How has research in the last 5 years changed my clinical practice?

This paper considers some of the changes in practice that have occurred in the last 5 years. There have been significant improvements in parental involvement in care. Not all changes have been based on evidence from research: practice has also been affected by changing technology and pressure by industry and other groups. Among the research-based changes were: an awareness of confidentiality, individualised developmental care, increased use of inhaled nitric oxide, therapeutic hypothermia, less postnatal steroids (although the dosage used is not evidence-based), sucrose as analgesia and permissive hypotension.

Additional therapy for young children with spastic cerebral palsy: a randomised controlled trial

OBJECTIVES

To investigate whether, in the short and medium term, additional support by (a) a physiotherapy assistant improved physical function in young children with spastic cerebral palsy and (b) a family support worker improved family functioning.

DESIGN

This was a multi-centre randomised controlled trial (RCT) with blinded assessments and a cost-effectiveness analysis. The children studied had spastic cerebral palsy that was the consequence of perinatal adversity. All were less than 4 years old on entry to the study.

SETTING

In the child development centre and in the home.

PARTICIPANTS

Seventy-six families completed the intervention period. Forty-three families were reassessed 6 months after the end of the intervention and 34 of these after a further 6-month period.

INTERVENTIONS

Randomisation was to: (a) a group who received extra physiotherapy from a physiotherapy assistant; (b) a group who received standard physiotherapy; and (c) a group where the child received standard physiotherapy and the family was also visited by a family support worker. Children in all groups continued to receive standard physiotherapy in addition to the study interventions.

MAIN OUTCOME MEASURES

The child outcome measures were motor functioning, developmental status and adaptive functioning. The family outcome measures were self-reported maternal stress, level of family needs and parental satisfaction.

RESULTS

There was no evidence that additional physical therapy for 1 hour per week for 6 months by a physiotherapy assistant improved any child outcome measure in the short or medium term. Intervention by a family support worker did not have a clinically significant effect on parental stress or family needs. Over the 6-month period the total cost of services for each child ranged from 250 pounds to 6750 pounds, with higher costs associated with children with more severe impairments. No significant relationship was found between measures of intensity of services received by the children and families and the main outcome measures. Low-functioning children, in terms of both motor and cognitive function, were more likely to receive more services in terms of range and frequency. Parents generally reported high satisfaction ratings after all interventions and some stated that the interventions had benefited the child and/or the family. There was therefore a discrepancy between the perceptions of these parents and the objective, quantitative measurements. The family support workers identified a small number of families who were experiencing considerable family problems, but who had not been referred for appropriate support by any other agency.

CONCLUSIONS

The findings of this study provide support for the current literature that there was no evidence that additional intervention (in this case by a physiotherapy assistant or family support worker) helped the motor or general development of young children with spastic cerebral palsy. Nor was there any quantitative evidence that providing extra family support helped levels of parental stress and family needs. The implication was that the provision of extra physical therapy does not necessarily improve the motor function of a young child with cerebral palsy and additional family support should not automatically be assumed to be beneficial. In addition, no significant association was found between the intensity of the local services provided and any outcome measure, other than a slight association with lowered family needs. The provision of local services was related to the severity of the child's impairments and not to family difficulties. A small group of families with complex family problems needed more service input. There was a wide range in the costs of services. Research is needed to examine what 'sufficient' levels of provision or therapy might be for which children and which families. A time series of different levels of input and outcomes would provide valuable information for practitioners. It is also recommended that future assessments of therapies of this type adopt a similar multifaceted approach, which is likely to be more suitable than a simple RCT for the evaluation of clinical interventions where the effects are complex. The most appropriate measures of outcome should be used, including assessment of provision of information and emotional support for families.

Congenital brachial palsy: incidence, causes, and outcome in the United Kingdom and Republic of Ireland

OBJECTIVES

To determine the incidence and study the causes and outcome of congenital brachial palsy (CBP).

DESIGN

Active surveillance of newborn infants using the British Paediatric Surveillance Unit notification system and follow up study of outcome at 6 months of age.

SETTING

The United Kingdom and Republic of Ireland.

PARTICIPANTS

Newborn infants presenting with a flaccid paresis of the arm (usually one, rarely both) born between April 1998 and March 1999.

MAIN OUTCOME MEASURES

Extent of the lesion at birth and degree of recovery at 6 months of age.

FINDINGS

There were 323 confirmed cases giving an incidence of 0.42 per 1000 live births (1 in 2300). Significant associated risk factors in comparison with the normal population were shoulder dystocia (60% v 0.3%), high birth weight with 53% infants weighing more than the 90th centile, and assisted delivery (relative risk (RR) 3.4, 95% confidence interval (CI) 2.9 to 3.9, p = 0.0001). There was a considerably lower risk of CBP in infants delivered by caesarean section (RR 7, 95% CI 2 to 56, p = 0.002). At about 6 months of age, about half of the infants had recovered fully, but the remainder showed incomplete recovery including 2% with no recovery. The relative risk of partial or no recovery in infants with extensive lesions soon after birth compared with those with less extensive lesions was 11.28 (95% CI 2.38 to 63.66, p = 0.000005).

