Long-term future risk of severe exacerbations: Distinct 5-year trajectories of problematic asthma.

BACKGROUND: Assessing future risk of exacerbations is an important component of asthma management. Existing studies have investigated short- but not long-term risk. Problematic asthma patients with unfavorable long-term disease trajectory and persistently frequent severe exacerbations need to be identified early to guide treatment. AIM: To identify distinct trajectories of severe exacerbation rates among "problematic asthma" patients and develop a risk score to predict the most unfavorable trajectory. METHODS: Severe exacerbation rates over five years for 177 "problematic asthma" patients presenting to a specialist asthma clinic were tracked. Distinct trajectories of severe exacerbation rates were identified using group-based trajectory modeling. Baseline predictors of trajectory were identified and used to develop a clinical risk score for predicting the most unfavorable trajectory. RESULTS: Three distinct trajectories were found: 58.5% had rare intermittent severe exacerbations ("infrequent"), 32.0% had frequent severe exacerbations at baseline but improved subsequently ("nonpersistently frequent"), and 9.5% exhibited persistently frequent severe exacerbations, with the highest incidence of near-fatal asthma ("persistently frequent"). A clinical risk score composed of ≥2 severe exacerbations in the past year (+2 points), history of near-fatal asthma (+1 point), body mass index ≥25kg/m2 (+1 point), obstructive sleep apnea (+1 point), gastroesophageal reflux (+1 point), and depression (+1 point) was predictive of the "persistently frequent" trajectory (area under the receiver operating characteristic curve: 0.84, sensitivity 72.2%, specificity 81.1% using cutoff ≥3 points). The trajectories and clinical risk score had excellent performance in an independent validation cohort. CONCLUSIONS: Patients with problematic asthma follow distinct illness trajectories over a period of five years. We have derived and validated a clinical risk score that accurately identifies patients who will have persistently frequent severe exacerbations in the future.

Simple aspiration versus chest-tube insertion in the management of primary spontaneous pneumothorax: a systematic review.

BACKGROUND: The initial treatment of a primary spontaneous pneumothorax (PSP) is controversial. Guidelines of the British Thoracic Society recommend simple aspiration for all PSP requiring intervention. The placement of chest tubes is only advocated for patients who fail simple aspiration. However, the American College of Chest Physicians Delphi Consensus Statement found simple aspiration to be rarely appropriate in the management of PSP. AIMS: To compare simple aspiration with chest-tube drainage in the initial management of PSP. METHODS: Meta-analysis of randomized controlled trials (RCTs). OUTCOME MEASURES: Reductions in duration of hospital stay, recurrence rate and pain or dyspnoea score were classified as benefits, whereas reductions in successful events were classified as risks. DATA COLLECTION AND ANALYSIS: For dichotomous data, the relative risk (RR) and 95% confidence intervals were calculated. For continuous data, weighted mean differences (WMD) were used. RESULTS: Three RCTs were identified with a combined total of 194 patients. Simple aspiration was associated with shorter hospitalization (WMD -1.30 days [-2.20 to -0.39]). The results for success rate could not be combined because of differences in outcome definitions. However, a pooled result for "success at 1 week or more" showed no significant difference between either intervention (RR 0.86 [0.67, 1.11]). Results of recurrence at 1 year were also not significantly different (RR 0.73 [0.39-1.38]). Different reporting systems for pain scores meant that data could not be pooled. Only one trial reported dyspnoea scores. CONCLUSION: RCT evidence in this field is limited, and the total sample size is too small to make any firm conclusion. On the basis of current available evidence, simple aspiration is advantageous in the initial management of PSP because of shorter hospitalization. There is no significant difference in recurrence at 1 year using either modality, and the efficacy data are inconclusive.

A case report of occupational asthma due to gluteraldehyde exposure.

INTRODUCTION: We report the first case of occupational asthma due to gluteraldehyde exposure in Singapore and also describe the use of a specific inhalational challenge (SIC) test in confirming the diagnosis. CLINICAL PICTURE: A 32-year-old laboratory technician presented with adult-onset asthma 2 years after daily exposure to gluteraldehyde which was used to sterilise the mouthpieces used for lung function testing. SIC testing showed a 25% drop in FEV1 after exposure to gluteraldehyde but not after exposure to a control, thus confirming the diagnosis. TREATMENT: Alternative arrangements were made for sterilisation of the mouthpieces so that gluteraldehyde could be removed from the workplace. There was a marked improvement in her asthmatic control thereafter. CONCLUSIONS: This case illustrates the use of a SIC test in the diagnosis of occupational asthma. Gluteraldehyde is a known cause of occupational asthma and should be kept in mind when evaluating asthmatic patients in at-risk occupations. Effective ventilation and proper storage should be ensured to minimise exposure to gluteraldehyde where its use is necessary.

