PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cannula”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1987

125I-fibrinogen uptake on peripheral venous cannulas: a comparison between different cannula materials and coatings.

Using a similar technique as 125I-Fibrinogen uptake test for detection of deep venous thrombi, the radioactivity over cannulas inserted into veins on the dorsal aspect of the hands was measured 1, 2, 4 and 24 h after insertion. In three groups of 10 postoperative patients it was by random allocation inserted on one side a siliconized tetrafluorethylene cannula and on the other side one of either: a nonsiliconized tetrafluorethylene cannula and on the other side one of either: a nonsiliconized tetrafluorethylene, a heparinized tetrafluorethylene or a fluorethylenpropylene cannula. The same volume and type of infusion was given in both cannulas. No difference in protein deposition was seen between siliconized and nonsiliconized tetrafluorethylene. A tendency of lower protein deposition, especially at 24 h on heparinized tetrafluorethylene was found. The fluorethylenpropylene cannulas had both over cannula and adjacent vein higher protein deposition at all measurements compared to the siliconized tetrafluorethylene cannula (p less than 0.01). The results implicate that fluorethylenprophylene could induce a higher incidence of thrombophlebitis than tetrafluorethylene cannulas.

Adsorption↗
PubMed1989

Cannula thrombophlebitis: a study in volunteers comparing polytetrafluoroethylene, polyurethane, and polyamide-ether-elastomer cannulae.

Cannulae made of polytetrafluoroethylene (PTFE: n = 11), thermoplastic polyether-urethane (TPEU: n = 11), and a new test material, polyamide-ether-elastomer (XLON: n = 10) were inserted into the veins of the dorsum of the hand in 32 healthy volunteers (10 women and 22 men), 21-50 years old. The cannulae were intended to be left in place for 5 days. No infusion was given and the dressings were not exchanged. The resulting thrombophlebitis, defined as two or more of the symptoms pain, redness, oedema and hardness, was estimated on a scale which took into account the incidence, location, intensity, and duration of the symptoms. Except for one volunteer in the XLON group, all the volunteers developed thrombophlebitis, generally observed on the third day of cannulation, and being more frequent and intense over the cannulae (P less than 0.001) and at the tip (P less than 0.01) than at the insertion sites. Pain and oedema were, on the whole, the most frequent and severe symptoms during the period of indwelling. After withdrawal, hardness was the most intense, and together with pain, the most long-lasting (up to 10 days) symptom. The differences between the materials in thrombophlebitis incidence and intensity were statistically significant only when each symptom was analysed separately. Thus, the PTFE cannulae caused more pain and hardness (probably because of greater platelet adhesion and a relatively greater stiffness), while the TPEU and XLON cannulae produced more periphlebitis (redness and oedema), probably because of potentially irritant and antigenic substances leaking from them (polyurethane oligomers and polyamide/polyethyleneglycol oligomers).

Adult↗
PubMed1975

[A new cannula for the introduction of catheters or other cannulas into the vascular system].

A new cannula is described consisting of a 25 cm. tube without a syringe attachment. It can be used for the introduction of other annuals (Hettler method) or for guide wires (Seldinger technique). The use of this cannula instead of the usual means of introducing catheters makes it possible to learn the technique quickly and to achieve correct placing of the cannula in the vascular lumen. The radiologist, using this method, achieves a safe and routine method very quickly. In this way angiographic examinations are made simpler they can be performed more quickly and the number of complications is reduced.

Angiography↗
PubMed1992

[A holder for right-angled metal cannula (Pacifico's venous cannula) for direct superior vena caval cannulation].

In pediatric open heart surgery, a right-angled metal cannula (Pacifico's venous cannula) for direct superior vena caval cannulation is frequently used. But it is often difficult to be inserted into superior vena cava due to "right-angled" shape especially in small babies. We developed a new holder which can make straight line from the metal tip to flexible plastic end of the cannula. It is easy and safe even in cases of small babies.

Catheterization, Central Venous↗
PubMed1985

Conservation of oxygen supply using a reservoir nasal cannula in hypoxemic patients at rest and during exercise.