CONCLUSIONS

The incidence of CBP in the United Kingdom and Republic of Ireland is strikingly similar to that previously reported nearly 40 years ago. Most cases are due to trauma at delivery, which is not necessarily excessive or inappropriate. Given the uncertainty about the appropriate management of these infants, serious consideration should be given to a formal clinical trial of microsurgical nerve repair.

An improved morphological approach to background normalization of ECG signals

This paper describes an improved morphological approach to remove baseline wander from neonatal electrocardiogram (ECG) signals, with particular emphasis on preserving the ST segment of the original signal. The algorithm consists of two stages of morphological processing. First, the QRS complex and impulsive noise component due to skeletal muscle contractions etc., are detected and removed from the input signal. Second, the corrected QT interval (QTc) and RR interval are used to determine a structuring element. With this structuring element, the same morphological operation as in the first stage is then applied to the QRS-removed signal to obtain and remove the baseline wander. The performance of the algorithm is evaluated with simulated and real ECGs. Compared with an existing morphological method, there is a substantial improvement, especially in reducing distortion of the baseline waveform within the PR and QT intervals.

Effect of blood transfusion on lipid peroxidation in preterm infants

OBJECTIVE

To see whether there was a link between blood transfusion and lipid peroxidation as measured by urinary malondialdehyde (MDA) concentration in preterm infants.

METHODS

Urine samples were collected before and after blood transfusions in preterm infants. Twenty blood transfusion episodes were studied in 12 infants (some infants were studied on more than one occasion). Twenty two infants who had not received a transfusion were used as controls. All infants were preterm and less than 1500 g birth weight. Urinary MDA was measured using a thiobarbituric acid assay and expressed as nmol/mg creatinine.

RESULTS

The median (interquartile range) urinary MDA concentration before transfusion was 9.1 (6.4-12.6) nmol/mg, and was not significantly different from that in the 22 non-transfused infants (11.3 (7.3-15.6) nmol/mg). There was a significant increase 24 hours after transfusion to 14.6 (7.3-23.7) nmol/mg, but it decreased to 10.1 (6.6-15.4) nmol/mg when measured a median (range) of 6 (3-9) days later.

CONCLUSIONS

Blood transfusions were associated with evidence of increased lipid peroxidation. If lipid peroxidation contributes to the pathogenesis of retinopathy of prematurity and chronic lung disease, these results suggest an explanatory mechanism.

A pilot randomised controlled trial of peripheral fractional oxygen extraction to guide blood transfusions in preterm infants

BACKGROUND

Peripheral fractional oxygen extraction (FOE) may be a better indicator of the need for transfusion than the haemoglobin concentration (Hb) because it is a measure of the adequacy of oxygen delivery to meet demand. A randomised controlled trial of the use of peripheral FOE to guide the need for blood transfusions in preterm infants was carried out to test this hypothesis.

METHOD

Infants less than 1500 g birth weight who were stable and less than 2 weeks old were randomised to receive transfusions guided by either a conventional protocol based on Hb (conventional group) or a protocol based on measurements of peripheral FOE made by near infrared spectroscopy (NIRS group). Measurements of Hb and FOE were made on all infants from randomisation until discharge. The primary outcome measures were number of transfusions received, rate of weight gain, and postmenstrual age at discharge.

RESULTS

Thirty seven infants were randomised to each group. Birth weight (median, range) (1200, 1004-1373 v 1136, 1009-1285 g) and Hb (median, range) at randomisation (160, 149-179 v 155, 145-181 g/l) did not differ between the two groups. The total number of transfusions given to the NIRS group was 56 and to the conventional group 84. The median number of transfusions per infant, the median volume of blood transfused to each group, and the total number of donors to which infants were exposed were similar in the two groups. Infants transfused according to the conventional protocol were more likely to be transfused earlier and at a higher Hb than those transfused in the NIRS group. Infants in the conventional group spent a significantly shorter period than those in the NIRS group with Hb < 100 g/l. Of the 56 transfusions given to the NIRS group, 33 (59%) were given because of clinical concerns rather than because of high FOE. There was no difference in the rate of weight gain, rate of linear growth, postmenstrual age at discharge, or the incidence of chronic lung disease or retinopathy of prematurity.

CONCLUSIONS

FOE measurements failed to identify many infants felt by clinicians to require blood transfusion. This may have been because clinicians relied on conventional indicators of transfusion that are vague and non-specific, or a peripheral FOE of 0.47 alone may not be a sensitive enough predictor of the need for transfusion. This requires further study.

