Radiologic interpretation of central venous catheter placement.

When used in veterinary medicine, central venous catheters are typically inserted through the external jugular vein, with their caudal extension within the cranial vena cava. Radiographic or fluoroscopic guidance is recommended to assist in correctly placing these catheters. This article provides radiologic examples of common central venous catheter malpositions and complications.

Transesophageal echocardiography for verification of the position of the electrocardiographically-placed central venous catheter

OBJECTIVE: Compare changes in P-wave amplitude of the intra-atrial electrocardiogram (ECG) and its corresponding transesophageal echocardiography (TEE)-controlled position to verify the exact localization of a central venous catheter (CVC) tip. DESIGN: A prospective study. SETTING: University, single-institutional setting. PARTICIPANTS: Two hundred patients undergoing elective cardiac surgery. INTERVENTIONS: CVC placement via the right internal jugular vein with ECG control using the guidewire technique and TEE control in 4 different phases: phase 1: CVC placement with normalized P wave and measurement of distance from the crista terminalis to the CVC tip; phase 2: TEE-controlled placement of the CVC tip; parallel to the superior vena cava (SVC) and measurements of P-wave amplitude; phase 3: influence of head positioning on CVC migration; and phase 4: evaluation of positioning of the CVC postoperatively using a chest x-ray. MEASUREMENTS AND MAIN RESULTS: The CVC tip could only be visualized in 67 patients on TEE with a normalized P wave. In 198 patients with the CVC parallel to the SVC wall controlled by TEE (phase 2), an elevated P wave was observed. Different head movements led to no significant migration of the CVC (phase 3). On a postoperative chest-x-ray, the CVC position was correct in 87.6% (phase 4). CONCLUSION: The study suggests that the position of the CVC tip is located parallel to the SVC and 1.5 cm above the crista terminalis if the P wave starts to decrease during withdrawal of the catheter. The authors recommend that ECG control as per their study should be routinely used for placement of central venous catheters via the right internal jugular vein.

Central venous catheter integrity during mechanical power injection of iodinated contrast medium

PURPOSE: To evaluate a widely used nontunneled triple-lumen central venous catheter in order to determine whether the largest of the three lumina (16 gauge) can tolerate high flow rates, such as those required for computed tomographic angiography. MATERIALS AND METHODS: Forty-two catheters were tested in vitro, including 10 new and 32 used catheters (median indwelling time, 5 days). Injection pressures were continuously monitored at the site of the 16-gauge central venous catheter hub. Catheters were injected with 300 and 370 mg of iodine per milliliter of iopamidol by using a mechanical injector at increasing flow rates until the catheter failed. The infusion rate, hub pressure, and location were documented for each failure event. The catheter pressures generated during hand injection by five operators were also analyzed. Mean flow rates and pressures at failure were compared by means of two-tailed Student t test, with differences considered significant at P < .05. RESULTS: Injections of iopamidol with 370 mg of iodine per milliliter generate more pressure than injections of iopamidol with 300 mg of iodine per milliliter at the same injection rate. All catheters failed in the tubing external to the patient. The lowest flow rate at which catheter failure occurred was 9 mL/sec. The lowest hub pressure at failure was 262 pounds per square inch gauge (psig) for new and 213 psig for used catheters. Hand injection of iopamidol with 300 mg of iodine per milliliter generated peak hub pressures ranging from 35 to 72 psig, corresponding to flow rates ranging from 2.5 to 5.0 mL/sec. CONCLUSION: Indwelling use has an effect on catheter material property, but even for used catheters there is a substantial safety margin for power injection with the particular triple-lumen central venous catheter tested in this study, as the manufacturer's recommendation for maximum pressure is 15 psig.

