Anesthesia in bronchial asthma

Asthma is defined as a chronic inflammatory airway disease in response to a wide variety of provoking stimuli. Characteristic clinical symptoms of asthma are bronchial hyperreactivity, reversible airway obstruction, wheezing and dyspnea. Asthma presents a major public health problem with increasing prevalence rates and severity worldwide. Despite major advances in our understanding of the clinical management of asthmatic patients, it remains a challenging population for anesthesiologists in clinical practice. The anesthesiologist's responsibility starts with the preoperative assessment and evaluation of the pulmonary function. For patients with asthma who currently have no symptoms, the risk of perioperative respiratory complications is extremely low. Therefore, pulmonary function should be optimized preoperatively and airway obstruction should be controlled by using steroids and bronchodilators. Preoperative spirometry is a simple means of assessing presence and severity of airway obstruction as well as the degree of reversibility in response to bronchodilator therapy. An increase of 15% in FEV1 is considered clinically significant. Most asymptomatic persons with asthma can safely undergo general anesthesia with and without endotracheal intubation. Volatile anesthetics are still recommended for general anesthetic techniques. As compared to barbiturates and even ketamine, propofol is considered to be the agent of choice for induction of anesthesia in asthmatics. The use of regional anesthesia does not reduce perioperative respiratory complications in asymptomatic asthmatics, whereas it is advantageous in symptomatic patients. Pregnant asthmatic and parturients undergoing anesthesia are at increased risk, especially if regional anesthetic techniques are not suitable and prostaglandin and its derivates are administered for abortion or operative delivery. Bronchial hyperreactivity associated with asthma is an important risk factor of perioperative bronchospasm. The occurrence of this potentially life-threatening condition in anesthesia practice varies from 0.17 to 4.2%. The anesthesiologists' goal should be to minimize the risk of inciting bronchospasm and to avoid triggering stimuli. As increases in airway resistance are noticed, therapy should be directed towards optimizing oxygenation and proper diagnosis needs to be established. With deepening anesthesia level and aggressive pharmacological management utilizing both, beta-agonists and steroids, respiratory failure may be properly controlled.     

Anesthesia in bronchial asthma

Between 2% and 5% of the population suffer from bronchial asthma. The disease is characterized by bronchial hyperreactivity to physical, chemical, pharmacological, and/or immunological irritants. The incidence of perioperative complications is higher in asthmatics than in non-asthmatics. Careful pre- and postoperative care can reduce complications in these patients. Successful management of an asthmatic patient undergoing anesthesia starts with the identification of patients with asthma, the preoperative assessment, and evaluation of the pulmonary function. No elective surgery should be performed in patients suffering from unstable asthma or an acute attack. Thorough knowledge of the effects and interactions of broncholytic therapy with anesthesia is mandatory. Preanesthetic management must take into consideration the etiology of the disease; intraoperatively, attention must be paid to the pathophysiology. Appropriate perioperative monitoring can help to prevent complications. No one type of anesthesia is associated with lower postoperative complications. The skill of the anesthesiologist, early recovery from general anesthesia, and good postoperative care greatly reduce the incidence of complications. Besides the changes in pulmonary function that occur following anesthesia and surgery, asthmatics may suffer from abnormalities in control of ventilation and mucociliary function postoperatively. The patient with a history of asthma needs close supervision during the postoperative period: many sudden deaths from asthma and many episodes of ventilatory arrest occur during the night and in the early morning.     

Ascorbic acid in bronchial asthma

Sixteen White children with bronchial asthma were divided into two groups; one received standard anti-asthma chemoprophylaxis (SAC) and the other SAC supplemented with 1 g ascorbic acid (Redoxon) given as a single daily dose for a 6-month period. In 10 patients the effects of ascorbic acid on exercise-induced bronchoconstriction (EIB) were assessed by comparing the pre-ascorbic acid results with those obtained 2 1/2 hours after the intravenous injection of 1 g ascorbic acid. Immunological investigations performed on the two groups were assessment of polymorphonuclear leucocyte (PMNL) motility, phagocytosis and nitroblue tetrazolium reduction and measurement of secretory IgA, serum immunoglobulin and total haemolytic complement levels and levels of the components C3 and C4, alpha 1-antitrypsin, antistreptolysin O (ASO), C-reactive protein and antibodies to certain respiratory viruses. These investigations were performed before and 1, 3 and 6 months after the commencement of therapy. Radio-allergosorbent testing for sensitivity to four common allergens was carried out at the outset and after 6 months of therapy. Injection of ascorbic acid had no detectable effects on the degree of EIB. Slight but not significant immunological changes were observed in the SAC group over the 6-month study period. However, in the SAC plus ascorbic acid group significantly improved PMNL motility and decreased ASO levels and reduced (although not to a significant extent) IgE levels and titres of antibodies to the respiratory viruses were observed.     

