Narendra Aladangady

Decision making and modes of death in a tertiary neonatal unit

Aims: To study the frequency and reason for withdrawal/withholding of life sustaining treatment (LST) and do not resuscitate (DNR) orders in infants who died in a tertiary neonatal unit. Methods: Infants who died at Homerton University Hospital between January 1998 and September 2001 were studied by retrospective analysis of patient records. Results: The case notes of 71 (84%) of 85 infants who died were studied. Mode of death was withdrawal of LST in 28 (40%), DNR in 11 (15%), withholding of LST in two (3%), and natural in 30 (42%) infants. Withdrawal of LST was discussed with the parents of 39 seriously ill infants; 28 (72%) parents agreed. There was no difference in birth weight and gestational age of babies whose parents agreed or refused withdrawal of LST. White and Afro-Caribbean parents and those from the Indian subcontinent (20 of 23) were more likely to agree to withdrawal of LST than Black African or Jewish (eight of 16, p  =  0.015) parents. The median age at withdrawal of LST was 4 days (range 1–57). The median duration between discussion and the parents agreeing to withdrawal of LST was 165 minutes (range 30–2160), and median duration between withdrawal of LST and death was 22 minutes (range 5–210). The most common reason for withdrawal of LST was complications of extreme prematurity (68%). Conclusion: The most common mode of death was withdrawal of LST, and the most common reason was complications of extreme prematurity. The ethnic and cultural background of the parents influenced agreement to withdrawal of LST.

A new method for the measurement of cerebral blood volume and total circulating blood volume using near infrared spatially resolved spectroscopy and indocyanine green: application and validation in neonates.

A new technique known as tissue dye densitometry (TDD) has been developed to simultaneously measure cerebral blood volume (CBV) and total circulating blood volume (TCV) using near infrared (NIR) spatially resolved spectroscopy (SRS) and the injection of indocyanine green (ICG). Using a medical NIR spectrometer with SRS capability (NIRO-300, Hamamatsu KK), a new parameter is calculated known as the ICG Hb index (IHI), which represents the ratio of ICG concentration to Hb concentration in tissue. Acting as a tracer, ICG is cleared by the liver over 15 min, providing a change of tracer concentration (ΔCICG,tis), which allows the calculation of the total Hb concentration in tissue (tcHb) using the equation:tcHbtis (μ molar) = ΔCICG,tis/ΔIHI. The CBV can subsequently be calculated from tcHbtis given the absolute Hb concentration in blood (g/dL), from which the ICG concentration in blood (ΔCICG,bl) is obtained. By back-extrapolating the ΔCICG,bl curve to the peak time, the initial ICG concentration in tissue blood (C0ICG,bl) can be found and TCV can then be calculated. The TCV of 17 neonates were measured using the TDD technique and for comparison using the previously reported fetal Hb dilution technique (FHD). The mean TCV measured by the FHD and TDD techniques were 70.19 ± 13.73 mL/kg and 70.80 ± 32.54 mL/kg. The Bland Altman plot showed that the bias was 0.61 ± 34.34 mL/kg and limits of agreement (2 SD) were −68.07 mL/kg and 69.30 mL/kg. The agreement is limited and the TDD technique needs further validation and development for use in a clinical environment.

Neonatal nephrocalcinosis: long term follow up

Aims: To assess the spontaneous resolution of neonatal nephrocalcinosis and its long term effects on renal function. Methods: Fourteen very low birthweight preterm babies with nephrocalcinosis were followed up at 5–7 years of age; 14 controls were matched for sex, gestation, and birth weight. Height, weight, blood pressure, and renal symptomatology were recorded, and a renal ultrasound scan was performed. Early morning urine osmolality and creatinine ratios of albumin, phosphate, calcium, oxalate and β microglobulin were determined. Urea and electrolytes in the study group were determined, and glomerular filtration rate (GFR) and TmP/GFR (tubular reabsorption of phosphate per GFR) were calculated. Statistical analysis was performed on a group basis using the Mann-Whitney confidence interval. Results: Mean age was 6.9 years (range 5.81–7.68). An early morning urine osmolality >700 mOsm/kg was achieved in all cases. In two cases and four controls, the calcium/creatinine ratio was >0.7 mmol/mmol. In all cases, the GFR was normal (median 132.6 ml/min/1.73 m2 (range 104.1–173.1)). Median TmP/GFR was 1.22 mmol/l (0.73–1.61), with two having levels below the normal range. These did not have persisting nephrocalcinosis. Nephrocalcinosis was found in three of the 12 cases scanned and one control. There were no significant differences in urine biochemistry. Conclusions: Resolution of nephrocalcinosis occurred in 75% of cases. No evidence was found to suggest that nephrocalcinosis is associated with renal dysfunction in the long term. There was evidence of hypercalciuria in the cases and controls, suggesting that prematurity may be a risk factor.

Hypernatraemia in preterm infants born at less than 27 weeks gestation

Aims:  To study the incidence of hypernatraemia (plasma sodium >145 mmol/L), identify predisposing factors to and associated complications of hypernatraemia in preterm infants born less than 27 weeks gestation in the first 5 days of life.

Biomarkers to decide red blood cell transfusion in newborn infants.

