A statewide quality improvement collaborative to reduce neonatal central line-associated blood stream infections

OBJECTIVE

The objective of this study was to reduce central line-associated blood stream infections (CLABSIs) among 13 collaborating regional neonatal intensive care units by 25%. We tested the hypothesis that change could be attributed to the quality improvement collaborative by testing for 'special cause' variation.

STUDY DESIGN

Our prevention project included five features: (1) leadership commitment, (2) potentially best practices, (3) collaborative processes, (4) audit and feedback tools and (5) quality improvement techniques. Baseline (1 January 2006 to 30 August 2006) data were compared with the intervention (1 September 2006 to 30 June 2007) and post-intervention (1 July 2007 to 30 December 2007) periods and analyzed using statistical process control (SPC) methods.

RESULT

We detected special cause variation, suggesting that the collaborative was associated with reduced infection rates, from 4.32 to 3.22 per 1000 line days (a 25% decrease) when comparing the baseline with the follow-up period.

CONCLUSION

The collaborative's process was associated with fewer infections. SPC suggested that systematic changes occurred. The remaining challenges include sustaining or even further reducing the infection rate.

Indomethacin-associated neutropenia with subsequent Gram-negative sepsis in a preterm infant. Cause or coincidence?

A preterm male infant with a patent ductus arteriosus developed neutropenia during treatment with indomethacin. Afterward, the mother described her own history of indomethacin-associated neutropenia. During the recovery from the neutropenia, the infant became septic with bacteremia caused by Enterobacter cloacae. Although indomethacin-related neutropenia has been described in adults, no case in a neonate has been reported. If neutropenia occurs after indomethacin therapy in a neonate, a familial history of indomethacin-associated neutropenia should be sought and the increased risk of infection should be considered.

Altered energetic properties in skeletal muscle of men with well-controlled insulin-dependent (type 1) diabetes

This study asked whether the energetic properties of muscles are changed by insulin-dependent diabetes mellitus (or type 1 diabetes), as occurs in obesity and type 2 diabetes. We used (31)P magnetic resonance spectroscopy to measure glycolytic flux, oxidative flux, and contractile cost in the ankle dorsiflexor muscles of 10 men with well-managed type 1 diabetes and 10 age- and activity-matched control subjects. Each subject performed sustained isometric muscle contractions lasting 30 and 120 s while attempting to maintain 70-75% of maximal voluntary contraction force. An altered glycolytic flux in type 1 diabetic subjects relative to control subjects was apparent from significant differences in pH in muscle at rest and at the end of the 120-s bout. Glycolytic flux during exercise began earlier and reached a higher peak rate in diabetic patients than in control subjects. A reduced oxidative capacity in the diabetic patients' muscles was evident from a significantly slower phosphocreatine recovery from a 30-s exercise bout. Our findings represent the first characterization of the energetic properties of muscle from type 1 diabetic patients. The observed changes in glycolytic and oxidative fluxes suggest a diabetes-induced shift in the metabolic profile of muscle, consistent with studies of obesity and type 2 diabetes that point to common muscle adaptations in these diseases.

Hemodynamic effects of positive end-expiratory pressure during partial liquid ventilation in newborn lambs

BACKGROUND/PURPOSE

The aim of this study was to compare the effect of positive end-expiratory pressure (PEEP) application on hemodynamics, lung mechanics, and oxygenation in the intact newborn lung during conventional ventilation (CV) and partial liquid ventilation (PLV) at functional residual capacity (FRC). CV or PLV modes of ventilation do not affect hemodynamics nor the optimum PEEP for oxygenation.

METHODS

Seven newborn lambs (1 to 3 days old) were instrumented to measure pulmonary hemodynamics and airway mechanics. Each lamb was used as their own control to compare different modes of ventilation (CV followed by PLV) under graded variations of PEEP (4, 8, 12, and 16 cm H(2)O) on the influence on pulmonary blood flow and pulmonary vascular resistance.

RESULTS

There was a significant drop in pulmonary blood flow (PBF) from baseline (PEEP of 4 cm H(2)O on CV, 1,229 +/- 377 mL/min) in both modes of ventilation on a PEEP of 16 cm H(2)O (CV, 750 +/- 318 mL/min v PLV, 926 +/- 396 mL/min, respectively; P <.05). Peak inspiratory pressure (PIP) was higher on PLV at PEEP states of 4 cm H(2)O (16.5 +/- 1.3 cm H(2)O to 10.6 +/- 2.1 cm H(2)O; P <.05) and 8 cm H(2)O (18.8 +/- 2.2 cm H(2)O to 15.1 +/- 2.6 cm H(2)O; P <.05) when compared with CV. Conversely, PIP required to maintain the pCO(2) was lower on PLV at PEEP states of 12 (22.5 +/- 3.6 cm H(2)O to 24.2 +/- 3.8 cm H(2)O; P <.05) and 16 cm H(2)O (27.0 +/- 1.6 cm H(2)O to 34.0 +/- 5.9 cm H(2)O; P <.05).

CONCLUSIONS

Hemodynamically, CO is impaired at a PEEP above 12 cm H(2)O in intact lungs. PFC at FRC does provide an advantage in lung mechanics more than 10 to 12 cm H(2)O of PEEP by decreasing the amount PIP needed to achieve the similar levels of gas exchange and minute ventilation, implying a reduced risk for barotrauma with chronic ventilation. Thus, selection of the appropriate level of PEEP appears to be important if PLV is to be utilized at FRC. The best strategy for PLV, including the selection of PEEP, remains to be determined.

