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Biomedical subjects

Q Mok

Publications and source records attributed to Q Mok.

At least 19 recordsLinked to original sources

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.

Bronchial Diseases↗

Clinical course and determination of brainstem death in a children's hospital.

AIM: To study the aetiology and clinical course of children with brainstem death in a paediatric intensive care unit (ICU) and to determine whether current the practices that are used to declare brainstem death conform to accepted criteria. METHODS: A retrospective review chart of all patients with brainstem death (n = 31) admitted to the paediatric ICU between January 1995 and December 1998 was drawn up. RESULTS: Mean age of the patients was 51.9 +/- 54.5 mo with the main diagnoses being head trauma in 11 children, anoxic encephalopathy in 7, brain tumour in 5, drowning in 4, CNS haemorrhage in 3 and CNS infection in 1 child; 32.3% of the children were given pre-ICU admission cardiopulmonary resuscitation. The average time from insult to suspected brainstem death was 27 h and suspected brainstem death to confirmation was 25 h, with an average of 1.6 examinations performed. EEG was done in 14 patients, with electrocerebral silence in 8 after the first examination and in a further 5 after repeat testing. Cerebral blood-flow scans were done in 3 children and evoked potentials in 1 child. CONCLUSIONS: Trauma remains the most common primary diagnosis leading to brainstem death. Intensivists in this large hospital for children mainly conform to accepted guidelines for determination of brainstem death although there is a wider use of ancillary tests to aid diagnosis. The study also showed a low rate of < 10% of organ procurement for transplantation.

Adolescent↗

Case report of a 13-year-old struck by lightning.

Lightning strikes kill 1,000 people per year worldwide. Cardiac arrests resulting from lightning strikes have good survival rates but there is a significant degree of morbidity amongst the survivors. This is the case report of a 13-year-old boy who had a cardiac arrest following a direct lightning strike, and his subsequent management.

Adolescent↗

Severe and unrecognised: pertussis in UK infants.

AIMS: To diagnose pertussis using culture, polymerase chain reaction, and serology, in children admitted to intensive care units (PICUs) and some paediatric wards in London, and in their household contacts to determine the source of infection. METHODS: Infants <5 months old admitted to London PICUs between 1998 and 2000 with respiratory failure, apnoea and/or bradycardia, or acute life threatening episodes (ALTE), and children <15 years admitted to paediatric wards at St Mary's and St George's Hospitals between 1999 and 2000 with lower respiratory tract infection, apnoea, or ALTE were studied. RESULTS: Sixty seven per cent of eligible children (142/212) were recruited; 23% (33/142) had pertussis, 19.8% (25/126) on the PICU and 50% (8/16) on wards. Two died. Only 4% (6/142) were culture positive. Pertussis was clinically suspected on admission in 28% of infants (7/25) on the PICU and 75% (6/8) on the wards. Infants on PICU with pertussis coughed for longer, had apnoeas and whooped more often, and a higher lymphocyte count than infants without pertussis. Pertussis and respiratory syncytial virus (RSV) co-infection was frequent (11/33, 33%). Pertussis was confirmed in 22/33 (67%) of those who were first to become ill in the family. For 14/33 children the source of infection was a parent; for 9/33 the source of pertussis was an older fully vaccinated child in the household. CONCLUSIONS: Severe pertussis is under diagnosed. An RSV diagnosis does not exclude pertussis. Future changes to the UK vaccination programme should aim to reduce pertussis transmission to young infants by their parents and older siblings.

Anti-Bacterial Agents↗

T cryptantigen activation is associated with advanced necrotizing enterocolitis.

BACKGROUND/PURPOSE: Thomsen-Friedenreich cryptantigen activation (TCA) exposes neonates with necrotizing enterocolitis NEC to the risk of hemolysis after transfusion of blood products. The authors aimed to determine the prevalence of TCA in neonates with NEC and to correlate TCA with severity of disease and outcome. METHODS: One hundred four neonates with NEC were tested for TCA on admission. Patients with TCA requiring transfusion were given packed red cells, low-titer anti-T fresh frozen plasma, and washed platelets to avoid hemolysis. RESULTS: Twenty-three infants had TCA, and 96% of these had stage III disease. The incidence of TCA was significantly higher in infants with stage III disease compared with those with stage II (30% v 4%; P <.01). A total of 91% of infants with TCA required laparotomy compared with 81% of those with no activation. At laparotomy, widespread disease was more common in the TCA group (71% v 55%). TCA did not significantly increase mortality rate (TCA, 39% v no TCA, 28%); this may reflect the transfusion policy of our unit. CONCLUSIONS: Twenty-two percent of neonates with NEC referred to our unit had TCA. There is an association between TCA and advanced NEC. Screening of neonates with advanced NEC for TCA is advised to identify those at risk of hematologic complications.