Dependency level of babies on the neonatal unit: a comparison of two different classification systems

BACKGROUND

Monitoring activity on the neonatal unit is important for planning service provision and as part of monitoring quality of care. The dependency level of the patients cared for must be taken into account as well as the number of patients. Two different systems for determining dependency level are in common use.

AIM

To develop a system that would allow the accurate determination of dependency level for babies in our care using both the British Association for Perinatal Medicine and Neonatal Nurses Association definitions and the Northern Neonatal Network definitions and to perform a comparison between these two systems.

METHOD

Forty details relating to current clinical status and treatment being given were recorded daily for every patient on two neonatal units over a 17 month period. These details were recorded in a computer database, and dependency levels were calculated for each patient day using both systems.

RESULTS

A total of 21 905 patient days were recorded for 1555 patients. There was good agreement between the two systems on what constituted the highest level of dependency, but overall comparability was poor, with the two systems assigning comparable dependency levels to only 76% of patient days.

CONCLUSIONS

There is limited comparability in dependency levels between these two widely used systems. There is a need for a standardisation of definitions to allow meaningful comparisons to be made between units.

Blood pressure and tissue oxygenation in the newborn baby at risk of brain damage

A cardinal aim of neonatal intensive care is the maintenance of an adequate oxygen supply to the tissues, particularly the brain. This process depends on several factors. These include an adequate blood oxygen content, blood flow to the tissues and the ability of cells to extract and utilise oxygen. Oxygen carriage depends on ventilation and haemoglobin concentration and type. Blood flow depends on cardiac output (in turn dependent on cardiac contractility, heart rate, blood pressure and vascular resistance). Different tissues also have different oxygen demands depending on their oxygen consumption, which are likely to vary within the tissue itself and with the activity of the infant. This paper discusses evidence that suggests that even in preterm neonates, cerebral blood flow may be independent of blood pressure, and that even very low cerebral blood flow seems to be consistent with healthy survival. Evidence is considered that cardiac output rather than blood pressure may be more important in determining brain tissue oxygenation. We have found a negative correlation between cardiac output and cerebral oxygen extraction in preterm infants, but no relationship between mean arterial blood pressure and cerebral oxygen extraction.

Peripheral fractional oxygen extraction and other measures of tissue oxygenation to guide blood transfusions in preterm infants

The physiological effects of anemia in the preterm infant are complex and the indications for transfusions in preterm infants are controversial. A measure of the adequacy of tissue oxygenation may be a better guide to the need for transfusions than currently used criteria. This article considers 2 measures of tissue oxygenation of preterm infants: 1) The whole blood lactate concentration, and 2) Peripheral fractional oxygen extraction (FOE) by using near infrared spectroscopy. Several studies have shown falls in blood lactate concentration after blood transfusion, but it has been difficult to establish a convincing link between raised lactate concentrations and significant anemia because even anemic infants have lactate concentrations that are within or close to the normal range. Lactate concentrations may be affected by the haematocrit of the blood sample. Peripheral FOE can be measured by using near infrared spectroscopy with partial venous occlusion and has been studied in preterm infants with symptomatic and asymptomatic anaemia. Mean (SD) FOE was significantly higher in symptomatic [0.425 (0.06)] (P< .01) but not asymptomatic [0.334 (0.05)] compared to controls [0.352 (0.06)], (P = .22). After transfusion there was a significant fall in FOE in symptomatic infants to 0.367 (0.06) (P = .001) but there was no change in infants who were asymptomatic. FOE correlated with other measures known to reflect the adequacy of oxygen availability during anemia. These results suggest that peripheral FOE may be suitable as a guide to the need for blood transfusions. A pilot randomized controlled trial is currently being undertaken to test this hypothesis.

Interventions for the treatment of twin-twin transfusion syndrome

BACKGROUND

Twin-twin transfusion syndrome, a condition affecting monochorionic twin pregnancies, is associated with a high risk of perinatal mortality and morbidity. A number of treatments have been introduced to treat the condition but it is unclear which intervention improves maternal and fetal outcome.

OBJECTIVES

The objective of this review was to evaluate the impact of treatment modalities in twin-twin transfusion syndrome.

SEARCH STRATEGY

We searched The Cochrane Pregnancy and Childbirth Trials Register and Cochrane Controlled Trials Register. We also searched conference proceedings and made personal contact with experts active in the area of the review. Date of last search: August 2000.

SELECTION CRITERIA

Randomised and quasi-randomised studies of amnioreduction versus laser coagulation, septostomy versus laser coagulation or septostomy versus amnioreduction.

DATA COLLECTION AND ANALYSIS

Eligibility was assessed by one reviewer. Study authors were contacted for additional information.

MAIN RESULTS

No studies were included.

REVIEWER'S CONCLUSIONS

There is no current evidence from randomised trials to influence practice. Three ongoing randomised studies have been identified.

