A review of selection criteria used by medical scheme advisers to approve or deny procedures with a cosmetic component.

OBJECTIVE: To review and apply statistical tests to the selection criteria used by two medical advisers to approve or deny applications for three common cosmetic or reconstructive procedures within a large group of medical schemes. DESIGN: A retrospective descriptive study which applied multiple regression analysis, frequency analysis, comparison of means and simple correlations to the data sets for three procedures. SETTING: Administrative records from the clinical files of medical advisers and the administrator's claims database. SUBJECTS: Data were reviewed for 1,143 members who, between January and December 1996, submitted applications for breast reduction, excimer laser refractive surgery, or otoplasty. MAIN OUTCOME MEASURES: The primary outcome measure was the statistical relationship between medical advisers' selection criteria and final decision. In addition, the financial implications of these cosmetic/reconstructive procedures were assessed. RESULTS: For the three procedures reviewed there was a statistically significant relationship between 5 of 13 preoperative criteria requested and the medical advisers' opinion. Excimer laser surgery was generally approved on the basis of the refractive error (myopia > -3.00; astigmatism > -1.5 dioptres); otoplasty was generally approved for children aged > or = 12 years; and breast reduction was usually covered for women with a sternal-nipple distance > 29.0 cm and with a cup size > or = DD. The other data submitted were similarly distributed between the approved and denied groups. CONCLUSIONS: Review of medical advisers' decisions is important in an era of protocols, guidelines and 'standard operating procedures'. Selection criteria for approval of applications for medically necessary cosmetic/reconstructive surgery must be reviewed and revised to provide a reliable, reproducible and statistically valid process.

The selection of infants for surfactant replacement therapy under conditions of limited financial resources.

The cost of surfactant replacement therapy (SRT) will restrict its use under conditions of limited health resources. Before the local advent of SRT, infants ventilated for hyaline membrane disease (HMD) had an overall survival rate of 87% and an incidence of bronchopulmonary dysplasia of 6.4%. This, together with the cost of SRT, prompted a study to identify those infants who would benefit the most from SRT. Twenty-two infants assessed as having severe HMD were randomised to receive SRT at 3 - 4 hours (9) or at 6 - 8 hours (13) after birth. Two infants (15%) in the latter group did not require SRT. The outcome of these two groups was the same. Of 56 infants assessed as having moderate HMD, only 24 (43%) qualified for SRT from 6 hours of age. The outcome of the SRT and non-SRT infants was comparable. The group of infants with moderate HMD had a significantly better outcome than those with severe HMD. A limited period of observation to assess the severity of illness did not compromise outcome in this group of 78 infants with moderate to severe HMD.

The cost and effectiveness of surfactant replacement therapy at Johannesburg Hospital, November 1991-December 1992.

OBJECTIVE: To assess the impact of surfactant replacement therapy (SRT) on the outcome of hyaline membrane disease (HMD) and to assess the cost implications of a policy of selective administration of artificial surfactant. DESIGN: The short-term outcome of 103 newborns ventilated for HMD (61 selected for SRT according to initial and/or ongoing oxygen requirements) was compared with that of a historical control group of 173 infants ventilated for HMD before the introduction of SRT. MAIN OUTCOME MEASURES: Mortality and morbidity of HMD including death, bronchopulmonary dysplasia, pneumothorax, pulmonary haemorrhage, patent ductus arteriosus and intraventricular haemorrhage. RESULTS: There were significant demographic differences between the treatment and control groups (black patients 74% v. 28%, P < 0.0001; unbooked mothers 72% v. 15%, P < 0.0001) as well as evidence of more severe lung disease in the treatment group (pressor support 44% v. 27%, P < 0.005; and paralysis during ventilation 38% v. 25%, P < 0.005). Pneumothorax was reduced in the SRT group (7% v. 17%, P < 0.01). There were no significant differences between the two groups in the incidence of BPD or mortality. The use of SRT added to the total cost of treating a patient ventilated for HMD. CONCLUSION: The selective use of SRT had the effect of converting severe disease into moderate disease rather than achieving maximal benefit in all cases of HMD through routine use of the product. A policy of restricting use may result in cost savings where resources are limited.

The late administration of surfactant.