A reservoir nasal cannula which stores oxygen during exhalation and delivers it as a bolus during inhalation has been reported to conserve oxygen delivery in patients with chronic obstructive pulmonary disease (COPD) at rest. We compared the effects upon arterial oxygen saturation (SaO2) of the reservoir cannula and a standard nasal cannula in hypoxemic obstructed and restricted patients at rest and during exercise. The SaO2 was monitored by ear oximeter. While at rest, 13 obstructed and four restricted patients breathed oxygen from the reservoir cannula at 0.5, 1.0, 1.5, and 2.0 L/min and from a standard cannula at 0.5, 1.0, 2.0, 3.0, and 4.0 L/min. Mean SaO2 was significantly higher with the reservoir cannula compared to the standard cannula at 1.0 and 2.0 L/min (p less than 0.0006) and tended to be higher at 0.5 L/min (p less than 0.1). Seven obstructed patients walked on a level treadmill at 0.75 mph while breathing oxygen at 0.5 and 1.5 L/min from the reservoir cannula and at 1.0 and 3.0 L/min from the standard cannula. The SaO2 during exercise with the reservoir cannula was comparable to that with the standard cannula at approximately half of the oxygen flow rate. The ratio of the oxygen flow rate of the standard to the reservoir cannula to produce 90 percent saturation was estimated and found to be 2.5 +/- 0.8 (mean +/- SD) for patients at rest and 2.9 +/- 1.8 during exercise. We conclude that in hypoxemic patients at rest and during exercise, the reservoir cannula uses less than half the oxygen of a standard cannula to produce similar improvement in SaO2 and thus has advantages of a reduced cost of ambulatory therapy with low-flow oxygen and a longer time permitted away from a stationary source of oxygen.

Carbon Dioxide↗
PubMed1985

Assessment of thromboresistance of intravenous cannulae by 125I-fibrinogen scanning.

Assessment of potentially thromboresistant polymers and other materials has been impeded by the lack of a simple and safe test procedure in man. This report describes the use of a portable gamma radiation detector to assess accumulation of 125I-fibrinogen in thrombi related to intravenous cannulae. The method was first employed in 19 dogs and one sheep with FEP-Teflon forelimb intravenous cannulae which were scanned for up to 6 h after insertion. Results were compared with findings at post mortem examination. Eleven thrombi developed, nine of which emitted more than 3500 counts per minute; eight of these (89%) were detected by external scanning. The smallest thrombus detected weighed 0.7 mg. The method did not distinguish between thrombus and hematoma. Fifty FEP-Teflon cannulae were then studied in 39 patients after injection of 100 microCi 125I-fibrinogen. Cannulae and control sites were scanned twice daily and an independent blind clinical appraisal was performed by an experienced nurse. A rise in percentage uptake (count at a limb site/heart count X 100) of 20 or a difference of 40 between adjacent sites was regarded as a positive test. Scans became positive up to 30 h before clinical evidence of phlebitis was observed. The interval between insertion and thrombosis of both large and small cannulae detected by scanning was significantly shorter than that determined by clinical assessment (p less than 0.001). Physical signs of phlebitis were noted with 58% of large cannulae (16 or 18 gauge)and 33% of small cannulae (22 gauge) at the time of removal. Positive 125I-fibrinogen tests were obtained with 70% of large cannulae and 75% of small cannulae. 125I-fibrinogen scanning is a safe simple sensitive technique to detect thrombosis related to intravenous cannulae. The test should enable comparisons of different cannula materials in man.

Animals↗
PubMed1990

Mupirocin for the reduction of colonization of internal jugular cannulae--a randomized controlled trial.

