Simon Broughton

Prospective study of healthcare utilisation and respiratory morbidity due to RSV infection in prematurely born infants

Background: A study was undertaken to determine the impact of respiratory syncytial virus (RSV) infection, both in hospital and the community, on healthcare utilisation and respiratory morbidity in prematurely born infants and to identify risk factors for symptomatic RSV infection. Methods: A hospital and community follow up study was undertaken of 126 infants born before 32 weeks of gestational age. Healthcare utilisation (hospital admissions and general practitioner attendances) in the first year, respiratory morbidity at follow up (wheeze and cough documented by parent completed diary cards), and RSV positive lower respiratory tract infections (LRTIs) were documented. Nasopharyngeal aspirates were obtained for immunofluorescence and culture for RSV whenever the infants had an LRTI, either in the community or in hospital. Results: Forty two infants had an RSV positive LRTI (RSV group), 50 had an RSV negative LRTI (RSV negative LRTI group), and 32 infants had no LRTI (no LRTI group). Compared with the RSV negative LRTI and the no LRTI groups, the RSV group required more admissions (p = 0.392, p<0.001) and days in hospital (p = 0.049, p = 0.006) and had more cough (p = 0.05, p = 0.038) and wheeze (p = 0.003, p = 0.003) at follow up. Significant risk factors for symptomatic RSV LRTI were number of siblings (p = 0.035) and maternal smoking in pregnancy (p = 0.005), for cough were number of siblings (p = 0.002) and RSV LRTI (p = 0.02), and for wheeze was RSV LRTI (p = 0.019). Conclusion: RSV infection, even if hospital admission is not required, is associated with increased subsequent respiratory morbidity in prematurely born infants.

Diminished lung function, RSV infection, and respiratory morbidity in prematurely born infants

Background: Diminished lung function appears to be a risk factor for respiratory syncytial virus (RSV) infection/bronchiolitis in term born infants. Aims: To determine if diminished lung function prior to neonatal unit discharge was associated with subsequent symptomatic RSV lower respiratory tract infection (LRTI) and respiratory morbidity in prematurely born infants. Methods: Of 39 infants in a tertiary neonatal intensive care unit (median gestational age 28 weeks, range 23–31), 20 had bronchopulmonary dysplasia. Lung function (compliance and resistance of the respiratory system (Crs and Rrs) and functional residual capacity (FRC)) was measured on the neonatal unit at 36 weeks postmenstrual age (PMA). Following neonatal unit discharge, nasopharyngeal aspirates were obtained on every occasion, at home or in hospital, an infant had an LRTI. RSV was identified by immunofluorescence and/or culture. Results: The 15 infants who suffered a symptomatic RSV LRTI had a higher mean Rrs and suffered more wheeze at follow up than the rest of the cohort. Regression analysis showed that a high Rrs was significantly associated with a symptomatic RSV LRTI; significant factors for cough were a high Rrs and a symptomatic RSV LRTI, and for wheeze were a high Rrs. Conclusion: Prematurely born infants, who had a symptomatic RSV LRTI and/or respiratory morbidity at follow up, had worse lung function prior to neonatal unit discharge.

Lung function prior to viral lower respiratory tract infections in prematurely born infants

Objective Prematurely born infants who develop respiratory syncytial virus (RSV) lower respiratory tract infections (LRTIs) have lung function abnormalities at follow-up. The aim of this study was to determine whether prematurely born infants who developed symptomatic RSV, or other viral LRTI(s), had poorer premorbid lung function than infants who did not develop LRTIs during the RSV season. Methods Lung function (functional residual capacity (FRC), compliance (Crs) and resistance (Rrs) of the respiratory system) was measured at 36 weeks postmenstrual age. After neonatal unit discharge, nasopharyngeal aspirates were obtained whenever the infants had an LRTI, regardless of whether this was in the community or in hospital. Nasopharyngeal aspirates were examined for RSV A and B, rhinovirus, influenza A and B, parainfluenza 1, 2 and 3, human metapneumovirus and adenovirus. Results 159 infants with a median gestational age of 34 (range 23–36) weeks were prospectively followed. 73 infants developed LRTIs: 27 had at least one RSV LRTI and 31 had at least one other viral LRTI, but not an RSV LRTI. Overall, there were no significant differences in the FRC (p=0.54), Crs (p=0.11) or Rrs (p=0.12) results between those who developed an RSV or other viral LRTI and those who did not develop an LRTI. Infants with RSV or other viral LRTIs who were admitted to hospital compared with those who were not had higher Rrs results (p=0.033 and p=0.039, respectively). Conclusion Diminished premorbid lung function may predispose prematurely born infants to severe viral LRTIs in infancy.