Form and function of fetal and neonatal pulmonary arterial bifurcations

Bifurcation is a basic form of vascular connection. It is composed of a parent vessel of diameter d(0), and two daughter vessels, d(1) and d(2), where d(0) > d(1) >/= d(2). Optimal values for the bifurcation area ratio, beta = (d(1)(2) + d(2)(2))/d(0)(2), and the junction exponent, x, in d(0)(x) = d(1)(x) + d(2)(x), are postulated to be universal in nature. However, we have hypothesized that the perinatal pulmonary arterial circulation is an exception. Arterial diameters were measured in pulmonary vascular casts of a fetal lamb (140 days gestation/145 days term) and a neonatal lamb (1 day old). The values for beta and x were evaluated in 10,970 fetal and 846 neonatal bifurcations sampled from the proximal and intermediate arterial regions. Mean values and confidence intervals (CI) for the fetus were beta = 0.890 (0.886-0.895 CI) and x = 1.75 (1.74-1.76 CI); and for the newborn were beta = 0.913 (0.90-0.93 CI) and x = 1. 79 (1.75-1.82 CI). These values are significantly different from Murray's law (beta > 1, x = 3) or the West-Brown-Enquist law (beta = 1, x = 2). Therefore, perinatal pulmonary bifurcation design appears to be distinctive and exceptional. The decreasing cross-sectional area with branching leads to the hemodynamic consequence of shear stress amplification. This structural organization may be important for facilitating vascular development at low flow rates; however, it may be the origin of unstable reactivity if elevated blood flow and pressure occurs.

Effects of correction of hypocalcemia on cardiac function in the newborn lamb

The effect of correction of hypocalcemia on cardiac function in the neonate is unclear. Therefore, we evaluated changes in hemodynamic variables and cardiac contractility in a hypocalcemic neonatal lamb model. Baseline serum ionized hypocalcemia was induced via chelation with intravenous EGTA. Cardiac contractility, measured as end-systolic elastance, did not change with correction of hypocalcemia in this model. In contrast, the variable dP/dt(max), a load-dependent index of contractility, showed an increase with calcium administration while the end-diastolic volume decreased, suggesting that diastolic function or early systolic function had changed. Systemic vascular resistance, cardiac output, and heart rate did not change significantly with correction of hypocalcemia. The results of this study suggest that in our newborn lamb model, cardiac contractility is insensitive to ionized calcium and may reflect cardiac immaturity, but that there may be an effect of calcium administration on diastolic or early systolic function.

Metastasis stage, adjuvant treatment, and residual tumor are prognostic factors for medulloblastoma in children: conclusions from the Children's Cancer Group 921 randomized phase III study

PURPOSE

From 1986 to 1992, "eight-drugs-in-one-day" (8-in-1) chemotherapy both before and after radiation therapy (XRT) (54 Gy tumor/36 Gy neuraxis) was compared with vincristine, lomustine (CCNU), and prednisone (VCP) after XRT in children with untreated, high-stage medulloblastoma (MB).

PATIENTS AND METHODS

Two hundred three eligible patients with an institutional diagnosis of MB were stratified by local invasion and metastatic stage (Chang T/M) and randomized to therapy. Median time at risk from study entry was 7.0 years.

RESULTS

Survival and progression-free survival (PFS) +/- SE at 7 years were 55%+/-5% and 54%+/-5%, respectively. VCP was superior to 8-in-1 chemotherapy, with 5-year PFS rates of 63%+/-5% versus 45%+/-5%, respectively (P = .006). Upon central neuropathology review, 188 patients were confirmed as having MB and were the subjects for analyses of prognostic factors. Children aged 1.5 to younger than 3 years had inferior 5-year estimates of PFS, compared with children 3 years old or older (P = .0014; 32%+/-10% v 58%+/-4%, respectively). For MB patients 3 years of age or older, the prognostic effect of tumor spread (MO v M1 v M2+) on PFS was powerful (P = .0006); 5-year PFS rates were 70%+/-5%, 57%+/-10%, and 40%+/-8%, respectively. PFS distributions at 5 years for patients with M0 tumors with less than 1.5 cm2 of residual tumor, versus > or = 1.5 cm2 of residual tumor by scan, were significantly different (P = .023; 78%+/-6% v 54%+/-11%, respectively).

CONCLUSION

VCP plus XRT is a superior adjuvant combination compared with 8-in-1 chemotherapy plus XRT. For patients with M0 tumors, residual tumor bulk (not extent of resection) is a predictor for PFS. Patients with M0 tumors, > or = 3 years with < or = 1.5 cm2 residual tumor, had a 78%+/-6% 5-year PFS rate. Children younger than 3 years old who received a reduced XRT dosage had the lowest survival rate.

Role of nitric oxide in cardiovascular responses to endotoxemia in neonatal lambs

To determine whether systemic cardiovascular responses to gram-negative endotoxemia are mediated by nitric oxide, we evaluated time-dependent changes in contractility and hemodynamics in a neonatal sheep model subjected to nitric oxide synthesis inhibition with L-Name (Nomega-nitro-L-arginine methyl ester). Four groups were studied: control (C), endotoxin (E), endotoxin L-Name where the nitric oxide synthase inhibitor was given prior to endotoxin (ELN), and a control L-Name group pretreated with L-Name (CLN). The contractility, measured as end-systolic elastance (Ees), increased transiently in the E group and then returned to baseline. In contrast, Ees declined over time in the ELN group. In terms of peripheral hemodynamics, both the E and ELN groups demonstrated significant progressive decreases in blood pressure and vascular resistance. The results of this study suggest that nitric oxide contributes to the newborn contractile response of the heart to endotoxin, but does not appear to mediate the systemic vascular relaxation response.

Survival and prognostic factors following radiation therapy and chemotherapy for ependymomas in children: a report of the Children's Cancer Group

OBJECT

Ependymomas in children continue to generate controversy regarding their histological diagnosis and grading. optimal management, and possible prognostic factors. To increase our knowledge of these tumors the authors addressed these issues in a cohort of children with prospectively staged ependymomas treated with radiotherapy and chemotherapy.

