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Biomedical subjects

J Whitehall

Publications and source records attributed to J Whitehall.

At least 19 recordsLinked to original sources
PubMed2002

Permissive hypercapnia in neonates: the case of the good, the bad, and the ugly.

Advances in neonatology have resulted in an increase in the absolute number of survivors with chronic lung disease (CLD), though its overall incidence has not changed. Though the single most important high-risk factor for CLD is prematurity, the focus of attention has recently changed over to minimizing the impact of other two risk factors: baro/volutrauma related to mechanical ventilation, and oxygen toxicity. Permissive hypercapnia (PHC) or controlled ventilation is a strategy that minimizes baro/volutrauma by allowing relatively high levels of arterial CO(2), provided the arterial pH does not fall below a preset minimal value. The benefits of PHC are primarily mediated by the reduction of lung stretch that occurs when tidal volumes are minimized. PHC can be a deliberate choice to restrict ventilation in order to avoid overdistention, while application of high airway pressures and large tidal volumes would permit normocapnia, or relative hypocapnia (PaCO(2), < or = 25-30 mmHg), but may result in CLD and be harmful to the developing lung. The current concept that PaCO(2) levels of 45-55 mmHg in high-risk neonates are "safe" and "well tolerated" is based on limited data. Further prospective trials are needed to study the definition, safety and efficacy of PHC in ventilated preterm and term neonates. However, designing disease/gestational-postnatal age-specific clinical trials of PHC will be difficult in neonates, given the diverse pathophysiology of their diseases and the various ventilatory modes/variables currently available. The potential benefits and adverse effects of PHC are reviewed, and its relationship to current ventilatory strategies like synchronized mechanical ventilation and high-frequency ventilation in high-risk neonates is briefly discussed.

Acidosis, Respiratory↗
PubMed2002

Postnatal changes in maternal and neonatal plasma antioxidant vitamins and the influence of smoking.

OBJECTIVE: To study the postnatal changes in the plasma concentrations of fat soluble antioxidant vitamins and malondialdehyde (MDA) in mothers and their newborns and their relation to smoking. DESIGN: Prospective cohort study. SETTING: Tertiary perinatal centre. SUBJECTS: Eighteen non-smoking and 14 smoking mothers and 33 infants. MAIN OUTCOME MEASURES: Plasma concentrations of vitamins E, A, and beta-carotene and MDA were measured in mothers and infants at delivery and on day 4 post partum. RESULTS: Neonatal plasma levels of vitamins E, A, and beta-carotene were significantly lower than maternal levels both at delivery and on day 4 in both groups. There was a significant postnatal increase in plasma vitamin E levels in smoking mothers and neonates of both groups. A significant postnatal increase in maternal, but not neonatal, plasma vitamin A was noted in both groups. Cord plasma vitamin E levels were significantly lower in infants of smoking mothers (mean 4.7 v 6.5 micromol/l, p = 0.041). Plasma MDA was paradoxically lower in smoking mothers at delivery (3.19 v 4.01 micromol/l, p = 0.03) and on day 4 (1.37 v 3.29 micromol/l, p = 0.005) and in infants of the smoking group on day 4 (2.18 v 3.12 micromol/l, p = 0.014). Also, there was a significant postnatal fall in plasma MDA levels on day 4 in mothers and infants in the smoking group. CONCLUSIONS: The postnatal changes in plasma vitamin E were more pronounced in the smoking group. The postnatal changes in plasma vitamins A and beta-carotene were similar in both groups. The rapid decline in plasma MDA in smoking mothers and their infants suggests withdrawal of oxidative stress from smoking around delivery. This coincided with the increase in plasma vitamin E.

Adolescent↗
PubMed2002

Congenital scoliosis in a neonate: can a neonatologist ignore it?

The frequency of diagnosis of congenital scoliosis in the neonatal period is expected to rise given the increasing survival of high risk neonates in the surfactant era and their frequent exposure to x rays. Considering its significant long term implications a neonatologist cannot afford to ignore the diagnosis of congenital scoliosis in a neonate as close surveillance, early detection, and treatment may prevent/minimise the wide spectrum of potentially serious deformities that can affect the developing spine. The review provides general guidelines to help the neonatologists in counselling the parents and in planning the multidisciplinary follow up for management of congenital scoliosis.

Counseling↗
PubMed2001

An in vitro study of the efficacy of rifampicin and minocycline coated umbilical venous catheters.

