Ultrasound-guided vascular access in critical illness.

Over the past two decades, ultrasound (US) has become widely accepted to guide safe and accurate insertion of vascular devices in critically ill patients. We emphasize central venous catheter insertion, given its broad application in critically ill patients, but also review the use of US for accessing peripheral veins, arteries, the medullary canal, and vessels for institution of extracorporeal life support. To ensure procedural safety and high cannulation success rates we recommend using a systematic protocolized approach for US-guided vascular access in elective clinical situations. A standardized approach minimizes variability in clinical practice, provides a framework for education and training, facilitates implementation, and enables quality analysis. This review will address the state of US-guided vascular access, including current practice and future directions.

[Cardiac herniation and torsion after transpericardial pneumonectomy]. / Herzluxation und Torsion nach erweiterter Pneumonektomie.

This article presents the case of a 43 year old woman with right-sided lung cancer. She underwent transpericardial pneumonectomy. After an uneventfull surgery, the patient was transferred to the intensive care unit for postoperative monitoring. She was hemodynamically stable and had already been extubated in the OR.On postoperative chest X­ray a mediastinal shift to the operated side as well as a herniation of the heart into the right chest cavity was detected. While the patient remained hemodynamically stable a computed tomography of the chest was performed which confirmed the diagnosis of cardiac herniation and torsion. The lady underwent rethoracotomy the following day where the heart was repositioned and the pericardial defect was closed. She made an uneventfull recovery.Five years after the pneumonectomy she remains well and is without relapse of lung cancer.Mechanism for cardiac herniation and torsion, the clinical presentation and the typical radiologic signs are discussed. However, the clue to early diagnosis is a high index of clinical suspicion.It is highlighted that a hemodynamically unstable patient under these circumstances demands urgent rethoracotomy.

[Sepsis masquerading as delirium]. / Listeriensepsis mit Leitsymptom Delir.

A previously healthy 60-year-old patient presented to the emergency department with severe headache, altered personality and fever. He was treated for bacterial meningitis with delirium of unknown cause but presumed to be due to alcohol withdrawal. Despite receiving the antibiotic therapy regimen recommended for bacterial meningitis the patient's condition rapidly deteriorated with profound delirium and tachypnea. The intensivist who was consulted immediately suspected sepsis-associated organ failure and admitted the patient to the intensive care unit (ICU). The blood culture was positive for Listeria. After 10 days the patient could be discharged from the ICU and ultimately recovered completely. In patients presenting with unexplained delirium or altered personality the suspicion of septic encephalopathy should always be considered. They should be admitted to the ICU and sepsis treatment should be initiated without delay.

Pre-procedure ultrasound increases the success and safety of central venous catheterization†.

BACKGROUND: Real-time ultrasound (US) in central venous catheterization is superior to pre-procedure US. However, moving real-time US into routine practice is impeded by its perceived expense and difficulty. Currently, pre-procedure US and landmark (LM) methods are most widely used. We investigated these techniques in internal jugular vein (IJV) catheterization in respect of operator experience, complications, and risk factors. METHODS: In an observational non-randomized study, we investigated 606 of ∼1300 procedures, that is, 200 patients were treated under pre-procedure US and 406 under LM [pathfinder (PF) n=202, direct cannulation (DC) n=204]. We recorded first needle pass success rate, success rate after the third attempt, and the cannulation time. Procedures were performed by inexperienced (<100) or experienced (>100 catheterizations) operators. RESULTS: Pre-procedure US was associated with more successful attempts and shorter cannulation times. Under pre-procedure US, 88% of first attempts were successful and 100% of third attempts. The median (range) cannulation time was 39 (10-330) s. Under PF, only 56% of first, and 87% of third, attempts were successful with a median (range) cannulation time of 100 (25-3600) s. Under DC, 61% of first and 89% of third attempts were successful; the median (range) cannulation time was 70 (10-3600) s. Remarkably, inexperienced operators using pre-procedure US (n=38) were significantly faster than experienced operators using PF or DC (n=343) (cannulation time: median 60 s, range 12-330, for inexperienced; 60 s, range 10-3600, for experienced). First puncture success rates were higher (pre-procedure US, inexperienced 84%, PF or DC, experienced 57%). CONCLUSIONS: Pre-procedure US for IJV catheterization is safe, quick, and superior to LM.