In a prospective study, 218 cardiothoracic patients, in whom 'Abbocath-T' cannulae had been inserted preoperatively into the internal jugular vein, were randomized to receive skin preparation of the insertion site with tincture of iodine (108 controls) or tincture of iodine followed by application of sterile 2% calcium mupirocin ointment (110 test patients). Cannulae were usually removed within 48 h of the operation. Patients receiving mupirocin were less likely to develop significant colonization of one or more of their cannulae as judged by Maki's criterion of a yield of greater than 15 colony forming units (cfu) from a cannula segment rolled on an agar plate (17% of mupirocin treated patients compared with 54% of the controls, P less than 0.001). Coagulase-negative staphylococci, micrococci, or both, were the commonest isolates and were cultured from 70% of the 186 control cannulae compared with 24% of 172 cannulae inserted through mupirocin-treated skin (P less than 0.001). A count of more than 15 cfu was found on the tips of 25% control cannulae compared with 5% of the cannulae from mupirocin-treated patients, an effect which was independent of in-situ time (P less than 0.001). For cannulae with colonized tips, the same species was isolated from the skin of the insertion site in 67%, from the exterior of the hub in 61% and from the lumen in only 15%. There were no side effects attributed to mupirocin or superinfection with resistant organisms. We conclude that in cardiothoracic patients the application of mupirocin after standard skin preparation with tincture of iodine significantly reduces the colonization of central venous cannulae by organisms derived from the skin insertion site.

Adolescent↗
PubMed1985

A comparison of flow gradients across disposable arterial perfusion cannulas.

Five-hundred members of The Society of Thoracic Surgeons were canvassed to discover which cannulas are currently used for open-heart surgical procedures in adults; 120 surgeons responded. The mean arterial line pressure produced by 29 disposable arterial perfusion cannulas (size range, 16F to 30F) at flow rates of 1 to 5 liters per minute was compared. A roller pump with perfusion tubing 95 mm (0.75 inch) in diameter was used with water as the test solution. Line pressures in these cannulas ranged from 22.4 +/- 2.30 (standard deviation) to 271.0 +/- 6.60 mm Hg at 5 L/min. Four 24F cannulas had gradients of less than 55 mm Hg at a flow rate of 5 L/min, and 6 cannulas--4 of which were 22F and 2, 24F--had gradients higher than 150 mm Hg at 5 L/min. A number of cannulas kinked easily, and these showed marked increases in line pressure. The following results were obtained from this study: (1) a wide range of line pressures was observed in disposable arterial perfusion cannulas currently in clinical use; (2) some cannulas currently used for cardiopulmonary bypass in adults generated excessive line pressure; and (3) both material and design affect function, with some designs being safer than others. Cardiac surgeons should base the choice of an arterial perfusion cannula on the best performance and safest design available to avoid cannula-related problems at operation.

Aorta↗
PubMedDate not supplied

An original inflow cannula for paracorporeal assist devices.

Cannulae for paracorporeal ventricular assist devices have been clinically shown to be limiting factors in optimal circulatory support. A new inflow cannula has been manufactured according to an original silicone rubber molding process, permitting a hemocompatible inner surface. The cannula is 200 mm in length, with a 10 mm internal diameter. The wall is 3 mm thick and reinforced by a stainless steel spiral spring embedded in the silicone. An external ring permits adequate interface between the cannula and the endocardial surface of the atrium. A compliant external segment on the inflow cannula, free of any spiral spring, allows adjustment of vacuum to optimal values, thus avoiding inflow obstruction. The cannula has been tested during 1 to 5 days of left ventricular bypass in calves (n = 15). A Symbion AVAD, Utah 85 VAD, or Centrimed pumps were used. Adequate heparinization was maintained throughout. Paracorporeal flow was 0.045 L min-1 kg-1. In vivo evaluation was made by hemodynamic studies and the incidence of thromboembolism. The cardiac cavities, cannulae, and peripheral vessels were carefully searched for thrombi and emboli at autopsy. The atrium, the interface between atrium and silicone cannula, and the cannula itself were found free of any deposit. This aspect differed from that observed previously with available PU or PVC cannulae.

Animals↗
PubMed1991

Development of thrombophlebitis in peripheral veins with Vialon and PTFE-Teflon cannulas: a double-blind, randomised, controlled trial.