Intervention after brain injury to reduce disability

After perinatal brain injury, motor function is generally more severely affected than cognition. This article reviews the evidence that intervention after brain injury can reduce disability. There have been few good quality randomized controlled trials. The reasons for this and the difficulties of doing such trials are discussed. The main reasons are: (i) cerebral palsy (CP) is a relatively rare condition; (ii) the patient population is heterogeneous; (iii) different patterns of CP have different prognoses; (iv) a variety of interventions have been used; and (v) outcome measures are relatively poor. Intervention for children considered at risk of developing CP have generally shown no benefit. After children have developed spastic CP, there is a suggestion of some effect due to increasing the frequency of intervention. The precise role of the therapist remains unclear: support of the family may be as important as physical therapy.

Determinants of cerebral fractional oxygen extraction using near infrared spectroscopy in preterm neonates

Cerebral fractional oxygen extraction (FOE) represents the balance between cerebral oxygen delivery and consumption. This study aimed to determine cerebral FOE in preterm infants during hypotension, during moderate anemia, and with changes in the PaCO2. Three groups of neonates were studied: stable control neonates (n = 43), anemic neonates (n = 46), and hypotensive neonates (n = 19). Cerebral FOE was calculated from the arterial oxygen saturation measured by pulse oximetry, and cerebral venous oxygen saturation was measured using near infrared spectroscopy with partial jugular venous occlusion. Mean +/- SD cerebral FOE was similar in control (0.292+/-0.06), anemic (0.310+/-0.08; P = 0.26), and hypotensive (0.278+/-0.06; P = 0.41) neonates. After anemic neonates were transfused, mean +/- SD cerebral FOE decreased to 0.274+/-0.05 (P = 0.02). There was a weak negative correlation with the hemoglobin concentration (n = 89, r = -0.24, P = 0.04) but not with the hemoglobin F fraction (n = 56, r = 0.24, P = 0.09). In the hypotensive neonates, there was no relationship between cerebral FOE and blood pressure (n = 19, r = 0.34, P = 0.15). There was a significant negative correlation between cerebral FOE and PaCO2 within individuals (n = 14, r = -0.63, P = 0.01), but there was no relationship between individuals (n = 14, r = 0, P = 1). Cerebral FOE was not significantly altered in neonates with either mild anemia or hypotension. There were, however, changes in cerebral FOE when physiological changes occurred over a relatively short period: Cerebral FOE decreased after blood transfusion and increased with decreasing PaCO2. As no change in cerebral FOE was seen during hypotension, it was speculated that cerebral oxygen delivery may have been maintained by cerebral blood flow autoregulation.

Peripheral oxygenation in preterm infants

When tissue oxygenation is impaired, compensatory mechanisms occur, including a redistribution of blood flow in order to maintain oxygen delivery to vital organs, resulting in a fall in peripheral blood flow. Monitoring peripheral oxygenation therefore has potential benefits as it may provide an early warning of changes in the state of tissue oxygenation. Clinical assessments of the state of peripheral perfusion are common, and several physiological measurements have been described or used which are able to monitor peripheral oxygenation. Some of the available methods and their clinical implications will be reviewed. Near infrared spectroscopy is a particularly promising technique that has only recently been used in the preterm neonate to quantify peripheral oxygenation. It may be of potential value in understanding pathophysiological changes that occur in certain situations and needs further assessment to determine whether it may be useful to guiding clinical interventions.

Peripheral oxygenation in hypotensive preterm babies

Monitoring oxygenation in peripheral tissues of preterm babies may be useful in understanding the redistribution of blood flow during hypotension. Hemoglobin flow and venous saturation were measured in the forearm using near infrared spectroscopy with venous occlusion and were used to calculate fractional oxygen extraction, oxygen delivery, and oxygen consumption. Thirty ventilated preterm babies (median birth weight 976 g) were studied; 15 were hypotensive and 15 normotensive. Treatment for hypotension was dopamine alone (median dose 5 microg/kg/min) in eight cases, 4.5% human albumin solution (20 mL/kg) with dopamine in five cases, and only a blood transfusion (20 mL packed cells/kg) in two cases. There was a weak correlation between hemoglobin flow and mean arterial blood pressure (r = 0.40, p = 0.03). In hypotensive compared with normotensive babies, there was a significantly lower median hemoglobin flow (10.2 versus 20.2 micromol/100 mL/min, p = 0.0006), forearm oxygen delivery (37.8 versus 75.2 micromol/100 mL/min, p = 0.0008), and oxygen consumption (11.0 versus 23.9 micromol/100 mL/min, p = 0.006), but the fractional oxygen extraction (0.327 versus 0.306, p = 0.48) and the blood lactate concentration (1.22 versus 1.20 mmol/L, p = 0.44) were similar. Following treatment of hypotension, oxygen delivery (p = 0.02) and oxygen consumption (p = 0.04) increased to 64.2 and 21.7 micromol/100 mL/min, respectively, but fractional oxygen extraction (p = 0.81) and blood lactate concentration (p = 0.94) after treatment were unchanged. VO2 was variable in the forearm of human infants. It reduced when DO2 was low, and there was no evidence of tissue injury or switch to anaerobic metabolism. Measurements of peripheral tissue oxygenation seem to be of some value in understanding the pathophysiologic changes that occur with hypotension.

