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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Recording of ventricular pressure by conventional catheter manometer systems. Efficiency of several combinations of conventional catheters, modern transducers and catheter-flush systems (author's transl)].

The experimentally in vitro determined dynamic response characteristics of 38 catheter manometer systems were uniform in the worst case to 5 c.p.s. and optimally to 26 c.p.s. Accordingly, some systems are only satisfactory for ordinary pressure recording in cardiac rest, while better systems record dp/dt correct up to moderate inotropic stimulation of the heart. In the frequency range of uniform response (amplitude error less +/- 5%) the phase distortion is also negligible. In clinical application the investigator is often restricted to special type of cardiac catheter. In this case a low compliant transducer yields superior results. In all examined systems the combination with MSD 10 transducers is best, whereas the combination with P 23 Db transducers leads to minimal results. An inadequate system for recording ventricular pressure pulses leads in most cases to overestimations of dp/dtmax. The use of low frequency pass filters to attenuate higher frequency artefacts is, under clinical conditions, not suitable for extending the range of uniform frequency response. The dynamic response of 14 catheter manometer systems with two types of continuous self flush units was determined. The use of the P 37 flush unit in combination with small internal diameter catheters leads to serious error in ordinary pressure recording, due to amplitude distortion of the lower harmonics. The frequency response characteristics of the combination of an Intraflow flush system and MSD 10 transducer was similar to the non-flushing P 23 Db transducer feature.

Blood Pressure Determination↗
PubMed1976

[A new modified wick catheter for measurement of the brain tissue pressure-an evaluation of static and dynamic properties of the catheter (author's transl)].

The interstitial pressure of the brain was measured with wick catheter by Lassen in 1972. But original wick catheter inserted into the brain tissue does not always measure the real interstitial pressure as indicated by experimental results of Brodersen, because, the interstitial pressure is always affected by solid pressure such as cells in the brain tissue, in the condition of which surrounded by positive CSF pressure in the semiclosed skull box. It is not yet clarified what kinds of the pressure are measured by wick catheter method in the brain tissue. The size of wick catheter is 300-500 times as large as the width of interspace of the brain tissue and the catheter is easily obstructed by brain tissue. Therefore, a new, modified wick catheter is made for improvement of these problems which is observed by using original wick catheter. The new, modified catheter has 0.4 mm inside diameter and 10 cm length. The tip of catheter is closed and 6 small side holes(0.1 mm0)are made. Inside the catheter, several pieces of 0.04 mm diameter nylon threads are inserted as shown in figure 1, and the catheter is filled up with the cerebrospinal fluid. In this paper, the structure of the new, modified catheter is demonstrated, and the brain tissue pressure is measured, comparing with the results of the original wick catheter to test the function of the new, modified catheter. The results of measurement of the brain tissue fluid pressure with the new, modified catheter are as follows; 1) The brain tissue fluid pressure is relatively constant and shows a positive pressure of 5.2 mmHg. 2) As there are few blocking effects in the catheter, the new, modified catheter is useful for the measurement of the brain tissue fluid pressure for a long time. 3) The brain tissue fluid pressure is not altered by the number's of nylon threads in the catheter at static condition, but movement of brain tissue fluid pressure with respiration is a little dumped by the increased conductancy with the numbers of nylon threads in the catheter. 4) The tissue fluid pressure affected by the viscosity and osmolarity of the fluid in the catheter, CSF should be used for correct measurement. According to these results, it might be concluded that the new, modified wick catheter is better than the original wick catheter regarding prevention of obstruction of the catheter by brain tissue fragments, artifacts which causet by movement of wick fibers, measurement of brain tissue fluid pressure for a long time and clarify the resistance of catheter to pressure conductancy.

Animals↗
PubMed2026

Pulmonary artery catheters or central venous catheters for cardiac surgery: the PUMA Pilot randomised clinical trial.