METHODS

Children between the ages of 2 and 17.3 years harboring an intracranial ependymoma confirmed by a central review of the tumor's pathological characteristics were treated according to Children's Cancer Group Protocol 921 from 1986 to 1992. Treatment following surgery and postoperative tumor staging (including brain computerized tomography or magnetic resonance [MR] imaging, spinal MR imaging or myelography, and cerebrospinal fluid cytological investigation) included craniospinal irradiation with a local boost to the primary tumor and patient randomization to receive adjuvant chemotherapy with either 1) CCNU, vincristine, and prednisone, or 2) the eight-drugs-in-1-day regimen. Centralized review of the tumor pathological characteristics revealed 20 ependymomas and 12 anaplastic ependymomas in the 32 children included in the study. Diagnoses made at the individual institutions included anaplastic (malignant) ependymoma (15 patients), ependymoma (four patients), ependymoblastoma (nine patients), ependymoastrocytoma (one patient), and primitive neuroectodermal tumor (three patients), which were discordant with the centralized review diagnosis in 22 of 32 cases. Only three of the 32 patients had metastatic disease (two with M and one with M3 stages). At surgery, 47% of tumors were estimated to be totally resected. Among the 14 of 17 patients who suffered a relapse and were evaluated for site of relapse, 10 (71%) had an isolated local relapse, three (21%) had concurrent local and metastatic relapse, and only one (7%) had an isolated metastatic relapse. Kaplan-Meier estimates of 5-year progression-free survival (PFS) and overall survival rates were 50 +/- 10% and 64 +/- 9%, respectively.

CONCLUSIONS

Predictors of PFS duration included an estimate of the extent of resection made at surgery (total compared with less than total, p = 0.0001) and the amount of residual tumor on postoperative imaging as verified by centralized radiological review (< or = 1.5 cm2 compared with > 1.5 cm2, p < 0.0001). No other factors, including centrally reviewed tumor histopathological type, location, metastasis and tumor (M and T) stages, patient age, race, gender, or chemotherapy treatment regimen significantly correlated with PFS duration. The pattern of predominantly local relapse and the important influence of residual tumor or the extent of resection on PFS duration confirms a prevailing impression that local disease control is the major factor in the prediction of outcome of ependymoma. Survival rates were comparable with those reported by other investigators who have treated patients with similar doses of radiation and no chemotherapy.

Cervical spine MRI in abused infants

OBJECTIVE

To determine clinical utility of screening with cervical spine MRI to detect unsuspected cord injury in children with head injury from child abuse.

DESIGN

Prospectively collected case series. Setting-Tertiary care children's hospital and county medical examiner's office.

PATIENTS

Twelve children with intracranial injury secondary to child abuse. None was clinically suspected to have cord injury. Includes all eligible children whose attending felt: (a) needed follow-up cranial imaging: (b) could be safely imaged; and (c) whose caretakers consented between November, 1991 and September, 1994.

INTERVENTIONS

MRI scans of the cervical spine were obtained either more than 3 days after clinical presentation or postmortem.

MAIN OUTCOME MEASURES

Clinical observations by neurologist, child protection team pediatrician and medicinal examiners by prospective protocol. MRI scans evaluated by prospective radiology protocol with emphasis on cervical cord injury.

RESULTS

Four of the five autopsied children had small subdural or subarachnoid hemorrhages at the level of the cervical spine; MRI scan did not identify them. MRI did not identify cord injury in any child studied.

CONCLUSION

Routine cervical spine MRI scans are probably not warranted in children with head injury secondary to child abuse without clinical symptoms of cervical cord injury.

Role of arterial design on pulse wave reflection in a fractal pulmonary network

A novel interpretation of pulmonary arterial input impedance was evaluated for the lung as a fractal vascular network. We hypothesized that local sources of reflection introduce trends of global reflection into the input impedance spectra. These trends are related to the network topology, geometry, and design according to Rb = Rdx, where Rb is the branching ratio, Rd is the diameter ratio, and x is the fractal dimension quantifying design. Simulations using values of Rd and x, which were derived morphometrically, confirmed two patterns of global reflection: a continuous trend attributed to a single effective site of reflection caused by frequency-dependent sources of impedance contrast and a discrete trend arising from a longitudinal distribution of frequency-independent sources of reflection. The continuous trend depended only on the network parameter Rd, whereas the discrete trend depended on Rd and x. Our results indicate that the impedance-matching properties of a deterministic pulmonary fractal network encode arterial geometry and topology via function and that typical values of Rd and x for the pulmonary circulation facilitate shear stress amplification in its peripheral vessels. Thus, inasmuch as shear forces may be involved in the endothelial mechanisms for pathological, or physiological, vascular remodeling, broadband input impedance analysis may reveal interactions between network organization and vascular function.

Prognostic factors and treatment results for supratentorial primitive neuroectodermal tumors in children using radiation and chemotherapy: a Childrens Cancer Group randomized trial

PURPOSE

To determine clinical characteristics and response to treatment for children with supratentorial primitive neuroectodermal tumors (S-PNETs).

PATIENTS AND METHODS

After surgery and staging, 55 patients aged 1.5 to 19.3 years with S-PNETs were randomized to receive craniospinal radiotherapy (RT) followed by eight cycles of 1-(2-chloro-ethyl)-3-cyclohexylnitrosourea (CCNU), vincristine (VCR), and prednisone (standard treatment) or two cycles of 8-in-1 chemotherapy followed by RT and then eight additional cycles of 8-in-1.

RESULTS

Three-year Kaplan-Meier estimates (estimate +/- SE) of survival and progression-free survival (PFS) rates for patients with confirmed diagnoses of S-PNET were 57% +/- 8% and 45% +/- 8%, respectively; survival and PFS rates for children with PNETs located in the pineal region were 73% +/- 12% and 61% +/- 13%, respectively, and were significantly different from the other S-PNETs (P < .03). The 8-in-1 arm had greater toxicity than the standard-treatment arm. Distributions of PFS between the two treatment groups were not significantly different (P > .5). Other univariate prognostic factors that influenced PFS included metastasis (M) stage (P < .03: M0 50% +/- 9% v M1-4 0%) and age (P < .02: 1.5 to 2 years 25% +/- 13% v > or = 3 years 53% +/- 9%).