Three year visual outcome for treated stage 3 retinopathy of prematurity: cryotherapy versus laser

BACKGROUND/AIMS

In the management of retinopathy of prematurity (ROP), several studies have demonstrated laser photocoagulation to be as effective as cryotherapy in reducing the incidence of unfavourable structural outcome. However, few data are available on the functional outcome. The 3 year visual acuity outcome of infants treated with laser or cryotherapy in a neonatal unit is presented.

METHODS

The case notes of 34 infants (64 eyes) treated with cryotherapy, between 1989 and 1992, and 32 infants (59 eyes) treated with laser, between 1992 and 1995, were reviewed.

RESULTS

In the cryotherapy group 69% of eyes had a favourable structural outcome. Of these structurally successful eyes 62.5%, 35.0%, and 33.3% of eyes had visual acuities within normal limits at the 12 month, 24 month, and 36 month corrected age milestones respectively. In the laser group 93% of eyes had a favourable structural outcome. Of these structurally successful eyes 96.4%, 66.7%, and 59.5% of eyes had visual acuities within normal limits at the 12 month, 24 month, and 36 month corrected age milestones respectively.

CONCLUSION

In the management of ROP, when laser photocoagulation induces a structurally successful result, the potential for normal visual acuity development at 3 years is high. Whether the poorer functional outcome of the eyes treated with cryotherapy is an artefact of the historical nature of the study or as a result of an adverse effect of the destructive transcleral application is unknown.

Measurement of cerebral oxygen consumption in the human neonate using near infrared spectroscopy: cerebral oxygen consumption increases with advancing gestational age

Measurements of cerebral oxygen consumption (CVO2) may improve our understanding of cerebral oxygenation, but there are few published data for sick neonates. Although cerebral maturation is associated with an increase in cerebral glucose consumption, the relationship between CVO2 and increasing gestational age has not previously been assessed in humans. The aims of this study were to evaluate a noninvasive method for the estimation of CVO2 in the neonate using near infrared spectroscopy, and to investigate the relationship between gestational age and CVO2. Twenty babies who were undergoing intensive care in the neonatal period were studied. Cerebral hemoglobin flow (CHbF) and cerebral venous oxyhemoglobin saturation (CSVO2) were measured using near infrared spectroscopy. Arterial oxyhemoglobin saturation was measure by pulse oximetry (SpO2). CVO2 was calculated from the equation: CVO2=CHbF x (SpO2 - SvO2 x 4. The median (range) CVO2 was 0.9 (0.52-1.76) mL x 100 g(-1) min(-1). There was an increase in CVO2 with advancing gestational age (n=20, p=0.55, p=0.014). We conclude that CVO2 can be estimated in sick neonates using noninvasive optical methods. The values obtained are similar to those obtained in other studies by more invasive methods, and are in agreement with values which would be expected from the known rate of cerebral glucose consumption in neonates. Mean (SD) CVO2 at 24-26 wk was 0.5 (0.18) mL x 100 g(-1) min(-1) and rose with increasing gestation to term by 0.03 mL x 100 g(-1) min(-1) per wk.

Peripheral oxygenation and anemia in preterm babies

A measurement of tissue oxygenation may be a better marker of transfusion need than the Hb concentration. Peripheral fractional oxygen extraction, oxygen consumption, and oxygen delivery were measured noninvasively using near infrared spectroscopy in babies, some of whom were given blood transfusions. The above indicators of oxygenation were measured in 96 preterm babies. The decision to transfuse was based on a standard protocol. Transfusions were not considered necessary for babies in group 1 but were given to those in groups 2 (asymptomatic) and 3 (symptoms attributed to anemia). Hb and Hb fraction F (HbF) were measured in each baby. Oxygenation, Hb, and HbF measurements were made again 12-24 h after transfusion, and red cell volume (RCV) was calculated. Fractional oxygen extraction was significantly higher in symptomatic (0.43 +/- 0.06) but not asymptomatic (0.33 +/- 0.05) babies compared with control subjects (0.35 +/- 0.06). Oxygen consumption and oxygen delivery were similar in the three groups before transfusion. After transfusion the mean fractional oxygen extraction fell significantly in symptomatic but not in asymptomatic babies. There was no significant change in either oxygen consumption or oxygen delivery in symptomatic babies. The asymptomatic group had no change in oxygen extraction or oxygen consumption after transfusion, although oxygen delivery increased significantly. Fractional oxygen extraction correlated with HbF (n = 66, r = 0.49, p < 0.001) and RCV (n = 19, r = -0.48, p = 0.04) and there was a weak correlation with Hb (n = 94, r = -0.21, p = 0.04). Peripheral fractional oxygen extraction monitored noninvasively correlated with variables known to determine oxygen availability to the tissues, namely RCV and HbF, and was higher in babies with symptomatic anemia and decreased after transfusion.

