Peripheral Venous Cannula Research Articles

Comparison of Four Blood Sampling Sites for Flow-Cytometric Analysis of Platelet Function

Background: The access site used for platelet sampling has been suggested to be an important variable for clinical flowcytometric platelet analysis. In this study, we have evaluated the influence of different blood sampling sites (16 G central venous catheter, 20 G radial artery cannula, 16 G peripheral venous cannula and 19 G hypodermic needle) on platelet activation and aggregation. Material and Methods: Blood samples were collected from 17 adult patients undergoing abdominal surgery who did not have any medication known to alter platelet function. All samples were taken and measured by the same investigator after catheter placement and 2 h later. Surface expression of the glycoprotein IIb/IIIa (CD41), the platelet activation marker P-selectin (CD62P), and the percentage of platelet-leukocyte complexes (CD45+/CD41+) were measured by flow cytometry. Results: Regarding the site of blood sampling, there were no significant differences in the expression of CD41, CD62P and plateletleukocyte complexes. Repeated failure to place a central vein catheter or an arterial cannula resulted in increased platelet activation which was not detectable anymore 2 h later. Conclusion: Besides withdrawal by hypodermic needles (blood sample taken without stasis), samples for flowcytometric platelet function tests could also be taken from arterial cannulae, central venous catheters, and peripheral venous cannulae. Repeated failure of central venous or arterial puncture should be avoided since it results in transient platelet activation.

Local warming and insertion of peripheral venous cannulas: single blinded prospective randomised controlled trial and single blinded randomised crossover trial

Objective: To determine whether local warming of the lower arm and hand facilitates peripheral venous cannulation.Design: Single blinded prospective randomised controlled trial and single blinded randomised crossover trial.Setting: Neurosurgical unit...

Venous drainage with a single peripheral bicaval cannula for less invasive atrial septal defect repair

New peripheral venous cannulae have recently been proposed for minimally invasive open cardiac surgery. We present a femoral venous cannula designed to simultaneously drain both superior and inferior vena cavae. Used in adult patients for atrial septal defect repair, the cannula allowed passive blood drainage of 70.6% ± 11.7% of theoretical cardiac output. Drainage was augmented to 93.4% ± 8.6% of theoretical cardiac output by means of a centrifugal pump.

The effects of chemical sympathectomy on testicular injury in varicocele.

To determine whether the sympathetic nervous system plays a role in the contralateral testicular deterioration encountered in varicocele. Forty male Sprague-Dawley albino rats (28 days old) were divided equally into four treatment groups, i.e. (1) sham operation, (2) with varicocele, (3) treated by chemical sympathectomy plus varicocele, and (4) chemical sympathectomy only. Chemical sympathectomy was induced by administering intraperitoneal 6-OH dopamine (100 microg/g for 5 days) in groups 3 and 4; groups 1 and 2 received equal volumes of physiological saline by the same route. All rats underwent laparotomy and part of the left renal vein (distal to the spermatic vein confluence) was isolated and encircled with a 4/0 silk suture. The suture was left untied in group 2, and tied around a 24 F peripheral venous cannula in groups 3 and 4. The testes were then excised when the rats were 70 days old; malondialdehyde (MDA) in the testicular tissue was assayed by the thiobarbituric acid-reactive substances method, and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels were determined by spectrophotometric analysis. Varicocele resulted in a significant increase in MDA levels in both testes and chemical sympathectomy prevented this effect. SOD and GSH-Px values were significantly decreased in both testes in group 2; chemical sympathectomy also prevented this effect. An induced unilateral varicocele significantly increases the biochemical indicators of tissue hypoxia in both testes. As this increase was prevented by chemical sympathectomy, the sympathetic nervous system may play a role in the testicular degeneration associated with varicocele.

Examining the care of patients with peripheral venous cannulas.

