Effects of dopexamine,dobutamine or dopamine on prolactin and thyreotropin serum concentrations in high-risk surgical patients

Objectives Catecholamines are often used for optimisation of cardiac index and oxygen delivery in high-risk surgical patients; however, infusions of dopamine and dopexamine are associated with dose-dependent hypophysiotropic and thyreotropic properties. The objective was to compare endocrine effects of equipotent inotropic doses of dopexamine, dobutamine and dopamine on prolactin and thyreotropin release perioperatively.Design A prospective, randomised, blinded clinical trial.Setting Adult surgical intensive care unit in a university hospital.Patients Thirty male patients (ASA III) undergoing elective major abdominal surgery.Interventions Patients were randomised to receive dopexamine (DX, n=10), dobutamine (DO, n=10) or dopamine (DA, n=10) on the first postoperative day for 8 h.Measurements and results All patients received a catecholamine infusion in doses adjusted to increase cardiac index by 35% within the first hour. Blood samples were obtained and prolactin and thyreotropin serum concentrations were determined by radioimmunoassays. Mean doses of dopexamine, dobutamine and dopamine used were 0.73±0.27, 4.06±1.95 and 5.0±1.84 µg kg^–1min^–1, respectively. Cardiac index was increased by 36% (DX group), 38% (DO group) and 38% (DA group). Alterations of oxygen delivery and oxygen consumption were not significantly different between the study groups. Dopexamine and dobutamine had no hypophysiotropic effects. In contrast, dopamine suppressed prolactin and thyreotropin secretion with a maximal effect after 4 h. After dopamine withdrawal, a rebound release of prolactin and thyreotropin was observed.Conclusions In high-risk surgical patients dopexamine or dobutamine produced fewer effects on prolactin and thyreotropin serum concentrations in comparison with DA when used in equivalent dosages.     

ProgressiveStaphylococcus lugdunensis endocarditis despite antibiotic treatment

A 68-year old man with fever chills and a diastolic murmur was diagnosed with aortic-valve endocarditis caused by coagulase-negative Staphylococcus lugdunensis. The clinical condition initially improved with antibiotic therapy. On day seven, transoesophageal echocardiography revealed large abscesses extending from the aortic root to the left ventricular wall. Emergency cardiac surgery was performed successfully and a stentless bioprosthetic valve was inserted. S. lugdunensis endocarditis is known for its aggressive clinical course with valve destruction, abscess formation and embolic complications despite appropriate antibiotics. Antibiotic treatment alone is associated with a high mortality rate which can be reduced by early valve replacement.     

Evaluation of the oesophageal-tracheal double-lumen tube (Combitube) during general anaesthesia

OBJECTIVES: Evaluation of safety and effectiveness of the Combitube during general anaesthesia. PATIENTS AND METHODS: 250 patients undergoing general anaesthesia were enrolled in the study. The respective types and duration of surgery, ease of insertion of the Combitube, and potential complications were recorded. Maximum ventilatory pressures and leak fraction were also evaluated in this study. RESULTS: Duration of surgery varied between 20 and 410 min. More than 96% of the blind Combitube insertions were successful at the first attempt, with a mean time of less than 18 +/- 5 seconds (range 12-24 seconds). In 99% of patients the Combitube worked well, and adequate oxygenation and ventilation was possible. All patients were haemodynamically stable during the entire duration of surgery. In all patients, pulse oximetry showed an oxygen saturation of 97 +/- 2% and an end-tidal carbon dioxide of 38 +/- 6 mmHg. Leak fraction, calculated as a fraction of the inspired volume, did not increase to more than 5% up to a ventilation pressure of 40 cm H2O. Superficial laceration occurred in 18 patients (7.2%) without further sequelae. No severe injuries were observed during the study period. CONCLUSION: Ventilation via the Combitube appears to be safe and effective during general anaesthesia. Practice in elective cases is a requirement for successful use in an emergency situation.     

Primary signet-ring cell carcinoma of the colorectum

Background Objective of the study was to investigate particular clinicopathological features of colorectal signet-ring cell carcinoma.Methods The data of 34 patients with primary colorectal signet-ring cell carcinoma were compared with those of 4,458 consecutive patients with primary non-signet-ring cell colorectal adenocarcinoma between 1978 and 1999. For outcome analysis patients, after curative resection of signet-ring cell cancer, were matched for age, gender, tumour site and stage with patients suffering from poorly differentiated non-signet-ring cell colorectal adenocarcinoma.Results Signet-ring cell carcinoma patients were significantly younger than patients with non-signet-ring cell colorectal adenocarcinoma (median age 60 years vs 64 years, P=0.033). The most common tumour sites were the rectum (47%) and the right hemicolon (29%). They presented with significantly more advanced tumour stages and a significantly higher frequency of distant metastases (44% vs 21%, P=0.002). The rate of curative resections was significantly lower (35% vs 79%, P<0.001). However, the prognosis after curative resection of signet-ring cell cancer was as poor as in poorly differentiated non-signet-ring cell colorectal adenocarcinoma of the same stage (5-year survival rate 46% vs 57%, p=0.935).Conclusions Colorectal signet-ring cell carcinoma is characterized by diagnosis in more advanced tumour stages resulting in lower rates of curative resection. Prognosis is as poor as in non-signet-ring cell colorectal cancer of low differentiation in the same stage.     

Intravenous bisphosphonate therapy for osteoporosis: Where do we stand?

The use of oral bisphosphonates, particularly members of the aminobisphosphonate subclass, is well established for the treatment of osteoporosis. In a number of clinical settings, intravenous administration appears to be advantageous. However, current dosing and efficacy data are limited while definitive, long-term trials with some of these agents are ongoing. In this article, we review the available information and discuss the use of these drugs on that basis.