Quen Mok

Human albumin administration in critically ill patients. Evidence needs to be shown in paediatrics.

Editor—We are concerned that the Cochrane Injuries Group’s meta-analysis regarding administration of albumin1 may alter the practice of resuscitating hypovolaemic hypotensive children, infants, and neonates. Although we are affiliated to the Institute of Child Health, we want to emphasise that this article does not reflect our own clinical practice, and at present we believe that it provides no compelling evidence to change our practice. We reviewed the 32 articles in the three groups. We identified only one paediatric study (So et al) in the hypovolaemia group, in which 63 preterm infants received albumin for hypotension. In the burns group there is only one paediatric study (n=70), in which albumin was given to maintain arbitrary serum concentrations (Greenhalgh et al). Finally, in the hypoproteinaemic group there are two studies of 64 neonates that addressed several hypotheses, including whether albumin was detrimental to respiratory status (Greenough et al) and was beneficial in weight gain (Kanarek et al). In a third study (n=27) that assessed the use of bicarbonate in acidotic neonates only the control groups of 5% dextrose and albumin were compared (Bland et al). We are now faced with concerns from parents about the “killer fluid,” and our junior staff are confused about the appropriate fluid to use for resuscitation of critically ill children. Have we been put into a legally indefensible position by this report from the Cochrane Injuries Group? We continue to use albumin for several reasons. To produce the same sustained increase in blood pressure as a 20 ml/kg bolus of albumin, up to five times as much volume of crystalloid would have to be given based on their relative oncotic pressures.2 This increased volume of crystalloid may lead to problems with fluid overload, hyperchloraemia in renal dysfunction, and pulmonary oedema. One leading manufacturer supplies £11.5 million of albumin to British hospitals each year.3 We must be certain that stopping the use of albumin is not a financially driven decision. We would be prepared to accept that albumin may be detrimental on the basis of appropriate data. At present we do not think, however, that there is enough evidence for us to stop using albumin for resuscitation in this population. In an attempt to resolve this controversy in a responsible manner we are about to embark on a prospective study to assess the safety of albumin use in children. Would the authors of the meta-analysis be prepared to enrol patients into such a study or would they consider it unethical?

Impregnated central venous catheters for prevention of bloodstream infection in children (the CATCH trial): a randomised controlled trial

BACKGROUND Impregnated central venous catheters are recommended for adults to reduce bloodstream infections but not for children because there is not enough evidence to prove they are effective. We aimed to assess the effectiveness of any type of impregnation (antibiotic or heparin) compared with standard central venous catheters to prevent bloodstream infections in children needing intensive care. METHODS We did a randomised controlled trial of children admitted to 14 English paediatric intensive care units. Children younger than 16 years were eligible if they were admitted or being prepared for admission to a participating paediatric intensive care unit and were expected to need a central venous catheter for 3 or more days. Children were randomly assigned (1:1:1) to receive a central venous catheter impregnated with antibiotics, a central venous catheter impregnated with heparin, or a standard central venous catheter with computer generated randomisation in blocks of three and six, stratified by method of consent, site, and envelope storage location within the site. The clinician responsible for inserting the central venous catheter was not masked to allocation, but allocation was concealed from patients, their parents, and the paediatric intensive care unit personnel responsible for their care. The primary outcome was time to first bloodstream infection between 48 h after randomisation and 48 h after central venous catheter removal with impregnated (antibiotic or heparin) versus standard central venous catheters, assessed in the intention-to-treat population. Safety analyses compared central venous catheter-related adverse events in the subset of children for whom central venous catheter insertion was attempted (per-protocol population). This trial is registered with ISRCTN number, ISRCTN34884569. FINDINGS Between Nov 25, 2010, and Nov 30, 2012, 1485 children were recruited to this study. We randomly assigned 502 children to receive standard central venous catheters, 486 to receive antibiotic-impregnated catheters, and 497 to receive heparin-impregnated catheters. Bloodstream infection occurred in 18 (4%) of those in the standard catheters group, 7 (1%) in the antibiotic-impregnated group, and 17 (3%) assigned to heparin-impregnated catheters. Primary analyses showed no effect of impregnated (antibiotic or heparin) catheters compared with standard central venous catheters (hazard ratio [HR] for time to first bloodstream infection 0.71, 95% CI 0.37-1.34). Secondary analyses showed that antibiotic central venous catheters were better than standard central venous catheters (HR 0.43, 0.20-0.96) and heparin central venous catheters (HR 0.42, 0.19-0.93), but heparin did not differ from standard central venous catheters (HR 1.04, 0.53-2.03). Clinically important and statistically significant absolute risk differences were identified only for antibiotic-impregnated catheters versus standard catheters (-2.15%, 95% CI -4.09 to -0.20; number needed to treat [NNT] 47, 95% CI 25-500) and antibiotic-impregnated catheters versus heparin-impregnated catheters (-1.98%, -3.90 to -0.06, NNT 51, 26-1667). Nine children (2%) in the standard central venous catheter group, 14 (3%) in the antibiotic-impregnated group, and 8 (2%) in the heparin-impregnated group had catheter-related adverse events. 45 (8%) in the standard group, 35 (8%) antibiotic-impregnated group, and 29 (6%) in the heparin-impregnated group died during the study. INTERPRETATION Antibiotic-impregnated central venous catheters significantly reduced the risk of bloodstream infections compared with standard and heparin central venous catheters. Widespread use of antibiotic-impregnated central venous catheters could help prevent bloodstream infections in paediatric intensive care units. FUNDING National Institute for Health Research, UK.