The purpose of this study was to examine nursing issues in the care of patients with peripheral venous cannulas (PVCs) with particular focus on duration of cannulation in order to minimize risk of infection. A tentative practice model evolved from this study. The research approach used involved qualitative methods utilizing grounded theory. Data analysis produced one tentative core category, 'effectiveness'. This allowed for the development of a 12-dimensional model explaining the nursing function against four interrelated models: development; practice; organizational support; effectiveness. Related to these four models were key professional aspects of 'autonomy-control' and 'knowledge-practice'. Interpretative findings from the study were plotted against this model, giving a graphic representation and highlighting strengths and weaknesses of nursing practice. Aspects requiring improvement included: PVC care as a syllabus subject; nursing practice; autonomy and control issues; shared responsibility problems; documentation systems; goal setting; outcomes. The policy, nurses' knowledge of PVC care and identification of critical issues were considered satisfactory. The model incorporates 12 important dimensions associated with effective practice that can be applied to nursing at different levels - clinical practice, education, management - and to other disciplines, providing a framework for narrowing the theory-practice gap and improving patient care.

Intracerebroventricular injection of interleukin-1 stimulates the release of high levels of interleukin-6 and interleukin-1 receptor antagonist into peripheral blood in the primate

Previous studies in the rodent have shown that the cytokine IL-1 can act within the brain to influence peripheral IL-6 secretion. In order to determine if such an interaction occurs in the primate, we have compared the effects of intracerebroventricular vs. intravenous injection of IL-1β on the release of IL-6 into the peripheral circulation of the monkey. The effects of i.c.v. IL-1β on the release of the IL-1 receptor antagonist (IL-1ra) were studied in parallel. For comparison, we have also measured the release of both IL-6 and IL-1ra into lumbar CSF after i.c.v. IL-1β injection. Ten ovariectomized rhesus monkeys with indwelling lateral ventricular and peripheral venous cannulae were studied. Human rIL-1β (400 ng) was infused either i.c.v. or i.v. over 30 min and blood samples were collected for IL-6 and IL-1ra measurement by monoclonal human ELISAs. Although both i.c.v. and i.v. IL-1β stimulated IL-6 and IL-1ra release into peripheral blood, the stimulation was much more profound after i.c.v. injection ( p<0.001). Peak IL-6 levels were 2010±590 pg/ml after i.c.v. IL-1β compared to 243±60 pg/ml after i.v. IL-1β. Peak IL-1ra levels were 61,310±16,190 pg/ml after i.c.v. IL-1β compared to 18,175±4270 pg/ml after i.v. IL-1β. There was no significant effect of an i.c.v. saline infusion on peripheral IL-6 or IL-1ra levels. In four animals, lumbar CSF was collected 7 h after i.c.v. IL-1β injection. The mean concentration of IL-6 in CSF was 103, 570±13,780 pg/ml after i.c.v. IL-1β vs. 224±190 pg/ml after i.c.v. saline injection; IL-1ra was 47,460±6290 pg/ml vs. 1040±550 pg/ml. As expected, both i.c.v. and i.v. IL-β stimulated ACTH and cortisol release; the stimulation was significantly greater after i.c.v. compared to i.v. administration ( p<0.001). Thus, in the monkey, i.c.v. injection of IL-1β stimulates the release of large amounts of IL-6 and IL-1ra into the CSF and the peripheral circulation. Both IL-6 and IL-1ra were released into the peripheral circulation to a much greater extent after i.c.v. compared to i.v. IL-1β infusion. These studies provide further support in the primate for a mechanism by which inflammation within the brain could induce a variety of systemic responses.

A blinded randomised, controlled trial comparing dopamine, noradrenaline, S-methylisothiourea sulphate and volume in a porcine model of endotoxin shock

