Does growth restriction increase the vulnerability to acute ventilation-induced brain injury in newborn lambs? Implications for future health and disease.

Fetal growth restriction (FGR) and preterm birth are frequent co-morbidities, both are independent risks for brain injury. However, few studies have examined the mechanisms by which preterm FGR increases the risk of adverse neurological outcomes. We aimed to determine the effects of prematurity and mechanical ventilation (VENT) on the brain of FGR and appropriately grown (AG, control) lambs. We hypothesized that FGR preterm lambs are more vulnerable to ventilation-induced acute brain injury. FGR was surgically induced in fetal sheep (0.7 gestation) by ligation of a single umbilical artery. After 4 weeks, preterm lambs were euthanized at delivery or delivered and ventilated for 2 h before euthanasia. Brains and cerebrospinal fluid (CSF) were collected for analysis of molecular and structural indices of early brain injury. FGRVENT lambs had increased oxidative cell damage and brain injury marker S100B levels compared with all other groups. Mechanical ventilation increased inflammatory marker IL-8 within the brain of FGRVENT and AGVENT lambs. Abnormalities in the neurovascular unit and increased blood-brain barrier permeability were observed in FGRVENT lambs, as well as an altered density of vascular tight junctions markers. FGR and AG preterm lambs have different responses to acute injurious mechanical ventilation, changes which appear to have been developmentally programmed in utero.

The cerebral critical oxygen threshold of ventilated preterm lambs and the influence of antenatal inflammation.

Perinatal inflammation is associated with adverse neurodevelopmental outcomes, which may be partly due to changes in the cerebral oxygen delivery/consumption relationship. We aimed to determine the critical oxygen delivery threshold of the brain of preterm, ventilated lambs and to determine whether the critical threshold is affected by exposure to inflammation in utero. Pregnant ewes received intra-amniotic injection of lipopolysaccharide or saline at 125 or 127 days of gestation. Pulmonary and systemic flow probes and catheters were surgically positioned in the fetus immediately before delivery at 129 days of gestation. After delivery, lambs were ventilated for 90 min using a positive end-expiratory pressure recruitment strategy. Cardio-respiratory variables and blood gases were measured regularly. Systemic and cerebral oxygen delivery, consumption (Fick), and extraction were calculated, and the relationship between cerebral delivery and consumption analyzed. Linear regression was used to define the transition or "critical" oxygen threshold as the point at which the slope of the oxygen delivery/consumption curve changed to be > 10°. Four subgroups were defined according to the calculated critical threshold. A total of 150 measurements were recorded in 18 lambs. Fetal cerebral oxygen consumption was increased by antenatal lipopolysaccharide (P < 0.05). The postnatal critical oxygen threshold was 3.6 ml·kg⁻¹·min⁻¹, corresponding to cerebral oxygen consumption of 0.73 ml·kg⁻¹·min⁻¹. High oxygen delivery and consumption were associated with increased pulmonary and carotid blood flow and systemic extraction compared with low oxygen delivery and consumption. No postnatal effect of antenatal inflammation was observed. Inflammation in utero increases fetal, but not postnatal, cerebral oxygen consumption. Adverse alterations to pulmonary blood flow can result in reduced cerebral blood flow, oxygen delivery, and consumption. Regardless of exposure to inflammation, there is a consistent postnatal relationship between cerebral oxygen delivery and consumption.

Tracking neonatal nosocomial infection: the continuous quality improvement cycle.

