Specific problems of arterial, Swan-Ganz, and hemodialysis catheters

The Use of Pulmonary Artery Catheter in Sepsis Patients: A Literature Review

This article was to review the literature regarding the use of the pulmonary artery catheter (PAC) in the management of patients with sepsis and septic shock. A PubMed search was conducted in order to identify publications evaluating the use of PAC as a tool for management and therapeutic guidance in patients with sepsis. The bibliographies of all identified publications were reviewed for additional relevant references. Much information is identified in the literature regarding the indications for pulmonary artery catheterization in the assessment and treatment of patients with sepsis. Although the PAC has been widely used for many years, there is no clear benefit with regard to outcome, and there is controversy regarding its use. It is not clear that use of the PAC contributes to reduced morbidity and mortality in patients with sepsis. The role of the PAC is becoming less clear, as newer, non-invasive techniques are developed for hemodynamic assessment of sepsis patients. Large, well-designed clinical trials are needed to better assess the role and potential benefit from use of the PAC in sepsis.

Catheter-related bloodstream infections in HIV-infected patients

Bloodstream infections (BSI) constitute a significant public health problem and represent an important cause of morbidity and mortality in hospitalized patients, with an approximate incidence of one episode per hundred hospital admissions. Studies on BSI in HIV+ patients have identified central venous catheters (CVC) as a risk factor, with an attributable mortality rate of 10-20%. The long-term CVC-related infection risk appeared to be 5 to 10-fold higher with respect to the infection rates among HIV- patients. CVC associated infection rate ranges from 1.3 to 12 infections per 1,000 catheter-days. Staphylococcus aureus is the most common etiologic agent causative of CVC-related BSI, likely the result of the high skin and nasal carriage of this organism among HIV+ patients, mostly intravenous drug users. Coagulase-negative staphylococci are also frequently identified as cause of CVC-related BSI, likely the result of breaches in infection control measures and in antiseptic technique during CVC management. Treating bacteremia without catheter removal would be optimal, but the reported efficacy of systemic antibiotic therapy alone is only 25-32%. Conversely, recent studies have shown that, using an antibiotic-lock procedure, up to 90% of HIV-infected and uninfected patients achieved complete eradication of catheter-related BSIs without catheter removal. Clinical trials using new materials such as covalently linked heparin on the CVC surface, electrically charged CVC, novel topical agents that interfere with bacterial colonization, antiadhesin molecules and agents that block the gene expression involved in the biofilm formation, are all needed to reduce the high catheter-related infection risk among HIV+ patients.

The safety and utility of pulmonary artery catheterization in severe preeclampsia and eclampsia

OBJECTIVE

The objective of this research was to study the safety and utility of pulmonary artery catheterization in the management of severe preeclampsia and eclampsia.

STUDY DESIGN

In a retrospective chart review from January 1, 1995, through December 31, 1997, a total of 115 patients admitted to the obstetric intensive care unit at Groote Schuur Hospital were found to have required placement of a pulmonary artery catheter. From this population 100 maternal charts were examined for medical and pregnancy history, including indication for pulmonary artery catheter placement, hemodynamic readings, complications, and subsequent management.

RESULTS

The initial indications for pulmonary artery catheter placement in cases of severe preeclampsia or eclampsia were renal failure in 53 cases (53%), pulmonary edema in 30 (30%), and eclampsia in 17 (17%). Subjective evaluation demonstrated that the pulmonary artery catheter was helpful in determining management in 93 cases (93%). There was a 4.0% complication rate, which included three venous thromboses and one case of cellulitis. Eleven patients required dialysis, and 3 women died. The mean (+/-SE) duration of catheter placement was 2.1 +/- 0.1 days and the mean (+/-SE) intensive care unit and hospital stays were 3.4 +/- 0.2 days and 11.4 +/- 0.8 days, respectively. The pulmonary artery catheter measurements of pulmonary artery wedge pressure and central venous pressure were increased in the cases of pulmonary edema (21.0 +/- 2.0 mm Hg and 9. 6 +/- 1.2 mm Hg, respectively) but were normal in the cases of renal failure and eclampsia.

CONCLUSION

Despite significant maternal morbidity and mortality, pulmonary artery catheter use in cases of severe preeclampsia or eclampsia was subjectively beneficial in 93 of 100 cases (93%), with an acceptable complication rate (4.0%).

Do anticoagulation with heparin and protamine reversal alter thrombogenicity of coated and noncoated pulmonary artery catheters?

OBJECTIVE

To clarify the role of anticoagulation with heparin and protamine reversal on the effectiveness of heparin bonding or coating of pulmonary artery catheters in preventing thrombus formation in the Rhesus monkey.