Macroscopic and microscopic process of long bone fracture healing

The growth of each type of callus (cortical, medullary and periosteal) depends on the mechanical condition of fracture fixation (elastic fixation and instability or rigid immobilization), the type of treatment (non-operative, close or open surgical procedure, intra-medullary nailing, external fixation, plate…) and the high or poor quality of soft tissue and the specific characteristics of the local vascularisation.     

Macroscopic and microscopic changes in the fallopian tube after bipolar cauterization

A total of 43 patients who had undergone laparoscopic tubal occlusion by means of bipolar cauterization underwent bilateral salpingectomy 6-30 months later. The macroscopic and microscopic changes in the fallopian tubes are described. Although 35 patients appeared to have occluded tubes on macroscopic examination, only 22 showed occlusion on microscopic examination.     

Macroscopic and microscopic appearance of arterial stumps in limb segment amputation

Until now, it has been assumed that in arterial lesions invagination of the intimal layer occurs. In a thigh and an upper-arm amputation this assumption was scrutinized. No hemorrhage or hypovolemic shock occurred in either case despite total amputation. The brachial and femoral arteries were closed and pulsed visibly within the soft tissue. Histology showed no invagination: the adventitial layer was drawn over the open lumen, which was filled with an extensive thrombus. Therefore, in these cases occlusion of the artery is presumed to occur by means of a fingertrap mechanism of the adventitia and the interaction of collagenous fibers with platelets. This hypothesis will be tested in an animal experiment.     

Macroscopic and microscopic anatomy of the rotator cable in the shoulder

BackgroundThe rotator cable, a semicircular fiber bundle in the lateral portion of the rotator cuff, has been believed to transmit forces among cuff tendons. This study was performed to clarify the functional anatomy of the rotator cable through histoanatomical methods.MethodsTwenty-two cuff-intact shoulders of fixed cadavers were dissected. The cable was investigated from the cuff surface and articular/bursal sides of the capsule. The width of the cable and distances from the capsule attachment to both of the lateral and medial borders of the cable were measured, and their correlations to the humeral head diameter were calculated. The location of the cable on the humeral head was observed and recorded. In additional five shoulders the cuff/capsule complex and greater tubercle were harvested en block and histologically investigated.ResultsThe rotator cable was evident in the capsule of 14 shoulders. One specimen demonstrated the cable of double curves. The capsule thickness alteration corresponding to the medial border of the cable with a single curve existed approximately on the so-called ‘flexion point’ where the humerus started to form a spherical curve from the greater tubercle to the joint surface. The ‘flexion point’ macroscopically corresponded to the medial boundary of the contact area between the cuff and head. The distance between the cable and capsule attachment showed marked negative correlation to the head diameter. Histologically the cable demonstrated cartilaginous metaplasia and vertical fiber orientation to the supraspinatus.ConclusionsThe rotator cable does not always exist in all the shoulders and its appearances are varied. The location and cartilaginous metaplasia of the cable suggested compression force between the cuff and humeral head, and the force would help cable creation in capsule layer. The vertical fiber orientation of the cable to the supraspinatus would be unlikely to explain force transmission among the cuff tendons.     

Right heart pressures in bronchial asthma

Right heart pressures, electrocardiograms, blood gases, and peak expiratory flow rates were measured in nine patients admitted to hospital with severe bronchial asthma. Low or normal right heart pressures were found despite electrocardiographic changes in five patients consisting of right atrial P waves, abnormal right axis deviation, and in one patient T-wave changes in precordial leads. These electrocardiographic changes reverted towards normal on recovery of the patient from the asthmatic attack.     

Macroscopic and microscopic evidence of prosthetic fixation with porous-coated materials

The host response to porous-coated prostheses appears favorable; there is little evidence of any adverse tissue response or significant osteoclastic activity except in grossly loose specimens. While the nature of retrieval specimens makes any statistical correlation problematic, some generalizations can be made. Femoral hip prostheses are most likely to present bone ingrowth along the lateral quadrant of their porous coating. The frequency of bone ingrowth of femoral components was nearly twice that of acetabular devices. Pore size, geometry, and porous-coating composition did not appear to influence the appearance of bone and fibrous tissue ingrowth. Direct bonding of bone to the uncoated portion of the prosthesis was rarely seen and occurred only in closest proximity to the porous-coated regions. Indications of pain and looseness are evidence that fibrous tissue ingrowth alone is not always sufficient to ensure stability. Additionally, some bone-ingrown prostheses were retrieved because of pain, which leads to the conclusion that local bone ingrowth cannot ensure a general freedom from pain, especially with partially coated prostheses. Bone and fibrous tissue response to the porous coatings generally consists of interdigitation, while the response to uncoated regions is fibrous tissue encapsulation. Burnishing the distal tips of many of the partially coated femoral prostheses is an indication of relative motion in that region, which may be a potential source of pain.