokinetics of gentamicin differ between venous-venous and venous-arterial bypass, and (3) if the pharmacokinetics of gentamicin are affected by oxygenator surface area (0.6 m2 vs 0.8 m2 oxygenators). The medical records of 29 term neonates who received gentamicin while on ECMO were reviewed. Data collected included gentamicin dosage, peak and trough serum concentrations determined at steady state, duration of treatment, time on ECMO, daily weights, and pertinent laboratory values. An initial dosage of gentamicin 2.5 mg/kg every 18 hours is suggested for term neonates on ECMO. Dosage adjustments should be based on gentamicin serum concentrations, and modifications may also be required after ECMO.

Bacterial Infections↗

Follow-up of infants treated with extracorporeal membrane oxygenation for newborn respiratory failure.

Follow-up studies were conducted to assess the medical and developmental outcome of 92 infants treated with extracorporeal membrane oxygenation at the University of Michigan. Of 118 near-term (greater than 34 weeks' gestation) infants who received extracorporeal membrane oxygenation, 103 (87%) were surviving and available for follow-up at between 1 and 7 years of age. Ninety-two of these children were seen on at least one occasion. Each visit included a history and physical examination, an evaluation by a physical therapist, and developmental testing by a pediatric psychologist. Medical outcome during year 1 found 31% of the children rehospitalized, primarily with respiratory illness. Outpatient-treated lower respiratory tract illness was seen in an additional 31% of the children. New or nonstatic neurologic problems were noted in 6% of the children. Abnormal growth during year 1 occurred in 26% of the children. At last clinic visit 16% of the children exhibited moderate-to-severe neurologic abnormalities, and 8% had moderate-to-severe cognitive delay. Sensorineural hearing loss occurred in 4% of children. Nine percent of the children were receiving speech and language therapy; screening tests showed that an additional 6% had speech and language delay. Overall, at last visit 16 (20%) of the children exhibited some type of handicap. A review of the literature on follow-up studies of non-extracorporeal membrane oxygenation-treated infants with persistent pulmonary artery hypertension produced an impairment rate of 18.5%. Outcome post-extracorporeal membrane oxygenation appears similar to that seen in less ill cohorts of infants treated with more "conventional" therapy. Long-term follow-up of all such infants remains essential.

Child↗

Asymmetric brain stem auditory evoked responses in infants treated with extracorporeal membrane oxygenation.

Brain stem auditory evoked responses (BAERs) were obtained in 25 infants who received extracorporeal membrane oxygenation (ECMO) for severe respiratory failure. Tracings were obtained by means of a Nicolet CA-2000 averager, using a conventional paradigm. The presence or absence of replicated responses at 35 and 75 dB nHL were recorded for each ear. Interpeak latencies I-III, III-V, and I-V were measured and differences between right and left ears were compared, using a matched pair t-test. Wave III-V latencies were longer on the left than right (p less than 0.05), but no significant right-left differences for latencies I-III were noted. Sixteen percent of the infants failed hearing sensitivity criteria, 45% (10/23) had prolonged I-V latencies. At follow-up (age 4 to 12 months) 6/10 infants with prolonged I-V latencies had additional neurologic abnormalities. In this population left ear III-V latencies are prolonged versus right, and the incidence of abnormal BAERs is high. Relative prolongation of left ear III-V latencies (generated from the right brain stem) may be result of right carotid artery and/or jugular vein ligation for ECMO, and abnormal I-V latencies prognosticate future neurologic abnormalities in this population.

Brain Diseases↗

Noninvasive measurements of bilirubin in the newborn.