CONCLUSION

In this first randomized treatment trial for S-PNETs in children, no significant differences were detected between the two treatment groups. M0 and pineal site of involvement were independent predictors of a better outcome. However, survival was better than previously reported.

Prognostic factors in children with supratentorial (nonpineal) primitive neuroectodermal tumors. A neurosurgical perspective from the Children's Cancer Group

Supratentorial primitive neuroectodermal tumors (S-PNETs), which have also been called cerebral neuroblastomas, have been considered to be the hemispheric equivalent of posterior fossa medulloblastomas. Twenty-seven children with S-PNETs (excluding pineoblastomas) which were confirmed by central pathology review were treated on the CCG-921 protocol from 1986 to 1992. After operation, all patients were staged with CSF cytology and spinal myelography or magnetic resonance scans and were treated with craniospinal irradiation and chemotherapy. Data from these 27 patients have been reviewed to evaluate neurosurgical treatment, survival, and prognostic variables that correlate with survival. Overall survival at 5 years was 34% (SE 20%) and progression-free survival (PFS) was 31% (SE 18%), which is lower than the survival of patients with posterior fossa PNETs (medulloblastomas). PFS was significantly worse in children 1.5-3 years of age at diagnosis and in those with evidence of tumor dissemination at the time of diagnosis. Large preoperative tumors were more likely to be associated with greater than 1.5 cm2 residual tumor postoperatively. Neurosurgeons estimated that less than 1.5 cm2 of residual tumor was present in 52% of the cases; postoperative scans confirmed that in 58%. For children with less than 1.5 cm2 residual tumor, postoperative survival at 4.0 years was 40% (SE 22%); for those with greater than 1.5 cm2 residual tumor, survival was 13% (SE 8%). The difference did not reach statistical significance, due to small numbers in this series, though a trend did exist (p = 0.19). Large series will be required to clarify the effects of extent of resection on survival.

Randomized phase III trial in childhood high-grade astrocytoma comparing vincristine, lomustine, and prednisone with the eight-drugs-in-1-day regimen. Childrens Cancer Group

PURPOSE

In a previous randomized trial, the addition of adjuvant chemotherapy to postoperative radiotherapy proved beneficial in the treatment of childhood high-grade astrocytomas. The present study tests the hypothesis that an eight-drug adjuvant chemotherapy regimen would improve survival in such children compared with the three-drug regimen of the prior study.

PATIENTS AND METHODS

Between April 1985 and May 1990, patients between the ages of 18 months and 21 years with newly diagnosed high-grade astrocytomas were eligible for this study, as determined by the treating institution's histopathologic diagnosis. Treatment consisted of postoperative local-field radiotherapy and adjuvant chemotherapy, either lomustine (CCNU), vincristine, and prednisone (control regimen) or eight-drugs-in-1-day chemotherapy (experimental regimen). Two cycles of postoperative preirradiation chemotherapy were administered in the experimental regimen. Patients were evaluated radiographically every 3 months after irradiation.

RESULTS

Eighty-five eligible patients were randomized to the control regimen and 87 to the experimental regimen. The progression-free survival (PFS) and overall survival (OS) at 5 years were 33% (SE = 5%) and 36% (SE = 6%), respectively. There was no statistical difference in outcome between the two chemotherapy regimens. In patients with confirmed diagnoses of anaplastic astrocytoma (AA) or glioblastoma multiforme (GBM), anaplastic astrocytoma, greater than 90% resection, and nonmidline tumor location were characteristics predictive of an improved PFS. There was a difference in toxicity between the two chemotherapeutic regimens, with greater myelosuppression and hearing loss in the experimental regimen. Tumor recurrence occurred primarily within the primary tumor site.

CONCLUSIONS

There is no benefit to the treatment of high-grade astrocytomas in children with eight-drugs-in-1-day chemotherapy compared with CCNU, vincristine, and prednisone. Extent of tumor resection and histopathologic diagnosis are significant prognostic variables. The overall outcome for children with high-grade astrocytomas remains poor.

Irreversibility of birth-related changes in the pulmonary circulation

We hypothesized that establishing conditions of hypoxia and fluid filling of the airways in lungs of newborns would reproduce the high levels of pulmonary vascular resistance (PVR) observed in the fetal state. We assessed the hemodynamics of the left pulmonary circulation of 1- to 3-day-old lambs during a variety of airway states while attempting to reestablish fetal conditions. Eleven animals were studied during both normoxemia and hypoxemia in a baseline airway state with a positive end-expiratory pressure (PEEP) of 4 cm H2O, and in experimental airway states, of atelectasis, and fluid filling to 15 and 30 mL/kg and with PEEP of 12 cm H2O. PVR increased while pulmonary blood flow decreased with all airway state changes as compared to baseline, suggesting a passive mechanism for these changes. With the addition of hypoxemia there was a further increase in PVR in all states accompanied by an increase in pulmonary blood flow, indicating that active vasoconstriction was responsible for the increase in PVR. The combined effects of hypoxemia and fluid filling, designed to approximate the fetal state, increased PVR to only 20-30% of fetal values. Thus, additional factors appear to be important in maintaining the high PVR of the fetal state. We speculate that ventilation of the lungs at birth irreversibly alters these factors.

Survival of infants with primitive neuroectodermal tumors or malignant ependymomas of the CNS treated with eight drugs in 1 day: a report from the Childrens Cancer Group

PURPOSE

Very young children with CNS primitive neuroectodermal tumors (PNETs) and ependymomas have a poor prognosis and commonly have impairment of growth and cognitive abilities, in part resulting from radiotherapy. Thus, an intensive chemotherapeutic regimen was used to treat children less than 18 months of age at diagnosis.

PATIENTS AND METHODS

Children were treated on a Childrens Cancer Group (CCG) protocol with an eight-drug chemotherapeutic regimen (vincristine, carmustine, procarbazine, hydroxyurea, cisplatin, cytarabine, prednisone, and cyclophosphamide) following surgery and postoperative staging. Delayed or reduced-volume radiotherapy was to be administered to all patients, but, in fact, was omitted in most cases.

