Central venous catheter tip migration due to tracheal extubation: a prospective randomized study.

Considerable numbers of patients undergo central venous catheterization (CVC) under mechanical ventilation. We hypothesized that the return of spontaneous breathing and tracheal extubation could be associated with distal CVC tip migration towards intracardiac positions due to decreasing intrathoracic pressures and subsequent readjustment of mediastinal organs. Patients scheduled for cardiac surgery were randomized for right or left internal jugular vein (IJV) CVC placement under general anesthesia and mechanical ventilation. CVC tips were positioned at the cavoatrial junction and measured at the time of placement, postoperatively under mechanical ventilation, and after tracheal extubation until 48 h after surgery. Measurement methods included intravascular electrocardiography (ECG) P-wave amplitude, transesophageal echocardiography, and chest radiography (CXR). Out of 70 patients, 60 were eligible for final statistical analysis (31 right and 29 left IJV CVC). According to ECG interpretation, CVC tip positions remained below the pericardiac reflection point in the distal superior vena cava over the course of the three measurement intervals. The ECG revealed significant proximal migration of CVC tips from the time of placement to the time of tracheal extubation (1.19 ± 0.55 vs. 0.62 ± 0.31 mV; P < 0.001). A CXR using CVC tip to carina distances revealed no significant tip migrations in the time between postoperative assessment and following tracheal extubation (5.1 ± 1.7 vs. 5.3 ± 1.5 cm; P = 0.196). In patients with CVCs positioned at the cavoatrial junction, tracheal extubation was not associated with significant postoperative CVC tip malposition, but tended to undergo proximal migration. This trend should be considered particularly in left-sided thoracocervical puncture approaches to avoid unfavorable CVC tip positions.

Different mechanical properties in Seldinger guide wires.

BACKGROUND AND AIMS: Most central venous catheters are placed using Seldinger guide wires. EN ISO 11070 is the guideline for testing guide wire flexing performance and tensile strength, and we can safely assume that guide wires in use meet these requirements. Unfortunately, EN ISO 11070 guidelines do not reflect the clinical requirements and we continue to see mechanical failures and their associated complications. MATERIAL AND METHODS: This in vitro study was performed in an accredited laboratory. With regard to flexing, we: (1) Established the minimum flexing performance needed to meet clinical requirements, (2) developed flexing performance tests which mimic clinical requirement, and (3) evaluated the mechanical properties of various guide wires relative to these requirements. With regard to tensile strength, we used the testing method prescribed in ISO 11070, but did not end the test at 5 Newton (N). We continued until the guide wire was damaged, or we reached maximum tractive force. We then did a wire-to-wire comparison. We examined two basic wire constructions, monofil and core and coil. RESULTS: Tensile strength: All wires tested, except one, met EN ISO 11070 requirements for 5 N tensile strength. The mean of the wire types tested ranged from 15.06 N to 257.76 N. Flexing performance: None of the wires kinked. The monofil had no evidence of bending. Two core/coil wires displayed minor bending (angle 1.5°). All other wires displayed bending angles between 22.5° and 43.0°. CONCLUSION: We recommend that: (1) Clinicians use guide wires with high-end mechanical properties, (2) EN ISO 11070 incorporate our flexing test into their testing method, raise the flexing requirement to kink-proof, (3) and raise the tensile strength requirement to a minimum of 30 N, and (3) all manufacturers and suppliers be required to display mechanical properties of all guide wire, and guide wire kits sold.

Effectiveness of different central venous catheter fixation suture techniques: An in vitro crossover study.

PURPOSE: Proper fixation of central venous catheters (CVCs) is an integral part of safety to avoid dislodgement and malfunction. However, the effectiveness of different CVC securement sutures is unknown. METHODS: Analysis of maximum dislodgement forces for CVCs from three different manufacturers using four different suture techniques in an in vitro tensile loading experiment: 1. "clamp only", 2. "clamp and compression suture", 3. "finger trap" and 4. "complete", i.e., "clamp + compression suture + finger trap". Twenty-five tests were performed for each of the three CVC models and four securement suture techniques (n = 300 test runs). RESULTS: The primary cause of catheter dislodgement was sliding through the clamp in techniques 1 and 2. In contrast, rupture of the suture was the predominant cause for dislodgement in techniques 2 and 3. Median (IQR 25-75%) dislodgement forces were 26.0 (16.6) N in technique 1, 26.5 (18.8) N in technique 2, 76.7 (18.7) N in technique 3, and 84.8 (11.8) N in technique 4. Post-hoc analysis demonstrated significant differences (P < .001) between all pairwise combinations of techniques except technique 1 vs. 2 (P = .98). CONCLUSIONS: "Finger trap" fixation at the segmentation site considerably increases forces required for dislodgement compared to clamp-based approaches.