The use of antibiotic coated catheters has been proposed as a means of reducing catheter related sepsis. In this study, an in vitro comparison of bacterial colonisation rates was made between uncoated umbilical venous catheters and catheters coated with rifampicin and minocycline. The following parameters were determined; the direct antimicrobial effect of coated and uncoated catheter segments against a range of organisms associated with line sepsis, the assessment of the decline in antimicrobial activity in coated catheters immersed in plasma and the inhibitory efficacy of the catheters to colonisation over a 28-day period. Minocycline and rifampicin coated umbilical catheters showed a superior inhibitory effect and prevented colonisation with the commoner line-related organisms, when compared with uncoated catheters. The inhibitory effect declined after 14 days in the human plasma. Resistance to colonisation in vitro may not extend beyond 21 days.

Anti-Bacterial Agents↗
PubMed2001

Maternal awareness of sudden infant death syndrome in North Queensland, Australia: an analysis of infant care practices.

OBJECTIVES: To assess awareness of sudden infant death syndrome (SIDS) and risk reducing recommendations in a sample of mothers in North Queensland, Australia, and to examine their infant care practices. METHOD: Interviews conducted with 195 women using a standardized questionnaire between October 1997 and January 1998. RESULTS: 191 questionnaires analyzed; 134 (70.2%) Caucasian and 57 (29.8%) indigenous women. Four women with previous SIDS experience were excluded from the analysis. Eight (4.2%) had never heard of SIDS. Twenty-nine (15.2%) had heard of SIDS and 154 (80.6%) had heard of SIDS and could list risk recommendations to reduce its incidence. Multivariate analysis identified ethnicity as the only significant predictor of maternal knowledge. Indigenous mothers knew less about SIDS: adjusted odds ratio (OR) = 5.4; 95% confidence interval (CI) = [2.1-14.0]. Avoidance of prone sleeping was the most frequently identified recommendation (n = 132), with no smoking in pregnancy (n = 48) and breastfeeding (n = 40) identified least frequently. There were 80.2% of mothers who put their infant in non-prone positions to sleep. Only 48 (25%) women identified smoking in pregnancy, and 93 (48.6%) smoking in the infant's environment as risk factors. Indigenous women were more likely to smoke in their pregnancy (P = 0.004), bed share with their infant (P = 0.0001), and have smokers in the home. CONCLUSION: There is a high level of awareness of SIDS and the main associated risk factor of infant prone sleeping, but the link between SIDS and smoking requires further emphasis. Future campaigns should ensure the SIDS message is delivered more effectively to the indigenous communities.

Adult↗
PubMed2001

Unusual presentation of neonatal Behcets disease.

Intrauterine growth retardation and neonatal transient mucocutaneous lesions ("transient Behcet syndrome") have been reported in pregnancies complicated by Behcets disease (BD). Neonatal neurological manifestations have not been reported in such pregnancies. Vascular and neurological involvement is known to worsen the prognosis in adults with BD. The clinical course and outcome of a 34-weeks' gestation neonate born to a mother with BD is reported. Progressive recovery from minimal respiratory distress syndrome was followed by catastrophic presentation on 6th day of life with generalized seizures. Cranial ultrasound revealed multiple hyperechoic lesions in the frontal, parietal, and periventricular regions with a few surrounded by a ring of reduced echogenicity suggesting haemorrhage into ischemic areas. Death occurred after withdrawal of life support on Day 9, after extensive discussions with parents in view of the progressive deterioration in the neonates' general condition and the cranial ultrasound findings. Strong family history of BD, clinical course, and laboratory results (no evidence of disseminated intravascular coagulation, normal levels of protein C and S, absence of factor V Leiden and anticardiolipin antibodies) suggested neurological manifestations of BD as the most probable diagnosis.

Adult↗
PubMed2001

Realtime fetal ultrasound by telemedicine in Queensland. A successful venture?

We have established a realtime fetal tele-ultrasound consultation service in Queensland, which has been integrated into our routine clinical practice. The service, which uses ISDN transmission at 384 kbit/s, allows patients in Townsville to be examined by subspecialists in Brisbane, 1500 km away. For the 90 tele-ultrasound consultations performed for the first 71 patients, 90% of the babies have been delivered, and outcome data have been received on all the pregnancies. All significant anomalies and diagnoses have been confirmed. The referring clinicians would have physically referred 24 of the 71 patients to Brisbane in the absence of telemedicine. A crude cost-benefit calculation suggests that the tele-ultrasound service resulted in a net saving of A$6340, and at the same time enabled almost four times the number of consultations to be carried out.