RESULTS

On central review of pathology, 82 children had diagnosis concordant with study entry criteria. Of these, 46 (56%) had posterior fossa (PF) PNET, eight (10%) had pineal PNET, 11 (12%) had nonpineal supratentorial PNET, 15 (18%) had ependymoma, and two had rhabdoid tumors. Fifty percent of tumor resections were complete, as verified by postoperative computed tomographic (CT) scan, and 23% of patients had metastatic disease at the time of diagnosis. Objective tumor response was documented following two cycles of chemotherapy in 28% of assessable patients. Toxicity of chemotherapy was primarily hematopoietic. Five children died of chemotherapy-related complications. Radiotherapy was administered to only nine patients before tumor progression. The 3-year progression-free survival (PFS) rates for PF PNET, pineal PNET, supratentorial nonpineal PNET, and ependymoma are 22% (SE = 6%), 0%, 55% (16%), and 26% (11%), respectively. The 3-year PFS rate for those children without metastatic disease was 29% (6%), as compared with 11% (6%) for those with metastatic disease. The only independent predictors of PFS were metastasis stage and location of the tumor within the pineal region. The median time to progression was 6 months. Twenty-four children completed the chemotherapeutic regimen without tumor progression; 19 are event-free survivors more than 2 years from diagnosis, only three of whom received radiation therapy.

CONCLUSION

While overall survival in this group of very young patients is poor, a subset of children who have received only chemotherapy as adjuvant treatment remain free from tumor recurrence.

Escherichia coli endotoxin depresses left ventricular contractility in neonatal lambs

We evaluated the effects of Escherichia coli endotoxin on the peripheral vascular hemodynamics and myocardial function of the newborn lamb to understand how gram-negative endotoxemia can lead to cardiovascular collapse in newborn infants. Fifteen lambs, 0-3 d old, were acutely instrumented with a micromanometer-tipped catheter and two pairs of ultrasonic crystals to measure left ventricular (LV) pressure and LV anterior-posterior and septal-free wall dimensions, a fluid-filled catheter for monitoring aortic pressure, and an electromagnetic flow probe to measure systemic blood flow. Cardiovascular performance was evaluated by measuring or deriving the following variables: mean arterial blood pressure (MABP), LV pressure, heart rate, stroke volume, systemic vascular resistance, LV dp/dt, end-diastolic area, arterial elastance, and end-systolic elastance (the slope of the end-systolic pressure-area relationship) as an index of contractility independent of loading conditions and heart rate. Once instrumented, nine lambs received endotoxin, 0.5 mg/kg i.v., and six animals, serving as controls, received a saline infusion. Of the endotoxin-treated lambs, five survived the duration of the study (120 min from the beginning of the endotoxin infusion), and four died by 90 min from the beginning of the endotoxin infusion. No significant changes in any of the cardiovascular variables occurred in the control group. A significant decrease in MABP was seen in all endotoxin-treated animals by 45 min after the beginning of the endotoxin infusion. MABP decreased by 52% from baseline in the survivors and 38% in the nonsurvivors. In the survivors, the MABP stabilized with saline boluses, whereas in the nonsurvivors MABP continued to decrease until death.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic diastolic pressure decay in congenital arteriovenous malformations

We describe three infants with large congenital arteriovenous malformations, two intracranial and one intrathoracic, who have high output congestive heart failure but normal pulse pressures. The theoretical basis of these pulse pressure findings in contrast to those in infants with shunting secondary to the patent ductus arteriosus is presented.

Stroke and mixed connective tissue disease

We describe the clinical presentation and course of two girls with cerebrovascular disease and mixed connective tissue disease. One developed rapid onset hemiparesis and aphasia secondary to left internal carotid artery occlusion. She experienced a complete recovery after treatment with prednisone and cyclophosphamide. The other patient was diagnosed as having mixed connective tissue disease but had acute neurologic deterioration. She died due to an intracerebral hemorrhage. Autopsy demonstrated small-vessel fibrinoid necrosis. Although cerebrovascular disease secondary to central nervous system vasculitis is a manifestation of systemic lupus erythematosus, this is the first description of cerebrovascular disease as a primary sign in mixed connective tissue disease. These cases demonstrate the range of cerebrovascular disease observed in children with mixed connective tissue disease.

Mechanically increased right ventricular afterload alters left ventricular configuration, not contractility, in neonatal lambs

Left ventricular dysfunction has been observed in human infants with pulmonary hypertension. The purpose of this study was to establish whether mechanically increased right ventricular afterload alters left ventricular performance by altering its contractility, configuration, or both. Six neonatal 3- to 7-d-old lambs were acutely instrumented with micromanometer-tipped catheters and two pairs of ultrasonic crystals to measure left ventricular pressure and anterior-posterior and septal-free wall dimensions. The product of these two dimensions, denoted left ventricular area, was used as an index of left ventricular volume. Two levels of mechanically increased right ventricular afterload were induced with a closed pericardium under three levels of left ventricular preload produced by whole-blood transfusions. Four brief increases in left ventricular afterload were induced by constricting the aorta under each right ventricular afterload and preload condition. Using multiple linear regression, we found that the slope of the end-systolic pressure-area relationship, an index of contractility, was unchanged [0.90 +/- 0.11 mm Hg/mm2 (SEM)], and stroke area (65.8 +/- 7 mm2) and cardiac output (the product of stroke area and heart rate) (13,400 +/- 1,660 mm2/min) were maintained. However, the area intercept of the pressure-area line at zero pressure (499 +/- 13 mm2) shifted significantly to the left in the presence of both levels of increased right ventricular afterload (by -39.2 +/- 13 and -76.2 +/- 15 mm2, respectively). Mechanically increased right ventricular afterload alters left ventricular configuration and causes a shift in the operating volume (area) range of the ventricle with no change in contractility in 3- to 7-d-old lambs.