INTRODUCTION: Pulmonary artery catheters are used widely in cardiac surgery despite observed associations with worse outcomes and guidelines that recommend against their routine use. No adequately powered randomised trials are available. METHODS: The PUMA Pilot was a multicentre, randomised, parallel assignment, open-label, pilot and feasibility trial conducted at three tertiary cardiac surgery centres. Eligible patients were adults undergoing coronary artery bypass grafting, aortic valve replacement or surgery on the aortic root or ascending aorta with or without aortic valve replacement, with a predicted surgical mortality of <&#x2009;2%. Patients were allocated randomly to receive a pulmonary artery catheter or a central venous catheter inserted immediately before surgery. The primary feasibility outcome was protocol compliance, defined as receiving the assigned intervention without crossover. Secondary feasibility outcomes were eligibility rate; recruitment proportion and rate; data completeness; and rate of clinician refusal. RESULTS: We screened 480 patients and 206 (43%) were eligible; 150/203 (74%) approached provided informed consent. Three of 206 (1%) eligible patients were not included due to clinician refusal. Of 149 patients who were randomised, 76 were assigned to the pulmonary artery catheter group and 73 to the central venous catheter group. For the primary feasibility outcome, 147 patients (99%) received the allocated intervention. Data were complete for 144 (97%) patients. Median (IQR [range]) days alive and at home at 30&#x2009;days was 23.7 (21.9-24.7 [7.0-26.0]) in the pulmonary artery catheter group and 22.9 (20.8-23.9 [8.6-25.8]) in the central venous catheter group. Acute kidney injury occurred in 26/76 (34%) patients in the pulmonary artery catheter group and 14/73 (19%) in the central venous catheter group. DISCUSSION: A randomised trial of pulmonary artery catheters compared with central venous catheters in low-risk cardiac surgery is feasible. Such a trial would address significant practice variability and inform international guidelines.

Humans↗
PubMed1976

Intraurethral pressure recording. A comparison betwen tip-transducer catheters and open-end catheters with constant flow.

This paper presents the results of a comparative study of intraurethral pressure recording with two different catheter systems: (1) Open-end water-filled catheters with constant flow connected to conventional pressure transducers, and (2) Micro-transducers mounted in the tip of a dacron catheter. When open-end catheters were used, the best reproducibility of the urethra pressure profile was obtained, if the catheter dimensions 6-8 F were used and if the flow in the catheters was kept to approximately 1-2 ml/min. In addition, the withdrawal rate of the open-end catheters should not exceed 3-4 mm/sec. The best reproducibility of the intraurethral pressure was obtained with the micro-transducer. It was free from measuring artefacts and seemed from this investigation superior to the open-end catheter systems, both for clinical practice and for research.

Humans↗
PubMed1979

Role of catheter surface morphology on intravascular thrombosis of plastic catheters.

The role of catheter surface roughness in initiation and propagation of intravascular catheter thrombosis was studied in dogs, utilizing the scanning electron microscope. Catheters were inserted in major arteries and veins for 200 min and the animals then sacrificed. Catheter segments, both with and without associated thrombi, were scrutinized with the scanning electron microscope. No correlation was found between catheter surface roughness and thrombus formation, suggesting that the inherent chemical characteristics of the catheter is most important in the initiation of intravascular catheter thrombus formation.

Animals↗
PubMed1977

Lateral-hole catheters compared with shielded-hole catheter systems in oesophageal manometry.

Water-filled catheters with lateral holes in the distal ends are frequently used in oesophageal manometry. However, the outward position of the recording holes makes mucosal interference a possible risk. A pilot study of oesophageal manometry was performed in five healthy volunteers comparing a conventional lateral-hole catheter with the orifices directed to the centre of the catheter bundle, protected from the mucosa. The centre-hole catheter curves showed a lower resting pressure in the upper oesophageal sphincter (UOS) showed a lower resting pressure in the upper oesophageal sphincter (UOS) and a more rapid decline of the UOS peristaltic wave. The motility curves of the oesophageal body were identical with both catheters.

Adult↗
PubMed1976

[Results of catheter biopsy and catheter aspiration in various lung diseases (author's transl)].

Results of 415 catheter biopsies and catheter aspirations in patients with various lung diseases are reported. Among 263 patients with suspected carcinoma of the lung, in 79% neoplastic cells could be obtained histologically from catheter biopsy specimens. Among 52 patients with suspected pulmonary tuberculosis but without positive sputum, tubercle bacilli were found in 23% by aspiration biopsy. The bacteriological examination of bronchial secretion in various lung diseases showed a prevailing growth by diplococcus pneumoniae, and more sterile conditions in the peripheral bronchial airways of 56 patients. Catheter biopsy proves to be a valuable diagnostic method for the detection of peripheral bronchial carcinomas and the catheter aspiration for the bacteriological examination in specific and non-specific lung diseases.

Adult↗
PubMed1979

Effect of heparinization of fluids infused through an umbilical artery catheter on catheter patency and frequency of complications.