Is traditional reading of the bedside chest radiograph appropriate to detect intraatrial central venous catheter position?

BACKGROUND: Traditionally, the positioning of central venous catheters (CVCs) outside the right atrium (RA) in patients receiving intensive care is determined by surrogate landmarks on bedside chest radiographs (CXRs). The validity of this method was examined by comparing readings of radiologists with the results of transesophageal echocardiography (TEE). METHODS: Prospective study at university hospital. Two hundred thirteen adults scheduled for cardiothoracic surgery were randomized to right or left internal jugular vein catheterization under ECG guidance. One senior radiologist and two radiologists in training independently read the CXRs, and determined whether the CVC tip ended in the RA and measured the vertical distance from the CVC tip to the carina (TC-distance). RESULTS: Two hundred twelve CVC tips could be identified by TEE. Only left-sided CVCs (n = 5) ended in the upper RA (2.4%). Three of those patients were shorter than 160 cm. Specificity was 94% for senior radiologist, 44% for the first radiologist in training, and 60% for the second radiologist in training. The TC-distance of intraatrial catheters was 39, 55, 59, 80, and 83 mm, respectively. Thus, a TC-distance < or = 55 mm ensured extraatrial tip position in four of five intraatrial CVCs (80%, p = 0.002). The TC-distance of extraatrial catheters ranged from - 26 to 102 mm. CONCLUSIONS: Reading of a bedside CXR alone is not very accurate to identify intraatrial CVC tip position. TC-distance is a helpful marker, and its specificity is as good as that of an experienced radiologist if a cutoff value of 55 mm is chosen.

The pivotal role of vasopressin in refractory anaphylactic shock.

BACKGROUND: Severe anaphylaxis can be associated with cardiovascular collapse that is difficult to manage and does not respond to treatment with epinephrine. Because anaphylaxis is uncommon, unpredictable and may be fatal, a prospective, randomized, controlled trial in humans on the best management is difficult and guidelines are based on theory and anecdotes only. METHODS AND RESULTS: We report six cases in which the use of vasopressin was successful in the treatment of anaphylactic shock. CONCLUSIONS: Standard treatment of anaphylactic shock, including discontinuation of the causative agent, administration of epinephrine, and infusion of IV fluids, did not stabilize cardiocirculatory function, and adding arginine vasopressors resulted in prompt hemodynamic stabilization.

Prospective clinical evaluation of a new manometer syringe that distinguishes pressures below 30 and above 50 mmHg.

STUDY OBJECTIVE: To evaluate a new disposable syringe (Certofix PresSure Check [B Braun Melsungen AG, Melsungen, Germany]) that serves as a manometer. DESIGN: Prospective study. SETTING: University hospital's cardiac surgery suite. PATIENTS: 21 consecutive patients with continuous invasive monitoring of central venous and arterial pressures during cardiothoracic surgery. INTERVENTIONS AND MEASUREMENTS: The Certofix PresSure Check syringe was connected to the side port of the central venous and arterial catheters. RESULTS: Central venous pressures were correctly indicated as below 30 mmHg and arterial pressures as above 50 mmHg in all 21 patients. CONCLUSIONS: Certofix PresSure Check provides a unique way of testing whether a catheter is placed in a low or high pressure system. It can be used for identifying inadvertent arterial punctures.

Central venous catheterization for acute trauma resuscitation: Tip position analysis using routine emergency computed tomography.

