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Biomedical subjects

G A Pearson

Publications and source records attributed to G A Pearson.

At least 19 recordsLinked to original sources

Calibration of the paediatric index of mortality in UK paediatric intensive care units.

AIM: To test a paediatric intensive care mortality prediction model for UK use. METHOD: Prospective collection of data from consecutive admissions to five UK paediatric intensive care units (PICUs), representing a broad cross section of paediatric intensive care activity. A total of 7253 admissions were analysed using tests of the discrimination and calibration of the logistic regression equation. RESULTS: The model discriminated and calibrated well. The area under the ROC plot was 0.84 (95% CI 0.819 to 0.853). The standardised mortality ratio was 0.87 (95% CI 0.81 to 0.94). There was remarkable concordance in the performance of the paediatric index of mortality (PIM) within each PICU, and in the performance of the PICUs as assessed by PIM. Variation in the proportion of admissions that were ventilated or transported from another hospital did not affect the results. CONCLUSION: We recommend that UK PICUs use PIM for their routine audit needs. PIM is not affected by the standard of therapy after admission to PICU, the information needed to calculate PIM is easy to collect, and the model is free.

Calibration↗

Extracorporeal membrane oxygenation and the treatment of critical pulmonary hypertension in congenital heart disease.

Certain forms of congenital heart disease (CHD) confer a high risk for the development of severe pulmonary hypertension before and after corrective cardiac surgery. Extracorporeal membrane oxygenation (ECMO) has theoretical benefits in the treatment of this complication in that it assures oxygenation, corrects acid-base balance and provides haemodynamic support at the same time as allowing lung rest from ventilation. We examined our experience of the 117 children and neonates supported with ECMO between November 1989 and July 1993. Of these, five received support for critical pulmonary hypertension associated with congenital heart disease. They comprised three who had undergone surgical repair of CHD, one whose total anomalous pulmonary venous drainage was diagnosed and corrected whilst on ECMO and one neonate with functional pulmonary atresia. Pulmonary artery pressure (PAP) was estimated by Doppler echocardiography in all patients and confirmed invasively in two. The median systolic PAP was 46 (range 42-65) mmHg prior to ECMO. The median ratio of pulmonary to systemic arterial pressure (PAP/SAP) was 0.75 (0.70-0.92). Following ECMO of 16-120 h duration, the median systolic PAP was 34 (30-49) mmHg with PAP/SAP 0.50 (0.35-0.60). All patients survived and there were no complications related to ECMO. Extracorporeal membrane oxygenation is an effective treatment in critical pulmonary hypertension and should be considered in all patients in whom this is refractory to conventional measures.

Acid-Base Equilibrium↗

Bronchopulmonary infection with Moraxella catarrhalis in infants requiring extracorporeal membrane oxygenation.

Moraxella (formerly Branhamella) catarrhalis is now a well-recognized pathogen of the upper and lower respiratory tract. Four pediatric cases of life-threatening pneumonia requiring extracorporeal membrane oxygenation are presented. M. Catarrhalis was isolated within 48 hours of admission in three of the cases and within 24 hours of an acute deterioration in the fourth. We conclude that M. catarrhalis is either a significant pathogen in its own right, a marker of severe disease, or a secondary invader.

Child, Preschool↗

Pathological complications of non-survivors of newborn extracorporeal membrane oxygenation.

The pathology was reviewed of the early deaths identified from the first 50 neonates treated with extracorporeal membrane oxygenation (ECMO) during its introduction to the UK. Fifteen neonates died during or shortly after ECMO between August 1989 and June 1992. Data on 12 are presented (three did not have a postmortem examination). The clinical diagnoses at referral for ECMO were as follows: persistent pulmonary hypertension of the newborn (six infants), primary congenital pneumonia (one infant), community acquired pneumonia (two infants), birth asphyxia (one infant), respiratory distress syndrome (one infant), and meconium aspiration syndrome (one infant). In our group, at necropsy, five had significant haemorrhage (three intracranial, one pulmonary, one pericardial and intraventricular). Three of five infants with evidence of haemorrhage also had signs of sepsis. Six infants had evidence at necropsy of systemic sepsis, five showed evidence of severe anoxic brain injury, and four infants had cerebellar haemorrhages. Three infants had evidence of myocardial ischaemia. It is difficult to discriminate between the relative influence of the primary diagnosis, the mode of treatment, and the severity of presentation in the genesis of this pathology. It is likely that the extent and severity of some of the findings represent a pathological progression that would have been interrupted by the death of the patient, had ECMO not been instituted.

