Management of pulmonary infection : experimental studies on oral immunization and surfactant replacement therapy

This thesis aims at evaluating two "new" concepts for the management of pneumonia. The first concept, oral immunization, seems a promising approach towards prevention of pneumonia. Extensive programs have been developed for active immunoprophylaxis to immunize against specific microbial pathogens, and vaccines introduced into clinical practice since the 1970s include those against H. influenzae, meningococs, pneumococs, pseudomonas, hepatitis B virus and rabies. However, controversies surrounding established vaccines and the search for vaccines against other pathogens constantly stimulate investigations on the development of new vaccines. Therefore, and because oral administration of vaccines is convenient, much attention has been paid to the development of vaccines for oral administration. It is proven that oral administration of vaccine of viral or bacterial origin can induce a mucosal immune response, but the possibility of oral immunization with bacterial lysate for the prevention of viral pneumonia has not been well documented. The first part of this thesis presents investigations on oral immunization with a new polyvalent bacterial lysate against both bacterial and viral pathogens that may cause pneumonia. The second concept, surfactant replacement therapy, has already proven its value in the prevention and treatment of idiopathic respiratory distress syndrome (IRDS) of the newborn, which is caused by a surfactant deficient state of the premature lungs. Several studies on the origin and nature of the adult respiratory distress syndrome (ARDS) have demonstrated a surfactant deficient state of the lungs of ARDS-patients and frrst clinical trials of surfactant replacement in ARDS patients have proven the beneficial effects of surfactant replacement. Pneumonia may lead to a clinical syndrome closely resembling ARDS. Therefore, the second part of this thesis presents investigations on surfactant replacement therapy during ARDS-like viral pneumoni

Safety and efficacy of xenon in routine use as an inhalational anaesthetic

Abstract 40 patients (24 male, 16 female, aged 21-59 years) of American Society of Anesthesiologists class I or II who were undergoing routine surgery took part in a randomised, double-blind comparison of the anaesthetic efficacy and potency of xenon and nitrous oxide and their effects on the circulatory and respiratory systems. During anaesthesia, for each rise in blood pressure of more than 20% of the preanaesthetic (baseline) value, the patient received 0·1 mg fentanyl. The total amount of fentanyl required per patient was used as an index of the anaesthetic potency of the study gases. Patients in the xenon group required on average only 0·05 mg fentanyl, whereas those in the nitrous oxide group required 0·24 mg fentanyl; the duration of anaesthesia was similar in the two groups. Changes in blood pressure were significantly greater throughout the study in the nitrous oxide than in the xenon group. Thorax-lung compliance fell during the study period in the nitrous oxide group but not in the xenon group. Thus, xenon is a potent and effective anaesthetic which can be safely used under routine conditions