Objective: To investigate the association between levels of nitric oxide metabolites and the cardiovascular response to endotoxin shock; and to compare the effects of dopamine, noradrenaline and S-methylisothiourea sulphate (SMT), a relatively selective inducible nitric oxide synthase inhibitor, on haemodynamics, oxygen transport, markers of global and regional perfusion and survival in an immature pig model of endotoxin shock. Design: Randomised, blinded laboratory study. Setting: Animal research laboratory in a university hospital. Subjects: Three- to four-week-old pigs. There were eight animals in each of four groups. Interventions: The animals were anaesthetised and ventilated. Peripheral arterial, pulmonary artery and central venous cannulae and a gastric tonometer were inserted. Endotoxin shock was induced by a continuous infusion of E. coli lipopolysaccharide. Animals were randomly allocated to one of four groups: i) dopamine at 5-20 μg/kg/min, ii) noradrenaline at 0.1-0.5 μg/kg/min, iii) SMT at 20-80 μg/kg/min, or iv) placebo, to which the investigators were blinded. The study drug was commenced 1 hour after initiation of endotoxaemia, and then infused continuously for 6 hours. Volume resuscitation was given to all groups throughout the study to maintain a pulmonary artery wedge pressure at 2-4 mm Hg above pre-endotoxin baseline levels. Measurements: At baseline after cannulation, 1 hour after the initiation of endotoxaemia, and every 90 minutes after the commencement of the study drug infusion, the following data were recorded: heart rate, systemic blood pressure, mean pulmonary artery pressure (PAP) and pulmonary artery wedge pressure (PAWP), central venous pressure (CVP), gastric intramucosal pH (pHi), base deficit, blood lactate, mixed venous oxygen saturation (SvO2), cardiac index, systemic and pulmonary vascular resistance indices (SVRI and PVRI) and oxygen delivery (DO2). Blood was collected for assay of combined serum nitrate and nitrite (nitrogen oxides). Endpoints: The major endpoints were: the relationship between background nitric oxide (NO) activity and initial haemodynamic response to endotoxin; and the relative effect of the study drugs over time on: DO2, SVR, PVR, blood lactate, pHi, SvO2 and base deficit. Results: There was a significant, albeit weak, relationship between baseline serum nitrogen oxide concentrations and the initial cardiovascular response to endotoxin: levels of serum nitrogen oxides were positively associated with change in cardiac index; and negatively associated with the change in SVRI and PVRI. SMT produced greater increases in SVRI than the other three treatment arms, but caused a decrease in DO2. Dopamine increased DO2 in the early stages, but not later in the course of the study. SMT produced a greater increase in PVR than dopamine. Conclusions: Endogenous NO activity may be one determinant of the cardiovascular response to infection. Use of SMT in endotoxin shock resulted in vasoconstriction and reduced DO2, compared with catecholamines or volume alone.

A blinded randomised, controlled trial comparing dopamine, noradrenaline, S-methylisothiourea sulphate and volume in a porcine model of endotoxin shock

Objective: To investigate the association between levels of nitric oxide metabolites and the cardiovascular response to endotoxin shock; and to compare the effects of dopamine, noradrenaline and S-methylisothiourea sulphate (SMT), a relatively selective inducible nitric oxide synthase inhibitor, on haemodynamics, oxygen transport, markers of global and regional perfusion and survival in an immature pig model of endotoxin shock. Design: Randomised, blinded laboratory study. Setting: Animal research laboratory in a university hospital. Subjects: Three- to four-week-old pigs. There were eight animals in each of four groups. Interventions: The animals were anaesthetised and ventilated. Peripheral arterial, pulmonary artery and central venous cannulae and a gastric tonometer were inserted. Endotoxin shock was induced by a continuous infusion of E. coli lipopolysaccharide. Animals were randomly allocated to one of four groups: i) dopamine at 5-20 μg/kg/min, ii) noradrenaline at 0.1-0.5 μg/kg/min, iii) SMT at 20-80 μg/kg/min, or iv) placebo, to which the investigators were blinded. The study drug was commenced 1 hour after initiation of endotoxaemia, and then infused continuously for 6 hours. Volume resuscitation was given to all groups throughout the study to maintain a pulmonary artery wedge pressure at 2-4 mm Hg above pre-endotoxin baseline levels. Measurements: At baseline after cannulation, 1 hour after the initiation of endotoxaemia, and every 90 minutes after the commencement of the study drug infusion, the following data were recorded: heart rate, systemic blood pressure, mean pulmonary artery pressure (PAP) and pulmonary artery wedge pressure (PAWP), central venous pressure (CVP), gastric intramucosal pH (pHi), base deficit, blood lactate, mixed venous oxygen saturation (SvO2), cardiac index, systemic and pulmonary vascular resistance indices (SVRI and PVRI) and oxygen delivery (DO2). Blood was collected for assay of combined serum nitrate and nitrite (nitrogen oxides). Endpoints: The major endpoints were: the relationship between background nitric oxide (NO) activity and initial haemodynamic response to endotoxin; and the relative effect of the study drugs over time on: DO2, SVR, PVR, blood lactate, pHi, SvO2 and base deficit. Results: There was a significant, albeit weak, relationship between baseline serum nitrogen oxide concentrations and the initial cardiovascular response to endotoxin: levels of serum nitrogen oxides were positively associated with change in cardiac index; and negatively associated with the change in SVRI and PVRI. SMT produced greater increases in SVRI than the other three treatment arms, but caused a decrease in DO2. Dopamine increased DO2 in the early stages, but not later in the course of the study. SMT produced a greater increase in PVR than dopamine. Conclusions: Endogenous NO activity may be one determinant of the cardiovascular response to infection. Use of SMT in endotoxin shock resulted in vasoconstriction and reduced DO2, compared with catecholamines or volume alone.