Heparinization of fluids (1 unit/ml) infused through an umbilical artery catheter (UAC) was efficacious in prolonging catheter patency in a double-blind, randomized, controlled clinical study. On the basis of life-table analysis, the half-life of catheter function was seven days in the heparinized group as compared with just over two days in the nonheparinized group (P less than .01). UAC occlusion occurred in 4 of 32 patients in the heparinized and 19 of 30 in the nonheparinized group (chi 2 = 17.6, P less than .01). Blood transfusions, number of arterial blood gases drawn through the UACs, and fluid infusion rates were not related to catheter occlusion. Heparinization of the UAC infusion did not alter the partial thromboplastin time or the incidence of catheter-related thromboembolic phenomena in the extremities. Heparinization of fluids infused through a UAC appears to be useful in the care of critically ill neonates.

Blood Gas Analysis↗
PubMed1979

Prophylaxis of indwelling urethral catheter infection: clinical experience with a modified Foley catheter and drainage system.

With the application of the oligodynamic bactericidal property of silver ions, modification of the urinary catheter and drainage system has been found effective in the prevention of urinary tract infections owing to prolonged bladder catheterization. The newly devised catheter and open drainage system were used in 102 patients for bladder catheterization postoperatively or in those with urinary retention for periods ranging from 4 to 77 days. During the period of indwelling catheterization usually no antibiotics were administered and no patient had overt bacteriuria (more than 10(5) bacteria per ml.) or symptoms of urethritis. In contrast, all 20 patients in the control group who had the conventional type of indwelling catheters had bacteriuria within 4 days of catheterization. The data obtained indicate that effective prevention of urinary tract infection, which frequently is associated with indwelling urethral catheterization, can be achieved by the use of the modified catheter and drainage system.

Adolescent↗
PubMed1978

[Urethro-cystometry: a comparison between open-end catheters with flow and microtransducer catheters (author's transl)].

In 40 women a comparative urethrocystometric study between microtransducer catheters and open-end catheters was performed. Analysis of resting and cough urethrapressure profile concerned clinical and practical value as well as reproducibility. All of these aspects can better be achieved by microtransducer catheters compared to the open-end catheter system. Best results were obtained when measuring with microtransducers in standing position.

Female↗
PubMed1976

Balloon catheter with a calibrated leak. A new system for superselective angiography and occlusive catheter therapy.

Problems with the use of the diagnostic angiography catheter as a therapeutic tool relate to difficulty in placing the catheter precisely in the desired area and controlling the infusion of the occluding agent. The author describes a soft microcatheter which has been developed to overcome these problems. The catheter ends in a balloon tip and thus can be flow-directed. To overcome the traditional difficulties of flow-guided catheters and the need for a double lumen, a calibrated leak in the balloon allows distal fluid delivery while the balloon remains inflated.

Aged↗
PubMed1977

Closed catheter drainage and urinary infection--a comparison of two methods of catheter drainage.

The incidence of urinary infection following urological operations is compared using 2 methods of closed catheter drainage in 214 patients. No significant difference was observed. The overall infection rates for the whole series were 32%. The most significant influence on the rate of infection appears to be the duration of catheter drainage. Failure of chemotherapy to eradicate infection while the catheter was still in situ was mostly due to the use of inappropriate antimicrobials. Only 2 of the 35 cases with infected urine had succeeded in clearing their infection at the 4-week follow-up without chemotherapy.

Adolescent↗
PubMed1979

Catheter and material selection for transarterial embolization: technical considerations. I. Catheters.

In this first part of the report, the authors discuss the selection of catheterization techniques and delivery systems. These include various introducer sheaths, tapered and non-tapered conventional catheters, and double-lumen, single-lumen, flow-guided single-lumen, and detachable balloon catheters. The selection is discussed with regard to the specifics of the lesion, such as location of the lesion and number and size of feeding arteries. The authors' experience with experimental embolizations in dogs and the clinical material in 34 patients in whom 61 embolization procedures were performed are presented.

Adult↗
PubMed1978

Urethral pressure profilometry with membrane catheter compared with perfusion catheter systems.

Urodynamic evaluation of urethral sphincter function can be carried out by constant carbon dioxide perfusion, constant water perfusion, or by the use of membrane catheters. A comparison of these 3 techniques was made in in vitro experiments. Results, and advantages and disadvantages of each technique are discussed. From all factors considered in this study--response to pressure changes, sensitivity to pressures along the urethra, and reproducibility of the profile--the membrane catheter was concluded to be superior to either of the perfusion systems.

Animals↗
PubMedDate not supplied

[Opacification of the aortic arch using a long needle-catheter. Modification of the catheter and precautions to be taken (author's transl)].

The authors modified the long needle-catheter used by Amplatz and Stocks, by adding lateral openings. The modified needle-catheter was used to study the aorta and its branches using the left translumbar approach. The high rate of blood flow (30 to 34 ml/s) gave excellent opacification of the thoracic and abdominal aortas, and the lower limbs.

Angiography↗