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Biomedical subjects

G Köhn

Publications and source records attributed to G Köhn.

6 recordsLinked to original sources
PubMed2000

Anaesthesia with midazolam and S-(+)-ketamine in spontaneously breathing paediatric patients during magnetic resonance imaging.

We evaluated safety and efficacy of a sedation technique based on rectal and intravenous S-(+)-ketamine and midazolam to achieve immobilization during Magnetic Resonance Imaging (MRI). Thirty-four paediatric patients were randomly assigned to undergo either the sedation protocol (study group) or general anaesthesia (control group). Imaging was successfully completed in all children. Children in the study group received a rectal bolus (0.5 mg x kg(-1) midazolam and 5 mg x kg(-1) S-(+)-ketamine) and required additional i.v. supplementation (20+/-10 microg x kg(-1) x min(-1) S-(+)-ketamine and 4+/-2 microg x kg(-1) x min(-1) midazolam), spontaneous ventilation was maintained. Transient desaturation occurred once during sedation and four times in the control group (P=0.34). PECO2 was 5.3+/-0.5 kPa (40+/-4 mm Hg) in the study group and 4.1+/-0.6 kPa (31+/-5 mm Hg) in the control group (P<0.001). Induction and discharge times were shorter in the study group (P<0.001), recovery times did not differ significantly between the groups. Our study confirms that a combination of rectal and supplemental intravenous S-(+)-ketamine plus midazolam is a safe and useful alternative to general anaesthesia for MRI in selected paediatric patients.

Administration, Rectal↗
PubMed1998

[Prognostic relevance of vena cava thrombosis in renal cell carcinoma].

The independent prognostic value of neoplastic extension of renal cell cancer (RCC) into the vena cava inferior has been the subject of several investigations reported to date. However, the use of vena cava thrombosis as an independent prognosticator of a patient's long-term survival is still debated. We have therefore correlated the clinical course of 53 patients with RCC and vena cava thrombosis with a control group consisting of 47 patients with renal cell tumors without vena cava thrombosis (follow-up: 1-154 months). The median long-term survival of patients with and without vena cava thrombosis was 32 and 35 months, respectively. Neither the propagation of the tumor into the vena cava (P = 0.391) nor the cranial extension of the thrombosis (P = 0.158)--even in case of propagation into the right atrium--could be identified as parameters of any prognostic value during univariate or multivariate statistical analysis.

Adult↗
PubMed1997

Frequency of deep vein thrombosis in patients with patent foramen ovale and ischemic stroke or transient ischemic attack.

To evaluate the additional value of transesophageal (TEE) compared with transthoracic (TTE) echocardiography and the role of patent foramen ovale (PFO) and deep vein thrombosis in the work-up of embolic events, patients with presumed cardiac embolic stroke or transient ischemic attack (neurovascular etiology was excluded) were prospectively studied by transthoracic and transesophageal contrast echocardiography. If PFO was detected echocardiographically, PFO size was assessed semiquantitatively and phlebography of both legs was performed. Two hundred forty-two consecutive patients (153 men, 60 +/- 15 years) were studied. In 197 patients, neuroimaging showed evidence of embolic infarction. TEE identified 138 potential cardiac sources of embolism in 111 patients, compared with 69 by TTE (p <0.01) in 59 patients. TEE detected potential cardiac sources in 52 patients with negative TTE examination and was significantly superior compared with TTE for identifying left atrial thrombi, spontaneous echo contrast, PFO, atrial septal aneurysm, and atheroma of the ascending aorta. In patients with a positive TTE, additional diagnostic information by TEE was found in only 6 patients and did not change therapy. Phlebography was performed in 53 patients with PFO and revealed deep vein thrombosis in 5 patients (9.5%); all had medium or large PFOs. Thus, in patients with cerebral ischemia of suspected cardiogenic origin and a normal TTE examination, TEE detects potential causes of embolism in 31% of patients and is therefore of diagnostic relevance. Conversely, in the presence of a diagnostic TTE an additional TEE confers only marginal diagnostic benefit. Deep venous thrombosis was detected in nearly 10% of patients with PFO as the sole identifiable cardiac risk factor. Given that in 4 of 5 patients deep vein thrombosis was clinically silent, phlebography should be performed in patients with medium or large interatrial shunts if paradoxical embolism is suspected.

Adult↗
PubMed1997

Prognostic relevance of intracaval neoplastic extension for patients with renal cell cancer.

OBJECTIVE: To assess the diagnosis of vena caval thrombosis (VCT) in patients with renal cell carcinoma (RCC) as an independent indicator of prognostic importance and when combined with additional tumour characteristics in a controlled multivariate analysis. PATIENTS AND METHODS: The clinical course of 53 patients (41 men and 12 women, mean age 60 years, range 35-79) with RCC and VCT was compared with that of a control group of 47 patients (37 men and 10 women, mean age 57 years, range 32-76) with RCC but no neoplastic extension into the vena cava. RESULTS: With a follow-up of 1-154 months and a mean long-term survival of 32 and 35 months, respectively, for patients with and without VCT, neither the propagation of the tumour into the vena cava (P = 0.391) nor the cranial extension of the thrombosis (P = 0.158) were identified as having any prognostic value during univariate or multivariate statistical analysis. The presence of regional lymph node (P < 0.001) or distant metastases (P = 0.009) was an independent prognostic variable for patients with RCC, with a significant decrease in long-term survival (13 and 14 months for patients with lymph node and distant metastases, respectively). CONCLUSION: A radical surgical approach is essential as standard therapy for the treatment of patients with RCC and neoplastic extension into the vena cava. Because they have a significantly decreased life expectancy, asymptomatic patients with lymph node or distant metastases should be treated conservatively.

Adult↗