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Biomedical subjects

O Volk

Publications and source records attributed to O Volk.

12 recordsLinked to original sources
PubMed2002

[Detection of air embolism by a re-usable Doppler probe integrated in a central venous line--application in-vivo].

PROBLEM: Air embolism frequently occurs under neurosurgical operations performed in the sitting position. Recently we reported the idea of inserting a re-usable doppler probe into a blind-ending lumen of a central venous catheter (Schregel-Volk-Catheter, SVC). In vitro testing in a circulation model showed a high sensitivity: air bubbles as small as 0.5 microliter were reliably detected at a distance up to 4 cm from the tip of the SVC. METHOD: After approval by the local ethics committee pigs were anaesthetised and a cardiopulmonary bypass was connected. During the bypass period a 12 F SVC (Medex Medical, Germany) with one blind-ending lumen was positioned into the proximal vena cava cranialis or vena cava caudalis. An 8 MHz doppler probe (MTB Basler, Suisse) was introduced into the SVC and connected with the doppler device Multi-Dop T (DWL, Germany). Well defined air bubbles (3-6 microliter) were generated by a bubble generator and injected into the right femoral vein or the left vena jugularis interna. RESULTS: All bubbles were reliably detected by the re-usable doppler probe. Embolic events can be documented, counted and quantified by the Multi-Dop T. CONCLUSION: Using SVC's with a blind-ending lumen could improve and simplify the detection of air embolism. We see several advantages (e.g. sensitivity, costs) compared with established methods (precordial doppler, TEE) for detection of air embolism.

Animals↗
PubMed2002

[Mobilization and retrieval of an entrapped guidewire in the righ coronary artery].

The elective PTCA of a highly stenotic right coronary artery was complicated by intracoronary entrapment of the guidewire. After transfer to a hospital with a stand-by cardiosurgical team, the interventional mobilization and withdrawal of the wire was performed. Initially the attempt to position a balloon-catheter through the entrapped guidewire failed due to a localized radiolucent piece of material attached to the tip of the wire. After introduction of an additional guidewire and consecutive dilation of the stenosis, gradual mobilization and removal of the wire was successful. During this maneuver the distal part of the guidewire ruptured and was caught in a side branch of the right femoral artery, where it could finally be retrieved, using a conventional retrieving device in a crossover technique. Intracoronary entrapment is a rare but potentially dangerous complication during coronary interventions, every cardiologist should be aware of, especially when treating tortuous vessels.

Angioplasty, Balloon, Coronary↗
PubMed2002

[Attempted suicide by intravenous injection of metasystox].

A 27-year old man was admitted to the hospital after having attempted suicide by injection of 30 ml of metasystox (demeton-s-methyl), an organophosphate compound, in a cubital vein of the left arm. He was suffering from the typical cholinergic symptoms. Local examination of the injection site revealed a local inflammation extending from the middle of the left upper arm to the distal forearm. Surgical débridement became necessary. In the third week of treatment he developed a rhabdomyolysis (CK 66.300 U/l) with an acute renal failure and needed haemodialysis. Later he showed signs of an intermediate syndrome.

Acute Kidney Injury↗
PubMed2001

[Detection of air embolism by a re-usable doppler probe integrated in a central venous line].

PROBLEM: Air embolisms frequently occur during neurosurgical operations. For detection of air embolisms, a re-usable doppler probe, integrated in a central venous line, is described. In an in-vitro test series the measuring sector as well as the function of a 8 MHz doppler probe are presented. METHOD: The 8 MHz doppler probe is a 1.1 mm diameter cable, into the distal end of which a cylindrical doppler crystal from lead-circonate-titanate (PZT5) of 2 x 1.7 mm is integrated and connected with a doppler unit. The detection of micro bubbles with a volume of 0.4-5 microliters was effected in still liquid for simple measuring of the spatial characteristics of the probe as well as in flowing liquid for simulation of a blood circulation system. RESULTS: The doppler probe detected qualitatively and reproducibly all gas bubbles offered up to 4 cm around the tip of the probe. CONCLUSION: A reliable detection of micro-bubbles in this test model is possible by means of a 8 Mhz doppler probe. Further animal and clinical studies are planned.