Very prematurely born infants wheezing at follow-up: lung function and risk factors

Objectives: To determine whether abnormalities of lung volume and/or airway function were associated with wheeze at follow-up in infants born very prematurely and to identify risk factors for wheeze. Design: Lung function data obtained at 1 year of age were collated from two cohorts of infants recruited into the UKOS and an RSV study, respectively. Setting: Infant pulmonary function laboratory. Patients: 111 infants (mean gestational age 26.3 (SD 1.6) weeks). Interventions: Lung function measurements at 1 year of age corrected for gestational age at birth. Diary cards and respiratory questionnaires were completed to document wheeze. Main outcome measures: Functional residual capacity (FRCpleth and FRCHe), airways resistance (Raw), FRCHe:FRCpleth and tidal breathing parameters (TPTEF:TE). Results: The 60 infants who wheezed at follow-up had significantly lower mean FRCHe, FRCHe:FRCpleth and TPTEF:TE, but higher mean Raw than the 51 without wheeze. Regression analysis demonstrated that gestational age, length at assessment, family history of atopy and a low FRCHe:FRCpleth were significantly associated with wheeze. Conclusions: Wheeze at follow-up in very prematurely born infants is associated with gas trapping, suggesting abnormalities of the small airways.

The Mortality Index for Neonatal Transportation Score: A New Mortality Prediction Model for Retrieved Neonates

Objective. To develop a mortality prediction score for retrieved neonates based on the information given at the first telephone contact with a retrieval service. Methods. Data from the New South Wales Newborn and Pediatric Emergency Transport Service database were examined. Analysis was performed with the results for 2504 infants (median gestational age: 36 weeks; range: 24–43 weeks) who were <72 hours of age at the time of referral and whose outcome (neonatal death or survival) was known. The study population was divided randomly into 2 halves, the derivation and validation cohorts. Univariate analysis was performed to identify variables in the derivation cohort related to neonatal death. The variables were entered into a multivariate logistic regression analysis with neonatal death as the outcome. Receiver operator characteristic (ROC) curves were constructed with the regression model and data from the derivation cohort and then the validation cohort. The results were used to generate an integer-based score, the Mortality Index for Neonatal Transportation (MINT) score. ROC curves were constructed to assess the ability of the MINT score to predict perinatal and neonatal death. Results. A 7-variable (Apgar score at 1 minute, birth weight, presence of a congenital anomaly, and infant’s age, pH, arterial partial pressure of oxygen, and heart rate at the time of the call) model was constructed that generated areas under ROC curves of 0.82 and 0.83 for the derivation and validation cohorts, respectively. The 7 variables were then used to generate the MINT score, which gave areas under ROC curves of 0.80 for both neonatal and perinatal death. Conclusion. Data collected at the first telephone contact by the referring hospital with a regionalized transport service can identify neonates at the greatest risk of dying.

Lung function in prematurely born infants after viral lower respiratory tract infections

Background: Chronic respiratory morbidity has been reported in prematurely born infants after respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) lower respiratory tract infections (LRTIs). The aim of this study was to determine the impact of viral LRTI on lung function at follow-up of prematurely born infants. Methods: Fifty-nine infants born before 32 weeks of gestational age were prospectively followed after neonatal unit discharge. Nasopharyngeal aspirates were obtained when the infants developed LRTIs in hospital or the community. RSV was identified by immunofluorescence and/or culture. In addition, RSV and other viral infections were identified by real time reverse transcription polymerase chain reaction. At a corrected age of 1 year, measurements of lung volume [functional residual capacity (FRC)pleth] and airway resistance (Raw) were made by plethysmography, and lung volume was also assessed by helium gas dilution (FRCHe). Before the measurements, parents completed diary cards for 1 month documenting on a daily basis whether their infant wheezed, coughed, or required bronchodilator therapy. Results: Twenty-five infants had at least 1 proven RSV LRTI (RSV-positive group). The RSV-positive group compared with the rest of the cohort had similar lung volumes, but significantly higher Raw (P = 0.002), more days of wheeze (P < 0.001), and bronchodilator requirement (P = 0.027). Regression analysis also identified that hMPV LRTI was associated with elevated airways resistance at follow-up. Conclusion: RSV and hMPV LRTIs in prematurely born infants are associated with abnormal lung function at follow-up.

Chorioamnionitis, lung function and bronchopulmonary dysplasia in prematurely born infants

Objective To determine whether prematurely born infants exposed to chorioamnionitis compared to those not exposed have poorer lung function and are more likely to develop severe bronchopulmonary dysplasia (BPD). Design Results were analysed from consecutive infants born at <33 weeks gestation with placental histology results and lung function measurement results on days 2 and/or 7 after birth and/or at 36 weeks postmenstrual age (PMA). Setting Tertiary neonatal intensive care unit. Patients 120 infants with a median gestational age of 29 (range 23–32) weeks were studied, 76 (63%) developed BPD and 41 (34%) had been exposed to chorioamnionitis and/or funisitis. Interventions Chorioamnionitis was diagnosed histologically. Main outcome measures Lung function was assessed by measurement of lung volume and compliance and resistance of the respiratory system. If the infants remained oxygen dependent beyond 28 days, they were diagnosed at 36 weeks PMA to have mild BPD (no longer oxygen dependent), moderate BPD (required less than 30% oxygen) or severe BPD (required more than 30% oxygen and/or positive pressure support). Results No significant differences were found in the lung function results between the chorioamnionitis and non-chorioamnionitis groups at any postnatal age. There was no significant relationship between chorioamnionitis and the occurrence or severity of BPD. Regression analysis demonstrated BPD was significantly related only to birth weight, gestational age and use of surfactant. Conclusion In prematurely born infants, routinely exposed to antenatal steroids and postnatal surfactant, chorioamnionitis was not associated with worse lung function or more severe BPD.

