Persistent left superior vena cava identified after cannulation of the right subclavian vein

IMPLICATIONS: We report the case of a patient with a chest radiograph suggestive of intraarterial placement of a central venous catheter. On investigation, the catheter was located in a previously undiagnosed persistent left superior vena cava.     

Assessing the Approach to a Thrombosed AV Graft

The patency of the vascular access (VA) is a fight for the attending nephrologist. A retrospective observational study was conducted to compare the success rate of surgical versus endovascular technique percutaneous transluminal angioplasty (PTA) for graft thrombosis treatment. Of 3008 patients, 22.1% patients were dialyzed through grafts. Forty‐five percent of all prevalent patients referred due to VA malfunction had a graft. For 18 months, 336 thrombosed grafts were submitted to surgery in 228 cases and to PTA in 126. PTA for thrombolysis included the Pharmaco‐Mechanical Technique and the Arrow‐Trerotola Device. Procedures were performed as outpatient, with an average delay of 1 day. Immediate success was 100% for surgery and 87.3% for PTA. The unassisted patency for thrombosed grafts for surgery/PTAwas 265.12 ± 15.30/230.59 ± 19.83 days respectively, favoring surgery. The primary patency for thrombosed grafts treated by surgery/PTA at 30, 90, and 180 days was, respectively, 74.1%/81%, 63.2%/67.5%, and 53.9%/55.6% all in favor of PTA. AV grafts have a much higher rate of thrombosis than fistulas. Graft thrombosis can be dealt either by surgery or PTA, with identical success.     

An evaluation of a new continuous blood pressure monitoring system in critically ill patients

STUDY OBJECTIVE: To determine if the DxTek monitor, which is a device that measures blood pressure (BP) noninvasively and continuously by means of pulse velocity and wave shapes derived from the pulse oximeter optical plethysmograph and electrocardiogram is as accurate as an oscillometric cuff device when compared with intraarterial BP measurement. DESIGN: Prospective, comparative study. SETTING: University Medical Center. PATIENTS: 28 intensive care unit patients. INTERVENTIONS: Blood pressures were reported every minute by intraarterial catheters and DxTek and every 10 minutes by an oscillometric monitor for 2 to 5 hours. DxTek calibration was performed initially and when specified patient manipulations by caretakers were performed (on average, every 100 minutes). Comparisons with intraarterial pressure included: 1) DxTek calibrated with arterial catheter pressure, 2) DxTek calibrated with oscillometric pressure, and 3) oscillometric pressure. MEASUREMENTS AND MAIN RESULTS: When comparing oscillometric pressure to intraarterial pressure, the averages of the mean differences (bias) were -4.0 mmHg for systolic (SBP) and < 1.5 mmHg for diastolic (DBP) and mean (MAP) pressures. The averages of the standard deviation of the differences (precisions) were 9.6, 6.4, and 6.3 mmHg, respectively. With the DxTek device calibrated to intraarterial pressure, comparison of the DxTek pressure to intraarterial pressure resulted in a bias < OR = 0.5 mmHg for all three pressures and an average precision of 10.1 mmHg for SBP, 6.0 mmHg for DBP, and 6.7 mmHg for MAP. With the DxTek device calibrated to the oscillometric pressure, the DxTek pressure compared to the intraarterial pressure resulted in average biases of -5.1, -0.8, and -2.2 mmHg and average precisions of 11.1, 7.7, and 8.1 mmHg for SBP, DBP, and MAP, respectively. CONCLUSIONS: The DxTek monitor provides continuous, noninvasive BP measurements with an accuracy comparable to oscillometric devices.     

Corynebacterium jeikeium native valve endocarditis following femoral access for coronary angiography.

We present a unique case of rapidly fatal native aortic-valve endocarditis due to Corynebacterium jeikeium, with inoculation as a complication of repeated femoral vascular access for coronary angiography.     

Mechanical Ventilation by EsophagealPressure Guided in Acute Lung Injury

Background：Survival of patients with acute lung injury or the acute respiratory distress syndrome （ARDS） has been improved by ventilation with small tidal volumes and the use of positive end-expiratory pressure （PEEP）; however, the optimal level of PEEP has been difficult to determine. In this pilot study, we estimated transpulmonary pressure with the use of esophageal balloon catheters. We reasoned that the use of pleuralpressure measurements, despite the technical limitations to the accuracy of such measurements, would enable us to find a PEEP value that could maintain oxygenation while preventing lung injury due to repeated alveolar collapse or overdistention.
Methods：We randomly assigned patients with acute lung injury or ARDS to undergo mechanical ventilation with PEEP adjusted according to measurements of esophageal pressure （the esophageal-pressure Cguided group） or according to the Acute Respiratory Ditress Syndrome Network standard-of-care recommendations （the control group）. The primary end point was improvement in oxygenation. The secondary end points included respiratory-system compliance and patient outcomes.
Results：The study reached its stopping criterion and was terminated after 61 patients had been enrolled. The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen at 72 hours was 88 mm Hg higher in the esophageal-pressure-guided group than in the control group （95% confidence interval, 78.1 to 98.3; P = 0.002）.This effect was persistent over the entire follow-up time （at 24, 48, and 72 hours; P = 0.001 by repeated-measures analysis of variance）. Respiratory-system compliance was also significantly better at 24, 48, and 72 hours in the esophagealpressureCguided group （ = 0.01 by repeated- measures analysis of variance）.
Conclusions：As compared with the current standard of care, a ventilator strategy using esophageal pressures to estimate the transpulmonary pressure significantly improves oxygenation and compliance. Multicenter clinical trials are needed to determine whether this approach should be widely adopted. （ClinicalTrials.gov number, NCT00127491 .）
Recent changes in the practice of mechanical ventilation have improved survival in patients with the acute respiratory distress syndrome （ARDS）, but mortality remains unacceptably high. Whereas low tidal volumes are cleady beneficial in patients with ARDS, how to choose a positive end-expiratory pressure （PEEP） is uncertain. Ideally, mechanical ventilation should provide sufficient transpulmonary pressure （airway pressure minus pleural pressure） to maintain oxygenation while minimizing repeated alveolar collapse or overdistention leading to lung injury. In critical illness, however, there is marked variability among patients in abdominal and pleural pressures ; thus, for a given level of PEEP, transpulmonary pressures may vary unpredictably from patient to patient.
We estimated pleural pressure with the use of an esophageal balloon catheter. Although this technique has been validated in healthy human subjects and animals, it has not been systematically applied in patients in the intensive care setting. We reasoned that we could adjust PEEP according to each patient＇s lung and chest-wall mechanics. We speculated that in patients with high estimated pleural pressure who are undergoing ventilation with conventional ventilator settings, underinflation may cause hypoxemia. In such patients, raising PEEP to maintain a positive transpulmonary pressure might improve aeration and oxygenation without causing overdistention. Conversely, in patients with low pleural pressure, maintaining low PEEP would keep transpulmonary pressure low, preventing overdistention and minimizing the adverse hemedynamic effects of high PEEP.
We report the results of a randomized, controlled pilot trial involving patients with acutelung injury or ARDS. The trial compared mechanical ventilation directed by esophageal-pressure measurements with mechanical ventilation managed according to the Acute Respiratory Distress Syndrome Network （ARDSNet） recommendations. We tested the hypothesis that oxygenation in patients can be improved by adjusting PEEP to maintain positive transpulmonary pressures.