Risk factors for early catheter-related infections in cancer patients

BACKGROUND: Early catheter-related infection is a serious complication in cancer treatment, although risk factors for its occurrence are not well established. The authors conducted a prospective study to identify the risk factors for developing early catheter-related infection. METHODS: All consecutive patients with cancer who underwent insertion of a central venous catheter were enrolled and were followed prospectively during 1 month. The study endpoint was occurrence of early catheter-related infection. RESULTS: Over 10,392 catheter-days of follow-up, 14 of 371 patients had early catheter-related infections (14 patients in 10,392 catheter-days or 1.34 per 1000 catheter-days). The causative pathogens were gram positive in 11 of 14 patients. In univariate analysis, the risk factors for early catheter-related infection were aged <10 years (P = .0001), difficulties during insertion (P < 10(-6)), blood product administration (P < 10(-3)), parenteral nutrition (P < 10(-4)), and use >2 days (P < 10(-6)). In multivariate analysis, 3 variables remained significantly associated with the risk of early catheter-related infection: age <10 years (odds ratio [OR], 18.4; 95% confidence interval [95% CI], 1.9-106.7), difficulties during insertion procedure (OR, 25.6; 95% CI, 4.2-106), and parenteral nutrition (OR, 28.5; 95% CI, 4.2-200). CONCLUSIONS: On the day of insertion, 2 variables were identified that were associated with a high risk of developing an early catheter-related infection: young age and difficulties during insertion. The results from this study may be used to identify patients who are at high risk of infection who may be candidates for preventive strategies.

Incidence of low central venous oxygen saturation during unplanned admissions in a multidisciplinary intensive care unit: an observational study

INTRODUCTION: It has been shown that early central venous oxygen saturation (ScvO2)-guided optimization of hemodynamics can improve outcome in septic patients. The early ScvO2 profile of other patient groups is unknown. The aim of this study was to characterize unplanned admissions in a multidisciplinary intensive care unit (ICU) with respect to ScvO2 and outcome. METHODS: Ninety-eight consecutive unplanned admissions to a multidisciplinary ICU (median age 63 [range 19 to 83] years, median Simplified Acute Physiology Score [SAPS II] 43 [range 11 to 92]) with a clinical indication for a central venous catheter were included in the study. ScvO2 was assessed at ICU arrival and six hours later but was not used to guide treatment. Length of stay in ICU (LOSICU) and in hospital (LOShospital) and 28-day mortality were recorded. RESULTS: ScvO2 was 70% +/- 12% (mean +/- standard deviation) at admission and 71% +/- 10% six hours later (p = 0.484). Overall 28-day mortality was 18%, LOSICU was 3 (1 to 28) days, and LOShospital was 19 (1 to 28) days. Patients with an ScvO2 of less than 60% at admission had higher mortality than patients with an ScvO2 of more than 60% (29% versus 17%, p < 0.05). Changes in ScvO2 during the first six hours were not predictive of LOSICU, LOShospital, or mortality. CONCLUSION: Low ScvO2 in unplanned admissions and high SAPS II are associated with increased mortality. Standard ICU treatment increased ScvO2 in patients with a low admission ScvO2, but the increase was not associated with LOSICU or LOShospital.

Bloodstream infection in paediatric cancer centres--leukaemia and relapsed malignancies are independent risk factors.