Neonatal nosocomial infection (NNI) is a major complication of neonatal care, increasing mortality, morbidity and the costs of healthcare. Management of NNI involves attention to many details of care, creating a culture of change within a neonatal unit and the implementation of a continuous quality improvement cycle. This paper describes the initiation of a quality improvement team (QIT) and the aspects of infection control bundles that have been implemented. The setting was a single large perinatal centre over a seven-year period. Statistical tracking of NNI in exceedingly premature infants was by control charting methodology. A steady and statistically significant decline in NNI rates from 13 to seven episodes per 1000 bed-days (censored to day 35) for infants less than 29 weeks of gestation has been recorded. A multidisciplinary QIT has managed the implementation of measures designed to reduce NNI in the unit. These have included raising awareness of the need for asepsis, improved hand hygiene, increased vigilance in using central lines, monitoring blood culture collection techniques and improving the environment. We believe such measures in conjunction with the positive feedback obtained from charting have been responsible for the steady decline in NNI. This study is one of the first to close the QIT loop and to demonstrate statistical improvement in NNI through the introduction of specific care bundles.

Analysis of neonatal nosocomial infection rates across the Australian and New Zealand Neonatal Network.

This paper describes the variation in neonatal nosocomial infection rates across 26 contributing units of the Australian and New Zealand Neonatal Network. Data collected during the years 2002-2004 have been analysed comprising a total of 3180 infants of <1000g birthweight and 260,694 hospital-days. Overall infection rates of 5.02 [95% confidence interval (CI): 4.75, 5.30] infections per 1000 days total admission for infants of <1000g birthweight are comparable with other published data. Censoring data to the first 35 days of admission demonstrated an infection rate of 13.88 (95% CI: 13.14, 14.65) infections per 1000 days. A standardised, expected, infection rate for each unit was calculated by correcting for gestational age and gender. Analysis of the difference between observed and expected infection rates demonstrated considerable variation in nosocomial infection rates between participating units. Three units demonstrated a nosocomial infection rate significantly (P<0.005) below the population value. Further analysis of clinical practice variations within these units may uncover potential beneficial practices for the network.

Predischarge screening of very low birthweight infants by click evoked otoacoustic emissions.

OBJECTIVE: To evaluate the role of transient evoked otoacoustic emission (TEOAE) in screening very low birthweight (VLBW) neonatal intensive care unit (NICU) graduates for hearing loss in comparison with visual reinforcement orientation audiology (VROA) at 10 months. METHODOLOGY: The study population was all VLBW neonatal survivors discharged from a single regional NICU at John Hunter Childrens Hospital (JHCH), Newcastle, New South Wales, Australia, between April 1994 and March 1996. A TEOAE screen was performed prior to discharge and repeated if necessary until a pass was obtained in at least one ear. Infants were further screened by VROA at their local Australian Hearing Services (AHS) office at 10 months corrected age. Repeated TEOAE failures were referred directly for an ENT opinion. RESULTS: A total of 193 infants were eligible for enrolment during the study period. One hundred and forty-four (75%) received TEOAE testing. The median age of first screen was 36 weeks gestational age. Ninety-five (66%) of infants tested passed on a single screen. Of the remaining 49 infants, 26 passed on retesting (overall pass rate 84%). Twenty-three (16%) were deemed to have failed the TEOAE screen. Of the 121 infants who passed TEOAE, only 67 (55%) completed VROA. Two of these infants have a high frequency sensorineural loss and one of them has been aided. In the 23 who failed TEOAE, nine have subsequently had normal VROA, another, though not tested is clinically normal. three have hearing loss with middle ear disease and eight have confirmed sensorineural deafness, all aided. One infant has died and an infant with Down's syndrome has been adopted out of the area. It is of interest to note that the eight aided infants are all of less than 28 weeks gestation. If we restrict analysis to infants with completed VROA testing, the TEOAE has a 97% negative predictive value for sensorineural deafness and a 38% positive predictive value. CONCLUSIONS: This study has highlighted both the prevalence of hearing impairment in the very premature survivors and difficulties in compliance with a VROA based hearing screen. We see an advantage in directing resources towards an early screening test, such as TEOAE, that can be applied while the target population is still captive.

Iatrogenic neonatal hypertrophic cardiomyopathy.