DESIGN

A controlled, unblinded, open-labeled study.

SETTING

A research laboratory at Tulane School of Medicine (New Orleans, LA).

PARTICIPANTS

Twenty-four anesthetized Rhesus monkeys.

INTERVENTIONS

The monkeys were assigned to one of four groups. In the first group (group A), non-heparin-coated catheters were inserted into a femoral vein through an incision, advanced proximally for a distance of 30 cm, and left in place for 1 hour. In the second group (group B), heparin-coated catheters were placed and evaluated in the same manner as in group A. In the third group (group C), the primates received 3 mg/kg of heparin intravenously (i.v.) before insertion of a non-heparin-coated pulmonary artery catheter. After the catheter had been in place for 1 hour, protamine, 3 mg/kg i.v., was administered, and the catheter was left in place for an additional hour. In the final group (group D), the primates received 3 mg/kg of heparin i.v. before insertion of a heparin-coated pulmonary artery catheter. After the catheter had been in place for 1 hour, protamine, 3 mg/kg i.v., was administered, and the catheter was left in place for an additional hour. In each group, the catheter was withdrawn with the balloon inflated to minimize any stripping of thrombus from the surface of the catheter. Thrombus was removed from the catheter through a femoral vein cutdown and weighed. Laboratory values were determined for each animal, and clot formation was evaluated in each group. After completion of the study, the animals were returned to the primate breeding colony.

MEASUREMENTS AND MAIN RESULTS

There were no significant differences in hematocrit, prothrombin time, partial thromboplastin time, or platelet levels among the four groups; therefore, the data were pooled. Clots were observed on five of six catheters in both groups A and C; however, clot formation was seen in one of six catheters in group B and three of six catheters in group D. There was a statistically significant difference (p < 0.01) in mean clot weight in group A (265 +/- 68 mg; range, 0 to 447 mg) compared with 13 +/- 13 mg in group B (range, 0 to 80 mg). There was no significant difference in mean clot weight in group C (104 +/- 35 mg; range, 0 to 202 mg) compared with group D (24 +/- 16 mg, range, 0 to 98 mg). Additionally, in group C, the mean clot weight was significantly less than in group A.

CONCLUSION

Anticoagulation of primates with heparin before catheter insertion imparts some protection to non-coated catheters, and protamine reversal of anticoagulation with heparin may partially negate the protective effect seen with heparin-coated pulmonary artery catheters.

Introducers and protective sleeves may increase thrombogenicity of pulmonary artery catheters

OBJECTIVE

To investigate the cause of clot formation on the surface of non-heparin coated/bonded pulmonary artery catheters.

DESIGN

A controlled, unblinded, open-labeled study.

SETTING

Research laboratory at Tulane School of Medicine, New Orleans, LA.

PARTICIPANTS

Rhesus and African Green monkeys.

INTERVENTIONS

Anesthetized monkeys (n = 24) were assigned to one of two groups. The first group (group A) had a pulmonary artery catheter inserted into a femoral vein through a cutdown without passage through an introducer or protective sleeve before insertion. In the second group (group B), the pulmonary artery catheter was passed through an introducer and protective sleeve before insertion in the femoral vein. After the study, the animals were returned to the primate breeding colony. Laboratory values were measured for each animal, and electron micrographs were taken of selected pulmonary artery catheters before and after passage of these catheters through the introducer sheath and/or protective sleeve.

MEASUREMENTS AND MAIN RESULTS

Between the two groups, there was a significant difference in fibrinogen level, but not in hematocrit, prothrombin time, partial thromboplastin time, and platelet count. Clots were visible on 11 of 12 catheters in group B, which was statistically significant (p < 0.01), compared with only 3 of 12 catheters in group A. The average clot weight was 0.014+/-0.014 g in group A (range, 0.00 to 0.170 g), which was statistically significant (p < 0.01), compared with 0.216 < 0.058 g in group B (range, 0.000 to 0.620 g). Electron micrographs taken after catheters were passed through an introducer and/or protective sleeve showed that both significantly altered the surface of the catheter. The surface of the catheter was smooth and homogenous in appearance before insertion. Conversely, both the introducer and protective sleeve produced marked furrowing and a nodular appearance on the catheter surface, as shown by electron micrographs.

CONCLUSION

The data from this study show that the incidence of clot formation and amount of clot formed on the surface of non-heparin-coated pulmonary artery catheters are significantly greater after passage through an introducer and/or protective sleeve. The electron micrographs also show that both introducers and protective sleeves abraded the catheters and were associated with thrombus formation on the catheter. Designing less traumatic valves on these devices is warranted and recommended.