UNLABELLED In a prospective multicentre study of bloodstream infection (BSI) from November 01, 2007 to July 31, 2010, seven paediatric cancer centres (PCC) from Germany and one from Switzerland included 770 paediatric cancer patients (58% males; median age 8.3 years, interquartile range (IQR) 3.8-14.8 years) comprising 153,193 individual days of surveillance (in- and outpatient days during intensive treatment). Broviac catheters were used in 63% of all patients and Ports in 20%. One hundred forty-two patients (18%; 95% CI 16 to 21%) experienced at least one BSI (179 BSIs in total; bacteraemia 70%, bacterial sepsis 27%, candidaemia 2%). In 57%, the BSI occurred in inpatients, in 79% after conventional chemotherapy. Only 56 % of the patients showed neutropenia at BSI onset. Eventually, patients with acute lymphoblastic leukaemia (ALL) or acute myeloblastic leukaemia (AML), relapsed malignancy and patients with a Broviac faced an increased risk of BSI in the multivariate analysis. Relapsed malignancy (16%) was an independent risk factor for all BSI and for Gram-positive BSI. CONCLUSION This study confirms relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. On a unit level, data on BSIs in this high-risk population derived from prospective surveillance are not only mandatory to decide on empiric antimicrobial treatment but also beneficial in planning and evaluating preventive bundles. WHAT IS KNOWN • Paediatric cancer patients face an increased risk of nosocomial bloodstream infections (BSIs). • In most cases, these BSIs are associated with the use of a long-term central venous catheter (Broviac, Port), severe and prolonged immunosuppression (e.g. neutropenia) and other chemotherapy-induced alterations of host defence mechanisms (e.g. mucositis). What is New: • This study is the first multicentre study confirming relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. • It describes the epidemiology of nosocomial BSI in paediatric cancer patients mainly outside the stem cell transplantation setting during conventional intensive therapy and argues for prospective surveillance programmes to target and evaluate preventive bundle interventions.

Gene therapy for immunodeficiency due to adenosine deaminase deficiency

BACKGROUND: We investigated the long-term outcome of gene therapy for severe combined immunodeficiency (SCID) due to the lack of adenosine deaminase (ADA), a fatal disorder of purine metabolism and immunodeficiency. METHODS: We infused autologous CD34+ bone marrow cells transduced with a retroviral vector containing the ADA gene into 10 children with SCID due to ADA deficiency who lacked an HLA-identical sibling donor, after nonmyeloablative conditioning with busulfan. Enzyme-replacement therapy was not given after infusion of the cells. RESULTS: All patients are alive after a median follow-up of 4.0 years (range, 1.8 to 8.0). Transduced hematopoietic stem cells have stably engrafted and differentiated into myeloid cells containing ADA (mean range at 1 year in bone marrow lineages, 3.5 to 8.9%) and lymphoid cells (mean range in peripheral blood, 52.4 to 88.0%). Eight patients do not require enzyme-replacement therapy, their blood cells continue to express ADA, and they have no signs of defective detoxification of purine metabolites. Nine patients had immune reconstitution with increases in T-cell counts (median count at 3 years, 1.07x10(9) per liter) and normalization of T-cell function. In the five patients in whom intravenous immune globulin replacement was discontinued, antigen-specific antibody responses were elicited after exposure to vaccines or viral antigens. Effective protection against infections and improvement in physical development made a normal lifestyle possible. Serious adverse events included prolonged neutropenia (in two patients), hypertension (in one), central-venous-catheter-related infections (in two), Epstein-Barr virus reactivation (in one), and autoimmune hepatitis (in one). CONCLUSIONS: Gene therapy, combined with reduced-intensity conditioning, is a safe and effective treatment for SCID in patients with ADA deficiency. (ClinicalTrials.gov numbers, NCT00598481 and NCT00599781.)

Catheter removal versus retention in the management of catheter-associated enterococcal bloodstream infections