Bone cement embolism attached to central venous catheter.

We report on a rare complication of poly(methyl methacrylate) (PMMA), injected into the spine, which then inadvertently leaked into the venous system. This resulted in an embolism of PMMA and produced a mass surrounding a triple lumen central venous catheter located in the superior vena cava. The catheter as well as the attached mass of PMMA was retrieved safely by cardiothoracic surgery. This case emphasizes the importance of prompt diagnosis and treatment and illustrates the need for close monitoring of patients undergoing any spinal surgery that includes vertebroplasty.

Optimized method for correct left-sided central venous catheter placement under electrocardiographic guidance.

BACKGROUND: Central venous catheter (CVC) placement under ECG guidance in the left thoracocervical area can lead to catheter misplacement. The aim of this study was to identify the cause and quantify the magnitude of this error. METHODS: CVCs were sited in either the left or right internal jugular (IJ), subclavian (SC), or innominate (brachiocephalic) vein using the Seldinger technique and a total of 227 insertions were studied. The position of the catheter tip was confirmed with two different intra-atrial ECG monitoring methods (Seldinger's wire vs 10% saline solution). Measurements were compared between the two methods and correlated to the different access sites. RESULTS: All right-sided CVC had the line tip in the optimal position and both intra-atrial ECG recording by Seldinger's wire or 10% saline delivered correct results. For left-sided lines, however, the two methods gave significantly different results regarding the position of the line tip for each insertion site. When using the Seldinger wire as intravascular ECG lead, the results differed from the saline method by a mean of 21 mm for the IJ and 10 mm for the SC. CONCLUSIONS: CVC placement under ECG guidance is a reliable method to site the line tip at the optimal position. However, when using a left-sided thoracocervical access point, the Seldinger wire-conducted ECG delivered a constant error. This could be adjusted for by advancing the CVC 20 mm in addition to the wire-based measurement of the insertion depth at the left IJ vein and 10 mm at the left SC vein.

Risk of extravasation after power injection of contrast media via the proximal port of multilumen central venous catheters: case report and review of the literature.

PURPOSE: Multilumen central venous catheters (CVCs) are not commonly used for power injection. However, in critically ill patients, CVCs-- most of which do not have FDA approval for power injection--may be the only available venous access. MATERIALS AND METHODS: The pitfalls of multilumen CVCs are illustrated by a case report of a patient in whom extravasation of intravenously administered contrast medium occurred after power injection in a triple-lumen CVC using the lumen with the port furthest from the catheter tip. RESULTS: The underlying mechanisms for the displacement of the initially correctly placed right subclavian CVC could include elevation of both arms of the obese patient or the power injection itself. The distances between port openings and catheter tips of various commercially available multilumen CVCs are assessed. We examine the possible caveats of ECG-guided CVC placement for optimal tip position, discuss technical difficulties related to power injection via CVCs, and review commonly used drugs that may cause extravasation injury. CONCLUSION: Knowledge of the distances between CVC port openings and the catheter tip are essential for safe intravasal administration of fluids.

[Ultrasound guidance for placement control of central venous catheterization. Survey of 802 anesthesia departments for 2007 in Germany]. / Ultraschall und Lagekontrolle bei der Anlage zentraler Venenkatheter. Umfrage unter 802 Anästhesieabteilungen im Jahr 2007 in Deutschland.