Acute Kidney Injury↗

Childhood pulmonary alveolar proteinosis. Extracorporeal membrane oxygenation with total cardiopulmonary support during bronchopulmonary lavage.

Partial cardiopulmonary bypass with extracorporeal membrane oxygenation to allow bilateral bronchopulmonary lavage in pulmonary alveolar proteinosis has been described. However, this technique is complicated by a very low arterial PO2 and cardiovascular embarrassment. Total cardiopulmonary support avoids these problems and was successfully used in a 2 1/2-year-old girl.

Cardiopulmonary Bypass↗

Neonatal extra corporeal membrane oxygenation (ECMO).

Extra corporeal membrane oxygenation (ECMO) is a novel, but invasive, form of life support developed from cardio pulmonary by pass technology. The technique has been used successfully in mature infants with severe respiratory failure since 1975. Where persistent pulmonary hypertension is a complicating problem the improved oxygenation resulting from the use of ECMO has a therapeutic role. Controversy exists, however, with regard to whether ECMO offers any advantage over more conventional life support in terms of improved survival. Descriptive data relating to cost and morbidity suggest no disadvantage from the use of ECMO. It is hoped that the current U.K. collaborative trial will clarify whether ECMO should be considered standard therapy for severe respiratory failure occurring in mature infants.

Extracorporeal Membrane Oxygenation↗

Salvage of postoperative pulmonary hypertensive crisis using ECMO via cervical cannulation in a case of truncus arteriosus.

The survival of patients with truncus arteriosus beyond one year of age is rare without surgical treatment [3 . Early surgery may be associated with a mortality but is still preferable, as the risks of established pulmonary hypertensive disease complicate delayed surgery [2]. We report the successful salvage of a pulmonary hypertensive crisis 24 h after corrective surgery in a late presenting patient using extracorporeal membrane oxygenation (ECMO) via cervical cannulation. Post-operative pulmonary hypertensive crises may present a difficult management problem. Extracorporeal membrane oxygenation is therapeutic in these circumstances in addition to providing life support. Cervical cannulation remains the method of choice in the postoperative cardiac patient.

Catheterization↗

Extracorporeal life support in paediatrics.

Extracorporeal membrane oxygenation (ECMO) is a life support technique based on modifications of heart-lung bypass technology. It is used to support severe but potentially reversible pulmonary or cardiopulmonary failure. There is increasing use of the technique for neonates and a return of interest in its use for adults. The number of non-neonatal paediatric patients receiving pulmonary support with ECMO worldwide is, however, small, and survival rates average less than 50%. Initial experience in 15 patients aged 3 months to 5 years with a high survival and low morbidity is reported.

Child, Preschool↗

UK experience in neonatal extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is a life support technique capable of supporting pulmonary, cardiac, or cardiopulmonary function. It has proved most successful in neonatal respiratory failure. We report the initial UK experience with a survival rate of 80% in 15 neonates (gestations 36-41 weeks, birth weights 2690-3990 g) whose condition exceeded American criteria for ECMO treatment for a prolonged period before referral. Ages at referral varied from 11 to 240 hours and the duration of bypass required varied from 30 to 240 hours respectively.

Costs and Cost Analysis↗

Evaluation of nuclear magnetic resonance spectroscopy for determination of deuterium abundance in body fluids: application to measurement of total-body water in human infants.

Nuclear magnetic resonance (NMR) spectroscopy was used to quantitate abundance of 2H in body water of human infants. This method provides precise measurement of total-body water without the extensive sample preparation requirements of previously described methods for determination of 2H content in body fluids. 2H2O (1 g/kg body weight) was administered to infants and saliva and urine were collected for up to 5 h. An internal standard was added directly to the fluid specimen and 2H enrichment in water was measured by NMR spectroscopy. Working range of deuterium abundance was 0.04-0.32 atom %. Coefficients of variation for saliva samples at 0.20 atom % 2H was 1.97%. 2H content in urine and saliva water reached a plateau by 4 h after administration, and amounts in the two fluids were virtually identical. Mean total-body water determination for six infants was 58.3 +/- 5.8% of body weight (range 53-66%).

Body Fluids↗