BACKGROUND Enterococci are an important cause of central venous catheter (CVC)-associated bloodstream infections (CA-BSI). It is unclear whether CVC removal is necessary to successfully manage enterococcal CA-BSI. METHODS A 12-month retrospective cohort study of adults with enterococcal CA-BSI was conducted at a tertiary care hospital; clinical, microbiological and outcome data were collected. RESULTS A total of 111 patients had an enterococcal CA-BSI. The median age was 58.2 years (range 21 to 94 years). There were 45 (40.5%) infections caused by Entercoccus faecalis (among which 10 [22%] were vancomycin resistant), 61 (55%) by Enterococcus faecium (57 [93%] vancomycin resistant) and five (4.5%) by other Enterococcus species. Patients were treated with linezolid (n=51 [46%]), vancomycin (n=37 [33%]), daptomycin (n=11 [10%]), ampicillin (n=2 [2%]) or quinupristin/dalfopristin (n=2 [2%]); seven (n=6%) patients did not receive adequate enterococcal treatment. Additionally, 24 (22%) patients received adjunctive gentamicin treatment. The CVC was retained in 29 (26.1%) patients. Patients with removed CVCs showed lower rates of in-hospital mortality (15 [18.3%] versus 11 [37.9]; P=0.03), but similar rates of recurrent bacteremia (nine [11.0%] versus two (7.0%); P=0.7) and a similar post-BSI length of hospital stay (median days [range]) (11.1 [1.7 to 63.1 days] versus 9.3 [1.9 to 31.8 days]; P=0.3). Catheter retention was an independent predictor of mortality (OR 3.34 [95% CI 1.21 to 9.26]). CONCLUSIONS To the authors' knowledge, the present article describes the largest enterococcal CA-BSI series to date. Mortality was increased among patients who had their catheter retained. Additional prospective studies are necessary to determine the optimal management of enterococcal CA-BSI.

Multicentre study on peri- and postoperative central venous oxygen saturation in high-risk surgical patients

Introduction Low central venous oxygen saturation (ScvO2) has been associated with increased risk of postoperative complications in high-risk surgery. Whether this association is centre-specific or more generalisable is not known. The aim of this study was to assess the association between peri- and postoperative ScvO2 and outcome in high-risk surgical patients in a multicentre setting. Methods Three large European university hospitals (two in Finland, one in Switzerland) participated. In 60 patients with intra-abdominal surgery lasting more than 90 minutes, the presence of at least two of Shoemaker's criteria, and ASA (American Society of Anesthesiologists) class greater than 2, ScvO2 was determined preoperatively and at two hour intervals during the operation until 12 hours postoperatively. Hospital length of stay (LOS) mortality, and predefined postoperative complications were recorded. Results The age of the patients was 72 ± 10 years (mean ± standard deviation), and simplified acute physiology score (SAPS II) was 32 ± 12. Hospital LOS was 10.5 (8 to 14) days, and 28-day hospital mortality was 10.0%. Preoperative ScvO2 decreased from 77% ± 10% to 70% ± 11% (p < 0.001) immediately after surgery and remained unchanged 12 hours later. A total of 67 postoperative complications were recorded in 32 patients. After multivariate analysis, mean ScvO2 value (odds ratio [OR] 1.23 [95% confidence interval (CI) 1.01 to 1.50], p = 0.037), hospital LOS (OR 0.75 [95% CI 0.59 to 0.94], p = 0.012), and SAPS II (OR 0.90 [95% CI 0.82 to 0.99], p = 0.029) were independently associated with postoperative complications. The optimal value of mean ScvO2 to discriminate between patients who did or did not develop complications was 73% (sensitivity 72%, specificity 61%). Conclusion Low ScvO2 perioperatively is related to increased risk of postoperative complications in high-risk surgery. This warrants trials with goal-directed therapy using ScvO2 as a target in high-risk surgery patients.

Treatment for superficial infusion thrombophlebitis of the upper extremity.

