PubMed Health⌕ Search

Biomedical subjects

T W Higenbottam

Publications and source records attributed to T W Higenbottam.

At least 73 records · Page 4Linked to original sources
PubMed1991

Infection and reactivation with cytomegalovirus strains in lung transplant recipients.

Cytomegalovirus pneumonia is a major cause of morbidity and death following lung transplantation (LT) (1). The case fatality rate is highest in the CMV-seronegative recipients (R-) of organs from seropositive donors (D+), which suggests that transmission of CMV may occur with the graft (1), but in seropositive recipients (R+) the comparative importance of reactivation of endogenous virus and reinfection with donor virus is poorly understood.

Cytomegalovirus↗
PubMed1991

Heart-lung transplantation for cystic fibrosis. 1: Assessment.

Forty five patients with cystic fibrosis (age 5-15 years) were assessed for heart-lung transplantation between September 1987 and March 1990. The two main conditions for acceptance were (i) life expectancy less than 2 years and (ii) a severely impaired quality of life. Patients were accepted onto an active waiting list (n = 26), a provisional waiting list (n = 15), or not accepted (n = 4). Selection was made on clinical grounds with objective measurements used as an aid in assessment. As expected, the mean values for objective measures were significantly different between patients on the active waiting list compared with the provisional waiting list/not accepted group for resting heart rate (118/minute v 101/minute), percentage of ideal weight (83.2% v 93.1%), forced expiratory volume at one second as percent of predicted normal (27.3% v 47.6%), Shwachman-Kulczycki score (33.6 v 52.5), Chrispin-Norman x ray score (25.8 v 22.1), 12 minute walk (540 m v 854 m), and minimal oxygen saturation (81.5% v 92%). Psychological evaluation demonstrated a 55% incidence of individual and a 50% incidence of family morbidity. Of the 26 patients accepted onto the active waiting list, 11 have been transplanted (mean waiting time 3.3 months), 10 have died within a mean of 3.7 months of acceptance, and five remain on the active list (mean 5.6 months).

Adolescent↗
PubMed1991

Heart-lung transplantation for cystic fibrosis. 2: Outcome.

From March 1988 to March 1990, 11 children with cystic fibrosis (age 5-15 years) underwent combined heart-lung transplantation at our institutes. Maintenance immunosuppression consisted of cyclosporin and azathioprine with corticosteroids and antithymocyte globulin used perioperatively and during rejection episodes. Six patients (55%) survive from 1.5-23 months all of whom have improved life quality. Actuarial survival to 1 year was 55%. At six months after transplant, mean forced expiratory volume at one second was 73.5% of predicted normal, compared with 25% before transplant. There was one perioperative death, three later deaths associated with obliterative bronchiolitis at two, eight, and nine months, and one from mediastinitis at four months. Of the 15 children accepted for transplantation but not receiving grafts, 10 have died (eight within four months of being placed onto the transplant list). Early postoperative problems included acute reversible rejection (n = 10), meconium ileus equivalent (n = 3), and pancreatitis (n = 1). There was a high incidence of later pulmonary rejection with a mean of 5.7 episodes per patient in the first six months. Pulmonary infection occurred relatively infrequently, with Pseudomonas aeruginosa being the most common pathogen. Persistent diabetes mellitus requiring insulin occurred in four and systemic hypertension developed in one.

Adolescent↗
PubMed1991

Adaptive modeling of the human rib cage in median sternotomy.

This paper describes a limited computer-analyzed kinematic model of the rib cage that can be adapted to individual subjects. Also described is its validation and use in assessing the changes in chest wall shape after coronary artery bypass graft (CABG) surgery in 12 patients. The positions of a small number of anatomic locations on the thoracic spine, ribs, manubrium, and sternum are measured from lateral and posterior-anterior chest radiographs. The computer program puts these two views together removing the magnification and reconstructs any missing points to give a three-dimensional picture of the rib cage to which mathematical models of the bones are scaled. The patients had chest radiographs taken at total lung capacity (TLC) and residual volume (RV) to investigate the source of the restrictive ventilatory defect that follows CABG. The predictions from the model were tested by comparing full-sized computer plots with the actual chest radiographs. The estimates of the bony structures were accurate to +/- 3 degrees for orientations and +/- 6 mm for positions. We found reduced rib motion both "pump-handle" (theta) and "bucket handle" (psi) going from theta, psi left, psi right = 9 degrees, 10 degrees, 14 degrees to 4 degrees, 10 degrees, 9 degrees, respectively, after surgery with P less than 0.025, 0.42, 0.07. The angles were measured from the horizontal and increased caudally. There was also reduction in the range of angles subtended by the arc of the thoracic vertebrae between TLC and RV, which went from 12 degrees to -1 degrees (P less than 0.015). These data explain the fall in lung volumes that follow CABG and provide insight into the contribution made by the ribs and spine in full inspiration and full expiration.