Respiratory outcome of prematurely born infants following human rhinovirus A and C infections.

Human rhinoviruses (HRVs) are a common cause of lower respiratory tract infections (LRTIs) and are associated with chronic respiratory morbidity. Our aim was to determine whether HRV species A or C were associated with chronic respiratory morbidity and increased health care utilisation in prematurely born infants. A number of 153 infants with a median gestational age of 34 (range 23–35) weeks were prospectively followed. Nasopharyngeal aspirates were collected whenever the infants had LRTIs regardless of hospitalisation status. Parents completed a respiratory diary card and health questionnaire about their infant when they were 11 and 12 months corrected age, respectively. The health-related cost of care during infancy was calculated from the medical records using the National Health Service (NHS) reference costing scheme and the British National Formulary for children. There were 32 infants that developed 40 HRV LRTIs; samples were available from 23 of the 32 infants for subtyping. Nine infants had HRV-A LRTIs, 13 HRV-C LRTIs, and one infant had a HRV-B LRTI. Exclusion of infants who also had RSV LRTIs revealed that the infants who had a HRV-C LRTI were more likely to wheeze (p < 0.0005) and use respiratory medications (p < 0.0005) and had more days of wheeze (p = 0.01) and used an inhaler (p = 0.02) than the no LRTI group. In addition, the respiratory cost of care was greater for the HRV-C LRTI than the no LRTI group (p < 0.0005). Conclusion: Our results suggest HRV-C is associated with chronic respiratory morbidity during infancy in prematurely born infants.

Rhinovirus infection and healthcare utilisation in prematurely born infants

Our aim was to determine whether rhinovirus (RV) lower respiratory tract infections (LRTIs) in prematurely born infants increase health-related cost of care during infancy. 153 infants born at <36 weeks of gestation were prospectively followed to 1 year. Cost of care was calculated from the National Health Service reference costing scheme and healthcare utilisation determined by examining hospital/general practitioner records. 20 infants developed RV LRTIs (RV group), 17 respiratory syncytial virus (RSV) LRTIs (RSV group), 12 both RV and RSV LRTIs (RV/RSV group) and 74 had no LRTI (no LRTI group). Compared with the no LRTI group, the RV/RSV LRTI group had the greatest increase in adjusted mean cost (difference GBP 5769), followed by the RV LRTI group (difference GBP 278) and, finally, the RSV LRTI group (difference GBP 172) (p=0.045). The RV group had more outpatient (p<0.05) and respiratory-related general practitioner (p<0.05) attendances, more wheezed at follow-up (p<0.001) than the no LRTI group and more had respiratory-related outpatient attendances than the RSV LRTI group (p<0.05). We conclude that RV LRTIs were associated with increased health-related cost of care during infancy; our results suggest that the RV group compared with the RSV group suffered greater chronic respiratory morbidity. Rhinovirus LRTIs in prematurely born infants increases health-related cost of care during infancy http://ow.ly/mxyZH

Simulation training for extracorporeal membrane oxygenation

Background: Extracorporeal membrane oxygenation (ECMO) is a complex treatment. Despite this, there are a lack of training programs designed to develop relevant clinical and nonclinical skills required for ECMO specialists. The aim of the current study was to describe the design, implementation and evaluation of a 1-day simulation course for delivering training in ECMO. Methods: A 1-day simulation course was developed with educational and intensive care experts. First, the delegates received a lecture on the principles of simulation training and the importance of human factors. This was, followed by a practical demonstration and discussion of the ECMO circuit, console components, circuit interactions effects and potential complications. There were then five ECMO simulation scenarios with debriefing that covered technical and nontechnical issues. The course culminated in a knowledge-based assessment. Course outcomes were assessed using purpose-designed questionnaires. Results: We held 3 courses with a total of 14 delegates (9 intensive care nurses, 3 adult intensive care consultants and 2 ECMO technicians). Following the course, 8 (57%) gained familiarity in troubleshooting an ECMO circuit, 6 (43%) increased their familiarity with the ECMO pump and circuit, 8 (57%) perceived an improvement in their communication skills and 7 (50%) perceived an improvement in their leadership skills. At the end of the course, 13 (93%) delegates agreed that they felt more confident in dealing with ECMO. Conclusions: Simulation-training courses may increase knowledge and confidence in dealing with ECMO emergencies. Further studies are indicated to determine whether simulation training improves clinical outcomes and translates to reduced complication rates in patients receiving ECMO.