Antigens, Tumor-Associated, Carbohydrate↗

Centralization of paediatric intensive care: are critically ill children appropriately referred to a regional centre?

OBJECTIVES: To evaluate the appropriateness of emergency referrals for inter-hospital transfers by local physicians in hospitals without intensive care facilities to a regional tertiary paediatric intensive care unit (PICU). DESIGN: A prospective, descriptive study in a tertiary PICU and hospitals without paediatric intensive care facilities in and around the London area, UK. PATIENTS: All patients (< 18 years) referred for emergency admission to the PICU from district hospitals (n = 436) as well as those admitted through other modes of admission (n = 286) between 1 October 1998 and 30 June 1999 were prospectively studied. Admissions and transfers were deemed appropriate if the risk of mortality using the Paediatric Risk of Mortality (PRISM II) score was greater than 1%, and/or if the patient required a unique ICU-dependent therapy. Effectiveness was estimated using PRISM II derived observed-to-expected mortality ratio. Of the 436 emergency referrals 398 (91.3%) were retrieved and transported to the PICU. Of these, 38 referrals were thought to be inappropriate after telephone consultation and were not transferred. Of the emergency referrals 376 (94.4%) had a mortality risk greater than 1% or required an ICU-dependent therapy on admission day. Thus 86.2% (376/436) of the referrals and 94.4% (376/398) of transfers were considered appropriate. The PRISM II derived standardized mortality rate was 0.694 (95% CI 0.517-0.913) in the overall population and 0.613 (95% CI 0.434-0.843) amongst the emergency referrals. CONCLUSION: Physicians at local hospitals within a centralized system of delivering paediatric intensive care were able to maintain adequate assessment skills in recognition and requesting for appropriate transfers of the most ill and efficiently utilized resources available at the regional centre.

Adolescent↗

Current management and outcome of tracheobronchial malacia and stenosis presenting to the paediatric intensive care unit.

OBJECTIVE: To identify factors associated with mortality and prolonged ventilatory requirements in patients admitted to our paediatric intensive care unit (PICU) with tracheobronchial malacia and stenosis diagnosed by dynamic contrast bronchograms. DESIGN: Retrospective review. SETTING: Tertiary paediatric intensive care unit. PATIENTS: Forty-eight cases admitted to our PICU over a 5-year period in whom a diagnosis of tracheobronchial malacia or stenosis was made by dynamic contrast bronchography (1994-1999). INTERVENTIONS: Conservative management, tracheostomy and long-term ventilation, surgical correction, internal or external airway stenting. MEASUREMENTS AND RESULTS: Recording of clinical details, length of invasive ventilation and appearance at contrast bronchography. Five groups of patients were defined: isolated primary airway pathology (n = 7), ex-premature infants (n = 11), vascular rings (n = 9), complex cardiac and/or syndromic pathology (n = 17) and tracheo-oesophageal fistulae (n = 4). The overall mortality was 29%. Median length of invasive ventilation in survivors was 38 days and in patients who died 45. Mortality was highest in the patients with complex cardiac and/or syndromic pathology (p = 0.039 Cox regression analysis) but was not related to any other factor. Patients with stenosis required a significantly longer period of ventilatory support (median length of ventilation 59 days) than patients with malacia (39 days). CONCLUSIONS: Length of ventilation and bronchographic diagnosis did not predict survival. The only factor found to contribute significantly to mortality was the presence of complex cardiac and/or syndromic pathology. However, patients with stenosis required longer ventilatory support than patients with malacia.

Bronchial Diseases↗

How safe is non-bronchoscopic bronchoalveolar lavage in critically ill mechanically ventilated children?