Cost-Benefit Analysis↗
PubMed2000

Congenital varicella syndrome in the absence of cutaneous lesions.

A case of congenital varicella syndrome characterized by intrauterine growth retardation, ocular and neurologic abnormalities, but no cutaneous lesions is reported. This case highlights the risk of embryopathy from varicella infection during pregnancy in non-immune women.

Chickenpox↗
PubMed2000

Clinical value of real-time tertiary fetal ultrasound consultation by telemedicine: preliminary evaluation.

Congenital fetal abnormalities are major causes of perinatal mortality and morbidity. The performance of ultrasound in the diagnosis and assessment of fetal anomalies varies enormously between tertiary referral centers and general units. Telemedicine offers a chance for tertiary realtime ultrasound consultations using standard telephone lines for remote sites. Preliminary investigations by our group have shown that real-time transmission of fetal ultrasound images over long distances via telephone (integrated systems digital network [ISDN]) lines is technically feasible. A live link of up to 2 Mb/s was established between Mater Mothers Hospital in Brisbane and Kirwan Hospital for Women in Townsville, which are 1,500 km apart. The objective of the current study was to evaluate the clinical value of a tertiary teleultrasound consultation service. Patients requiring tertiary ultrasound consultations were recruited from North Queensland. Clinicians from the referral site established an initial diagnosis and management plan. Using standard ISDN lines, the real-time ultrasound images were transmitted to the maternal fetal medicine subspecialists in Brisbane. The ultrasound examination was completed under the direction of the subspecialist. The subspecialist explained the findings to the patient at the end of the session, and discussed the diagnosis and management plans with the clinicians involved. Any diagnosis and management variations were classified into minor and major upon agreement by the two teams of clinicians involved. The clinicians and patients in Townsville rated the value of the consultation, and the subspecialists rated the confidence of their diagnoses on five-point scales. Pregnancy outcomes were obtained and the data analyzed. Over a 3-month period, 24 teleultrasound consultations were carried out. The indications for referral were: assessment of growth restriction/fetal wellbeing in the third trimester (6); detailed assessment for high-risk patients (5); evaluation of markers for anomalies (5); isolated fetal anomalies (1); and complex fetal problems such as twin/twin transfusion, multiple anomalies, etc. (7). Overall, the consultations resulted in some modifications to the clinical diagnosis in 45.8% of the cases, and modifications to the management plan in 33.3% of the cases (about half of which were minor variations). The clinicians rated the teleconsultations highly (mean rating 4.7, SD 0.44). The patients also rated the consultations highly, and were comfortable that their privacy and confidentiality were maintained during the consultation. The subspecialists were confident in making their diagnoses by telemedicine (mean score for confidence 4.2, SD 0.43). All the pregnancies have now been completed, with all antenatal diagnoses confirmed to be correct postnatally. Tertiary real-time ultrasound consultation by telemedicine is not only technically feasible, it is welcomed by the clinicians and patients involved. It also contributes to diagnostic and management differences. Larger scale clinical trials are needed to evaluate the true benefits and costs involved. The social benefits in bridging the healthcare gap between the country and the city, and in enabling patients in remote areas to stay close to their family under times of stress is well recognized by all involved.

Congenital Abnormalities↗
PubMed1999

Hypertension-hyponatremia syndrome in neonates: case report and review of literature.

Hypertension hyponatremia syndrome occurred in a 32-week male neonate following septicemic shock on Day 9. The systolic blood pressure rose from 60 to 85 mmHg as the serum sodium dropped from 136 to 121 mmol/L associated with natriuresis, polyuria, and dehydration. Convulsions occurred at a systolic blood pressure of 102 mmHg. Investigations for hypertension revealed hyper-reninemia without cardio/renovascular or neuroendocrine abnormalities. Salt supplementation and antihypertensive therapy with captopril led to resolution of natriuresis and hyponatremia. Review of literature revealed associated renovascular pathology in all neonatal cases of the syndrome reported so far. Renal ischemia from possible renal microthrombi may have been the triggering event in our case. Decline in renin levels during follow-up favors this hypothesis.

Captopril↗