Prevention of intraabdominal adhesions in Kasai portoenterostomy.

An infant with biliary atresia had the right side of his liver covered with a sodium hyaluronate-based bioresorbable membrane during his initial Kasai portoenterostomy procedure. When his peritoneal cavity was entered 10.6 months (317 days) later for a liver transplant operation there was a remarkable absence of intraabdominal adhesions leading to a smooth operation and an uncomplicated recovery.

Conservative management of mesenchymal hamartomas of the chest wall.

Mesenchymal hamartomas of the chest wall are rare benign lesions usually discovered in infancy. The authors present their experience with 3 cases. All of these cases were managed initially conservatively, although 1 child required a thoracotomy and partial tumour resection at 5 months of age because of respiratory compromise. The other 2 children have now reached 5 and 6 years of age with the tumors becoming less prominent. The authors believe many cases can be managed conservatively because malignant change has not been reported, and the lesions often become relatively smaller as the child grows.

Surgical complications and long-term outcome in pediatric liver transplantation.

BACKGROUND/AIMS: Liver transplantation has been widely accepted for the treatment of children with end-stage liver disease over the last 10 years particularly with the advent of reduced-size liver transplant technique. This study reviewed the perioperative and long-term results in the pediatric program of the Queensland Liver Transplant Service, Brisbane, Australia. METHODOLOGY: Retrospective analysis was performed in 153 children who received 176 liver grafts between 1985 and 1995, including 109 (62%) reduced-size and 67 (38%) whole liver grafts. Median follow-up period was 5.3 years. RESULTS: One-, 5-, and 10-year patient and graft survival rates were 82% and 74%, 75% and 63%, and 70% and 60%, respectively. Normal physical and intellectual development was observed in 98% of survivors. There were no significant differences in patient or graft survival rates between transplants using reduced-size and whole liver grafts. Portal vein thrombosis was the most common vascular complication, occurring in 8%. Hepatic artery thrombosis occurred in 7%, including 11% of children less than 1 year old and 8% of those under 10 kg. Biliary complication was found in 16% and posttransplant gastrointestinal perforation in 19%. CONCLUSIONS: Liver transplantation has the potential to cure and allow development in children with end-stage liver disease.

Gastrostomy button: clinical appraisal.

We retrospectively studied all gastrostomy buttons inserted in the Royal Children's Hospital, Brisbane between 1988 and 1995. One hundred and thirty-two patients (M = 60, F = 72) and 388 buttons were analysed. Intellectual handicap and cystic fibrosis comprised the majority of patients. Thirty-three patients had gastrostomy buttons inserted primarily, whereas, 99 patients received gastrostomy buttons inserted into matured gastrostomy stoma. The average longevity of all determined buttons (n = 280) was 360.43 days (SD = 310.24). The first buttons inserted primarily (n = 25) had longer longevity than the first buttons inserted into matured gastrostomy stoma (n = 82) with statistical significance. The average longevity of subsequent buttons was significantly less than the first buttons. Valve incompetence and leakage of gastric content around the shaft were the most common causes of button removal. We concluded that the gastrostomy button is the method of choice for long term enteral feeding in children.

Comparison between mushroom-type and balloon-type gastrostomy buttons.

The gastrostomy button has been improved rapidly over the last ten years. The gastrostomy button was divided into two groups. The first group had a mushroom tip and, in this study, the Bard button represented this group. The other had a balloon as an internal stabilizer and the Mic-key button represented this group. The authors retrospectively studied all buttons inserted at the Royal Children's Hospital, Brisbane between 1988 and 1995. The average longevity of Bard and Mic-key buttons were 378.82 and 259.62 days respectively. Valve incompetence was the most common cause of removal of the Bard button (38%), whereas, balloon rupture was the major cause of removal of Mic-key button (44%). Each type of gastrostomy button had its own advantages and disadvantages and these special characteristics will be discussed.

Primary gastrostomy button: a means of long-term enteral feeding in children.