Coronary Artery Bypass↗
PubMed1991

The alpha 1-adrenergic agonist methoxamine and the "loop" diuretic frusemide reduce nasal potential difference.

Pretreatment by inhalation with the alpha 1-adrenergic agonist methoxamine and the "loop" diuretic frusemide reduces the bronchial response to certain airway challenges in asthma. To test whether these drugs may act by altering airway epithelial ion and water transport, their effect on nasal potential difference (PD) when applied topically in eight normal volunteers was measured. For comparison, the effect of the Na(+)-channel blocking drug amiloride and the beta 2-adrenergic agonist salbutamol was also tested. Both methoxamine and frusemide significantly reduced PD: at the highest concentration given (10(-3) mol.l-1), there was a mean drop in PD from baseline of 39.5% following methoxamine treatment (p less than 0.05) and a mean drop of 30.2% following frusemide (p less than 0.05). Neither drug was as effective as amiloride, which caused a mean drop in PD of 27.5% from baseline at 10(-6) mol.l-1 and a drop of 71.6% at 10(-3) mol.l-1 (p less than 0.01 for each concentration). Salbutamol had no significant effect on PD (p greater than 0.05). We conclude that methoxamine and frusemide may derive their protective effect on some bronchial challenge, at least in part, from their effect on airway epithelial ion flux.

Adult↗
PubMed1990

The histological changes in transbronchial biopsy after treatment of acute lung rejection in heart-lung transplants.

Transbronchial lung biopsies taken during episodes of acute lung rejection in heart-lung transplant patients were examined histologically. When the diagnosis was confirmed by microscopy, the patients were treated with augmented immunosuppression by high-dose corticosteroids. A second biopsy was obtained an average of 23.5 days after commencement of treatment. These biopsies were examined to determine the histological changes caused by treatment. In most cases, there were both quantitative and morphological differences between the infiltrates in acute rejection and in the remaining perivascular infiltrates after treatment. In acute rejection, 26 of 28 biopsies contained perivascular lymphocytic infiltrates, lymphocytes being large and blast-like. Although 20 of 28 follow-up biopsies still contained perivascular infiltrates, they were smaller and the lymphocytes smaller in size. Half the biopsies in rejection contained neutrophils, but less than half contained eosinophils in the perivascular infiltrates. After treatment, all these cells were less numerous. Another feature of treated rejection was the presence of haemosiderin around vessels suggesting earlier acute vascular injury. However, haemosiderin persists long after the cellular infiltrate has disappeared and cannot be considered a reliable feature of recently treated acute lung rejection. The bronchiolar infiltrates showed a similar pattern of responses to the perivascular infiltrates.

Adult↗
PubMed1990

Validation of impedance cardiography measurements of cardiac output during limited exercise in heart transplant recipients.

Twenty-one patients were studied at rest and during exercise after heart transplantation to compare cardiac output measured by thermodilution and impedance cardiography. Exercise was performed on a bicycle ergometer over a limited range of work load (25 and 50 watt) whilst metabolic gas exchange was recorded. One patient was studied at rest whilst his circulation was maintained by a Jarvik-7 artificial heart. The values of cardiac output measured by impedance cardiography corresponded closely with the flow rate from the artificial heart. There was also close agreement between the impedance and thermodilution measurements of cardiac output at rest and during exercise. Both measurements followed the changes in heart rate and oxygen consumption. Both thermodilution and impedance cardiography methods elicited good reproducibility of cardiac output measurements at rest and during exercise. These observations suggest that the noninvasive and continuous record of cardiac output obtained by impedance cardiography can be used for the postoperative monitoring of heart transplant recipients.

Adult↗
PubMed1990

Intensive care management of children following heart and heart-lung transplantation.