Penetration forces in cannulation of the dorsal veins of the hand: I. A comparison between polyurethane (Insyte®) and polytetrafluoroethylene (Venflon®) cannulae

The functional tip tapering design of peripheral venous cannulae (introducer steel needle + catheter) made of polyurethane (PUR-Instye) and polytetrafluoroethylene (PTFE-Venflon) was studied with 3 techniques: A) Scanning electron microscopy (SEM). B) Measurement of penetration forces in vitro through latex membranes and lamb skins with a tensile-compression apparatus (Instron-1122) at 1) the introducer steel-needle point, 2) the needle heel (the spot marking the passage from the point of the needle to its shaft). 3) the catheter top (i.e. the beginning of the plastic sheath), 4) the catheter tip, i.e. the beginning of the largest diameter of the plastic sheath, and 5) between the catheter tip and its hub (catheter friction). C) Two cannulae (one of each type for every subject were inserted at random into the dorsal veins of the left and right hand in 37 volunteers, and the penetration forces were measured with a force transducer. A) The PUR-cannulae had a lancet-like appearance and a smoother transition at the catheter top, whilst the PTFE cannulae were arrow-like, cut back and had a less accentuated conical design. B) Penetration forces in vitro through latex membranes were 9-41 times lower (P less than 0.0001) than those through the large skins. The highest forces (mean +/- s.d.) registered in vitro (lamb skins) were 4.1 +/- 0.2 Newtons (N) with PUR-cannulae at the catheter tip, and 3.4 +/- 0.6 with the PTFE-cannulae at the catheter top (P less than 0.05). C).(ABSTRACT TRUNCATED AT 250 WORDS)

Tussive effect of a fentanyl bolus

The aim of this study was to investigate the incidence of pre-induction coughing, after an iv bolus of fentanyl. The study sample was 250 ASA physical status I-II patients, scheduled for various elective surgical procedures. The first 100 were randomly allocated to receive 1.5 micrograms.kg-1 fentanyl via a peripheral venous cannula (Group 1), or an equivalent volume of saline (Group 2). Twenty-eight per cent of patients who received fentanyl, but none given saline, coughed within one minute (P less than 0.0001). The second 150 patients were then randomly assigned to three equal pretreatment groups. Group 3 received 0.01 mg.kg-1 atropine iv one minute before fentanyl. Groups 4 and 5 received 0.2 mg.kg-1 morphine im, and 7.5 mg midazolam po, respectively, one hour before fentanyl. Thirty per cent of patients in Group 3, 6% in Group 4, and 40% in Group 5, had a cough response to fentanyl. Fentanyl, when given through a peripheral cannula, provoked cough in a considerable proportion of patients. This was not altered by premedication with atropine or midazolam, but was reduced after morphine (P less than 0.01). Coughing upon induction of anaesthesia is undesirable in some patients, and stimulation of cough by fentanyl in unpremedicated patients may be of clinical importance.

