Aspergillosis is an infectious, non-contagious fungal disease caused by species within the ubiquitous opportunistic saprophytic genus Aspergillus, in particular Aspergillus fumigatus. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolised spores. The respiratory tract is the primary site for A. fumigatus colonisation, leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. It infects the respiratory system of many kinds of birds, leading to a range of disease manifestations from acute to chronic infections. Acute cases are seen in young birds following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and appears more sporadically. Treatments for infected poultry are non-existent; therefore, prevention is the only way to protect poultry. The mechanism of host-pathogen interaction, early diagnostic methods and antifungal treatment schedules need to be further studied in order to control this disease.

Weakness of the limbs and respiratory muscles has increasingly been found to be a frequent event that complicates the medical history of patients in Intensive Care. The problem normally affects more serious cases and presents as muscular weakness leading to flaccid paralysis and difficulty in weaning patients off mechanical ventilation. This latter sign leads the intensivist to suspect possible involvement of the neuromuscular respiratory system. Unfortunately, in-depth clinical assessment of the neuromuscular respiratory system is difficult with critically ill patients, and electrophysiological studies have been used instead to overcome this problem. Of these latter, electric and electromagnetic stimulation of the phrenic nerve have been successful (along with needle electromyography of the diaphragm) in identifying the causes of neuromuscular respiratory insufficiency, especially in Intensive Care. In this brief chapter, we will be discussing the technique of electric stimulation of the phrenic nerve and neuromuscular respiratory insufficiency within the field of critical illness polyneuropathy.

Although it is widely believed that management of the airway is difficult in surgery for retrosternal goitre, a review of the literature, revealing management of 1969 patients with retrosternal goitre, provided scant evidence of difficult intubation or post-operative tracheomalacia resulting in tracheal collapse. This was reflected in our own series of 18 thyroidectomies for retrosternal goitre performed at our hospitals.

Background and objective The main objective of this study was to assess mortality and morbidity after thoracic surgery in a medical centre, without resident chest surgeons and anaesthesiologists, and to determine specific risk factors.

Methods A prospective cohort study using a local database which includes patients’ clinical characteristics, results of preoperative investigations, surgical and anaesthesia data and all postoperative complications was undertaken. Two hundred and seventy-three consecutive patients undergoing thoracic surgery from 1992 to 1999 were studied. The referral chest medical centre was without resident thoracic surgeons or anaesthesiologists; postoperative care was led by local chest physicians according to standardized protocols and in close collaboration with university-based surgeons and anaesthesiologists.

Results The majority of patients had lung cancer (71%) and underwent resection of at least one lobe (62%). Thirty-day mortality rate was 2.2% and one or more complications occurred in 74 patients (27%). Three patients had to be transferred to a university hospital for further treatment. Univariate predictors of complications included age (> 70 years), history of smoking, body mass index, as well as the extent and duration of surgery. After multiple logistic regression analysis, smoking (current or past), prolonged surgery (>120 min) and major lung resection (pneumonectomy or bilobectomy) remained the only independent risk factors.

Conclusions Overall perioperative mortality and morbidity rates did not exceed those reported from large teaching hospitals. In selected patients, thoracic surgery can be safely performed in a specialized chest medical centre without on-site surgeons and anaesthesiologists.

Background and objective Few and conflicting data are available regarding the changes of plasma potassium concentration during acute respiratory acidosis in human beings. This study compares the acute changes in plasma potassium concentration in acutely hypercapnic patients and in non–hypercapnic patients during general anaesthesia.

Methods Thirty-three patients undergoing interventional rigid bronchoscopy were studied. Ventilation of the lungs was randomly conducted using either spontaneous–assisted ventilation or intermittent negative–pressure ventilation. All patients received the same anaesthetic protocol. Arterial blood gases and osmolality, and plasma concentrations of glucose, sodium, potassium and chloride were measured.

Results Intraoperatively, PaCO2 was higher during spontaneous-assisted ventilation than during intermittent negative-pressure ventilation (9±1.8 vs. 5.4±1.2 kPa, P < 0.001) and the pH was also lower during spontaneous-assisted ventilation than during intermittent negative-pressure ventilation (7.24±0.07 vs. 7.4 ±0.08, P < 0.001). Plasma potassium concentration remained similar in both groups (3.8± 0.2mmolL−1 with spontaneous–assisted ventilation vs. 3.7± 0.4mmol L−1 with intermittent negativepressure ventilation).

Conclusion Acute respiratory acidosis does not affect plasma potassium concentration.

Eosinophilic angiocentric fibrosis (EAF) is an unusual fibrotic condition affecting the mucosa of the upper respiratory tract, of which there have been eight reported cases. The condition is thought to be associated with the rare skin disorder granuloma faciale, which is histologically identical, and was present in two cases of EAF. We report the third case where EAF and granuloma faciale occurred together, to highlight this type of intranasal fibrosis as a distinct pathological entity.

An isolated tracheo-oesophageal fistula could be caused by close proximity of the epithelia of both organs (O'Rahilly & Müller, 1984; Kluth et al. 1987) at certain embryonic stages, the most frequent location being the tracheal bifurcation. Thus the relative position and degree of separation between the digestive and the respiratory tubes throughout their development may be relevant to the origin of this anomaly. The aim of this study was to analyse along the different segments of the tracheo-oesophageal septum (TES) where the closest relationship between both lumina occurred and what degree of separation was present at each segment. Computer imaging techniques were applied on cross sections of a graded series of normal human embryos (Carnegie stages (CS) 13–23). In addition, the differentiation of the primitive TES was also studied (from CS 12) by light microscopy. Between CS 13 and 16 both tubes tended to separate (phase of separation), principally at the proximal segments of the laryngopharyngeal and the tracheo-oesophageal portions of the TES. During this phase the separation between the trachea and oesophagus was wider than between the larynx and pharynx. From CS 17 to CS 23 the digestive and respiratory lumina reached their widest separation at different levels of the laryngopharyngeal portion. Below these levels they tended to come closer together, principally at the proximal segment of the tracheo-oesophageal portion, but also at the distal part of the laryngopharyngeal portion. During this phase of approximation they reached their closest relationship at the proximal (CS 17) and the distal (from CS 18) segments of the tracheo-oesophageal portion. When finally the distal segment of the trachea (which includes the bifurcation) comes closest to the oesophagus, the coats of both organs have already undergone an appreciable differentiation. According to these observations, the origin of the most frequent isolated tracheo-oesophageal fistula at the bifurcation region could not be explained from the normal development of the TES.

In the period between 1940 and 1955 the indications for tracheotomy were extended. For centuries tracheotomies were performed to treat obstructive diseases of the upper airway (hypopharynx, larynx, trachea). With the end of the second World War tracheotomy was indicated more and more for the therapy of lower airway disturbances.

Medical empiricism is thought to be responsible for the gradual shift in the indications during that period from upper to lower airway disturbances. Knowledge about the underlying principles of respiratory physiology was, however, already present at the end of the 19th century, but the shift in the indications did not occur until relatively recently. For many victims of World War II the discovery of the beneficial effect of a tracheotomy in a variety of traumatic disorders may have come too late.