OBJECTIVES AND METHODS: In 2007 a survey on the development of the current practice of using ultrasound to assist central venous catheter (CVC) placement was carried out in 802 departments of anesthesiology and intensive care medicine in hospitals with more than 200 beds in Germany. These data were compared to data from a survey in 2003. Additionally, data regarding control of CVC positioning were collected. RESULTS: The response rate was 58%. In these 468 departments approximately 340,000 CVCs are placed annually and 317 departments have access to an ultrasound machine. Ultrasound guidance is used by 188 (40%) departments for central venous cannulation. Of these only 24 (12.7%) use ultrasound routinely and 114 (60.6%) use it when faced with a difficult cannulation. Approximately one-third of the users perform continuous ultrasound guidance for CVC placement. Equipment was not at disposal in 115 (41.1%) departments not using ultrasound for CVC placement did not possess the equipment and 93 (33.2%) did not consider ultrasound necessary. Positioning of CVCs was controlled either by electrocardiogram (ECG) guidance and/or chest radiograph in 92%. CONCLUSION: In Germany placement of central venous catheters is still usually based on anatomical landmarks. However, compared to 2003, ultrasound guidance for CVC placement is gradually being introduced (40% compared to 19%). Given the well-documented advantages of ultrasound guidance compared to landmark based approaches for central venous cannulation, acquisition of this technology should belong to the training programme of an anesthesiologist.

[Central venous pressure. Validity, informative value and correct measurement]. / Zentraler Venendruck. Validität, Aussagekraft und korrekte Messung.

The trends in central venous pressure (CVP) are more informative than the isolated values. The CVP should always be evaluated in the context of the patient's clinical condition. It indicates the relationship between circulating blood volume and the capacity of the heart at a given time. In the ideal situation CVP reflects cardiac preload and there are many variables that influence its numerical value as well as its interpretation. The CVP is a meaningful parameter if it is measured correctly. For accurate measurement the transducer must be zeroed and leveled to a correct external reference level for the right atrium. Only a CVP measured at the end of expiration can be compared on condition that the catheter is placed correctly in the central venous system.

Influence of systolic-pressure-variation-guided intraoperative fluid management on organ function and oxygen transport.

BACKGROUND: Dynamic variables, for example, systolic pressure variation (SPV), are superior to filling pressures for assessing fluid responsiveness. We analysed the effects of SPV-guided intraoperative fluid management on organ function and perfusion when compared with routine care. METHODS: Eighty patients (44 female and 36 male) undergoing elective major abdominal surgery were randomly assigned to a control group [n=40, mean age 66 (sd 10), range 40-84 yr] or SPV group [n=40, age 61 (16), range 26-100 yr] in which intraoperative fluid management was guided by SPV (trigger: SPV>10%). Central venous O2 saturation (ScvO2), lactate and bilirubin, creatinine, indocyanine green plasma disappearance rate (ICG-PDR), and gastric mucosal CO(2) tension were measured after induction of anaesthesia, after 3, 6, 12, and 24 h. RESULTS: Patient characteristics, duration of surgery [5.8 (2.5) vs 5.4 (2.5) h], and infusion volumes (median 4865 vs 4330 ml) were comparable between the groups. At 3 and 6 h, SPV (P=0.04, P=0.01) and Deltadown (P=0.005, P=0.01) were significantly higher in the control group. Oxygen transport and organ function were comparable: baseline and 24 h values for ICG-PDR: 28.5 (7.9) and 22.7 (7.8) vs 23.9 (6.9) and 26.1 (5.9)% min(-1), 77.7 (6.6) and 72.6 (5.5) vs 79.3 (7.1) and 72.8 (6.7)% for ScvO2 and 1.0 (0.4) and 1.2 (0.6) vs 0.9 (0.2) and 1.3 (0.5) mmol litre(-1) for lactate. Length of mechanical ventilation, ICU stay, and mortality were comparable. CONCLUSIONS: In comparison with routine care, intraoperative SPV-guided treatment was associated with slightly increased fluid adminstration whereas organ perfusion and function was similar.