Computed tomography versus bronchography in the diagnosis and management of tracheobronchomalacia in ventilator dependent infants

Aim: To assess the relative accuracy of dynamic spiral computed tomography (CT) compared with tracheobronchography, in a population of ventilator dependent infants with suspected tracheobroncho-malacia (TBM). Setting: Paediatric intensive care unit in a tertiary teaching hospital. Patients and methods: Infants referred for investigation and management of ventilator dependence and suspected of having TBM were recruited into the study. Tracheobronchography and CT were performed during the same admission by different investigators who were blinded to the results of the other investigation. The study was approved by the hospital research ethics committee, and signed parental consent was obtained. Results: Sixteen infants were recruited into the study. Fifteen had been born prematurely, and five had cardiovascular malformations. In 10 patients there was good or partial correlation between the two investigations, but in six patients there was poor or no correlation. Bronchography consistently showed more dynamic abnormalities, although CT picked up an unsuspected double aortic arch. Radiation doses were 0.27–2.47 mSv with bronchography and 0.86–10.67 mSv with CT. Conclusions: Bronchography was a better investigation for diagnosing TBM and in determining opening pressures. Spiral CT is unreliable in the assessment of TBM in ventilator dependent infants. In addition, radiation doses were considerably higher with CT.

How parents and practitioners experience research without prior consent (deferred consent) for emergency research involving children with life threatening conditions: a mixed method study.

Objective Alternatives to prospective informed consent to enable children with life-threatening conditions to be entered into trials of emergency treatments are needed. Across Europe, a process called deferred consent has been developed as an alternative. Little is known about the views and experiences of those with first-hand experience of this controversial consent process. To inform how consent is sought for future paediatric critical care trials, we explored the views and experiences of parents and practitioners involved in the CATheter infections in CHildren (CATCH) trial, which allowed for deferred consent in certain circumstances. Design Mixed method survey, interview and focus group study. Participants 275 parents completed a questionnaire; 20 families participated in an interview (18 mothers, 5 fathers). 17 CATCH practitioners participated in one of four focus groups (10 nurses, 3 doctors and 4 clinical trial unit staff). Setting 12 UK childrens hospitals. Results Some parents were momentarily shocked or angered to discover that their child had or could have been entered into CATCH without their prior consent. Although these feelings resolved after the reasons why consent needed to be deferred were explained and that the CATCH interventions were already used in clinical care. Prior to seeking deferred consent for the first few times, CATCH practitioners were apprehensive, although their feelings abated with experience of talking to parents about CATCH. Parents reported that their decisions about their childs participation in the trial had been voluntary. However, mistiming the deferred consent discussion had caused distress for some. Practitioners and parents supported the use of deferred consent in CATCH and in future trials of interventions already used in clinical care. Conclusions Our study provides evidence to support the use of deferred consent in paediatric emergency medicine; it also indicates the crucial importance of practitioner communication and appropriate timing of deferred consent discussions.