PURPOSE: Central venous catheter insertion for acute trauma resuscitation may be associated with mechanical complications, but studies on the exact central venous catheter tip positions are not available. The goal of the study was to analyze central venous catheter tip positions using routine emergency computed tomography. METHODS: Consecutive acute multiple trauma patients requiring large-bore thoracocervical central venous catheters in the resuscitation room of a university hospital were enrolled retrospectively from 2010 to 2015. Patients who received a routine emergency chest computed tomography were analyzed regarding central venous catheter tip position. The central venous catheter tip position was defined as correct if the catheter tip was placed less than 1 cm inside the right atrium relative to the cavoatrial junction, and the simultaneous angle of the central venous catheter tip compared with the lateral border of the superior vena cava was below 40°. RESULTS: During the 6-year study period, 97 patients were analyzed for the central venous catheter tip position in computed tomography. Malpositions were observed in 29 patients (29.9%). Patients with malpositioned central venous catheters presented with a higher rate of shock (systolic blood pressure <90 mmHg) at admission (58.6% vs 33.8%, p = 0.023) and a higher mean injury severity score (38.5 ± 15.7 vs 31.6 ± 11.8, p = 0.041) compared with patients with correctly positioned central venous catheter tips. Logistic regression revealed injury severity score as a significant predictor for central venous catheter malposition (odds ratio = 1.039, 95% confidence interval = 1.005-1.074, p = 0.024). CONCLUSION: Multiple trauma patients who underwent emergency central venous catheter placement by experienced anesthetists presented with considerable tip malposition in computed tomography, which was significantly associated with a higher injury severity.

Mechanical complications and malpositions of central venous cannulations by experienced operators. A prospective study of 1794 catheterizations in critically ill patients.

OBJECTIVE: Incidence of primary mechanical complications and malpositions associated with landmark-guided central venous access procedures (CVAP) performed by experienced operators. DESIGN: Prospective 5-year observational study on two intensive care units. INTERVENTION: Only CVAPs using Seldinger technique were evaluated. Age, gender, puncture site, number of cannulation attempts, and complications within 24 hours and malpositions were recorded. PATIENTS: 782 CVAPs in females aged 9-92 yrs and 1012 CVAPs in males aged 6-89 yrs. RESULTS: We analyzed 1794 (1017 right- and 777 left-sided CVAP), of which 87.7% were accomplished without adverse events. More than one cannulation attempt was a risk factor for failed catheterization, other mechanical complications but not for malposition. Complications/malpositions were encountered in 220 CVAPs.In 51 CVAPs (2.8%) the cannulation failed at the attempted site, here 18 CVAPs were accompanied by further complications (35.3%). Otherwise, the rate for mechanical complications was low (3.3%). The most common mechanical complications (n = 127) were arterial punctures (n = 52; 2.9%), including four arterial cannulations (0.2%), and pneumothorax (n = 9; 0.6%). There was significant risk for arterial puncture with the internal jugular vein approach in comparison to the innominate vein (p = 0.004), but not to the subclavian vein (p = 0.065). Male patients had a lower risk for failure (2.1%) than females (3.8%, p = 0.028). One-hundred-twenty-one central venous catheters were malpositioned (6.7%) of which 35 were related to the left internal jugular vein. CONCLUSIONS: Even experienced operators cause a considerable number of early mechanical complications and malpositions. After two unsuccessful cannulation attempts failure and associated complications are very likely.

Ultrasound-guided central venous cannulation: is there a difference between Doppler and B-mode ultrasound?

STUDY OBJECTIVE: To compare the success of Doppler and B-mode ultrasound-guided internal jugular vein (IJV) catheterization with respect to body mass index (BMI). STUDY DESIGN: Prospective, randomized study. SETTING: Section for cardiovascular anesthesia of a university hospital. PATIENTS: 338 consenting patients were analyzed. INTERVENTIONS: Subjects receiving central venous catheters for scheduled cardiac surgery were divided into two groups. After induction of general anesthesia, the right or left IJV was assessed for midcervical cannulation approach. In the Doppler group (n = 189), a SonoGuide2 with a 5.0-MHz probe was used. In the B-mode group (n = 149), the SiteRite II ultrasound system with a 7.5-MHz transducer was used. MEASUREMENTS AND MAIN RESULTS: There was a significant difference in the success rate of first needle pass between the two groups: Doppler group, 91% (172/189); B-mode group, 96.6% (144/149) (P = 0.045). A BMI of 30 and greater was associated with a significantly lower first needle pass success rate in the Doppler group (Doppler group, 77.1% [27/35]; B-mode group, 97.4% [38/39]; P = 0.011). The success rates in patients with a BMI below 30 for both methods were not different (Doppler group, 94.2% [145/154]; B-mode group, 96.4% [106/110]; P = 0.567). Arterial punctures occurred three times under Doppler guidance and twice under B-mode guidance. CONCLUSION: Cannulation of the IJV can be ensured and first needle pass success rate maximized by both ultrasound techniques. In patients with a BMI greater than 30, B-mode technique is superior to Doppler ultrasound.