A series of 54 normal subjects were randomised to have either a Vialon or a PTFE-Teflon peripheral vein cannula inserted in a vein in each forearm to observe the development of thrombophlebitis. Cannulas were inspected twice daily for up to 5 days to observe the development of three signs, erythema, oedema or hardness and one symptom, pain. Each sign and symptom was recorded twice daily at three points, the cannula insertion site, the mid-point of the cannula and the cannula tip. The degree of change was recorded as less than 1, 1-2 and greater than 2 cm. Any cannula causing any sign greater than 2 cm was removed. By the end of the study over 40% of both types of cannula had been removed. There were no significant differences between the numbers of each type of cannula removed at any time point throughout the duration of the study. There were no significant differences in the amounts of erythema or hardness, but minimally increased swelling was observed at the mid-point of the PTFE-Teflon cannulas (P = 0.022). Despite the theoretical superiority of Vialon as a cannula material, under controlled conditions there appears to be little difference in its inherent capacity to cause the thrombophlebitis.

Adult↗
PubMed1991

Arthroscopy update #9. Posterior compartment observation and instrumentation in the knee using anteromedial and anterolateral portals and an interchangeable cannula system.

The technique for routine posterior compartment observation in the knee described here uses cannulae that are 75 mm long and either 4.6 mm or 5.6 mm in diameter. Once they have been introduced, they remain in place while instruments and the arthroscope are interchanged within them. The arthroscope is attached to a bridge that connects to either cannula. Anteromedial and anterolateral portals are used with the interchangeable cannulae system. Once the arthroscope has been attached to the cannula in the anterolateral portal, an identical cannula with a blunt obturator is passed from the anteromedial portal into the posterolateral compartment under direct vision. The position of the arthroscope and blunt obturator are then reversed so that the arthroscope views the posterolateral compartment. To view the posteromedial compartment, the maneuver is repeated with the arthroscope in the anteromedial portal. The cannula with the blunt obturator is then advanced from the anterolateral portal under direct vision into the posteromedial compartment, and the position of the arthroscope and obturator are again interchanged. Hypertrophic synovium and osteophytes in the notch can be removed by passing shavers or burrs through the cannulae. Posteromedial and posterolateral portals are established with the 70 degree arthroscope under direct vision; once a cannula has been placed in a posterior portal, instrumentation and observation through the posterior cannula can be performed. The cannula from the opposite anterior portal remains in the posterior compartment. Hand and power instruments can be passed safely across the notch and into the posterior compartments while viewing the procedure through the posteriorly positioned arthroscope. The posterior cruciate ligament is then observed from the posteromedial portal while palpating the ligament with instruments entering the posterior compartment from the anterolateral portal.

Arthroscopes↗
PubMed1990

An improved method for bonding heparin to intravascular cannulae.

The patency of chronically implanted intravascular cannulae is usually limited by thrombus formation at the cannula tip. In the present experiments, methods of improving the antithrombotic properties of the cannulae have been examined using a number of different heparin-bonding treatments. These treatments were evaluated by determining cannula patency in the thoracic aorta of a chronically cannulated rat preparation. Cannulae treated with a heparin-bonding procedure remained patent longer than untreated cannulae. Cannulae treated with tridodecylmethylammonium chloride-heparin-glutaraldehyde remained patent longest (mean patency, 13.3 days compared with 4.0 days in rats with untreated cannulae). This technique provides a simple and effective method of improving the antithrombotic properties of intravascular cannulae by bonding heparin to the lumenal and extralumenal surfaces.

Animals↗
PubMed1991

Technical note: a double L intestinal cannula for cattle.

A double L-shaped intestinal cannula was developed in an attempt to overcome problems observed previously with simple T-type cannulas. The cannula was constructed from cyclopolyvinyl chloride water pipe fittings. Construction materials were fairly rigid, but by connecting the split cannula pieces with elastic castration bands the cannula had some flexibility. Placing a short cone over the exposed cannula barrel reduced mechanical damage to the intestine. The double L cannula required a much smaller incision in the intestine during surgical insertion than a T-type cannula; it also simplified replacement. Construction is described; use and performance of the cannula has been satisfactory.

Animals↗