Martin Geisen

Clinical validation of a new thermodilution system for the assessment of cardiac output and volumetric parameters

IntroductionTranspulmonary thermodilution is used to measure cardiac output (CO), global end-diastolic volume (GEDV) and extravascular lung water (EVLW). A system has been introduced (VolumeView/EV1000™ system, Edwards Lifesciences, Irvine CA, USA) that employs a novel algorithm for the mathematical analysis of the thermodilution curve. Our aim was to evaluate the agreement of this method with the established PiCCO™ method (Pulsion Medical Systems SE, Munich, Germany, clinicaltrials.gov identifier: NCT01405040)MethodsSeventy-two critically ill patients with clinical indication for advanced hemodynamic monitoring were included in this prospective, multicenter, observational study. During a 72-hour observation period, 443 sets of thermodilution measurements were performed with the new system. These measurements were electronically recorded, converted into an analog resistance signal and then re-analyzed by a PiCCO2™ device (Pulsion Medical Systems SE).ResultsFor CO, GEDV, and EVLW, the systems showed a high correlation (r2 = 0.981, 0.926 and 0.971, respectively), minimal bias (0.2 L/minute, 29.4 ml and 36.8 ml), and a low percentage error (9.7%, 11.5% and 12.2%). Changes in CO, GEDV and EVLW were tracked with a high concordance between the two systems, with a traditional concordance for CO, GEDV, and EVLW of 98.5%, 95.1%, and 97.7% and a polar plot concordance of 100%, 99.8% and 99.8% for CO, GEDV, and EVLW, respectively. Radial limits of agreement for CO, GEDV and EVLW were 0.31 ml/minute, 81 ml and 40 ml, respectively. The precision of GEDV measurements was significantly better using the VolumeView™ algorithm compared to the PiCCO™ algorithm (0.033 (0.03) versus 0.040 (0.03; median (interquartile range), P = 0.000049).ConclusionsFor CO, GEDV, and EVLW, the agreement of both the individual measurements as well as measurements of change showed the interchangeability of the two methods. For the VolumeView method, the higher precision may indicate a more robust GEDV algorithm.Trial registrationclinicaltrials.gov NCT01405040.

Performance of a new pulse contour method for continuous cardiac output monitoring: validation in critically ill patients

BACKGROUND A new calibrated pulse wave analysis method (VolumeView™/EV1000™, Edwards Lifesciences, Irvine, CA, USA) has been developed to continuously monitor cardiac output (CO). The aim of this study was to compare the performance of the VolumeView method, and of the PiCCO2™ pulse contour method (Pulsion Medical Systems, Munich, Germany), with reference transpulmonary thermodilution (TPTD) CO measurements. METHODS This was a prospective, multicentre observational study performed in the surgical and interdisciplinary intensive care units of four tertiary hospitals. Seventy-two critically ill patients were monitored with a central venous catheter, and a thermistor-tipped femoral arterial VolumeView™ catheter connected to the EV1000™ monitor. After initial calibration by TPTD CO was continuously assessed using the VolumeView-CCO software (CCO(VolumeView)) during a 72 h period. TPTD was performed in order to obtain reference CO values (COREF). TPTD and arterial wave signals were transmitted to a PiCCO2™ monitor in order to obtain CCO(PiCCO) values. CCO(VolumeView) and CCO(PiCCO) were recorded over a 5 min interval before assessment of CO(TPTD). Bland-Altman analysis, %(errors), and concordance (trend analysis) were calculated. RESULTS A total of 338 matched sets of data were available for comparison. Bias for CCO(VolumeView)-CO(REF) was -0.07 litre min(-1) and for CCO(PiCCO)-CO(REF) +0.03 litre min(-1). Corresponding limits of agreement were 2.00 and 2.48 litre min(-1) (P<0.01), %(errors) 29 and 37%, respectively. Trending capabilities were comparable for both techniques. CONCLUSIONS The performance of the new VolumeView™-CCO method is as reliable as the PiCCO2™-CCO pulse wave analysis in critically ill patients. However, an improved precision was observed with the VolumeView™ technique. CLINICALTRIALS.GOV IDENTIFIER: NCT01405040.

