Sepsis associated with central vein catheters in critically ill patients

In 440 critically ill patients, the association between different central vein catheter insertion sites, the duration of catheter insertion and catheter-associated sepsis was examined. Of 780 catheter tips studied, 19% were colonized by microorganisms. The incidence of colonization varied with the different insertion sites. The lowest percentage of colonized catheters occurred with catheters inserted via the subclavian vein (15%) and the highest, at the femoral vein insertion site (34%,p<0.01). The percentage of catheters colonized increased as the duration of insertion increased, at all insertion sites studied. Catheter colonization was closely related to the development of bacteraemia and was associated with approximately 10% of colonized catheters. Our results suggest that the subclavian site is associated with the lowest infective complication rate. To minimize catheter associated sepsis, catheters at all insertion sites should be used with parsimony and only kept in place for the minimum amount of time that their continuing use is necessary.     

Focus on peripherally inserted central catheters in critically ill patients

Venous access devices are of pivotal importance for an increasing number of critically ill patients in a variety of disease states and in a variety of clinical settings (emergency, intensive care, surgery) and for different purposes (fluids or drugs infusions, parenteral nutrition, antibiotic therapy, hemodynamic monitoring, procedures of dialysis/apheresis). However, healthcare professionals are commonly worried about the possible consequences that may result using a central venous access device (CVAD) (mainly, bloodstream infections and thrombosis), both peripherally inserted central catheters (PICCs) and centrally inserted central catheters (CICCs). This review aims to discuss indications, insertion techniques, and care of PICCs in critically ill patients. PICCs have many advantages over standard CICCs. First of all, their insertion is easy and safe -due to their placement into peripheral veins of the arm- and the advantage of a central location of catheter tip suitable for all osmolarity and pH solutions. Using the ultrasound-guidance for the PICC insertion, the risk of hemothorax and pneumothorax can be avoided, as well as the possibility of primary malposition is very low. PICC placement is also appropriate to avoid post-procedural hemorrhage in patients with an abnormal coagulative state who need a CVAD. Some limits previously ascribed to PICCs (i.e., low flow rates, difficult central venous pressure monitoring, lack of safety for radio-diagnostic procedures, single-lumen) have delayed their start up in the intensive care units as common practice. Though, the recent development of power-injectable PICCs overcomes these technical limitations and PICCs have started to spread in critical care settings. Two important take-home messages may be drawn from this review. First, the incidence of complications varies depending on venous accesses and healthcare professionals should be aware of the different clinical performance as well as of the different risks associated with each type of CVAD (CICCs or PICCs). Second, an inappropriate CVAD choice and, particularly, an inadequate insertion technique are relevant-and often not recognized-potential risk factors for complications in critically ill patients. We strongly believe that all healthcare professionals involved in the choice, insertion or management of CVADs in critically ill patients should know all potential risk factors of complications. This knowledge may minimize complications and guarantee longevity to the CVAD optimizing the risk/benefit ratio of CVAD insertion and use. Proper management of CVADs in critical care saves lines and lives. Much evidence from the medical literature and from the clinical practice supports our belief that, compared to CICCs, the so-called power-injectable peripherally inserted central catheters are a good alternative choice in critical care.     

Clinical utility of blood cultures drawn from central venous or arterial catheters in critically ill surgical patients