Making co-enrolment feasible for randomised controlled trials in paediatric intensive care.

Aims Enrolling children into several trials could increase recruitment and lead to quicker delivery of optimal care in paediatric intensive care units (PICU). We evaluated decisions taken by clinicians and parents in PICU on co-enrolment for two large pragmatic trials: the CATCH trial (CATheters in CHildren) comparing impregnated with standard central venous catheters (CVCs) for reducing bloodstream infection in PICU and the CHIP trial comparing tight versus standard control of hyperglycaemia. Methods We recorded the period of trial overlap for all PICUs taking part in both CATCH and CHiP and reasons why clinicians decided to co-enrol children or not into both studies. We examined parental decisions on co-enrolment by measuring recruitment rates and reasons for declining consent. Results Five PICUs recruited for CATCH and CHiP during the same period (an additional four opened CATCH after having closed CHiP). Of these five, three declined co-enrolment (one of which delayed recruiting elective patients for CATCH whilst CHiP was running), due to concerns about jeopardising CHiP recruitment, asking too much of parents, overwhelming amounts of information to explain to parents for two trials and a policy against co-enrolment. Two units co-enrolled in order to maximise recruitment to both trials. At the first unit, 35 parents were approached for both trials. 17/35 consented to both; 13/35 consented to one trial only; 5/35 declined both. Consent rates during co-enrolment were 29/35 (82%) and 18/35 (51%) for CATCH and CHiP respectively compared with 78% and 51% respectively for those approached for a single trial within this PICU. The second unit did not record data on approaches or refusals, but successfully co-enrolled one child. Conclusions Co-enrolment did not appear to jeopardise recruitment or overwhelm parents. Strategies for seeking consent for multiple trials need to be developed and should include how to combine information for parents and patients.

Deferred Consent for Randomized Controlled Trials in Emergency Care Settings

BACKGROUND: There is limited experience in using deferred consent for studies involving children, which was legalized in the United Kingdom in 2008. We aimed to inform future studies by evaluating consent rates and reasons for nonconsent in a large randomized controlled trial in pediatric intensive care. METHODS: In the CATCH trial, eligible children from 14 PICUs in England and Wales were randomly assigned to 3 types of central venous catheters. To avoid delay in treatment, children admitted on an emergency basis were first randomly assigned to a trial central venous catheter, and we deferred seeking consent to use already collected data and blood samples until after stabilization. RESULTS: Consent was obtained for 984/1358 (72%) of children admitted on an emergency basis. Failure to obtain consent resulted mainly from a lack of opportunity (early discharge or transfer) for survivors and difficulties in seeking consent for children who died. For admissions where there was an opportunity to approach (n = 1298), inclusion rates differed according to survival status: 93/984 (9%) of consented patients died, compared with 58/314 (18%) of nonconsented patients. For children admitted on an emergency basis whose families were approached, 984/1178 (84%) provided deferred consent (n = 15 sites), compared with 441/641 (69%) of children admitted on an elective basis who were approached for prospective consent (n = 9 sites). CONCLUSIONS: Design of emergency randomized controlled trials should balance the potential burden that seeking consent in difficult situations may cause against risk of bias by disproportionately excluding children who die or are transferred. Ethics committees could consider approving the use of already collected data when best efforts to obtain deferred consent are unsuccessful.