Detection of tracheal malpositioning of nasogastric tubes using endotracheal cuff pressure measurement.

BACKGROUND: Insertion of a gastric tube (GT) in anaesthetized, paralyzed and intubated patients may be difficult. Tracheobronchial malposition of a GT may result in deleterious consequences. The purpose of this study was to determine the reliability of tracheal cuff pressure measurement to detect endobronchial malposition of GTs. We compared this new method with the measurement of exhaled CO(2) through the GT. METHODS: Thirty patients under general anesthesia and orotracheal intubation were analysed. First, the cuff pressure of the low-volume endotracheal tube (ET; ID 7.0-8.5 mm) was increased to 40 cmH(2)O. Then, in a randomized fashion, the GT (18 Charrière) was inserted consecutively into the trachea and oesophagus or vice versa. Cuff pressure was monitored continuously while advancing the GT. Furthermore, a capnograph was connected to the gastric tube and the aspirated PCO(2) was monitored. RESULTS: Advancement of the gastric tube into the oesophagus increased ET cuff pressure by 1 +/- 1 cmH(2)O, while endotracheal placement of the GT increased cuff pressure by 28 +/- 8 cmH(2)O (P < 0.001). Using an increase of >10 cmH(2)O in cuff pressure detected endotracheal malpositioning of the GT with 100% sensitivity and specificity. In 28 out of 30 cases, PCO(2) increased by more than 2.6 kPa. Thus, the PCO(2) approach failed to detect tracheal malpositioning in two cases resulting in a sensitivity of 93.3%. CONCLUSIONS: In intubated patients, cuff pressure measurement during insertion of a gastric tube is a new, simple and reliable bedside method to detect endotracheal malpositioning of a GT.

[Tracheal agenesis. A rare cause of respiratory insufficiency in neonates]. / Trachealagenesie. Eine seltene Ursache der respiratorischen Insuffizienz des Neugeborenen.

Tracheal agenesis is a very rare congenital anomaly that occurs isolated or in combination with other anomalies. It presents immediately after birth with an absolute respiratory insufficiency and lack of crying. The immediate precise anatomical classification of the anomaly is crucial in order to decide if surgical therapy is possible. This report describes a newborn boy with tracheal agenesis type II. The diagnosis was confirmed by spiral computed tomography and a selection of the pictures is presented. The treatment was discontinued due to a lack of therapeutical options. Based on this case report we discuss the special situation of this rare anomaly. Interesting information on tracheal agenesis was gathered, the differential diagnosis of respiratory insufficiency of the newborn is summarised and a modified algorithm of the current newborn resuscitation guidelines of the American Heart Association is presented.

[Modified ECG-guidance for optimal central venous catheter tip positioning. A transesophageal echocardiography controlled study]. / Optimierte Positionierung zentraler Venenkatheter durch eine modifizierte Anwendung der intravasalen Elektrokardiographie. Validierung mithilfe der transösophagealen Echokardiographie.

BACKGROUND: Intraatrial electrocardiography (ECG) is a well-established method for central-venous catheter (CVC) placement and an intraatrial position is assumed, when a significantly increased P-wave is registered. However, an increase in P-wave amplitude also occurs in other positions. Therefore we evaluated CVC tip positioning by means of transesophageal echocardiography (TEE) at a maximum P-wave amplitude. PATIENTS AND METHODS: In this prospective randomized study the right or left internal jugular vein was cannulated with 100 patients in each group and catheter tip positioning was guided by means of ECG. The catheter was fixed at the position of maximum P-wave amplitude and the insertion depth was registered. The relationship of the CVC tip position to the superior edge of the crista terminalis was demonstrated with the help of TEE. RESULTS: In all patients the catheter tip was found +/- 0.5 cm from the superior edge of the crista terminalis at the transition from the superior vena cava to the right atrium. On x-ray control, all catheters ran along the length of the vessel wall of the superior vena cava. CONCLUSIONS: A maximum P-wave is derived even at the entrance to the right atrium. This explains why ECG-guided CVC placement -- based on the largest P-wave amplitude -- consistently resulted in correct positioning of the CVC tip at the transition from the superior vena cava to the right atrium.