Cerebral oxygenation during cardiopulmonary bypass

Cerebral fractional oxygen extraction (FOE) was monitored in 30 children, using near infrared spectroscopy during cardiopulmonary bypass, to investigate the effect of hypothermia and circulatory arrest. One group of children (n = 15) underwent profound hypothermia with total circulatory arrest (n = 8) or continuous flow (n = 7). Another group (n = 15), of whom only one had circulatory arrest, underwent mild (n = 6) or moderate (n = 9) hypothermia. The mean FOE (SD) before bypass was 0.35 (0.12) and this correlated negatively with the preoperative arterial oxygen content (r = -0.58). Between the stage of cooling on bypass and cold bypass there was a reduction in FOE in all groups. Between cold bypass and rewarming there was an increase in FOE only in the groups with continuous flow. In the circulatory arrest group, the FOE remained low during rewarming and was significantly lower than that of the continuous flow group. No patients died and none had neurological abnormalities postoperatively. Apparent changes in oxidised cytochrome oxidase concentration were also monitored using near infrared spectroscopy. There was a fall in cytochrome aa3 on starting cardiopulmonary bypass, but there were no significant differences in the changes in cytochrome aa3 between any stage in any of the patient groups. Using this non-invasive technique, cooling was shown to reduce cerebral FOE. During rewarming on bypass there was an increase in cerebral FOE only in patients who had had continuous flow bypass. In contrast, the cerebral FOE in those with circulatory arrest remained constant after arrest and during the duration of the study. This may have implications for the timing of hypoxic brain injury.

Measurement of venous oxyhaemoglobin saturation in the adult human forearm by near infrared spectroscopy with venous occlusion

Measurement of the oxygenation of the peripheral tissues provides useful information about tissue perfusion. A method is described for the measurement of peripheral venous oxyhaemaglobin saturation (SvO2) in the adult forearm by a noninvasive technique, near infrared spectroscopy (NIRS) with venous occlusion. A series of studies is performed on healthy adults to compare measurements of forearm SvO2 made by NIRS with measurements of superficial venous SvO2 made by co-oximetry, and to study the effect of different optode spacings. There is a significant correlation between forearm SvO2 measured by NIRS and SvO2 of superficial venous blood measured by co-oximetry (n = 19, r = 0.7, p < 0.0001). Higher values for SvO2 were obtained using a 2.5 cm spacing than with a 4 cm spacing (mean difference = 4.1% (95% CI 1.4%-6.8%) n = 16). This difference is likely to have been due to a more superficial volume of tissue being studied with the closer optode spacing. Peripheral SvO2 can be measured non-invasively using NIRS with venous occlusion. It may prove to be a useful method to study circulatory disturbances.

A randomized controlled trial of early physiotherapy for high-risk infants

The aim of this study was to investigate the hypothesis that infants at high risk of cerebral palsy would benefit from early physiotherapy. In total, 105 infants with abnormal cranial ultrasound scans were randomized at around term to early physiotherapy or standard treatment (delaying physiotherapy until abnormal physical signs became apparent). At 12 and 30 months there were clinical and objective assessments. Nine infants died and nine were lost to follow-up by 12 months when 87 infants were assessed. One other child had died and three others were lost to follow-up by 30 months when 83 children were assessed. Cerebral palsy was only accurately predicted in 45 (54%) infants. There was no difference in outcome. The difficulty of predicting cerebral palsy reliably and the heterogeneity of the condition should be borne in mind when planning treatment and assessing its efficacy.

The measurement of peripheral venous oxyhemoglobin saturation in newborn infants by near infrared spectroscopy with venous occlusion

A novel, noninvasive method for measuring peripheral venous oxygen saturation (Svo2) in newborn infants using near infrared spectroscopy (NIRS) with venous occlusion is described, along with a comparison with co-oximetry of peripheral venous blood. Peripheral Svo2 was measured in 16 newborn infants by NIRS with venous occlusion, and the results were compared with those obtained by co-oximetry of blood from a forearm vein. There was a significant correlation between the two measurements (r = 0.85, p < 0.0001) and close agreement between the two techniques (mean difference (co-oximeter-NIRS) 6%, limits of agreement-5.1% to 17.1%). Three different methods for analysis of the NIRS data were examined to determine which period during the venous occlusion provided the most accurate measurement. The agreement was the same for all methods of analysis.