Bronchomegaly as a complication of fetal endoscopic tracheal occlusion. A caution and a possible solution

Fetal medicine is developing rapidly and aims to improve the outcome for fetuses with congenital anomalies. Fetal endoscopic tracheal occlusion (FETO) has been developed for fetuses with congenital diaphragmatic hernia to counterbalance the compression of the lung by the abdominal viscera, preserving the pulmonary maturation. Because the perinatal morbidity and mortality of patients treated with FETO have decreased, new complications are emerging in the older survivors. Tracheomegaly has been reported to be a late complication of FETO, sometimes requiring tracheostomy. We report a case of bronchial dilatation after FETO and suggest an alternative surgical treatment.

Generalisability and Cost-Impact of Antibiotic-Impregnated Central Venous Catheters for Reducing Risk of Bloodstream Infection in Paediatric Intensive Care Units in England

Background We determined the generalisability and cost-impact of adopting antibiotic-impregnated CVCs in all paediatric intensive care units (PICUs) in England, based on results from a large randomised controlled trial (the CATCH trial; ISRCTN34884569). Methods BSI rates using standard CVCs were estimated through linkage of national PICU audit data (PICANet) with laboratory surveillance data. We estimated the number of BSI averted if PICUs switched from standard to antibiotic-impregnated CVCs by applying the CATCH trial rate-ratio (0.40; 95% CI 0.17,0.97) to the BSI rate using standard CVCs. The value of healthcare resources made available by averting one BSI as estimated from the trial economic analysis was £10,975; 95% CI -£2,801,£24,751. Results The BSI rate using standard CVCs was 4.58 (95% CI 4.42,4.74) per 1000 CVC-days in 2012. Applying the rate-ratio gave 232 BSI averted using antibiotic CVCs. The additional cost of purchasing antibiotic-impregnated compared with standard CVCs was £36 for each child, corresponding to additional costs of £317,916 for an estimated 8831 CVCs required in PICUs in 2012. Based on 2012 BSI rates, management of BSI in PICUs cost £2.5 million annually (95% uncertainty interval: -£160,986, £5,603,005). The additional cost of antibiotic CVCs would be less than the value of resources associated with managing BSI in PICUs with standard BSI rates >1.2 per 1000 CVC-days. Conclusions The cost of introducing antibiotic-impregnated CVCs is less than the cost associated with managing BSIs occurring with standard CVCs. The long-term benefits of preventing BSI could mean that antibiotic CVCs are cost-effective even in PICUs with extremely low BSI rates.

Monitoring quality of care through linkage of administrative data: national trends in bloodstream infection in U.K. PICUs 2003-2012.

Objectives: Interventions to reduce hospital-acquired bloodstream infection have succeeded in reducing rates in U.S. PICUs, but there is a lack of evidence for the impact of similar interventions in the United Kingdom. We assessed variation in bloodstream infection rates within and between PICUs over a 10-year period, during which time infection control strategies (care bundles) were implemented. Design: Observational study linking laboratory data to national audit data of pediatric intensive care admissions (Paediatric Intensive Care Audit Network). Setting: Twenty PICUs in England and Wales, 2003–2012. Patients: One hundred and two thousand nine hundred ninety-nine children less than 16 years. Interventions: Implementation of infection control strategies in PICU captured through a survey of clinicians. Measurements and Main Results: Rates of bloodstream infection per 1,000 bed-days were estimated from samples taken between 2 days after admission and up to 2 days following discharge from PICU. Two percent of children experienced at least one bloodstream infection, corresponding to 5.11 (95% CI, 4.90–5.31) per 1,000 bed-days. There was a significant difference in trends preimplementation of infection control strategies (annual decrease of 8.0%; 95% CI, 6.3–9.7%) versus postimplementation (annual decrease of 13.4%; 95% CI, 10.3–16.4%). By 24 months postimplementation, the rate of bloodstream infection had fallen 25.5% and was 15.1% lower than would have been expected if preimplementation trends had continued. Conclusions: Our population-based study of PICUs in England and Wales demonstrates a steady decline in bloodstream infection rates over time. In addition, there was a significant and incremental further decrease in rates associated with timing of implementation of infection control strategies. Assessment of bloodstream infection trends before as well as after implementation of infection control strategies can be facilitated using data linkage and is important to avoid overestimating the impact of unit-level interventions to improve infection control. Advances in collection and linkage of real-time data could further support quality improvement efforts.