The influence of the Univent endotracheal tube on internal jugular vein cannulation.

This prospective clinical investigation assessed the effect of placement of a Univent tube on the anatomy of the internal jugular veins and the success of cannulation of the left internal jugular vein. After obtaining informed consent, 48 adult patients were enrolled. Of these, 42 patients were eligible and were divided into two groups: Univent tube (group U, n=21) and wire enforced endotracheal tube (group C, n=21). The Univent tube group were having a left thoracotomy. Using horizontal ultrasound scans just above the thyroid gland, the internal jugular vein was visualized and measured before and after Univent placement. The number of needle passes necessary to cannulate the left internal jugular vein in the two groups was also compared. Univent tubes were associated with lateral displacement of the right carotid artery and internal jugular vein on the convex side of the Univent tube, with compression of the right internal jugular vein by the artery, resulting in a kidney-shaped cross-section of the vein. On the left (concave side of the tube), the neck was indented, the sheath of the left carotid artery was displaced medially, and the left internal jugular vein distorted to an ellipse. There was a significant increase in the lateral diameter and a decrease in the cross-sectional area of the left internal jugular vein (t-test, P < 0.05). The first attempt at cannulation of the left internal jugular vein failed significantly more often in the Univent group (13/21 vs 5/21 in group C, Chi-square 6.22, P=0.025). Cannulation of the internal jugular vein before placement of the Univent tube, or placement with ultrasound guidance is suggested.

[Extravasal position of central venous catheters despite unsuspicious ECG-guidance]. / Extravasale Lage von zentralen Venenkathetern bei korrekter EKG-Ableitung.

OBJECTIVE: Does the electrocardiographic method for central venous catheter positioning distinguish between a correct intravasal and a malpositioned extravasal position? METHODS: 24 cardiac surgical patients were enrolled in this prospective observational study. In 18 patients the left, in another 6 patients the right internal jugular vein was cannulated. Using a J-wire within a triple-lumen catheter the amplitude of the P-wave was measured at 3 different intravasal sites: Intra-1: (intravasal baseline electrocardiogram), i. e. 10 cm marking of the catheter on skin level; Intra-2: clear rise of the P-wave amplitude upon further insertion of the catheter; Intra-3: maximum P-wave amplitude. At this position the control of the catheter tip was achieved by means of transoesophageal echocardiography (TOE). Intraoperatively, another J-wire within a triple-lumen catheter was placed by the heart surgeon on 3 extravasal sites and the ECG was recorded: Extra-1: extravasal at the left innominate vein above the pericardial reflection; Extra-2: extravasal on the superior vena cava below the pericardial reflection; Extra-A: extravasal on ascending aorta below the pericardial reflection. The catheter was suture fixed with its tip in position Intra-3. Post surgery a chest radiograph was taken. RESULTS: All catheter tips were visualised at the basis of the Crista terminals (border between right atrium and superior vena cava) by TOE control. The rise of the P wave amplitude at Intra-2, Extra-2 and Extra-A was highly significant compared to the base line at Intra-1 (Intra-1/Intra-2, Intra-1/Extra-2, Intra-1/Extra-A: p in each case < 0.001). The P wave amplitudes of the corresponding intra- and extravasal positions of the left innominate vein (Intra-1/Extra-1, n = 18, p = 0.096)) as well as those of the superior vena cava (Intra-2/Extra-2, n = 24, p = 0.859) did not differ. CONCLUSION: The electrocardiographic method can not differentiate between intra- and extravasal position of a central venous catheter, and thus, presumably fails to identify malpositioning as a result of vascular perforation.