Childhood polymyositis as a paraneoplastic phenomenon

Childhood polymyositis and dermatomyositis are rare conditions that are not generally associated with malignancy even though an association between adult-onset and malignancy has been reported. A child is presented with typical polymyositis in whom an immunoblastic sarcoma subsequently became manifest; the literature also is reviewed concerning the association between malignancy and these childhood conditions.

The effect of age on the latency of radiation myelopathy

The latent period to forelimb paresis following photon irradiation of the cervical spinal cord was evaluated in Sprague-Dawley rats ranging in age from 9 days to adulthood. The radiation was administered dorsally in single fractions, and in 15-day-old animals, to different lengths of the rostral cord and in doses ranging from 16 to 38 Gy. The duration of the latent period was found to be directly proportional to the age of the animal at the time of irradiation, and independent of radiation dose or the volume of the cervical cord which was irradiated. In the majority of paretic animals, the irradiated segment of the spinal cord demonstrated white matter necrosis. The results indicate that in the developing rat, the manifestations of radiation myelopathy are delayed by an interval determined in part by the age of the animal at the time of irradiation.

Favorable prognosis for brainstem gliomas in neurofibromatosis

Over a two year interval, we have treated five children with neurofibromatosis who developed brainstem gliomas. They had an insidious onset of symptoms and other indicators of low grade tumor despite several features that have been ascribed to rapidly progressive brainstem gliomas. Following standard radiation therapy a more protracted improvement was observed with the persistence of preradiation findings for several months. This experience confirms the better prognosis in brainstem glioma associated with neurofibromatosis.

Fatal infantile muscle phosphorylase deficiency

A premature female infant born of a consanguineous union exhibited joint contractures and signs and symptoms of perinatal asphyxia. A muscle biopsy examined by light microscopic, histochemical, and electron microscopic techniques exhibited changes of muscle phosphorylase deficiency and glycogenosis, identical to those of McArdle's disease. Postmortem ultrastructural examination of liver and heart did not reveal lysosomal storage. This case and one previously reported example of fatal infantile phosphorylase deficiency suggest that the clinical spectrum of McArdle's disease may be broader than previously recognized.

Radiation, methotrexate, and white matter necrosis: laboratory evidence for neural radioprotection with preirradiation methotrexate

To investigate the interactions between methotrexate (MTX) and irradiation of the central nervous system, adult rats were infused with MTX via the lateral cerebral ventricle either before, during, or following single fraction irradiation to the cervical spine. Single doses ranging from 1600 cGy to 3200 cGy were administered and the dose-response curve for forelimb paralysis was compared with that seen in irradiated animals which did not receive MTX. There was no effect on the dose-response curve when MTX was administered simultaneously with or following irradiation compared to radiation alone. When MTX was given prior to irradiation, however, the entire dose-response curve shifted in the direction of radioprotection by approximately 225 cGy. Histopathologic examinations were consistent with this observation, with animals pretreated with methotrexate demonstrating significantly less white matter necrosis than observed in untreated controls. Protection of normal CNS tissue from radionecrosis, and from the associated paralysis, may be achieved with preradiation methotrexate.

Eight drugs in one day chemotherapy in children with brain tumors: a critical toxicity appraisal

The toxicity of a new chemotherapeutic regimen for CNS tumors using eight anticancer agents administered in a 12-hour period was evaluated in 34 children with newly diagnosed and recurrent tumors treated at the Children's Hospital and Medical Center in Seattle. The chemotherapy included methylprednisolone, vincristine, lomustine (CCNU), procarbazine, hydroxyurea, cisplatin (CDDP), and either cyclophosphamide or imidazole carboximide (DTIC). The first five patients additionally received high-dose methotrexate (HDMTX), but because of excessive toxicity this was replaced by cytarabine. Of 125 courses administered without HDMTX, red cell transfusions were required in 15% of the courses and platelet transfusions were required in 8%. Hospitalization for empiric treatment of fever associated with neutropenia occurred in 6% of courses. Three episodes of documented sepsis occurred. Virtually all hematologic toxicity occurred in patients with recurrent disease. Renal toxicity occurred in 14% of patient courses. One patient died of renal failure and sepsis following therapy. Neurologic and hepatic complications were infrequent. High-frequency hearing loss above the voice range was common, but clinically significant hearing loss occurred in only three patients. Severe nausea and vomiting were infrequent. Overall, the toxicity of "eight in one" chemotherapy in newly diagnosed patients was minimal; toxicity was greater in patients with recurrent disease.

Hydromyelia associated with arrested hydrocephalus

A 16-year-old male with a 9-year history of spontaneously arrested hydrocephalus was noted to have hydrosyringomyelia and increased intracranial pressure shortly after sustaining minor head trauma. His symptoms resolved completely following ventriculoperitoneal shunt replacement. Hydrosyringomyelia may occur in the setting of long-standing, apparently arrested hydrocephalus.

Ondine curse and neurocristopathy

Two newborns, 1 male and 1 female, had both Ondine curse, also known as congenital, central hypoventilation syndrome, and Hirschsprung disease. Both infants demonstrated insufficient respiration while asleep and normal respiration when awake. The lesser affected child had an otherwise normal neurologic examination, but suffered from seizures. He died at 18 months of age; neuropathologic examination of the brain was unremarkable. The girl had a severe and ultimately fatal form of this disorder and manifested a variety of neurologic abnormalities indicative of developmental failure of the neural crest-derived tissues. These abnormalities included unreactive pupils and deafness. She died at 40 days of age; autopsy permission was denied. The etiology of sleep apnea is not known. Mechanisms of central integration may be abnormal but the association with neural crest maldevelopment implicates the peripheral nervous system.

Effect of pulmonary hypertension on lung compliance in newborn lambs

We studied the effects of increased pulmonary arterial pressure and vascular resistance on lung compliance in 12 anesthetized newborn lambs. Lung compliance was unaffected by large changes in pulmonary artery pressure and pulmonary vascular resistance (80% increase) that were induced by either hypoxia or acidosis. We conclude that contraction of the pulmonary vascular smooth muscle in normal newborn lambs does not affect the stiffness of the lung in the parenchymal regions undergoing volume change during ventilation.