BACKGROUND Although superficial thrombophlebitis of the upper extremity represents a frequent complication of intravenous catheters inserted into the peripheral veins of the forearm or hand, no consensus exists on the optimal management of this condition in clinical practice. OBJECTIVES To summarise the evidence from randomised clinical trials (RCTs) concerning the efficacy and safety of (topical, oral or parenteral) medical therapy of superficial thrombophlebitis of the upper extremity. SEARCH METHODS The Cochrane Vascular Group Trials Search Co-ordinator searched the Specialised Register (last searched April 2015) and the Cochrane Register of Studies (2015, Issue 3). Clinical trials registries were searched up to April 2015. SELECTION CRITERIA RCTs comparing any (topical, oral or parenteral) medical treatment to no intervention or placebo, or comparing two different medical interventions (e.g. a different variant scheme or regimen of the same intervention or a different pharmacological type of treatment). DATA COLLECTION AND ANALYSIS We extracted data on methodological quality, patient characteristics, interventions and outcomes, including improvement of signs and symptoms as the primary effectiveness outcome, and number of participants experiencing side effects of the study treatments as the primary safety outcome. MAIN RESULTS We identified 13 studies (917 participants). The evaluated treatment modalities consisted of a topical treatment (11 studies), an oral treatment (2 studies) and a parenteral treatment (2 studies). Seven studies used a placebo or no intervention control group, whereas all others also or solely compared active treatment groups. No study evaluated the effects of ice or the application of cold or hot bandages. Overall, the risk of bias in individual trials was moderate to high, although poor reporting hampered a full appreciation of the risk in most studies. The overall quality of the evidence for each of the outcomes varied from low to moderate mainly due to risk of bias and imprecision, with only single trials contributing to most comparisons. Data on primary outcomes improvement of signs and symptoms and side effects attributed to the study treatment could not be statistically pooled because of the between-study differences in comparisons, outcomes and type of instruments to measure outcomes.An array of topical treatments, such as heparinoid or diclofenac gels, improved pain compared to placebo or no intervention. Compared to placebo, oral non-steroidal anti-inflammatory drugs reduced signs and symptoms intensity. Safety issues were reported sparsely and were not available for some interventions, such as notoginseny creams, parenteral low-molecular-weight heparin or defibrotide. Although several trials reported on adverse events with topical heparinoid creams, Essaven gel or phlebolan versus control, the trials were underpowered to adequately measure any differences between treatment modalities. Where reported, adverse events with topical treatments consisted mainly of local allergic reactions. Only one study of 15 participants assessed thrombus extension and symptomatic venous thromboembolism with either oral non-steroidal anti-inflammatory drugs or low-molecular-weight heparin, and it reported no cases of either. No study reported on the development of suppurative phlebitis, catheter-related bloodstream infections or quality of life. AUTHORS' CONCLUSIONS The evidence about the treatment of acute infusion superficial thrombophlebitis is limited and of low quality. Data appear too preliminary to assess the effectiveness and safety of topical treatments, systemic anticoagulation or oral non-steroidal anti-inflammatory drugs.

Central and peripheral components of exercise-related fatigability in myotonic dystrophy type 1

Fatigue frequently occurs in myotonic dystrophy type 1 (DM1), but its pathophysiology remains unclear. This study assessed central and peripheral components of exercise-related fatigability in patients with DM1, compared to controls.

Central venous pulse pressure analysis using an R-synchronized pressure measurement system

Objective. The information derived from central venous catheters is underused. We developed an EKG-R synchronization and averaging system to obtained distinct CVP waveforms and analyzed components of these. Methods. Twenty-five paralyzed surgical patients undergoing CVP monitoring under mechanical ventilation were studied. CVP and EKG signals were analyzed employing our system, the mean CVP and CVP at end-diastole during expiration were compared, and CVP waveform components were measured using this system. Results. CVP waveforms were clearly visualized in all patients. They showed the a peak to be 1.8+/- 0.7 mmHg, which was the highest of three peaks, and the x trough to be lower than the y trough (-1.6+/- 0.7mmHgand-0.9+/- 0.5mmHg, respectively), withameanpulsepressureof3.4mmHg.ThedifferencebetweenthemeanCVPandCVPatend-diastoleduringexpirationwas0.58+/- 0.81 mmHg. Conclusions. The mean CVP can be used as an index of right ventricular preload in patients under mechanical ventilation with regular sinus rhythm. Our newly developed system is useful for clinical monitoring and for education in circulatory physiology.