Initial Clinical Experience With a Miniaturized Transesophageal Echocardiography Probe in a Cardiac Intensive Care Unit

OBJECTIVE To investigate the safety of a novel, miniaturized, monoplane transesophageal echocardiography probe (mTEE) and its potential as a hemodynamic monitoring tool. DESIGN This was a retrospective analysis of the clinical evaluation of a disposable mTEE in ventilated patients with severe cardiogenic shock requiring hemodynamic support. mTEE assessment was performed by operators with mixed levels of TEE training. Information on hemodynamic interventions based on mTEE findings was recorded. SETTING A tertiary university cardiac critical care unit. PARTICIPANTS Male and female critical care patients admitted to the unit with severe hemodynamic instability. INTERVENTIONS Insertion of miniaturized disposable TEE probe and hemodynamic and other critical care interventions based on this and conventional monitoring. MEASUREMENTS AND MAIN RESULTS In 41 patients (51.2% female, 73.2% after cardiac surgery), hemodynamic support probe insertion was accomplished without major complications. A total of 195 mTEE studies were performed, resulting in changes in therapy in 37 (90.2%) patients based on mTEE findings, leading to an improvement in hemodynamic parameters in 33 (80.5%) patients. Right ventricular (RV) failure was diagnosed in 25 patients (67.6%) and mTEE had a direct therapeutic impact on management of RV failure in 17 patients (68 %). CONCLUSIONS Insertion and operation of a novel, miniaturized transoesophageal echocardiography probe can be performed for up to 72 hours without major complications. Repeated assessment using this device provides complementary information to invasive monitoring in the majority of patients and has an impact on hemodynamic management.

Echocardiography-Based Hemodynamic Management in the Cardiac Surgical Intensive Care Unit

INTRAOPERATIVE TRANSESOPHAGEAL echocardiography (TEE) is well established within the cardiac operating room. Confirmation of the preoperative diagnosis is sought and additional relevant information is communicated to the surgeon. Following the procedure, the results of surgery are examined together with any complications, and information from echocardiography is used to optimize hemodynamic status. As the patient moves to the cardiac critical care unit and the TEE probe is removed, this information is no longer available. Echocardiography is indicated to troubleshoot unstable patients in the immediate postoperative phase, but compared with intraoperative use, postoperative use may occur less frequently. In comparison with some other types of surgery, cardiac surgery has a low mortality, but complications are common and costly. Good hemodynamic management should seek to reduce the incidence and impact of such complications. There have been considerable developments in critical care monitoring and echocardiography in recent years, and the authors review the implications for adult cardiac critical care management.

Disseminated cutaneous mucormycosis in a patient on high-dose steroid therapy for severe ARDS

Dear Editor, A 65-year-old male patient was transferred to our institution for rescue therapy after developing severe ARDS (PaO2/FiO2 = 51) refractory to conventional ventilation (FiO2 1, 0, PEEP 12 cm H2O) following femoral thrombendarterectomy. Veno-venous ECMO therapy was initiated on the day of arrival. The patient was ventilated using a lungprotective strategy. Treatment with methylprednisolone (2 mg/kg/day) had been initiated by the referring institution and was continued throughout the patient’s stay in our ICU. The patient was repeatedly placed in the prone position. Initial blood cultures and tracheal secretions showed Enterococcus and coagulasenegative Staphylococcus, suggesting perioperative pneumonia as the underlying trigger of ARDS. Antibiotic treatment consisted of piperacillin/tazobactam 4.5 g every 8 h. Throughout the first 7 days of treatment the patient required no vasopressor support. There were no signs of further organ failure. Repeated neurological assessment was unremarkable. Oxygenation and lung compliance gradually improved following treatment initiation. A repeat CT scan of the chest on treatment day 9 showed improved aeration of lung tissue and a marked resolution of infiltrates. On treatment day 9 the patient developed severe sepsis with multiple organ failure and a rapid increase of serum creatine kinase. Clinically there were no signs suggestive of compartment syndrome or limb ischemia, as monitored continuously by near-infrared spectroscopy. Duplex ultrasonography showed adequate renal perfusion, and cardiac assessment by TOE showed no valvular pathology suggestive of endocarditis and a normal left-ventricular function. On treatment day 10, red maculae developed on the lower extremities and were present over the whole body surface within hours, progressing to dermal necrosis with black eschar formation (Fig. 1). The patient developed intractable metabolic acidosis and vasoplegia, and died on treatment day 11. Biopsies from skin lesions revealed cutaneous mucormycosis on culture. The diagnosis of Absidia corymbifera was confirmed posthumously by agent-specific PCR. Repeated blood cultures and broad-spectrum molecular analysis of the blood specimen remained negative. Mycologic examination of bronchoalveolar lavage fluid showed no pathogens. Autopsy was not performed. ARDS represents a major health problem, with current estimates pointing to its incidence being greater than previously reported [1]. Recent data suggest a mortality benefit in severe refractory ARDS by administration of corticosteroids [2]. Steroidinduced immunosuppression is a potential side effect of this therapy that has been addressed in the literature, although none of the randomized controlled trials on glucocorticoid use in ARDS have reported an increased rate of infection [3]. Absidia corymbifera is a fungal agent belonging