Eight drugs in one day chemotherapy for brain tumors: experience in 107 children and rationale for preradiation chemotherapy

The development of a new multidrug chemotherapy regimen for primary brain tumors was based upon the cellular heterogeneity within individual tumors, the Goldie-Coldman and Price-Goldie-Hill hypotheses, and known agonistic effects of certain drug combinations and sequences. Eight drugs (vincristine [VCR], hydroxyurea, procarbazine, CCNU, cisplatin, cytosine arabinoside [Ara-C] high-dose methylprednisolone, and either cyclophosphamide or dacarbazine) were administered within 12 hours in an attempt to minimize myelosuppression. Courses were repeated at 2- to 4-week intervals. The regimen was devised to include lipid and water soluble drugs, polar and nonpolar agents, phase-specific and cell-cycle independent agents, and antineoplastics with different mechanisms of action. More than 330 courses of the regimen were administered to 107 children with brain tumors whose tumor had recurred or had been incompletely resected at diagnosis. Tumor response according to protocol-specified criteria and independent review was evaluable in 78% of the patients. After just two cycles of chemotherapy and within a 4- to 6-week interval, 50% had an objective tumor response including 15.5% who had a complete response (CR). Nephrotoxicity and high-frequency hearing losses were noted after three to five courses of therapy in approximately half of the patients. Transfusions with red cells or platelets and use of antibiotics for fever and neutropenia were required in 10% to 25% of patients. The regimen appears satisfactory for preradiation chemotherapy in newly diagnosed patients with residual tumor after surgery, but it must be compared with standard therapeutic approaches in prospective controlled trials before its relative value can be established.

Increased right ventricular afterload alters left ventricular function in newborn lambs

The effects of acutely increased right ventricular afterload induced by mechanical constriction of the main pulmonary artery or with alveolar hypoxia on function of the left ventricle were assessed in six and nine lambs, respectively (aged 1 to 3 days). Mechanical constriction of the main pulmonary artery in newborn lambs compromised left ventricular function with significant decreases in systemic blood flow and the peak first derivative of left ventricular pressure when considered simultaneously and as single variables. In contrast, alveolar hypoxia augmented left ventricular function with significant increases in systemic blood flow and the peak first derivative of left ventricular pressure when considered simultaneously or as single variables. Interaction appears to exist between the right and left ventricles during the newborn period. The mechanically increased afterload may have compromised left ventricular function by altering its end-diastolic size, inotropic state, or both. On the other hand, the augmented left ventricular function in the presence of hypoxia may have been due to an increase in inotropic background. The clinical implications in some infants with pulmonary hypertension and left ventricular dysfunction are raised.

Sclerema neonatorum: a sign of transient hyperammonemia of the newborn

We cared for four neonates with transient hyperammonemia of the newborn (THAN), all of whom exhibited sclerema during their course. Sclerema is a hardening of the subcutaneous tissues, which gives the tissue a firm, rubber-like quality. This association has not been previously reported, and it may provide a clue to early diagnosis and intervention in THAN.

Normocarbic hyperventilation fails to induce pulmonary vasodilation

The pulmonary vasodilator effect of increased rate of mechanical ventilation, with and without respiratory alkalosis, was studied in chronically instrumented newborn lambs. Pulmonary hypertension was first induced by ventilating with a hypoxic gas mixture. Subsequent respiratory alkalosis caused significant decreases in pulmonary arterial pressure and pulmonary vascular resistance. When normocarbia was re-established by adding carbon dioxide to the inspired gas, with the ventilator rate being held constant, the pressure and resistance returned to the baseline hypertensive state. Therefore, mechanical factors, either direct or indirect, appear to be of minor importance in the mechanism of pulmonary vasodilation secondary to frequency-induced hyperventilation.

Pulmonary vascular responses to nitrous oxide in newborn lambs

The hemodynamic effects of N2O and N2O plus hypoxia were studied in six lambs (0-3 days of age) that were instrumented with pulmonary artery flow probes and catheters, as well as aortic and left atrial catheters. N2O was administered to the awake lambs through a mask in mixtures of 75% N2O:25% O2 and 75% N2O:11% O2:14% N2. Pulmonary arterial pressure and resistance increased significantly upon exposure to N2O both during normoxia and hypoxia, and nitrous oxide also significantly elevated left atrial pressure and decreased pulmonary artery blood flow during normoxia. Aortic pressure was essentially unchanged by nitrous oxide. The data indicate that in newborn lambs the pulmonary vasculature responds to N2O with vasoconstriction.

Sleep patterns in nonambulatory boys with Duchenne muscular dystrophy

Sleep patterns and respiratory function during sleep were studied in five nonambulatory boys with Duchenne muscular dystrophy to clarify why patients with this disease awaken frequently at night. It was hypothesized that hypoxemia during sleep due to severe restrictive lung disease might cause nighttime arousals. Each boy underwent electroencephalography, electro-oculography and electromyography. Also determined were arterial oxyhemoglobin saturation, airflow from the nose and mouth, chest and abdominal excursions, and carbon dioxide tension of exhaled breaths. All five subjects had pulmonary function abnormalities consistent with severe restrictive lung disease and respiratory muscle weakness but none had evidence of respiratory failure or cor pulmonale. The boys awakened three times more frequently than age-matched published norms and experienced sleep stage shifts twice as often as normal children. Rapid-eye movement (REM) sleep as a proportion of total sleep was significantly reduced; sleep stage I was increased compared to normal values. No subject developed oxyhemoglobin desaturation during sleep. End-tidal CO2 tensions rose during sleep stages I, II and V (REM) in association with reduced chest wall excursion, suggesting transient episodes of mild hypoventilation which were not associated with arousals. Sleep fragmentation, frequent arousals and REM sleep deprivation occur in some boys with Duchenne muscular dystrophy but are not associated with significant disorders in breathing during sleep.