Current recommendations for surfactant replacement therapy (SRT) in the treatment of hyaline membrane disease (HMD) are to administer the drug as soon as possible after starting ventilation in order to prevent ventilator lung damage. We present a review of 18 infants (gestational age 32.4 +/- 1.9 weeks and birth weight 1,795 +/- 427 g) who received the initial dose of SRT after they were 12 hours old. Fourteen infants were assessed as having HMD and 4 as having congenital pneumonia. Overall there was a significant and sustained improvement in oxygenation as measured by arterial/alveolar oxygen ratios. The outcome of these infants was good, with a duration of ventilation of 7.9 +/- 4.3 days and a duration of hospitalisation of 26.2 +/- 12.6 days. No infant developed bronchopulmonary dysplasia. Of particular interest is that 3 infants weighing > 2,400 g with congenital pneumonia responded to a single delayed dose of SRT. Late SRT is effective and there may be a place for SRT in the treatment of conditions other than HMD.

Human B19 parvovirus infection in an obstetric population. A prospective study determining fetal outcome.

In a prospective study of 1,967 pregnant women who were routinely screened for recent human B19 parvovirus infection, 64 (3.3%) were identified as being IgM positive. No adverse effects were documented by ultrasound in any of the fetuses. The outcome of pregnancy was favorable in 95.1% of these women, with no evidence of hydrops fetalis or any congenital abnormalities. Two neonates (3.4%) were small for gestational age, and there was one abortion. Samples of blood obtained from 20 neonates born to women with evidence of recent infection were B19 parvovirus IgM negative. Recent infection with human B19 parvovirus in pregnancy constitutes a low risk for the development of adverse fetal effects; hence, routine antenatal screening is not warranted.

Bandwidths of respiratory gas flow and pressure waveforms in mechanically ventilated infants.

The frequency content of airway pressure and gas flow in mechanically ventilated infants (MVIS) has not been adequately investigated. Pressure-cycled infant ventilators generate pressure pulses with short rise-times. Gas flow is approximately equal to the derivative of pressure when lung compliance is low, and hence contains high-frequency components. We defined bandwidth as that frequency fm below which 99.9% of the energy of the signal resided. Simulation of the measurement process using measurement systems with frequency response similar to sixth-order Bessel filters and a lung model comprising series resistance, inertance and compliance showed that measurement systems with frequency response flat +/- 10% to fm yield time domain errors less than 3% of the peak value. We digitized pressure and flow signals from 10-20 ventilator (Healthdyne 105) breaths in 33 stable MVIS. The transducers' (Gould P50, Hans Rudolph 8300 screen pneumotach) frequency responses had been measured between 1 Hz and 100 Hz and phase matched at 10 Hz. We calculated total respiratory resistance R and elastance E using multiple linear regression, and ensemble-average power spectral density using the FFT with a rectangular time window and padding to 2048 points. Power spectra were compensated for non-unity transducer and anti-alias filter responses up to 60 Hz. Measured data sequences that were not self-windowing due to spontaneous breathing efforts, that yielded regression R2 < 0.95 or that contained flow oscillations due to secretions in the airway were discarded. Satisfactory results were obtained from more than eight breaths in 18 infants. Mean bandwidths (+/- SD) of pressure and flow waveforms were 4.7 +/- 0.7, range 3.5-5.9 and 19.6 +/- 6.5, range 10.8-32.1 Hz, respectively. Flow bandwidths B correlated with the respiratory time constant tau (B = -77.2 tau + 26.8, R2 = 0.55, P < 0.0002), and with elastance E (B = 61.4E + 10.1, R2 = 0.74, P < 0.0001). We conclude that the bandwidth of the flow waveform increases with decreasing compliance and mechanical time constant. The frequency response of pressure and flow measurement systems should be flat +/- 10% at least up to 6 and 32 Hz respectively to obtain data with dynamic errors less than 3% in infants with low-compliance lung disease.

Does hypoxemia prevent brain damage in birth asphyxia?