The effect of a child's disability on mother's mental health

The prevalence of maternal depression was investigated in the mothers of 96 children: 30 premature infants at risk for the development of cerebral palsy; 35 premature infants considered not to be at risk for the development of cerebral palsy; and 31 healthy fullterm infants. There were equally high levels of depression in all three groups of mothers, regardless of birth status, prediction of disability, or presence of actual disability, throughout the first year of the children's lives. Depressed mothers were, however, found to have significantly more psychosocial stress. An early physiotherapy intervention had no effect on the prevalence of depression in mothers whose children were at risk for the development of cerebral palsy.

Internalization of pleuroamniotic shunt causing neonatal demise

Internalization of a pleuroamniotic shunt previously has not been associated with significant fetal or neonatal problems. We report a case in whom the shunt internalized and compressed the lung hilum. A review of the complications of antenatal pleuroamniotic shunting is also presented.

Measurement of cerebral venous oxyhemoglobin saturation in children by near-infrared spectroscopy and partial jugular venous occlusion

Changes in cerebral venous oxyhemoglobin saturation reflect changes in the balance between cerebral oxygen delivery and cerebral oxygen consumption. Invasive monitoring of cerebral venous saturation (CSVO2) has provided useful information in the management of critically ill adults at risk of cerebral hypoxia. This study describes the development and validation of a non-invasive method of measuring CSVO2 suitable for use in sick neonates using near-infrared spectroscopy (NIRS) and partial jugular venous occlusion. This technique was validated by comparison with an invasive measurement of CSVO2, co-oximetry of jugular bulb blood obtained during cardiac catheterization. Agreement between the two methods was assessed using the method of J. M. Bland and D. G. Altman. Fifteen children were studied, aged 3 mo to 14 y (median 2 y). CSVO2 by co-oximetry ranged from 36 to 80% (median 60%). The mean difference (Co-Oximeter - NIRS) was 1.5%. Limits of agreement were -12.8 to 15.9%. Three different methods of analyzing the NIRS signal were compared. The best agreement was obtained when the changes occurring during the first 5 s of partial jugular venous occlusion were studied. Greatest accuracy was seen in those subjects with least movement artifact, and we believe this technique will be reliable in sick neonates.

Raised pulmonary artery pressure in very low birthweight infants requiring supplemental oxygen at 36 weeks after conception

This study aimed to investigate the changes in pulmonary artery pressure in infants with chronic lung disease who then developed prolonged oxygen dependency. The time to peak velocity: right ventricular ejection time (TPV:RVET) ratio calculated from the Doppler waveform, which correlates negatively with pulmonary artery pressure, was used. Thirty four infants with chronic lung disease were studied. At 36 weeks after conception 19 infants still required supplemental oxygen (POD group) and 16 infants were in air (controls). Over the first three weeks, there was a significant rise in the ratio in both groups, indicating a fall in pulmonary arterial pressure. From the third week onwards the ratio was significantly lower in the POD group. There was a significant rise in the ratio from four to 36 weeks after conception in the control group; the POD group showed a tendency towards a fall over the same time period. The requirement for supplemental oxygen almost mirrored the changes in the ratio in both groups but was not significantly different until the fifth week after birth. These data suggest that pulmonary arterial pressure has a significant role in the pathophysiology of prolonged oxygen dependency and may be important in the subsequent morbidity associated with this group of very low birthweight infants.

Neonatal intracranial lesions following placental abruption

A case-controlled study of the cerebral ultrasound appearances of neonates following placental abruption was undertaken. Twenty-nine index subjects (median gestation 29 weeks) were identified over a 2-year period with gestation- and sex-matched controls. Placental abruption was associated with a four-fold increased incidence of periventricular leukomalacia and extensive periventricular haemorrhage, without increased mortality. Ten infants (34%) developed cystic periventricular leukomalacia following placental abruption, compared with three (10%) in the control group. Intraventricular haemorrhage (excluding subependymal haemorrhage) and haemorrhage into the brain parenchyma occurred in 21 (72%) infants in the abruption group, compared with 14 (48%) in the control group (P < 0.05).

Ureaplasma urealyticum and chronic lung disease

Neonatal lower respiratory tract colonisation with mycoplasma organisms was examined for an association with chronic lung disease. Ureaplasma urealyticum colonised 9/70 (13%) infants less than 1500 g. Seven (78%) colonised and 33 (54%) non-colonised infants developed chronic lung disease. Logistic regression analyses revealed early gestation, but not mycoplasma colonisation, was independently associated with chronic lung disease.

The apparent role of blood transfusions in the development of retinopathy of prematurity

During a 30-month-period, 184 very low birth weight infants from two Liverpool neonatal intensive care units were screened for evidence of retinopathy of prematurity (ROP). Seventeen clinical variables previously considered relevant to the development of ROP, blood gas and blood pressure data over the first 7 days, and the maximum stage of ROP reached in either eye were recorded, together with the need for cryotherapy and current visual status. Ninety-two infants developed any stage of ROP and 15 required cryotherapy or became blind. Logistic regression showed that only gestational age and frequency of blood transfusion were independently associated both with the risk of occurrence of ROP and its severity.