OBJECTIVE: To determine the sensitivity, specificity, and predictive values of cultures done with blood drawn through a central venous or arterial catheter compared with peripheral venipuncture. DESIGN: Retrospective cohort study of critically ill surgical patients in whom samples for paired cultures were drawn through a central venous or arterial catheter and peripheral venipuncture. SETTING: Tertiary-care, university-affiliated medical center. PATIENTS: Two hundred seventy-one patients hospitalized on a surgical and a cardiothoracic intensive care unit between November 1994 and August 1997. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Blinded assessments of culture results done by two physicians were used as the gold standard. Sensitivity, specificity, and positive and negative predictive values were compared for culture of blood from catheters and culture of blood from peripheral venipuncture. Of 499 observations, 426 were catheter-negative/venipuncture-negative, 19 were catheter-positive/venipuncture-positive, 18 were catheter-negative/venipuncture-positive, and 36 were catheter-positive/venipuncture-negative pairs. For catheter draws compared with peripheral venipuncture, sensitivity was 78% (confidence interval [CI], 65% to 90%) and 65% (CI, 50% to 79%) (p = .2), specificity was 95% (CI, 94% to 97%) and 98% (CI, 97% to 99%) (p = .002), positive predictive value was 63% (CI, 51% to 76%) and 78% (CI, 64% to 91%) (p = .1) and negative predictive value was 98% (CI, 96% to 99%) and 97% (CI, 95% to 98%) (p = .3). When central venous specimens as differentiated from arterial catheter specimens were compared with peripheral venipuncture, the difference between positive predictive values reached statistical significance (61% and 82%; p = .04). CONCLUSIONS: In critically ill surgical patients, cultures of blood drawn through a catheter are less specific than those obtained from a peripheral venipuncture. Both types of cultures have an excellent negative predictive value. Positive predictive value of cultures of blood drawn through a catheter is low and, when obtained from a central line, statistically less than from a peripheral venipuncture. Additional cultures seem to be necessary for the proper interpretation of a positive culture drawn through a catheter in critical care patients.     

Influence of infusion flow rates on central venous pressure measurements through multi-lumen central venous catheters in intensive care

Objective To study the influence on central venous pressure (CVP), measured at the distal port, of crystalloid infusions administered through the proximal port(s) of a central venous multi-lumen catheter. Patients Thirty-one intensive care patients. Interventions CVP was measured at the distal port of a multi-lumen catheter inserted in the subclavian or internal jugular vein. Using the proximal port(s), saline (0.9%) was infused at rates varying from 2 ml/h to 14,340 ml/h. Results CVP measured before the infusion and during infusion (after 30 s to 1 min) were not significantly different. Positive pressure ventilation with PEEP (5.6 ± 2.5 cmH₂O) and/or norepinephrine infusion (0.25 ± 0.21 μg kg⁻¹ min⁻¹) did not produce any significant change in CVP during infusion. Conclusion The administration of crystalloids at different flow rates through the proximal port(s) of a multi-lumen catheter placed in the superior vena cava does not affect CVP measurement at the distal port, even in mechanically ventilated patients or patients receiving vasopressors.     

不同体位对机械通气患者中心静脉压测量的影响

目的 探讨在机械通气条件下,不同体位对危重病患者中心静脉压(CVP)的影响.方法 采用前瞻性自身对照研究.选择右锁骨下静脉王管的33例机械通气的危重病患者,分别测定平卧位(0°)和半卧位(45°)时的CVP,以及两体位条件下测CVP时心率(HR)、呼吸频率(RR)、平均动脉压(MAP)、经皮血氧饱和度(SpO2)的变化.结果 平卧位和半卧位时,机械通气的危重病患者CVP的变化无统计学意义(P＞0.05),两体位分别测量CVP时,HR、RR、MAP、SpO2的变化差异均无统计学意义(P＞0.05).结论 机械通气的患者常规体位为半卧位,体位改变对其CVP无显著影响.因此,在常规体位下测量CVP,可减少对患者的不利影响,增加患者的安全性和舒适性,简化CVP的测量程序.     

Monitoring of central venous oxygen saturation versus mixed venous oxygen saturation in critically ill patients

Continous monitoring of mixed venous (SvO₂) and central venous (ScO₂) oxygen saturation was compared in 7 critically-ill patients (Apache II score: 19±2.1) to determine whether or not information derived from ScO₂ were reliable in clinical practice. Patients were catheterized with both a pulmonary artery (PA) and a central venous (CV) catheter, each of them mounted with fiberoptic sensors (Opticath PA Catheter P7110 and Opticath CV Catheter U440, Abbott). A total of 580 comparative measurements were obtained during periods without and with therapeutic interventions (drug-titration, bronchial suction, use of PEEP, changes in FiO₂...). The systematic error between the 2 measurement techniques was 0.6% and 0.3% in periods with and without therapeutic interventions, respectively. The variability between the 2 techniques was 10% for both periods. Differences between the values were 5% in 49% of values during periods of stability and in 50% of values during periods with therapeutic interventions. There were poor correlations between the values during periods without (r=0.48) and with therapeutic interventions (r=0.62). Better, but still less than ideal, correlations were obtained with changes in SvO₂ and ScO₂ during periods without (r=0.70) and with therapeutic interventions (r=0.77). Although there is a need to develop a simple technique to monitor mixed venous oxygen saturation, the present study indicates that ScO₂ monitoring was not reliable in the study patients.     