The clinical syndrome of hypoxic ischemic encephalopathy (HIE) which occurs in association with birth asphyxia, is thought to represent a reperfusion injury consequent upon the generation of cytotoxic oxygen derived free radicals. It has recently been suggested that resuscitation of asphyxiated infants with unrestricted oxygen may aggravate the brain damage by causing hyperoxia and increased free radical production. To determine whether sustained hypoxemia may be protective in birth asphyxiated infants, we investigated the relationship between HIE and persistent pulmonary hypertension of the neonate (PPHN). The latter condition is also related to intrauterine and intrapartum birth asphyxia but is associated with persistent hypoxemia in the infant. In a retrospective analysis of 39 asphyxiated neonates admitted to the neonatal intensive care unit, we found that 28 had HIE, 10 had PPHN and only 1 had both HIE and PPHN. We therefore suggest that the hypoxemia due to PPHN may limit the production of oxygen derived free radicals in asphyxiated neonates and hence protect against the development of HIE. These findings lend support to current research into air vs. oxygen resuscitation for infants with birth asphyxia.

Effect of stress on birth weight in two Johannesburg populations.

The effect of stress on birth weight was assessed in mothers delivering at Johannesburg (predominantly white) and Baragwanath (exclusively black) Hospitals. The Social Readjustment Rating Scale of Holmes and Rahe was used to assign maternal stress scores established during an interview conducted within 36 hours of delivery. Only mothers without medical problems who had delivered liveborn infants were included. Maternal age, obstetric history, smoking history and stresses present during the 12 months preceding delivery were recorded. Of 535 Johannesburg and 662 Baragwanath mothers studied, 48% and 55% respectively reported significant stresses. Analysis of the two groups revealed that for the Johannesburg mothers, smoking, cumulative stress score and previous preterm birth were important determinants of birth weight. Of the stress factors studied, marital separation and death of a spouse were significantly associated with a lower birth weight. For Baragwanath mothers the major determinants of low birth weight were maternal age, loss of income through being dismissed from work, or having to leave school as a consequence of the pregnancy.

Effect of Intralipid infusion on transcutaneous oxygen and carbon dioxide tension in sick neonates.

We evaluated the change in transcutaneous oxygen (tcPo2) and carbon dioxide (tcPco2) tension in response to 60 minutes' infusion of Intralipid (Kabi Vitrum (Saphar] (mean dose (0.16 +/- 0.07 g/kg/h) in neonates with lung disease (hyaline membrane disease or bronchopulmonary dysplasia). The tcPo2 was 10% lower following Intralipid infusion (P less than 0.05), whereas no significant change occurred in tcPco2 measurements. The data confirm the need for limited use of Intralipid in this category of patients.

Tracheal aspirate cytology and bronchopulmonary dysplasia.

Sequential tracheal aspirates from 39 neonates with hyaline membrane disease were examined to correlate cytological findings with the development of bronchopulmonary dysplasia (BPD). A total of 224 tracheal aspirates were examined from these infants, 15 of whom developed BPD as diagnosed by conventional clinical and radiological criteria. Hyperplastic and metaplastic epithelial changes were observed in all infants studied. Dysplastic changes occurred in 14 of 15 who developed BPD, and 14 of 24 who had a normal outcome (P less than 0.02). The exfoliation of dysplastic metaplastic bronchial cells was thus 95% specific and 71% sensitive for the subsequent development of BPD. Factors associated with the development of BPD were very low birth weight and gestational age, persistence of a patent ductus arteriosus, high peak inspiratory pressure (cm of H2O/kg), prolonged assisted ventilation, and rapidity of development of class III (dysplastic) changes in tracheal aspirates.

Hypertension as the major problem of idiopathic arterial calcification of infancy.

We describe two infants with severe hypertension associated with idiopathic arterial calcification of infancy. In both children, blood pressure control was refractory to aggressive antihypertensive therapy. There was radiologic and laboratory evidence of renovascular disease requiring the use of specific renin antagonists and later nephrectomy, resulting in moderate improvement of hypertension. Although on occasion there is a familial incidence, in the vast majority of cases the diagnosis hinges on a high index of suspicion.

Changes in mean esophageal pressure during early recovery in mechanically-ventilated neonates--evidence for airway-closure and gas-trapping?

We studied transmission of a constant mean airway pressure through the lungs to the pleural space in nine mechanically-ventilated neonates with low-compliance lung disease. Infants were studied for 3.1 +/- 1.6 hr during a period of clinical improvement, but at a time when lung compliance was still markedly reduced. Two of our infants were studied during recovery from fluid overload, while seven infants with hyaline membrane disease were studied at a stage of disease during which maximal diuresis has been found to occur. During the study period, mean esophageal pressure decreased in all infants from 5.6 +/- 1.3 to 4.2 +/- 1.8 cm H2O (P less than 0.001) while total compliance increased slightly.