Formulas for prediction of insertion depths of internal jugular vein catheters adjusted to body height categories.

PURPOSE: Whether formulas for prediction of central venous catheter (CVC) insertion depths have different applicability in patients with different body heights is not known. Goal of study was to test formulas for catheterizations of internal jugular veins (IJVs) in a population of different body height classes with correct CVC tip positions. METHODS: Consecutive adult patients requiring CVC for cardiac surgery were enrolled and those with tip positions at the junction of the superior vena cava and the right atrium ±1 cm underwent formula analysis. Precision of formula prediction was calculated for three classes of body height. RESULTS: Of the 635 included patients, 254 underwent right IJV catheterization and 381 underwent left IJV catheterization, respectively. Formula-guided approach for both right [formulas (height/10) (in cm) and (height/10) -1 (in cm)] and left [formula (height/10) + 4 (in cm)] IJV CVC was more precise in patients with a body height of 170-180 cm compared with patients with a body height <170 cm (who required deeper insertion than predicted by formula) and patients with a body height >180 cm (who required a more proximal insertion than predicted by formula). CONCLUSIONS: Independent from body height classes, all formulas calculated a relatively low likelihood of atrial positions but high risks of proximal mal-positioning. Thus, considering inter-individual differences of vascular anatomy and for safety reasons, formulas cannot be recommended.

Cerebral venous flow velocity predicts poor outcome in subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Predictors of clinical outcome in aneurysmal subarachnoid hemorrhage (SAH) vary in reliability. Measurement of cerebral venous hemodynamics by transcranial color-coded duplexsonography (TCCS) has become of increasing interest lately, and correlation with intracranial pressure (ICP) seems to be high. The aim of the presented study was to assess changes of cerebral venous hemodynamics in SAH and evaluate its relationship with clinical outcome. METHODS: We performed sequential TCCS of venous peak flow velocities (vp-FVs) in the transversal sinus in 28 consecutive patients with aneurysmal SAH (Hunt and Hess scale 1 to 5). Measurement was initiated at onset of arterial vasospasm up to 5 days after SAH. All patients had a continuous ICP monitoring. Clinical outcome was evaluated with the modified ranking scale (MRS) 30 days after SAH. Patients were divided according to outcome: group I good recovery (MRS 0-III) and group II poor outcome (death or MRS IV-V). Maximum vp-FV, time-averaged vp-FV (mv-FV), and ICP were compared between groups. RESULTS: Vp-FV and mv-FV as well as ICP of group II exceeded values of group I (P<0.001 for all 3 parameters). Vp-FV showed a positive correlation with ICP (r=0.63; P<0.001). A vp-FV exceeding 35.4 cm/s (sensitivity 100%; specificity 90.9%), an mv-FV exceeding 27.3 cm/s (sensitivity 94.1%; specificity 81.8%), and an ICP exceeding 24 mm Hg (sensitivity 87.5%; specificity 81.8%) predicted poor outcome (receiver operating characteristic analysis). CONCLUSIONS: Increased ICP values correlate with increased venous flow velocities. In SAH, increased ICP and increased venous flow velocities are associated with poor outcome. Flow velocity of the transversal sinus is a highly sensitive, reliable, and early predictor of outcome in SAH.

Doppler-guided cannulation of internal jugular vein, subclavian vein and innominate (brachiocephalic) vein--a case-control comparison in patients with reduced and normal intracranial compliance.