OBJECTIVE: To assess the safety of non-bronchoscopic bronchoalveolar lavage (NB-BAL) in critically ill mechanically ventilated children. SETTING: Paediatric intensive care unit in a tertiary children's hospital. METHODS: The data from 60 consecutive critically ill mechanically ventilated children who underwent NB-BAL was reviewed from November 1997 to December 1999. PRISM score prior to NB-BAL, observations at the time of NB-BAL and arterial blood gases, oxygenation index (OI), ventilator settings, haemodynamic variables and temperature taken at 1 h before, and 1 and 6 h after NB-BAL, were retrieved from the archived computerised database. RESULTS: Median age was 7 months (IQR 2.8-43 months) and median weight was 5.5 kg (IQR 4-14 kg). Four (7%) patients exhibited significant immediate complications, requiring escalation of respiratory or haemodynamic support. Forty-two (70%) patients had complete data for calculation of OI; there was no significant change in median OI at 1 and 6 h after NB-BAL. However 5 (12%) of these patients experienced an increase in OI of between 10 and 45 at 1 h post NB-BAL, which returned to baseline at 6 h post NB-BAL. Complications did not correlate with any of the available variables: baseline OI, PRISM score or with deterioration at the time of the procedure, although it was observed that four out of the six patients with baseline OIs of greater than 20 experienced complications. CONCLUSION: Non-bronchoscopic bronchoalveolar lavage in critically ill mechanically ventilated neonates and children is generally a well-tolerated procedure, but for some patients, in whom it was not possible to elucidate predictive factors, complications developed. All patients, particularly those with OIs of greater than 20, require careful monitoring during and after the procedure.

Blood Gas Analysis↗

Identifying futility in a paediatric critical care setting: a prospective observational study.

AIMS: To determine the extent of futile care provided to critically ill children admitted to a paediatric intensive care setting. METHODS: Prospective evaluation of consecutive admissions to a 20 bedded multidisciplinary paediatric intensive care unit of a North London teaching hospital over a nine month period. Three previously defined criteria for futility were used: (1) imminent demise futility (those with a mortality risk greater than 90% using the Paediatric Risk of Mortality (PRISM II) score); (2) lethal condition futility (those with conditions incompatible with long term survival); and (3) qualitative futility (those with unacceptable quality of life and high morbidity). RESULTS: A total of 662 children accounting for 3409 patient bed days were studied. Thirty four patients fulfilled at least one of the criteria for futility, and used a total of 104 bed days (3%). Only 33 (0.9%) bed days were used by patients with mortality risk greater than 90%, 60 (1.8%) by patients with poor long term prognosis, and 16 (0.5%) by those with poor quality of life. Nineteen of 34 patients died; withdrawal of treatment was the mode of death in 15 (79%). CONCLUSIONS: Cost containment initiatives focusing on futility in the paediatric intensive care unit setting are unlikely to be successful as only relatively small amounts of resources were used in providing futile care. Paediatricians are recognising futility early and may have taken ethically appropriate measures to limit care that is futile.

Child↗

Heparin-bonded central venous lines reduce thrombotic and infective complications in critically ill children.

OBJECTIVE: To determine whether heparin bonding reduces the incidence of catheter-related thrombosis and infection in critically ill children. DESIGN: A prospective double-blind randomized controlled study. SETTING: A tertiary paediatric intensive care unit. PATIENTS: Two hundred and nine patients, 123 males and 86 females, aged 0-16 years, admitted to the intensive care unit and needing a central venous line (CVL), were randomized to receive either a heparin-bonded (HB, n = 102) or a non-heparin-bonded line (NHB, n = 107). Nine patients were excluded owing to incomplete data. INTERVENTION: HB or NHB CVL. MEASUREMENTS: Blood cultures were carried out on insertion of the line and every 3 days thereafter. Ultrasound was performed within the first 3 days and every 3 days thereafter. On removal the line was sent for culture. RESULTS: The two groups were comparable for age, sex, severity of illness and length of time that the catheter was in situ. Proportional hazards modelling showed that heparin bonding was associated with a significant reduction in infections (hazard ratio 0.11, P < 0.00005). The incidence of infection was 4% and 33% in HB and NHB CVLs, respectively (4/97 vs. 34/103, P < 0.0005). The incidence of thrombosis was 0% and 8% in HB and NHB CVLs, respectively (0/97 vs. 8/103, P = 0.006). The number of HB CVLs which would need to be used to avoid one episode of infection or thrombosis was 3 and 13, respectively. CONCLUSION: Our study shows a significant reduction in the incidence of infection and thrombosis associated with the use of HB CVLs.

Adolescent↗

Persistent pulmonary hypertension of the term neonate: a strategy for management.

UNLABELLED: The management of 32 consecutive term infants referred with persistent pulmonary hypertension of the newborn were reviewed. Despite indices suggesting severe cardiorespiratory failure with a median alveolar-arterial oxygen gradient of 591 torr (inter-quartile range 432-618) and oxygenation index of 31 (18-44), all but one patient responded to conventional treatment with inhaled nitric oxide and high frequency oscillatory ventilation. CONCLUSION: Patients should be referred early to centres where maximal conventional support can be offered before consideration for extracorporeal membrane oxygenation.

Administration, Inhalation↗