Search PubMed⌕ Search

Biomedical subjects

H Mal

Publications and source records attributed to H Mal.

At least 55 records · Page 3Linked to original sources

[Graft dysfunction, acute rejection and bronchiolitis obliterans in lung and heart-lung transplantation].

Three complications which influence both survival and quality of life in transplanted patients will be the object of this chapter. Graft dysfunction: this is a severe re-implantation oedema leading to inefficiency of the graft as regards haemostasis whether or not associated with haemodynamic complications. The liberation of free radicals and/or cytokines induced by ischemia-reperfusion of the graft plays an important role in the pathogenesis of this syndrome. Acute rejection: the mechanism is complex leading to the intervention of an immune response stimulated by the detection of allo-antigens. The clinical picture is often non-specific. Treatment requires boluses of methyl prednisolone completed by decreasing dose of corticosteroid therapy orally. The syndrome of bronchiolitis obliterans: this is a progressive failure of the airways. This syndrome occurs in the long term in 50% of patients and presents with progressive dyspnoea associated with persistent or recurrent cough. The pathogenesis is brought about principally by a chronic rejection with a specific cytotoxic reaction of T lymphocytes against the airway epithelium which expresses Class II major histocompatibility antigens. Attempts at curative treatment can be extremely deceptive and leads to, at best, a slowing in decline of respiratory function.

Acute Disease↗

[Asthma and its treatment during pregnancy].

Asthma occurs in 0.4 to 4.0% of pregnant women and is considered to be the most frequent respiratory disease during pregnancy. Physiological modifications during pregnancy, including hyperventilation due to increased progesterone levels and lower residual volume and functional capacity resulting from increased uterine volume can interfere with the asthmatic disease and require adapted management. Results of studies evaluating the interaction between asthma and pregnancy provide a wide variety of results. For some authors, manifestations of asthma may worsen during pregnancy requiring reinforced medical treatment in as many as 42% of the patients. For others bronchial hyperreactivity is significantly diminished during pregnancy. These findings should be examined in light of several individual factors including the spontaneous clinical course of asthma itself and more rigorous control during pregnancy. It is thus very difficult to predict the effect of pregnancy on clinical manifestations of asthma in any given patient or from one pregnancy to another. Certain authors have observed a correlation between IgE levels and the gravity of asthma in pregnant women: normally IgE levels tend to decline during pregnancy but may remain unchanged or increase if asthma manifestations worsen. Therapeutic options remain unchanged during pregnancy although only drugs proven safe for the fetus may be used. If carefully managed, pregnancy in the asthmatic patient usually reaches term with no major problem.

Adrenal Cortex Hormones↗

Mucosal T-lymphocytes in central airways of lung transplant recipients.

The immunohistochemical profile of mucosal lymphocytes was investigated in the central airways of lung transplant recipients. Bronchial and transbronchial biopsies (BB and TBB, respectively) and bronchoalveolar lavage for culture of bacteria and viruses were performed during a fibroscopic procedure in patients without evidence of chronic rejection, 3 to 10 mo after surgery. Analysis was restricted to samples without concurrent airway infection: 23 pairs of BB and TBB from 18 transplant recipients were analyzed. An immunohistochemical technique was used to identify and score mucosal cells that reacted with monoclonal antibodies against CD4, CD8, CD45-Ro (memory T-cells), and HLA-DR molecules. The same procedure was applied in nine nonsmoking control subjects (NS group). Data from transplant recipients were allocated to R+ (n = 11) or R- groups (n = 12), depending on the presence or absence of histologic evidence of acute rejection on TBB. A statistically significant depletion of every immunoreactive cell subset was observed in the R+ and the R- groups, but not in the NS group. Conversely, no significant difference for either score of immunoreactive cells were found between R+ and R- groups. The immunosuppressive regimen is suspected to play to play a major role in this depletion of bronchial mucosal T-cells. The acute lung rejection process does not appear to affect concurrently the immunohistochemical profile of immunoreactive cells in the bronchial mucosa.

Biopsy↗

Pulmonary reimplantation response in single-lung transplantation.

We studied the characteristics of the pulmonary reimplantation response (PRR) in single-lung transplantation (SLT), and detailed the occurrence, evolution, prognosis and risk factors of this complication. Forty single-lung transplant recipients were studied. Twenty four patients developed hypoxaemia and allograft infiltrates consistent with the PRR. In 40% of the cases hypoxaemia was severe, precluding weaning and requiring prolonged mechanical ventilation with high fractional inspiratory oxygen (FIO2). The mean duration of ventilation was 7 days (range 1-19 days). Clearing of the chest radiographs was progressive, with complete resolution between 6 and 21 days. In all cases, the pulmonary arterial wedge pressure was normal (6 +/- 2 mmHg) suggesting low pressure oedema. Sampling of the pulmonary oedema fluid revealed that the ratio of protein concentration in oedema fluid to that in serum exceeded 0.5. In patients with severe PRR (40% of cases) clinical, radiographic and haemodynamic abnormalities were identical to adult respiratory distress syndrome (ARDS), but the prognosis was more favourable with no death directly related to PRR in our patients. The mean duration of graft ischaemia of the oedematous grafts (241 +/- 103 min) was significantly longer than that of nonoedematous grafts (155 +/- 71 min). These date suggest that prolongation of graft ischaemia increased the incidence of PRR.