Almost 90% of extremely low birthweight infants receive red blood cell (RBC) transfusion during their stay in the neonatal unit (NNU). Currently most NNUs use a combination of clinical signs and laboratory findings such as hemoglobin (Hb), hematocrit (Hct), and cardiorespiratory or ventilation status to decide the need for RBC transfusion. Various other laboratory (lactate, reticulocyte count, RBC volume) and bedside measurements (near infrared spectroscopy and Doppler ultrasound scan) have been investigated to identify a suitable trigger for RBC transfusion in newborn infants. The evidence to apply any of these investigations or measurements to clinical practice is lacking. Further research is required to identify a suitable biomarker for RBC transfusion in newborn infants.

The attitudes of neonatologists towards extremely preterm infants: a Q methodological study

Objectives The attitudes and biases of doctors may affect decision making within Neonatal Intensive Care. We studied the attitudes of neonatologists in order to understand how they prioritise different factors contributing to decision making for extremely preterm babies. Design Twenty-five neonatologists (11 consultants and 14 senior trainees) participated in a Q methodological study about decision making that involved the ranking of 53 statements from agree to disagree in a unimodal shaped grid. Results were explored by person factor analysis using principle component analysis. Results The model of best fit comprised 23 participants contributing a three-factor model, which represented three different attitudes towards decision making and accounted for 59% of the variance. Fourteen statements were ranked in statistically significant similar positions by 23 participants; consensus statements included placing the baby and family at the centre of care, limitation of intervention based upon perceived risk and non-mandatory intervention at birth. Factor 1 participants (n=12) believed that treatment should not be limited based on gestational age and technology should be used to improve treatment. Five factor 2 participants identified strongly with a limit of 24 weeks for treatment, one of whom being polar opposite, believing in treatment at all costs at all gestations. The remaining six factor 3 participants identified strongly with statements that treatment should be withheld on quality of life grounds. Conclusions This study has identified differences in attitudes towards decision making between individual neonatologists and trainees that may impact how decisions are communicated to families.

Measuring circulating blood volume in newborn infants using pulse dye densitometry and indocyanine green

Background:  Circulating blood volume (BV) is an important, but often unconsidered, variable in newborn infants undergoing intensive care. The data on validation and repeatability of BV measurement are limited.

Withholding or withdrawal of life sustaining treatment for newborn infants.

In the last two decades the survival of extreme preterm infants and sick newborn infants has improved significantly due to the advances in perinatal medicine. Despite this advance, for some babies, withholding or withdrawal of life sustaining treatment may be the best option in the interest of the baby. An overview of when to consider withholding or withdrawal of life sustaining treatment is described. The decision making process and factors influencing parents decision, how to resolve disagreement, what treatment can be withheld or withdrawn are explained. High quality palliative care must be provided after withholding or withdrawal of life sustaining treatment.

Short-term outcome of treatment limitation discussions for newborn infants, a multicentre prospective observational cohort study

Objective To determine the short-term outcomes of babies for whom clinicians or parents discussed the limitation of life-sustaining treatment (LST). Design Prospective multicentre observational study. Setting Two level 3, six level 2 and one level 1 neonatal units in the North-East London Neonatal Network. Participants A total of 87 babies including 68 for whom limiting LST was discussed with parents and 19 babies died without discussion of limiting LST in the labour ward or neonatal unit. Outcome measures Final decision reached after discussions about limiting LST and neonatal unit outcomes (death or survived to discharge) for babies. Results Withdrawing LST, withholding LST and do not resuscitate (DNR) order was discussed with 48, 16 and 4 parents, respectively. In 49/68 (72%) cases decisions occurred in level 3 and 19 cases in level 2 units. Following the initial discussions, 34/68 parents made the decision to continue LST. In 33/68 cases, a second opinion was obtained. The parents of 14/48 and 2/16 babies did not agree to withdraw and withhold LST, respectively. Forty-seven out of 87 babies (54%) died following limitation of LST, 28/87 (32%) died receiving full intensive care support, 5/87 (6%) survived following a decision to limit LST and 7/87 (8%) babies survived following decision to continue LST. Conclusions A significant proportion of parents chose to continue treatment following discussions regarding limiting LST for their babies, and a proportion of these babies survived to neonatal unit discharge. The long-term outcomes of babies who survive following limiting LST discussion need to be investigated.

The Cobweb Sign: Percutaneous Silastic Long Line Tip Placement in Tributaries of Superficial Veins

We report a method for preventing misplacement of percutaneous silastic catheters in superficial vein tributary or venous plexus. Catheters inserted less than the length calculated by surface anatomy measurement due to resistance were studied in three patients. Contrast X-rays (Omnipaque, Nycomed Imaging AS, Oslo, Norway) of the catheters was performed to confirm the catheter tip placement position. On initial assessment, the catheter tip placement was thought to be satisfactory and infusion of TPN commenced. Following signs of extravasation, re-examination of the contrast X-rays demonstrated that multiple thin rays of omnipaque could be traced in different directions like a cobweb. In the third infant, we recognised the “cobweb” sign and prospectively withdrew the catheter tip 2 cm. Repeat contrast X-ray confirmed that the catheter tip was in a major superficial vein, infusion continued without further complication. We conclude that when the “cobweb” sign is noticed then the catheter should be removed or withdrawn 2 to 3 cm and repeat contrast X-ray performed.