Blood contamination of anaesthetic and related staff

The incidence of skin contamination of anaesthetic and related staff by patient's blood and saliva was studied during 270 anaesthetics in Cardiff hospitals over seven continuous days in October 1989. A survey was also made of current Hepatitis B immunisation status and glove-wearing habits of 75 anaesthetists. Blood from 35 (14%) patients caused skin contamination of 65 staff during 46 incidents. Twenty-eight (61%) of the contamination incidents occurred during vessel cannulation. Five (8%) of the 65 staff contaminated by blood already had cuts on their hands. There were nine incidents (4%) of skin contamination by saliva. Fifty-three (71%) anaesthetists were immunised against Hepatitis B. Only seven (9%) anaesthetists wear gloves for oral or nasal intubation, six (8%) for insertion of peripheral venous cannulae, 47 (63%) for insertion of arterial lines and 67 (89%) for insertion of central lines. All anaesthetic and associated staff should wear gloves on a routine basis.

Tussive effect of a fentanyl bolus administered through a central venous catheter

One hundred and ten male patients scheduled for coronary artery bypass grafting were allocated randomly into one of three groups. Patients in group A received fentanyl 7 micrograms/kg via a central venous catheter, those in group B were given fentanyl 7 micrograms/kg through a peripheral venous cannula, and patients in group C received sterile water via a central venous catheter. In group A, 45.9% of patients coughed after injection of fentanyl; the mean onset time from the end of fentanyl administration to the beginning of coughing was 10.6 seconds. Only one patient in group B and no patient in the control group exhibited a cough response (p less than 0.0001). We hypothesise that fentanyl can evoke the pulmonary chemoreflex.

Comparison of polyurethane and polytetrafluro-ethylene peripheral venous cannulas in the development of thrombophlebitis: a randomised double-blind study

Comparison of polyurethane and polytetrafluro-ethylene peripheral venous cannulas in the development of thrombophlebitis: a randomised double-blind study

Quantitative bacteriology of peripheral venous cannulae in neonates

In a study of 50 peripheral venous cannulae removed from neonates in the special care baby unit, quantitative and qualitative techniques for cannula culture were compared and the results correlated with detailed clinical information. High-density colonization was demonstrated on the external and internal surfaces of nine, and on the external surface alone of four, cannula tips. Internal surface colonization was always associated with heavy external surface growth. In predicting high-density colonization by quantitative methods, qualitative culture in broth was 100% sensitive and 89% specific. There was a significant association between high-density colonization of the cannula tip and hub colonization, surrounding skin colonization, longer duration of cannula insertion, and slower average infusion rate. Similar organisms were isolated more frequently from the cannula tip and the hub than from the cannula tip and surrounding skin. These findings indicate that peripheral venous cannulae are a potential source of infection in neonates, that there is no advantage of techniques that identify internal surface colonization, and that most cannula tip infections have their origin in a colonized hub.

Quantitative bacteriology of peripheral venous cannulae in neonates

Quantitative bacteriology of peripheral venous cannulae in neonates

A Morphological Study of Bacterial Colonisation of Intravenous Cannulae

In an investigation of bacterial colonisation of intravascular cannulae, 16 peripheral venous cannulae of the Venflon variety and 24 chronic haemodialysis cannulae were studied after removal from patients. Studies of colonisation included semi-quantitative microbiological culture and scanning electronmicrographic (SEM) observations. The microbiological findings indicated colonisation of the intravascular portion of the catheter in 4 of 16 Venflon cannulae and 18 of 26 haemodialysis cannulae, largely with skin commensal organisms. The results of the SEM studies were in broad agreement with the microbiological observations. Surface defects on the cannulae were shown to be associated with microbial colonisation which occurred either as isolated colonies or in association with a cellular fibrinous matrix. These observations are illustrated and discussed.