CATheter Infections in CHildren (CATCH): a randomised controlled trial and economic evaluation comparing impregnated and standard central venous catheters in children

BACKGROUND Impregnated central venous catheters (CVCs) are recommended for adults to reduce bloodstream infection (BSI) but not for children. OBJECTIVE To determine the effectiveness of impregnated compared with standard CVCs for reducing BSI in children admitted for intensive care. DESIGN Multicentre randomised controlled trial, cost-effectiveness analysis from a NHS perspective and a generalisability analysis and cost impact analysis. SETTING 14 English paediatric intensive care units (PICUs) in England. PARTICIPANTS Children aged < 16 years admitted to a PICU and expected to require a CVC for ≥ 3 days. INTERVENTIONS Heparin-bonded, antibiotic-impregnated (rifampicin and minocycline) or standard polyurethane CVCs, allocated randomly (1 : 1 : 1). The intervention was blinded to all but inserting clinicians. MAIN OUTCOME MEASURE Time to first BSI sampled between 48 hours after randomisation and 48 hours after CVC removal. The following data were used in the trial: trial case report forms; hospital administrative data for 6 months pre and post randomisation; and national-linked PICU audit and laboratory data. RESULTS In total, 1859 children were randomised, of whom 501 were randomised prospectively and 1358 were randomised as an emergency; of these, 984 subsequently provided deferred consent for follow-up. Clinical effectiveness - BSIs occurred in 3.59% (18/502) of children randomised to standard CVCs, 1.44% (7/486) of children randomised to antibiotic CVCs and 3.42% (17/497) of children randomised to heparin CVCs. Primary analyses comparing impregnated (antibiotic and heparin CVCs) with standard CVCs showed no effect of impregnated CVCs [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.37 to 1.34]. Secondary analyses showed that antibiotic CVCs were superior to standard CVCs (HR 0.43, 95% CI 0.20 to 0.96) but heparin CVCs were not (HR 1.04, 95% CI 0.53 to 2.03). Time to thrombosis, mortality by 30 days and minocycline/rifampicin resistance did not differ by CVC. Cost-effectiveness - heparin CVCs were not clinically effective and therefore were not cost-effective. The incremental cost of antibiotic CVCs compared with standard CVCs over a 6-month time horizon was £1160 (95% CI -£4743 to £6962), with an incremental cost-effectiveness ratio of £54,057 per BSI avoided. There was considerable uncertainty in costs: antibiotic CVCs had a probability of 0.35 of being dominant. Based on index hospital stay costs only, antibiotic CVCs were associated with a saving of £97,543 per BSI averted. The estimated value of health-care resources associated with each BSI was £10,975 (95% CI -£2801 to £24,751). Generalisability and cost-impact - the baseline risk of BSI in 2012 for PICUs in England was 4.58 (95% CI 4.42 to 4.74) per 1000 bed-days. An estimated 232 BSIs could have been averted in 2012 using antibiotic CVCs. The additional cost of purchasing antibiotic CVCs for all children who require them (£36 per CVC) would be less than the value of resources associated with managing BSIs in PICUs with standard BSI rates of > 1.2 per 1000 CVC-days. CONCLUSIONS The primary outcome did not differ between impregnated and standard CVCs. However, antibiotic-impregnated CVCs significantly reduced the risk of BSI compared with standard and heparin CVCs. Adoption of antibiotic-impregnated CVCs could be beneficial even for PICUs with low BSI rates, although uncertainty remains whether or not they represent value for money to the NHS. Limitations - inserting clinicians were not blinded to allocation and a lower than expected event rate meant that there was limited power for head-to-head comparisons of each type of impregnation. Future work - adoption of impregnated CVCs in PICUs should be considered and could be monitored through linkage of electronic health-care data and clinical data on CVC use with laboratory surveillance data on BSI. TRIAL REGISTRATION ClinicalTrials.gov NCT01029717. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 18. See the NIHR Journals Library website for further project information.