OBJECTIVE: A case-control comparison of Doppler guidance on the success rate of central venous cannulation in patients with normal or reduced intracranial compliance. DESIGN: A single operator performed central venous access procedures with continuous wave Doppler guidance. It was used on patients on a ventilator. The position of patients with reduced intracranial compliance (RIC) was not changed for the procedure. Patients with normal intracranial compliance (NIC) were put in the Trendelenburg position. SETTING: We prospectively evaluated 249 Doppler-guided central venous access procedures performed over a 12-month period at our 10-bed neuro-intensive care unit at a university hospital. PATIENTS AND PARTICIPANTS: The group with RIC included 26 males and 35 females (n=61) aged 16-79 years. In this group 155 Doppler-guided cannulation procedures (62%) were performed. The group with NIC (n=52) comprised 29 males and 23 females aged 34-76 years; 94 Doppler-guided cannulation procedures (38%) were carried out. MEASUREMENTS AND RESULTS: The veins cannulated in RIC and NIC, respectively, were: right innominate vein: 24/18, left innominate vein 26/12, right subclavian vein 12/7, left subclavian vein 25/14, and right internal jugular vein 33/18 and left internal jugular vein 35/24. The absence of one left internal jugular vein was identified in the NIC group. The success rate of first needle pass in patients with RIC was 92% and in patients with NIC 89%. CONCLUSIONS: This study showed that Doppler guidance allows the cannulation of central veins in patients with RIC placed in head-up position. Cannulation can be ensured and first-pass needle placement maximised.

Toxic epidermal necrolysis after phenytoin usage in a brain trauma patient.

Toxic epidermal necrolysis is a drug-induced, rare, but life-threatening skin eruption. The main differential diagnoses are drug-induced erythema (hypersensitivity syndrome), acute graft-versus-host disease, staphylococcal scalded skin syndrome, and toxic shock syndrome. Because the therapy for toxic epidermal necrolysis and acute graft-versus-host disease differs largely from the others, it is necessary to make an accurate diagnosis. In addition to a detailed medical history, skin biopsy is mandatory because the skin eruptions are not always unequivocal. Discontinuation of the causing agent is crucial, and treatment in specialized intensive care units or burn units is supportive. Currently there is no specific treatment for toxic epidermal necrolysis. Advantages from corticosteroids, plasmapheresis, intravenous immunoglobulin, cyclophosphamide, cyclosporin, and N-acetylcysteine still remain to be established by controlled trials, or have failed to prove a benefit (thalidomide). The patient presented here demonstrates the difficulties in diagnosing toxic epidermal necrolysis in a critically ill patient. A short overview of the pathogenesis and the management of toxic epidermal necrolysis is provided.

Unrecognized internal jugular vein obstruction: cause of fatal intracranial hypertension after tracheostomy?

We report an unusual case of fatal intracranial hypertension following tracheostomy due to the obstruction of the internal jugular veins (left side: thrombosis after central venous cannulation, right side: hypoplastic vein) and their collaterals. Principal cerebral outflow through the internal jugular veins can be substituted by the internal and external vertebral vein plexus because blood drains from the brain by two major routes: the internal jugular veins and the vertebral venous plexus. We suggest transcranial color-coded duplex sonography as a simple bedside method to detect patients with significant reduction of venous drainage who are at risk of developing massive cerebral venous congestion as a result of reduced intracranial elastance.

Persistent left superior vena cava: clinical implications for central venous cannulation.

In general, persistence of the left superior vena cava (LSVC), the most common anomaly of the venous circulation, is asymptomatic. Diagnosis of a catheter in a persistent LSVC is not straight forward, and a LSVC can create difficulties during central venous and pulmonary artery catheterization. We discuss the differential diagnosis of left-sided central venous catheters (CVC). Finally a directive is given to prevent dilator-induced vessel injuries. We report the cannulation of an unsuspected persistent LSVC in two patients. A dilator-induced vessel injury contributed significantly to the fatal outcome in the first case. On a plain chest X-ray, a catheter in a LSVC will run down the left mediastinal border and can be confused with other intravascular malpositions and extravascular malpositions. Contrast-enhanced lateral chest radiograph is an inexpensive and readily available method that can be used to determine exact position.

Expect the unexpected: malposition of a large-bore central venous catheter in the urinary bladder.

We report the case of a femoral vein cannulation in a critically ill trauma patient with the malposition of a large-bore central venous catheter in the urinary bladder. Recognition of the malposition was hampered by bloody tamponade of the bladder in the context of blunt thoraco-abdominal trauma with kidney and liver laceration. A high index of clinical suspicion and the institution of adequate therapy were the key to achieving a successful clinical outcome. We discuss the anatomy of femoral veins, including their close relation to a distended bladder. The application of ultrasound even in emergency situations is stressed.