Female↗

[Post-lung transplantation bronchiolitis obliterans].

Bronchiolitis obliterans is an anatomical lesion with multiple aetiologies. In the lung transplant patient the pure forms of bronchiolitis obliterans are probably the consequence of a process of chronic rejection; in fact necropsy tissue or lungs removed which have been transplanted show that the lesions of bronchiolitis obliterans are often associated with parenchymal disorders, vascular and proximal bronchial disease, which are sequelae of phenomena of rejection or infection. The effect of bronchiolitis obliterans on lung function is constant; this may appear progressively or in stages. Increasing immunosuppressive treatment may arrest the progress. This rarely occurs and the development of respiratory failure tends to be the rule. It is exceptional to achieve the diagnosis of bronchiolitis obliterans from the examination of a transbronchial biopsy. It is a combination of features, both clinical and respiratory function, negative bacteriology and virological investigations as well as the absence of any efficacy of conventional treatment for rejection which leads to the diagnosis. In certain cases the question of a pulmonary re-transplantation is raised.

Bronchiolitis Obliterans↗

[Severe acute asthma in adults].

Despite a better understanding of the physiopathology of asthma and the availability of potent drugs, severe acute asthma is still a frequent cause of death (1500 to 2000 patients die each year of asthma in France). Among the different clinical presentations, hyperacute attack with an attack duration (period from onset of attack to mechanical ventilation or to fatality) of less than 3 hours has to be individualized. The agents of choice in the treatment of acute life-threatening asthma are oxygen, beta-adrenergic sympathomimetic amines given intravenously or by nebulization, and corticosteroids. Theophylline is not any more the first choice of treatment but should not be rejected. Anticholinergics given by nebulization in combination with sympathomimetic agents are effective. Beside these treatment, hydratation and antibiotics are important adjunctive treatment. Mechanical ventilation is rarely necessary but has to be instituted either in emergency in case of near fatal asthma or electively because of deterioration of clinical status and blood gases, despite full medical treatment.

Acute Disease↗

Nebulized versus intravenous albuterol in hypercapnic acute asthma. A multicenter, double-blind, randomized study.

In a multicenter, randomized, double-blind study, we compared the effects of nebulized (5 mg x 2) and intravenous (0.5 mg) albuterol (salbutamol) over 1 h in 47 patients admitted to hospital with severe acute asthma defined as a peak expiratory flow (PEF) below 150 L/min and hypercapnia (Pa(CO2) > or = 40 mm Hg). Additional treatment included nasal oxygen and hydrocortisone succinate. The efficacy was assessed after 1 h. In the group treated by nebulization (NEB group, n = 22) 19 (86%) patients (95% confidence interval: 65 to 97%) had been treated successfully according to predefined criteria, versus 12 (48%) patients (95% confidence interval: 28 to 69%) in the intravenously treated group (i.v. group, n = 25), p = 0.006. The mean increase in PEF was greater in the NEB group than in the i.v. group (+107 +/- 94 L/min versus +42 +/- 66 L/min, p = 0.01) as well as the decrease in Pa(CO2) values (-10 +/- 5 mm Hg versus -2 +/- 12 mm Hg, p < 0.01). Beta agonist-induced hypokalemia was more pronounced in the i.v. group than in the NEB group. We conclude that, in hypercapnic acute asthma, the nebulized route has a greater efficacy and fewer side effects than the intravenous route.

Acute Disease↗

Functional results of single-lung transplantation for chronic obstructive lung disease.

The feasibility and immediate tolerance of single-lung transplantation were recently demonstrated in patients with severe obstructive lung disease. Since initial reports, hundreds of procedures have been performed worldwide in such patients, but views regarding the results are still controversial. Since few data concerning medium-term functional results are available, we report here our series of 20 patients with chronic obstructive pulmonary disease who received a single-lung transplant. A group of 16 patients who survived for 6 mo or more form the basis of this report. Current 1- and 2-yr actuarial survival are 75 and 70%, respectively, with 4 perioperative deaths and 2 deaths at 9 and 15 mo after transplantation. Before transplantation the patients were severely obstructive, with a FEV1 of 17 +/- 6% of predicted, a PaO2 of 51 +/- 10 mm Hg, a PaCO2 of 49 +/- 11 mm Hg, and a 6 min walk test of 99 +/- 84 m. A significant functional improvement was observed postoperatively, the patients' FEV1 at 3 mo reached 53 +/- 13%, PaO2 81 +/- 3 mm Hg, and PaCO2 39 +/- 3 mm Hg. The distance covered during 6 min was 587 +/- 147 m at 6 mo. Throughout postoperative follow-up, lung function remained stable in some patients but decreased in others after several mo, this decline related to the occurrence of bronchiolitis obliterans, except in two patients who had airway complications. Impairment in lung function led to retransplantation in four patients, with good clinical results in three patients, one patient dying postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

Single-lung retransplantation for late graft failure.