We report the intensive care management of 23 children (age 3-15 years) following orthotopic heart (HT) and combined heart and lung transplantation (HLT) performed at our 2 institutes between February 1985 and August 1989. Cyclosporin A, azathioprine and steroids were given as routine immunosuppression, whilst anti-thymocyte globulin (ATG) was used for the first 3 post-operative days. Mean ventilation time was 24.6 h (range 4-74 h). Cardiovascular support comprised isoprenaline infusions in all patients (mean period 65.7 h) whilst dopamine and other inotropic agents were used less frequently. Sequential atrioventricular pacing was required more often in the HT patients (n = 9) than in the HLT patients (n = 4). Fluid input was restricted to maintain a plasma osmolality of 290-300 mosm/kg. There were 2 perioperative deaths both due to acute right heart failure. Other post-operative complications included: bleeding (n = 3); acute graft rejection (n = 4); infection (n = 3); systemic hypertension (n = 6); neurological abnormalities (n = 2); renal dysfunction (n = 6) and hyperglycaemia (n = 6).

Adolescent↗
PubMed1990

Management following heart and lung transplantation: five years experience.

Since April 1984, 70 patients have received heart-lung transplants at our institution. Actuarial survival is 76% at 1 year and 68% at 2 years. All but 4 surviving patients have an unrestricted life style. Rejection was confirmed by lung transbronchial biopsy (TBB) on 277 occasions in 66 patients. Forty-two percent of episodes occurred within 1 month of surgery. Eight patients have developed evidence of chronic rejection with progressive irreversible fall in FEV1, of whom 4 have died or undergone single lung retransplantation. Seven patients had primary cytomegalovirus (CMV) of whom 4 patients died. Eight patients developed pneumocystis pneumonia of whom 1 died. Seven episodes of herpes simplex pneumonitis occurred of which one episode was fatal. Heart-lung transplantation is a valuable treatment for terminal cardiopulmonary disease and offers increasing hope of long-term survival.

Biopsy↗
PubMed1990

Cystic fibrosis: a new challenge for cardiothoracic surgery.

Cystic fibrosis (CF) is the most common fatal inherited disease in caucasian populations. Between 80-120 CF patients die each year in England and Wales, the majority from pulmonary disease. Since October 1985, 17 patients with CF have undergone heart-lung transplantation (HLT) at our institution. Only 3 early deaths have occurred in the first 2 postoperative months. Another patient died 9 months after transplantation. Thirteen patients are now alive 1-46 months (mean 14 month) post transplantation. Actuarial survival at 6 months is 80% for CF patients compared to 73% for non-CF patients. Both groups of patients have similar profiles of rejection and infection. In the Caucasian population, CF patients form the largest potential recipient group for HLT and our experience suggests that those CF patients who undergo HLT have a favourable outcome.

Actuarial Analysis↗
PubMed1990

Primary pulmonary hypertension: diagnosis, medical and surgical treatment.

Primary pulmonary hypertension continues to present both diagnostic and therapeutic challenges to the physician, reflecting the lack of understanding about the basic mechanism of the disease. The natural history of the condition has been described only recently, and this has allowed a reasonably accurate prognosis for the individual patient to be determined. New treatments have been found effective, including heart-lung transplantation, which can now offer improved survival. Long-term intravenous infusion of prostacyclin has a place in the treatment of severely affected patients awaiting heart-lung transplantation. However, the major impact of prostacyclin has been, perhaps, to concentrate research upon the role of the endothelial cell in the development of this disorder, in particular the potential role of an impairment of release of the recently described endothelium-derived relaxing factor in certain forms of pulmonary hypertension. We have attempted in this review to focus on the problems of diagnosis and treatment together with current developments in the understanding of primary pulmonary hypertension.

Heart-Lung Transplantation↗
PubMed1990

Altered pharmacokinetics of cyclosporin in heart-lung transplant recipients with cystic fibrosis.

The cyclosporin dose versus blood concentration relationship for 11 heart-lung transplant recipients with cystic fibrosis was studied retrospectively. Eleven patients, closely matched for age and gender, who received heart-lung transplantation for other diseases were selected as controls. Cystic fibrosis patients received 16.7 (SD 7.2) mg/kg/day of oral cyclosporin compared with 8.2 (SD 1.9) mg/kg/day given to the control patients (p less than 0.01). Nine of the cystic fibrosis patients received higher mean daily doses of cyclosporin. Mean blood cyclosporin concentrations were, however, not significantly different (p = 0.58), and there were no apparent differences in clinical outcome in terms of rejection, infection, and nephrotoxicity in the two groups. The apparent oral clearance of cyclosporin was significantly higher (p less than 0.01) in cystic fibrosis patients. Cyclosporin dosage individualization with the aid of cyclosporin blood concentration measurements is critically important in this subpopulation of heart-lung transplant recipients.

Administration, Oral↗