The influence and reliability of neurologic assessment and Karnofsky performance score on prognosis

The neurologic examination is important in the early diagnosis of brain tumors in children. Only in brain stem gliomas may the neurologic examination be better than computed tomographic scans in determining the progression. However, in general, the traditional neurologic examination has little or no value for prognosis. Reversible, associated features of brain tumors such as seizures or increased intracranial pressure may alter the patient's ability to function neurologically, but may not influence the prognosis regarding the tumor status. The Karnofsky functional status, to a large extent, reflects an adult's ability to work and has prognostic value but is largely inapplicable to children. Thus, a quality-of-life scale for children is needed.

Effect of pulmonary artery distention on systemic vascular resistance in newborn lambs

Balloon distention of the left pulmonary artery (PA) was produced in 14 lambs (aged 1 to 3 days) to assess whether an increase in systemic vascular resistance results from such distention. The lambs were anesthetized with chloralose and instrumented to enable measurement of systemic blood flow, PA pressure, aortic pressure, heart rate and right atrial pressure. PA distention resulted in an increase in systemic vascular resistance and aortic pressure (p less than 0.05). This result was probably due to a systemic vasoconstrictor response, since systemic blood flow and right atrial pressure did not change significantly. Limited trials using autonomic blocking agents suggested that the response is either a reflex under autonomic control or a response to humoral release of alpha-adrenergic substances. In conclusion, some interdependence appears to exist between the systemic and pulmonary vascular beds. It is postulated that such changes may be important in fetal life when they may affect redistribution of cardiac output during adaptation to hypoxemia.

Effect of hydration on experimentally induced cerebral edema

Although fluid restriction is often used to manage cerebral edema, there have been no controlled studies which demonstrate its benefit. We evaluated the effects of dehydration and overhydration on the development of cerebral edema in rats subjected to triethyltin poisoning or anoxic ischemia. Four days after triethyltin poisoning, the brains of control rats receiving maintenance hydration had a mean percentage of water of 79.56%; dehydration (5% of body weight) and overhydration groups were not statistically different at 79.95% and 79.86%, respectively. Forty-seven hours after an anoxic-ischemic insult consisting of unilateral carotid artery ligation and subsequent exposure to a 4% oxygen atmosphere for 30 min, the percentage of water in control rats was 79.12%; dehydration (13% of body weight) and overhydration groups were 79.10% and 79.16%, respectively. Histopathologic analysis of brain sections did not differentiate the hydration groups (triethyltin model only). Thus, cerebral edema was not altered by hydration status in either poisoned or ischemic animals.

Tracheal agenesis in infants with VATER association

Four newborns had tracheal agenesis and numerous features of the VATER (vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia) association. Forty-two additional reported cases of tracheal agenesis have been reviewed to establish whether this defect usually occurs in association with other VATER abnormalities. Since tracheal agenesis usually is accompanied by other VATER-associated defects and since similar abnormalities in embryological mechanisms and timing are implicated, according to current theories of development, we propose that tracheal agenesis should be considered a component of the VATER association.

Pulmonary vascular response to digoxin in newborn lambs

The effects of digoxin on pulmonary vascular resistance (PVR) were evaluated in normoxic (N) and hypoxic (H) newborn lambs with normal and elevated PVR, respectively. Lambs were anesthetized and instrumented to enable continuous measurement of mean pulmonary arterial pressure (PPA), mean left atrial pressure (PLA), mean pulmonary blood flow (Qp), and mean aortic pressure (PAO). Digoxin (10-20 micrograms/kg) was injected via central venous catheters in 11 N lambs and 4 H lambs. Under N conditions, baseline PVR was equal to 0.12 mm Hg/ml/min/kg, PPA was 33 mm Hg, PLA was 6 mm Hg, Qp was 235 ml/min/kg, and PAO was 69 mm Hg. Following digoxin, mean PVR increased by 24% (P less than 0.001) and PPA increased by 23% (P less than 0.001) for an average duration of 199 sec while QP increased by 5% (P less than 0.02) and PLA was constant suggesting a direct vasoconstrictive effect. Under H conditions, baseline PVR was equal to 0.26 mm Hg/ml/min/kg, PPA was 58 mm Hg, PLA was 4 mm Hg, Qp was 208 ml/min/kg, and PAo was 65 mm Hg. Following digoxin, mean PVR, Qp, PLA, and PAo did not change appreciably although PPA had a uniform increase of 5% (P less than 0.001). The blunted response may suggest that either the pulmonary vascular bed was maximally constricted or that digoxin and hypoxia share a common mechanism. In conclusion, digoxin has a direct pulmonary vasoconstrictor action in newborn lambs. Because of its short duration, this action probably should not alter the clinical use of this drug in newborn humans.

Cerebral vascular resistance in premature infants

The cerebral vascular bed is a low-resistance system in which continuous forward or advancing diastolic blood flow can be demonstrated. This advancing flow increases progressively with vasodilation and decreases or is absent when vessels are constricted. By using the Doppler technique, an indirect assessment of vascular resistance can be made by comparing systolic and diastolic flow amplitudes. We examined nine premature infants and found that respiratory acidosis alone, or hypoxia and acidosis in combination, resulted in significant vasodilation. This effect was reversible when arterial blood gas tensions returned to normal. The results indicate that within a physiologic range of BPs, premature infants with acute respiratory distress can alter their cerebral vascular resistance in response to spontaneous changes in blood gas tensions.

Hypertrophic cardiomyopathy is a component of subacute necrotizing encephalomyelopathy

Twelve patients, ranging from the neonatal period through adolescence, with subacute necrotizing encephalomyelopathy (Leigh disease) were studied. Autopsies of these patients demonstrated an associated hypertrophic cardiomyopathy in seven; of these, four had asymmetric septal hypertrophy. In two patients, the cardiac lesion was observed by premortem echocardiograms. The common occurrence of a cardiac lesion emphasizes the probable systemic nature of SNEM and may serve to segregate these patients into two groups. Because of the involvement of the two systems, we suggest that SNEM may have some relation to a variety of other cardioneurologic syndromes.