In lung or heart-lung recipients, an irreversible graft-failure may develop in connection with chronic rejection, infection or bronchial complications. A limited number of transplant-recipients have undergone a retransplantation procedure in several centres. First results are discouraging, especially in the case of early retransplantation. We decided, 3 yrs ago, to evaluate the feasibility and benefits of single-lung retransplantation in lung-transplant recipients with late graft-failure. Eight consecutive single-lung retransplantations were performed in patients with previous single-lung (n = 7), or double-lung (n = 1) transplant. Primary graft and native lung were removed in 5 and 3 patients, respectively. The delay between the two surgical procedures was 16 +/- 10 months (range 6-37 months). Three patients died within 3 months. Long-term survivors experienced stable and satisfactory functional results (forced expiratory volume in one second (FEV1 63 +/- 21% predicted; range 40-103% predicted), with survival values ranging 8-20 months. One patient died of septic shock 16.5 months after retransplantation. The remaining four patients are alive. These data suggest that the retransplantation option could be considered in selected patients with late graft-failure. The final decision for retransplantation, however, is largely influenced by the current shortage of donor lungs.

Bronchiolitis Obliterans↗

Pulmonary lymphangiomyomatosis treated by single lung transplantation.

Pulmonary lymphangiomyomatosis is a rare disease resistant to almost all medical treatments to date. We describe the case of a 44-yr-old woman with end-stage pulmonary lymphangiomyomatosis who was treated by single-lung transplantation. The patient is doing well in her sixteenth post-transplantation month and has a marked improvement in her pulmonary function tests and walking distance as compared with preoperative values, and she is enjoying an unrestricted life-style.

Adult↗

Single-lung transplantation in emphysematous patients.

We report six single-lung transplantations in emphysematous patients with end-stage disease. Compression of the graft or ventilation/perfusion imbalance were not observed. Rejection episodes were generally documented through transbronchial biopsies and the radiological changes related to acute infections or rejections were restricted to the transplanted lung. Three patients died from CMV pneumonia, status epilepticus and fibrosis of the graft following bronchography, respectively. The three remaining patients are well, with documented improvement of pulmonary function tests and arterial blood gases. Bronchial complications were observed in all patients and have in some cases required dilatation or insertion of a stent. Although requiring a longer follow up, single transplantation is feasible and beneficial in patients with end-stage emphysema.

Adult↗

[Unilateral lung transplantation in panlobular emphysema].

Out of 8 unilateral transplantations, 5 were performed for panlobular emphysema. The operation and the post-operative period were highly satisfactory, although the oldest patients, those who had lost much weight, had prolonged post-operative asthenia. Only 2 patients could be followed up for a sufficient length of time; the functional result is favourable, except for stenosis of the suture in one case.

Aged↗

Dopamine effects on diaphragmatic strength during acute respiratory failure in chronic obstructive pulmonary disease.

STUDY OBJECTIVE: To assess the effects of dopamine, which has an inotropic effect on the myocardium and increases renal and splanchnic blood flow, on diaphragmatic contraction. DESIGN AND PATIENTS: We studied the changes in transdiaphragmatic pressure during electrical bilateral supramaximal stimulation of the phrenic nerves in eight patients with chronic obstructive pulmonary disease during acute respiratory failure. In three patients, changes in diaphragmatic blood flow were also evaluated. METHODS: All patients were intubated and artificially ventilated. Stimulated transdiaphragmatic pressure, cardiac output, evaluated with a Swan Ganz catheter, and diaphragmatic blood flow, evaluated by timed volume collections of left phrenic venous effluent (a catheter was introduced into the right femoral vein and advanced into the left inferior phrenic vein) were measured before dopamine infusion, every 10 minutes after the onset of dopamine infusion (10 micrograms/kg body weight.min during 30 minutes) and 15 minutes after the end of dopamine infusion. Arterial blood gases and pH were measured before and at the end of dopamine infusion. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases and pH were maintained within normal range by mechanical ventilation throughout the study. With dopamine infusion, heart rate increased by 17% (P less than 0.001) and cardiac output by 40% (P less than 0.001) on the average. The increase in cardiac output was accompanied by a marked increase in diaphragmatic blood flow (30% on the average) in the three patients in whom it was measured (P less than 0.001). Diaphragmatic strength also increased significantly during dopamine administration. Transdiaphragmatic pressure for an identical phrenic stimulation increased by 30% (P less than 0.001) on the average. The changes in cardiac output, diaphragmatic blood flow, and transdiaphragmatic pressure persisted throughout the infusion period; all values returned to control values 15 minutes after the end of dopamine administration. CONCLUSIONS: Dopamine has a potent effect on diaphragmatic strength generation and diaphragmatic blood flow in patients with chronic obstructive pulmonary disease during acute respiratory failure. It is possible to improve diaphragmatic contraction in these patients by administering pharmacologic agents that augment diaphragmatic blood flow.

Action Potentials↗