Between June 1992 and December 1997, forty-two patients (M 19, F 23) received 94 primary gastrostomy buttons due to 22 intellectual handicap, 7 cystic fibrosis, 4 severe gastrooesophageal reflux, 2 bronchopulmonary dysplasia, 2 tumours in the neck region and 5 miscellaneous causes. Open fundoplication concomitant with primary button, primary open button and laparoscopic fundoplication concomitant with primary button were performed in 20, 15 and 7 patients respectively. The average longevity +/- standard deviation of all buttons was 388.36 +/- 360.35 days. The average longevity of the buttons of the laparoscopic fundoplication group was significantly lower than the others. The major causes of removal of Bard buttons were valve incompetence and flap damage, whereas, balloon leakage was the major cause of removal of the Mic-key button. There were merely minor stomal complications and no gastric separation and peritonitis. Because of the acceptable longevity of the buttons and minimal complications, we concluded that the primary gastrostomy button was the preferable method of long term enteral feeding in children.

Ethnicity, obstructive sleep apnoea and ischaemic heart disease.

We studied the relationship between different ethnic groups, obstructive sleep apnoea (OSA) and ischaemic heart disease. Four hundred and thirty-two inpatients from the medical wards were interviewed. Limited overnight sleep studies were done in 129 of those who had habitual snoring, daytime sleepiness based on an Epworth sleepiness scale of 8 or more, or a large neck size of 40 cm or more. There were 315 Chinese (72.9%), 67 Malays (15.5%), 43 Indians (10%) and 3 from other races (1.4%). The prevalence of OSA was 19.7%, 30% and 12% among the Chinese, Malays and Indians, respectively. The prevalence ratio for OSA was 1.52 in Malays using Chinese patients as the baseline (P = 0.07). The median neck circumference was 37 cm in both racial groups. The median body mass index was 22.7 kg/m2 in Chinese compared to 23.6 kg/m2 in Malays. The median apnoea-hypopnoea index was 22.7, 19.0 and 26.9 events/hour among the Chinese, Malays and Indians, respectively. OSA was independently associated with the prevalence of IHD (adjusted prevalence ratio 1.68; 95% CI: 1.15, 2.46; P = 0.009). The prevalence of ischaemic heart disease (IHD) was 31%, 24% and 28% in Chinese, Malays and Indians, respectively. The prevalence ratio for IHD in Malays compared to Chinese was 0.77. After adjusting for OSA, there was an even greater reduction in the risk of IHD (adjusted prevalence ratio 0.70). This suggests that OSA is a confounder in the relationship between race and ischaemic heart disease.

Liver transplantation in Japanese and Australian/New Zealand children with biliary atresia: a 10-year comparative study.

OBJECTIVE: To compare Japanese with Australian/New Zealand (ANZ) children with biliary atresia who were treated by liver transplantation, and evaluate the indications for and timing of transplantation. DESIGN: Retrospective study. SETTING: Queensland Liver Transplant Service (QLTS), Australia. SUBJECTS: 43 Japanese and 30 ANZ children with biliary atresia who required transplantation between 1985 and 1992. INTERVENTIONS: The 43 Japanese children had 52 transplants, and the 30 ANZ children had 33. MAIN OUTCOME MEASURES: Morbidity, mortality, and long term survival. RESULTS: The Japanese children had significantly lower serum albumin concentrations than the ANZ children preoperatively (mean (SD) 32 (7) g/L compared with 37 (5), p<0.05). The actuarial survival at 7 years of the ANZ children was significantly higher than that of the Japanese children (79% compared with 49%, p<0.05). There were 24 deaths (17 Japanese, 40%, and 7 ANZ, 23%); 2 of the ANZ and 7 of the Japanese children died more than a year after transplantation. All 26 children who were well-nourished at the time of transplantation defined as a Z-score (weight or height minus mean weight or height for age, sex, and race, divided by the SD) of -1 or more were alive at 1 month compared with 11 of the 47 poorly-nourished children (Z-score <-1). Survival among the Japanese declined after 1 year, and there was no association with Z-scores. Overall, Z-scores for weight improved significantly after transplantation, whereas those for height improved a little, but not significantly so. Japanese children were significantly shorter than ANZ children, and their Z-scores for height did not improve after transplantation. CONCLUSION: liver transplantation should be done as soon as possible for children with biliary atresia to maximise survival and growth.

Additional techniques adopted for major vascular anastomoses during orthotopic liver transplantation.

Of 372 patients who underwent liver transplants between January 1985 and March 1995, 7 required variations in vascular anastomoses due to discrepancies in the size-match of the donor and recipient vessels, the presence of a thrombosed hepatic artery or portal vein, or complete absence of the portal vein. The techniques described herein enabled us to perform successful transplantation in all patients. Although rethrombosis of the portal vein developed in one patient after a third transplant, this patient remains clinically well. The use of an operating microscope and the harvesting of an extended length of donor superior mesenteric vein or vascular grafts of the donor iliac or saphenous vessels, for potentially difficult transplants, are invaluable techniques.

Critical appraisal of surgical venous access in children.

