Central venous access devices have become important tools in the management of pediatric patients with malnutrition, malignancy, and infections requiring long-term antibiotic treatment. Hemophilia presents a lifetime challenge for venous access and at times can be an urgent or life-threatening situation. Since 1986, the authors have implanted 11 subcutaneous infusion ports in nine patients with hemophilia. The systems have remained in place for up to 7 years, without major complications or problems. Two catheters were replaced, after 4 and 6 years, because of skin erosion and blockage, respectively. One catheter was removed after 7 years because of blockage following local trauma and was not replaced. A recent survey through the Canadian Hemophilia Centre Directors Group obtained a further 45 subcutaneous infusion ports in other centers across Canada. The benefits of this system are overwhelming enthusiasm by the parents and children and no major complications. Some of the patients are now HIV-positive and are able to use their system for ongoing drug therapy.
Since the time of Virchow, the concept of 'hypercoagulability' of the blood has been an attractive factor in the pathogenesis of thrombosis. Support for this concept may be found, over the last 50 years, in the large number of haematological abnormalities that have been reported to be associated with thombosis. Such associations may be of an acute and transient nature, for example in a patient with postoperative venous thrombosis, or alternatively of a longstanding nature, for example in a patient with recurrent thromboembolism. However, it has been difficult to determine whether such laboratory abnormalities in vitro are indeed a valid reflection of true hypercoagulability in vivo. Thus, while one or more of these abnormalities may truly predispose towards thrombosis, it is also possible that they may solely reflect the presence of thrombosis or may even be coincidental. A true causal relationship between a laboratory abnormality and a clinical condition in
Although sophisticated intensive care units have become universal in major public hospitals in Australia, this complex and expensive form of patient care is usually not available in independent private hospitals. Such a unit was recently established in a large private hospital which had expanded its facilities to encourage major surgery and its admission policies to include complex specialist medical problems. The unit's organisation included an appropriate physical area, comprehensive equipment, skilled nursing staff, resident medical staff, accredited medical specialists, and a common set of policies and protocols. In its first 12 months, the unit had 301 admissions, 82% of whom were surgical. Unit mortality was 3.3% and hospital mortality 6%. Patients were similar in age and sex distribution to those admitted to an intensive care unit in a public hospital but their numbers, type of illness, duration of admission and mortality differed. Despite the feasibility of establishing a sophisticated intensive care unit in a private hospital, there were potential problems related to staffing (especially insufficient numbers of trained nurses), funding (especially inadequacy of hospital and medical insurance and unavailability of many drugs on the Government's Schedule of Pharmaceutical Benefits) and relations with medical staff outside the unit.
SummaryAlthough calcium antagonists such verapamil are used primarily in cardiovascular disease, they appear to relax smooth muscle generally. Therefore, the possibility that verapamil might have bronchodilator properties was explored using the guinea‐pig tracheal ring technique. Verapamil was found to produce considerable tracheal smooth muscle relaxation from a threshold concentration of 2 × 10−7M and with maximum effect at 10−3M. The responses to the contractile agonists histamine and prostaglandin F2α and especially methacholine and serotonin were substantially reduced by prior administration of verapamil. Verapamil 2 × 10−4M was equally effective as isoprenaline 10−8M in producing 50% maximum direct relaxation but was more effective than isoprenaline as an antagonist of the contractile agonists, methacholine, histamine and serotonin, but not prostaglandin F2α. Verapamil abolished the contractile responses to barium chloride. It is concluded that, although verapamil was not very potent as a direct bronchodilator, it could potentially be of prophylactic benefit in asthma because of its efficacy as an antagonist of common contractile agonists.
The high incidence (50-60%) of deep venous thrombosis of the legs (DVT) after major thoracic surgery is reduced only by about half with routine low-dose heparin prophylaxis. The present study compared the efficacy of a higher dose of heparin (7500 U twice daily) with the commonly used dose of 5000 U twice daily in preventing scan-detected DVT in 100 consecutive patients having thoracotomy for carcinoma of the lung or oesophagus. After the higher dose of heparin, postoperative DVT was not significantly less frequent (22% compared with 33% for total DVT) but was significantly less extensive (8% and 14%, respectively, for bilateral calf DVT, and 0% and 4% for popliteal DVT). Despite prophylaxis, DVT was especially common after oesophagogastrectomy (41% total DVT, 30% extensive DVT). No excessive postoperative bleeding was noted in either group. It is concluded that an increased dose of heparin safely offers increased prophylaxis against DVT in patients undergoing major thoracic surgery for cancer.