Transient hypertrophic cardiomyopathy is a rare sequela of both glucocorticoid and insulin excess. We report two ELBW infants who developed hypertrophic cardiomyopathy as an iatrogenic complication of the concurrent therapeutic administration of a glucocorticoid and insulin. In both cases the hypertrophic cardiomyopathy resolved completely on cessation of therapy. We advise caution when using this therapeutic combination and stress the need for regular echocardiography.

Direct inguinal hernias in the newborn.

Direct inguinal hernias occur in newborn babies, both term and premature. Five cases are reported to illustrate three types of direct hernia. The first is a direct weakness without associated significant indirect hernial sac; the second, a sliding direct hernia. The third might be called a 'secondary' direct weakness resulting from a primarily indirect hernia which assumes such large size and develops such a wide neck at the internal ring that the posterior wall of the inguinal canal is stretched and weakened. This is most likely to occur in very low birthweight babies, who develop giant inguinoscrotal hernias. Full exploration and repair of the posterior wall of the inguinal canal should be performed in such babies with huge indirect hernial sacs and in all babies where the size of the processus vaginalis identified at the internal ring is not consistent with the hernial swelling identified clinically. Repair should be performed in conventional manner with non-absorbable sutures reinforcing the transversalis fascia. Overlying Bassini repair with or without Tanner's slide can be performed. The repair should be carried out before the baby leaves a high dependency area.

Pharmacy practice in the United States Army.

The current status of pharmaceutical services in the United States Army Medical Department is described. The mission of the Army Medical Department is to ensure the health of the soldier during times of peace and war. Of the 225 commissioned pharmacy officers currently on active duty, 156 are assigned to U.S. Army medical centers and community hospitals in the United States, and 29 are stationed at hospitals in Europe, Korea, Panama, and Japan. Army pharmacy officers are supported by 879 Army-trained pharmacy technicians and 319 civilian pharmacists employed by the Army. Army Medical Department hospital pharmacies provide inpatient and ambulatory-care services as well as specialized nuclear pharmacy, oncology, investigational drug, and materials development services. Pharmacy officers assigned to the Pharmacy Branch of the U.S. Army Academy of Health Sciences conduct 17-week technician training programs six times a year and provide other pharmacy courses and continuing education programs. The U.S. Army Allergen Extract Laboratory dispenses diagnostic and immunotherapy agents by mail in response to prescriptions submitted by military allergy clinics. Pharmacy officers may be deployed with field hospitals during times of combat or for extended training exercises in places such as Egypt, Grenada, and Honduras. Pharmacy officers may also be assigned to three- or four-year tours of duty in Army hospitals located in Europe. In the future, the emphasis of Army pharmacy practice will be on the expansion of clinical pharmaceutical services and the development of advanced interactive communication systems, quality assurance programs, and peer-review programs.

Clinical pharmacy in an emergency medicine setting.

A decentralized emergency medicine clinical pharmacy program was initiated and has operated now for over 1 year. The program attempted to answer two questions: is there a viable clinical pharmacy role in emergency medicine, and could staff pharmacists successfully function in such a role without formal clinical training and experience? Initial primary objectives were to provide an on-the-spot pharmaceutical consultation service and to initiate new or expanded traditional pharmacy support to staff and patients. A secondary objective was to provide expanded outpatient prescription service to emergency room patients.

Fast and slow neutrons in an 18-MV photon beam from a Philips SL/75-20 linear accelerator.

Fast- and slow-neutron contamination in an 18-MV photon beam from a Philips SL/75-20 linear accelerator has been measured. Aluminum and indium foils were activated to determine fast- and slow-neutron fluence, which were largely independent of field sizes. Measured fast-neutron fluences were typically 13.9 X 10(4) and 4.4 X 10(4) neutrons/cm2/rad of x ray inside and 5 cm outside the field, respectively. Slow-neutron fluences, 1.3 X 10(4) neutrons/cm2/rad of x ray, remained relatively constant inside and outside the field. The reported results are about three times higher than neutron fluences recently reported with a betatron operated at the same energy.