Use of femoral venous catheters in critically ill adults: prospective study

OBJECTIVE: To determine the frequency of clinically important complications of femoral venous catheters. DESIGN: Prospective survey of major and minor complications. SETTING: A mixed medical/surgical ICU in a university hospital. PATIENTS: One hundred twenty-three patients admitted to the ICU who underwent femoral venous catheterization over a 2-yr period. MEASUREMENTS AND MAIN RESULTS: There were 150 catheters inserted in 123 patients for a mean duration of 6.4 days. There were no major complications including catheter-related sepsis. Minor complications consisted of arterial puncture (9.3%), local bleeding (10%), and local inflammation (4.7%). Critical care fellows had a significantly lower rate (6%) of insertion complications than interns or medical students (16%). We did not specifically look at the frequency of deep venous thrombosis. CONCLUSIONS: Femoral venous catheterization offers an alternative site of insertion to the subclavian and jugular veins for central venous access in the critically ill. The occurrence rate of clinically important complications is acceptably low.     

Peripherally inserted central venous catheters and central venous catheters related thrombosis in post-critical patients

Background  

Peripherally inserted central venous catheters (PICC) have been proposed as an alternative to central venous catheters (CVC). The aim of this study was to determine the thrombosis rate in relation to PICC placement in patients discharged from the intensive care unit (ICU).     

Relationship between central venous pressure and bioimpedance vector analysis in critically ill patients

OBJECTIVE: To assess the relationship between central venous pressure values and bioelectrical impedance vector analysis (BIVA), which may be used as complementary methods in the bedside monitoring of fluid status. DESIGN: Cross-sectional evaluation of a consecutive sample. SETTING: Intensive care unit of a university hospital. PATIENTS: One hundred and twenty-one consecutive Caucasian, adult patients of either gender, for whom routine central venous pressure measurements were available. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Central venous pressure values and impedance vector components (i.e., resistance and reactance) were determined simultaneously. Total body water predictions were obtained from regression equations according to either conventional bioimpedance analysis or anthropometry (Watson and Hume formulas). Variability of total body water predictions was unacceptable for clinical purposes. Central venous pressure values significantly and inversely correlated with individual impedance vector components (r2 = .28 and r2 = .27 with resistance and reactance, respectively), and with both vector components together (R2 = .31). Patients were classified in three groups according to their central venous pressure value: low (0 to 3 mm Hg); medium (4 to 12 mm Hg); and high (13 to 20 mm Hg). Three BIVA patterns were considered: vectors within the target (reference) 75% tolerance ellipse (normal tissue hydration); long vectors out of the upper pole of the target (dehydration); and short vectors out of the lower pole of the target (fluid overload). The agreement between BIVA and central venous pressure indications was good in the high central venous pressure group (93% short vectors), moderate in the medium central venous pressure group (35% normal vectors), and poor in low central venous pressure group (10% long vectors). CONCLUSIONS: Central venous pressure values correlated with direct impedance measurements more than with total body water predictions. Whereas central venous pressure values >12 mm Hg were associated with shorter impedance vectors in 93% of patients, indicating fluid overload, central venous pressure values <3 mm Hg were associated with long impedance vectors in only 10% of patients, indicating tissue dehydration. The combined evaluation of intensive care unit patients by BIVA and central venous pressure may be useful in therapy planning, particularly in those with low central venous pressure in whom reduced, preserved, or increased tissue fluid content can be detected by BIVA.     

中心静脉导管胸腔置管患者规范化管理的实施与效果

目的探讨中心静脉导管胸腔置管规范管理的方法与效果。方法成立中心静脉导管胸腔置管护理小组,建立胸腔置管患者护理管理档案,发放家庭护理手册。结果置管期间并发症减少;提高了患者满意度。结论对中心静脉导管胸腔置管患者实施规范管理,可以减少置管并发症,提高患者满意度。     

Pericardial tamponade in patients with central venous catheters.

Cardiac (pericardial) tamponade occurs when the pressure of the fluid within the pericardial sac is high enough to impair the venous return to the heart. Cardiac tamponade can occur during central venous catheter placements. Nursing members of a central vascular catheter placement team benefit from quickly recognizing this clinical situation and understanding the appropriate clinical response. A methodical approach to this potentially fatal condition can greatly increase patient safety. This article reviews this condition, its clinical presentation and diagnosis, and strategies for avoiding central vascular access-associated tamponade.     