Central venous catheters (CVC) have become an important adjunct to the overall management of paediatric patients, but their use is associated with frequent complications resulting in premature removal. This report evaluates the insertion techniques and complications of 295 consecutive surgically inserted CVC from 1987 to 1991 in a paediatric hospital. Fully implanted catheters had significantly less incidence of catheter-related problems necessitating removal (infection, dislodgment, leaking, blockage, or migration - 31%) compared to exteriorised catheters (58%). One-third of catheters were removed because of infection, one-third as they were no longer needed, and the remaining for multiple reasons. Infected (110+/-18 days), dislodged (18+/-4 days), or migrated (44+/-6 days) catheters were removed significantly earlier than those removed because they were no longer needed (195+/-24 days). Catheters became dislodged more frequently in the younger patients. Catheters with the tip in the subclavian vein (29%) migrated more frequently than those in the right atrium. There was a significantly increased incidence of infection in catheters inserted into the saphenous vein (43%) compared to those in the internal jugular vein (11%). Some episodes of catheter infection were managed with antibiotics, with short-term resolution of symptoms and signs. However, all 71 infected catheters ultimately required removal for further sepsis. Fully implanted catheters had 1.1 episodes of catheter-related sepsis per 1,000 catheter days compared to 3.7 for exteriorised catheters. The position of the catheter tip, vein used for insertion, training of young surgeons, and location of the subcutaneous tunnel need particular attention in order to reduce catheter complications.

Chronic copper toxicosis presenting as liver failure in an Australian child.

A 20 month old Caucasian male child, after a five week illness, developed liver failure which was successfully treated by liver transplantation. The explanted liver had a histology identical to that seen in Indian childhood cirrhosis and its copper content was increased tenfold. Water used to prepare the child's milk feeds came from a bore via copper conduits and at times contained 120 mumol/l of copper, eight times the recommended maximum for human consumption. Because non-Indian cases of Indian childhood cirrhosis associated with excess copper ingestion are increasingly being recognised, and as early treatment can restore normal liver morphology, we support the use of the previously suggested alternative term for this condition, ie; 'copper-associated liver disease in childhood'. Measurement of hepatic copper concentrations in all children less than six years of age who develop hepatic failure of unknown cause will increase its recognition. On diagnosis sources of increased dietary copper should be investigated to ensure that younger siblings are not similarly exposed.

The management of difficult abdominal closure after pediatric liver transplantation.

Between January 1985 and December 1994, 164 liver transplantations were performed on 141 children. There were 100 reduced-size and 64 whole-liver grafts. Primary closure of the abdominal wound was not possible in 21 patients because of liver size, bowel edema, and distension. Temporary SILASTIC patch closure of the abdominal wound was used. For 16 of the 21 patients, removal of the SILASTIC patch and abdominal wall closure were completed by the seventh postoperative day; for the others, these were accomplished by the end of 2 weeks. The method is recommended when primary wound closure is not possible.

Resolution of cirrhosis-related pulmonary shunting in two children with a transplanted liver.

We treated two children with hypoxemia caused by intrapulmonary shunting associated with cirrhosis secondary to extrahepatic biliary atresia. Following orthotopic liver transplantation, digital clubbing and intrapulmonary shunting were resolved, as demonstrated by normalization of room air arterial blood gases, reduction in shunt fraction, and perfusion lung scanning with 99mTc-labeled macroaggregates of albumin. We recommend that early liver transplantation be considered for young subjects with a severe hepatopulmonary syndrome.

Use of the donor iliac vein to replace the retrohepatic vena cava in pediatric reduced-size liver retransplantation.

The authors describe a new technique that used the donor common iliac vein and its bifurcation into the external iliac and internal iliac veins to replace the retrohepatic vena cava; this was used in a recipient who underwent her second reduced-size transplantation (segments II and III). Anastomosis of the donor hepatic vein to the internal iliac vein, with use of this segment of the venous graft to replace the retrohepatic vena cava, is for patients who have had more than one surgical procedure before liver transplantation.

Liver transplantation in the presence of situs inversus totalis: application of reduced-size graft.

Because of the anatomical features associated with situs inversus, technical difficulties will be encountered during orthotopic liver transplantation. This report describes the case of a patient with situs inversus totalis and end-stage liver disease from biliary atresia who was treated by segmental orthotopic liver transplantation. The segmental graft was safely placed in the left subphrenic space, and a suitable orientation was obtained for anastomoses of the hilar vessels. Chronic rejection necessitated retransplantation, by the same method, 19 months later. This technique has potential advantages in coping with anatomical obstacles encountered in patients with situs inversus.