Meperidine and skin surface warming additively reduce the shivering threshold: a volunteer study

INTRODUCTION: Mild therapeutic hypothermia has been shown to improve outcome for patients after cardiac arrest and may be beneficial for ischaemic stroke and myocardial ischaemia patients. However, in the awake patient, even a small decrease of core temperature provokes vigorous autonomic reactions-vasoconstriction and shivering-which both inhibit efficient core cooling. Meperidine and skin warming each linearly lower vasoconstriction and shivering thresholds. We tested whether a combination of skin warming and a medium dose of meperidine additively would reduce the shivering threshold to below 34 degrees C without producing significant sedation or respiratory depression. METHODS: Eight healthy volunteers participated on four study days: (1) control, (2) skin warming (with forced air and warming mattress), (3) meperidine (target plasma level: 0.9 mug/ml), and (4) skin warming plus meperidine (target plasma level: 0.9 mug/ml). Volunteers were cooled with 4 degrees C cold Ringer lactate infused over a central venous catheter (rate asymptotically equal to 2.4 degrees C/hour core temperature drop). Shivering threshold was identified by an increase of oxygen consumption (+20% of baseline). Sedation was assessed with the Observer's Assessment of Alertness/Sedation scale. RESULTS: Control shivering threshold was 35.5 degrees C +/- 0.2 degrees C. Skin warming reduced the shivering threshold to 34.9 degrees C +/- 0.5 degrees C (p = 0.01). Meperidine reduced the shivering threshold to 34.2 degrees C +/- 0.3 degrees C (p < 0.01). The combination of meperidine and skin warming reduced the shivering threshold to 33.8 degrees C +/- 0.2 degrees C (p < 0.01). There were no synergistic or antagonistic effects of meperidine and skin warming (p = 0.59). Only very mild sedation occurred on meperidine days. CONCLUSION: A combination of meperidine and skin surface warming reduced the shivering threshold to 33.8 degrees C +/- 0.2 degrees C via an additive interaction and produced only very mild sedation and no respiratory toxicity.

Postoperative sepsis in infants below 6 months of age

BACKGROUND: Sepsis is a threatening postoperative complication especially in small infants. Regarding the advances in perinatal medicine, its incidence is unknown to date. We aimed to investigate the incidence, risk factors, laboratory findings and outcome of postoperative sepsis in infants younger than 6 months old. METHODS: We examined postoperative sepsis in babies below 6 months of age during a 4-year period at a tertiary pediatric institution. RESULTS: The rate of postoperative sepsis was 6.9%. Laparotomy with enterotomy, thoracotomy and diaphragmatic hernia repair (P<0.05, respectively) as well as low postnatal age and long operation time (P<0.001, respectively) were correlated with the incidence of sepsis. Significant independent predictors for the development of sepsis were the presence of a central venous catheter and perioperative antibiotic treatment (P<0.001, respectively). Coagulase negative Staphylococci were the major infecting organism associated with postoperative sepsis, accounting for 53% of monomicrobial infections. Complete blood counts with differential were not different between infants with sepsis and controls, who had undergone the same surgical procedures. Outcome was favorable in all cases; however, the length of hospital stay was significantly longer in sepsis patients (P<0.05). CONCLUSIONS: Postoperative sepsis syndrome is a frequent complication in infants below 6 months of age and causes significant prolongation of hospital stay. Adequate prevention and therapeutic strategies warrant further prospective investigations.

When drugs disappear from the patient: elimination of intravenous medication by hemodiafiltration

Twenty-three hours after heart transplantation, life-threatening acute right heart failure was diagnosed in a patient requiring continuous venovenous hemodiafiltration (CVVHDF). Increasing doses of catecholamines, sedatives, and muscle relaxants administered through a central venous catheter were ineffective. However, a bolus of epinephrine injected through an alternative catheter provoked a hypertensive crisis. Thus, interference with the central venous infusion by the dialysis catheter was suspected. The catheters were changed, and hemodynamics stabilized at lower catecholamine doses. When the effects of IV drugs are inadequate in patients receiving CVVHDF, interference with adjacent catheters resulting in elimination of the drug by CVVHDF should be suspected.