Urokinase administration in pediatric patients with occluded central venous catheters

The effectiveness of urokinase in declotting central venous catheters was retrospectively assessed in a pediatric population of 63 patients ranging in age from 4 days to 22 years (mean, 6.4 years). Results of treatment from 103 episodes of catheter occlusion were evaluated. Urokinase was instilled into occluded single-lumen catheters and into each lumen of double-lumen catheters, as well as into occluded implanted ports. Patency was restored to 101 of 103 occluded catheters, with no side effects observed subsequent to clearance of the catheters with the urokinase infusion. Significant cost savings were seen using urokinase to restore patency as compared to the cost of replacing the catheter. These data clearly support the use of urokinase in a pediatric population as a safe and cost-effective alternative to catheter replacement in cases of thrombotic occlusion.     

Double lumen umbilical venous catheters in critically ill neonates: a randomized prospective study

OBJECTIVES: To compare relative efficacies and complications associated with the use of double lumen vs. single lumen umbilical venous catheters in critically ill neonates. DESIGN: Prospective randomized control trial. SETTING: Neonatal ICU. PATIENTS: Forty-three critically ill neonates. INTERVENTIONS: Group 1 patients (n = 20) received single lumen umbilical venous catheters and group 2 patients (n = 23) received double lumen catheters. A record of the following information was kept: demographic data including diagnosis and indication for umbilical venous catheter insertion, catheter tip location, length of catheterization (days), number of additional iv catheters and complications (sepsis, hepatic necrosis, thrombosis, or mechanical complications). MEASUREMENTS AND MAIN RESULTS: Double lumen umbilical venous catheters were well tolerated and were associated with no significant increased risk of mechanical complications when compared with single lumen umbilical venous catheters. The number of additional iv catheters required (0.8 +/- 0.1 [SD]) was significantly (p less than .05) less in the double lumen umbilical venous catheter group as compared with additional iv catheters required (2.3 +/- 0.8) in the single lumen umbilical venous catheter group. CONCLUSION: Double lumen umbilical venous catheters are well tolerated for short-term use, decrease the need for additional venous catheters in critically ill neonates, and may not significantly increase the risk of mechanical complications when compared with single lumen umbilical venous catheters.     

体外循环术后经不同途径留置中心静脉管道发生感染的比较

目的:中心静脉留置管道感染是体外循环心脏手术后面临的重要课题.比较分析体外循环心脏手术后经不同途径留置中心静脉管道而发生感染的差异.方法:西京医院心血管外科重症监护病区2002-12/2004-11收治体外循环术后患者2218例,共行经皮穿刺留置中心静脉管道治疗2 743例次,其中经股静脉放置573例次,经颈静脉放置1 997例次,经锁骨下静脉放置136例次,经外周静脉放置37例次.对出现明确的或可疑的感染患者,留取外周血和中心静脉导管标本进行培养,比较不同途径留置的中心静脉管道的感染情况.结果:共观察留置导管2 743例次,无漏检现象.①经股静脉途径留置的中心静脉管道感染率为12.6%,经锁骨下静脉途径的感染率为8.1%,经颈静脉途径的感染率为4.1%,经外周静脉途径留置的感染率为2.7%.不同留置途径的中心静脉管道感染率差异具有显著性意义(P＜0.01).②中心静脉留置管道感染的致病菌以革兰氏阳性菌为主.结论:体外循环术后中心静脉留置管道的感染率与留置途径有一定相关性,中心静脉留置管道感染的致病菌以革兰氏阳性菌为主.     

Sodium citrate versus saline catheter locks for non-tunneled hemodialysis central venous catheters in critically ill adults: a randomized controlled trial

Purpose  

Sodium citrate has antibacterial and anticoagulant properties that are confined to the catheter when used as a catheter lock. Studies of its use as a catheter lock in chronic hemodialysis patients suggest it may be efficacious in preventing infection and thrombotic complications. We compared sodium citrate with saline catheter locks for non-tunneled hemodialysis central venous catheters in critically ill adult patients. Primary endpoint was catheter life span without complication.