Catheterization, Central Venous↗
PubMed2001

[Central venous cannulation - always with ultrasound support?].

Central Venous Cannulation - Always with Ultrasound Support?.Ultrasound guided puncture (UGP) improves success and complication rates of central venous cannulation. By some authors UGP with imaging devices are strongly recommended for all cannulations of subclavian or internal jugular veins. In order to review the current literature a computer based abstract search in Medline was performed for the period from January 1972 to May 2000 limited by the key words "catheterization, central venous catheter, internal jugular vein, subclavian vein, axillary vein, femoral vein, ultrasound, ultrasonography, Site-Rite und Smart Needle". UGP of the internal jugular vein was recommended in 29 prospective randomized studies, 21 prospective and three retrospective studies as well as in several clinical reports. UGP of the subclavian vein was supported by only 4 studies, whereas two studies did not show any improvement of puncture results with UGP. Due to the visualisation of the vessel and the cannula imaging techniques represent the "gold standard". However, with conventional Doppler devices nearly the same success rates can be obtained. It does not seem to be justified to perform every central venous cannulation with Doppler or ultrasound support. Each anaesthetist and intensive care physician should be able to perform central venous cannulation without a Doppler or ultrasound device. However, in cases of abnormal anatomy UGP can be helpful to prevent complications. Especially children, patients with coagulation disorders and physicians with limited experience in central venous cannulation can benefit from UGP.

Jugular Veins↗
PubMed2001

[Current diagnosis and therapy in heart valve diseases].

We present a survey of the current standard in diagnosis and therapy of the most frequent heart valve lesions. During the last 50 years there has been a dramatic shift concerning the etiology of valve lesions with a rise of the age-dependent degenerative towards rheumatic valve diseases. The aim of the diagnostic evaluation of valve lesions is primarily the clinical and hemodynamic grading of the severity of the valve disease, the recognition of relevant coexisting cardiac and extracardiac diseases and furthermore, an optimal timing of surgery in close correlation with the cardiac surgeons.

Adult↗
PubMed2000

[The symptomatic patient with pathologic coronary angiogram. "evidence-based" or "best-evidence medicine" in the interventional cardiology].

Ischemic heart disease is the most frequent cause of death in industrialized countries. This is a result of persistent risk factors and aging of the population. Medical progress with application of conservative, surgical or interventional strategies indeed reduced the morbidity and mortality of arteriosclerotic diseases, but markedly increased the medical care costs. The result is a discussion about the optimal use of the different therapeutic measures under consideration of the evidence based medicine. This article reviews several recently published clinical trials and discusses, which patient with symptomatic coronary artery disease should undergo a conservative strategy, percutaneous or surgical revascularization.

Adrenergic beta-Antagonists↗
PubMed2000

The place of rotablator for treatment of in-stent restenosis.

In-stent restenosis (ISR) is still a growing problem in interventional cardiology due to the increasing number of stent implantations. Various treatment modalities are available at present. As a non ablative strategy balloon angioplasty is the strategy of choice for focal ISR, while ablative techniques such as directional coronary atherectomy, Excimer laser coronary angioplasty and rotational atherectomy are used preferentially in diffuse restenosis processes. These debulking techniques are optimized by peri-interventional use of intravascular ultrasound and adjunctive balloon angioplasty. Study data comparing different interventional approaches, usually with adjunct balloon angioplasty, have not proven an optimal treatment modality for ISR yet.

Angioplasty, Balloon, Coronary↗
PubMed1999

[Starch aspiration].

Starch is a white, neutral smelling, insoluble and harmless powder. The case of a 24-year old worker with a pronounced bronchospasm and arterial hypoxaemia after a collapse and aspiration during working in a silo filled with corn starch will be reported. Medication consisted mainly in mucolytics. Intensive airway clearing consisted of repeated bronchoscopies, bedding, tapotement and vibration massage. The patient has made a complete recovery in 3 days.

Accidents, Occupational↗