Randomised controlled trial of plasma protein fraction versus dopamine in hypotensive very low birthweight infants

Around 20% of very low birthweight infants admitted to a neonatal intensive care unit become hypotensive within 24 hours of their admission. Standard treatment is either expansion of the circulating volume by the infusion of plasma protein fraction or by using dopamine to improve cardiac function. The purpose of this study was to investigate by a randomised controlled trial which was the most appropriate treatment. Thirty nine infants were randomised to receive either plasma protein fraction or dopamine as first line treatment if they became hypotensive within 24 hours of admission to the neonatal intensive care unit. Seventeen of 19 (89%) infants responded to dopamine, whereas only 9/20 (45%) responded to plasma protein fraction. The median dose of dopamine needed to increase the blood pressure to at least the 10th centile was 7.5 micrograms/kg/min and was infused for a median duration of 18 hours. These observations suggest that dopamine should be used earlier in the treatment of these infants than has previously been recommended.

A comparison of three procedures to assess the motor ability of 12-month-old infants with cerebral palsy

This study compared three methods of assessing motor impairment during infancy. The 77 infants studied were considered to be at high risk of motor impairment because of abnormal neonatal cranial ultrasound scans or abnormal somatosensory responses. The children were assessed at eight and 12 months post-term by the Movement Assessment of Infants, the Griffiths locomotor development quotient and the limb-by-limb approach, and the results were compared with clinical assessment at 12 months post-term. The sensitivity of the limb-by-limb approach was highest, although its specificity was slightly lower than the other tests. It was also the easiest to perform. While giving information about the quality of movement, none of these methods is a quantitative test of movement.

Nursing staff requirements for neonatal intensive care

A study to estimate the number of nursing staff required for neonatal nursing was undertaken. Certain nursing tasks, such as transporting any infant, caring for the dying infant, and looking after the very unstable infant required continuous attention by one nurse (5.5 whole time equivalent (wte) nurses for each cot). The stable ventilated infant required 10.5 nursing hours each day-that is, 2.4 wte/cot. Infants with intravenous infusions, but not ventilated, required only slightly less nursing time: 9.25 nursing hours each day or 2.12 wte/cot. Each special care patient needed 6.50 nursing hours each day, or 1.49 wte/cot. It is emphasised that each neonatal unit will have to take its own practices into account when calculating neonatal nursing requirements.

Pulmonary artery pressure changes in the very low birthweight infant developing chronic lung disease

Pulmonary artery pressure may be estimated non-invasively in the premature newborn infant because of its negative correlation with the time to peak velocity:right ventricular ejection time (TPV:RVET) ratio calculated from the pulmonary artery Doppler waveform. We studied 54 very low birthweight infants on days 1, 2, 3, 7, 14, 21, and 28 after birth. Thirty four infants developed chronic lung disease (CLD). Twenty did not and acted as controls. After correcting the TPV:RVET ratio for heart rate (TPV:RVET(c)), during the first 14 days the TPV:RVET(c) ratio rose progressively in both groups suggesting a fall in pulmonary artery pressure. This occurred at a significantly slower rate in the CLD group. From days 14 to 28 there was a significant fall in the ratio in the CLD group only, suggesting an increase in pulmonary artery pressure. Using CLD as the end point, a TPV:RVET(c) ratio < 0.54 on day 7 had a predictive value of 78% (sensitivity 73%, specificity 65%). This rose to a predictive value of 97% (sensitivity 88%, specificity 95%) on day 28. The non-invasive assessment of pulmonary artery pressure may be useful in the early clinical management of the very low birthweight infant at risk of developing CLD.

Echocardiographic assessment of cardiac function in shocked very low birthweight infants

The contribution of abnormal cardiac function to hypotension and metabolic acidosis, which affect approximately 40% of ventilated very low birthweight infants in the first 24 hours after birth was assessed using M mode, two dimensional, and Doppler echocardiography in 75 very low birthweight infants during the first few hours after birth. Thirty four infants whose blood pressure was less than the 10th centile or who had a metabolic acidosis in the first 24 hours were compared with 41 who showed neither feature. The median shortening fraction was significantly lower in the hypotensive/acidotic (shocked) group than in the controls. In 16 of 34 (47%) shocked infants left ventricular contractility and output were significantly worse than in the control subjects. One and five minute Apgar scores were also significantly lower in the shock group when compared with controls. Cardiac dysfunction was an important feature in the shocked very low birthweight infants. It is speculated that volume expansion may not always be the most appropriate first line treatment for such infants.

Neonatal meningococcal conjunctivitis associated with meningococcal meningitis

Two infants are described in whom identical strains of meningococcus were isolated from both the eyes and the cerebrospinal fluid. This suggests that the eye may be a portal of entry in at least some cases of perinatally acquired neonatal meningococcal disease and has important implications for the management of purulent conjunctivitis in the newborn.