Technologic advances have allowed a means for more precise measurement of cutaneous bilirubin. These advances have led investigators to examine the correlation between cutaneous and blood bilirubin in hopes of either replacing or reducing the number of serum bilirubin values obtained. In the past other investigators attempted to do the same, using visual estimates of jaundice with and without the help of reference devices. The establishment of an acceptable correlation between cutaneous and serum bilirubin requires (1) accurate measurement of serum bilirubin, (2) accurate measurement of cutaneous bilirubin, and (3) steady-state conditions between the blood-cutaneous bilirubin "compartments." The accuracy with which cutaneous bilirubin can be measured appears similar or better than that with which serum bilirubin is measured; with older transcutaneous devices significant interobserver variability may exist. Bias in the form of other skin chromogens also interferes with accuracy. Rapid changes in serum or cutaneous bilirubin concentration or nonhomogeneous distribution of cutaneous bilirubin interferes with our knowledge of cutaneous-blood bilirubin kinetics. At present transcutaneous bilirubinometry cannot replace routine serum measurements, but both new and old transcutaneous devices can serve as effective screening devices. The choice of which device to use depends on its cost-effectiveness in any given clinical setting.

Bilirubin↗

Effect of prenatal lignocaine on auditory brain stem evoked response.

To test the hypothesis that there would be a positive correlation between the interpeak wave (I-V) interval as measured by auditory brain stem evoked response and the ratio of umbilical cord blood arterial to venous lignocaine concentrations in infants born after maternal epidural anaesthesia, 10 normal infants born at full term by elective caesarean section were studied. Umbilical cord arterial and venous plasma samples were assayed for lignocaine, and auditory brain stem evoked responses were elicited at 35 and 70 dB at less than 4 (test 1) and greater than or equal to 48 hours (test 2). Mean wave I-V intervals were prolonged in test 1 when compared with test 2. Linear regression showed the arterial:venous ratio accounted for 66% (left ear) and 43% (right ear) of the variance in test 1 intervals. No association was found in test 2. In newborn infants, changes in serial auditory brain stem evoked response tests occur after maternal lignocaine epidural anaesthesia and these changes correlate with blood lignocaine concentrations.

Anesthesia, Epidural↗

The impact of gestational age on dysmaturity/postmaturity.

The medical records of 403 infants admitted to the neonatal intensive care unit were reviewed. All were postterm (greater than or equal to 42 weeks' gestation) infants or infants who were full term (greater than or equal to 38 weeks' gestation) and had clinical diagnoses associated with the neonatal postmaturity/dysmaturity syndrome. Data collected from these 403 records were used to generate frequency distribution tables for a variety of obstetric and neonatal outcome variables. Regression analyses were used to assess associations among these variables and the presence or absence of fetal malnutrition (dysmaturity) or postdatism. Fetal distress and neonatal acidosis were associated with both dysmaturity and postdatism. Primigravidas, meconium-stained amniotic fluid, cesarean section, birth trauma, and neonatal death were associated with postdatism but not with dysmaturity. Preeclampsia, maternal smoking, oligohydramnios, low Apgar score, neonatal pulmonary hypertension, neurologic abnormalities, and a need for extracorporeal membrane oxygenation were associated with dysmaturity. No interaction between postdatism and dysmaturity was seen for any outcome variable. Postdatism and dysmaturity appear to contribute risk factors independently to infants admitted to the intensive care unit.

Female↗

Neonatal vocal cord paralysis following extracorporeal membrane oxygenation.

Five cases of unilateral vocal cord paralysis/paresis were diagnosed following extracorporeal membrane oxygenation for newborn respiratory failure. All were right sided and transient in nature. None of the five patients had other findings commonly associated with vocal cord palsy. The extracorporeal membrane oxygenation procedure requires surgical dissection in the carotid sheath on the right side of the neck, an area immediately adjacent to both the vagus and recurrent laryngeal nerve. It is speculated that vocal cord paralysis in these infants was acquired as a result of the extracorporeal membrane oxygenation cannulation. Although the vocal cord paralysis resolved in all cases, two patients had difficult courses after extracorporeal membrane oxygenation. Therefore, laryngoscopic examination should be considered for patients after extracorporeal membrane oxygenation.

Extracorporeal Membrane Oxygenation↗