ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
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Since recirculation during venovenous extracorporeal membrane oxygenation (VV ECMO) reduces oxygen delivery to the patient, monitoring recirculation is necessary to guide clinicians in interventions that may reduce recirculation and thereby optimize patient care. The use of dilutional ultrasound may be a clinically practical way to quantify recirculation during VV ECMO. This study evaluates in a swine model of VV ECMO a dilutional ultrasound techniques ability to provide accurate recirculation data under changing conditions. ⋯ The time for results was much faster with the use of dilutional ultrasound. Induction of recirculation changes by repositioning the cannula or changing cardiac output was rapidly detected using dilutional ultrasound and showed significant differences from baseline recirculation. Dilutional ultrasound provides a clinically practical method to quantify and monitor recirculation in VV ECMO applications and may aid in assessing interventions to improve oxygen delivery.
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Editorial Review Comparative Study
An evaluation of the benefits of pulsatile versus nonpulsatile perfusion during cardiopulmonary bypass procedures in pediatric and adult cardiac patients.
The controversy over the benefits of pulsatile and nonpulsatile flow during cardiopulmonary bypass procedures continues. The objective of this investigation was to review the literature in order to clarify the truths and dispel the myths regarding the mode of perfusion used during open-heart surgery in pediatric and adult patients. The Google and Medline databases were used to search all of the literature on pulsatile vs. nonpulsatile perfusion published between 1952 and 2006. ⋯ We also found evidence that pulsatile flow significantly improved vital organ recovery in several types of animal models when compared with nonpulsatile perfusion. Several investigators have also shown that pulsatile flow generates more hemodynamic energy, which maintains better microcirculation compared with nonpulsatile flow. These results clearly suggest that pulsatile flow is superior to nonpulsatile flow during and after open-heart surgery in pediatric and adult patients.
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Extracorporeal CO2 removal may reduce minute ventilation requirements and allow for better tolerance of low tidal volume ventilating strategies in patients with severe respiratory insufficiency. Conventional extracorporeal gas exchange is labor-intensive, expensive, and usually requires systemic anticoagulation. In this study, a simplified venovenous circuit was developed by using regional citrate anticoagulation to avoid potential complications associated with systemic heparin. ⋯ CO2 transfer ranged from 31 ml/min (500 ml/min blood flow; 2 l/min gas flow) to 150 ml/min (1000 ml/min blood flow; 15 l/min gas flow) and was directly proportional to blood flow and gas flow (p < 0.05). Normocapnia was maintained despite a 75% reduction in minute ventilation. At 24 hours, there was no significant clot formation in the circuit.
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Comparative Study
Pharmacokinetics and the most suitable regimen of panipenem/beta mipron in critically ill patients receiving continuous renal replacement therapy: a pilot study.
Critically ill patients often have complications of acute renal failure induced by severe infection or sepsis. The patients need administration of broad-spectrum antibiotics as well as continuous renal replacement therapy (CRRT). However, there is no uniform pharmacokinetics of antibiotics during the CRRT because CRRT is performed with the various combinations of dialysate flows (QD) and ultrafiltrate flows (QF). ⋯ In patients with CRRT, the PAPM total clearance (PAPM CLtot) was calculated as the sum of PAPM clearance dependent on the living body and CRRT and shown as follows:PAPM CLtot (ml/min) = (1.2 CLcre + 66.5) + 0.86 (QD + QF) where CLcre is creatinine clearance. Pharmacokinetic values of PAPM were measured in 4 patients with CRRT. According to these results, the most appropriate treatment regimen regarding PAPM CLtot (ml/min) showed as follows:PAPM CLtot < 80 0.5 g every 12 hours or 1 g every 15 hoursPAPM CLtot 80 to 120 0.5 g every 8 hours or 1 g every 12 hoursPAPM CLtot 120 to 160 0.5 g every 6 hours or 1 g every 8 hours.
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Comparative Study
An electrocardiogram-based method for early detection of abrupt changes in blood pressure during hemodialysis.
Clinical techniques for early detection of acute hypotension during conventional hemodialysis treatment are lacking, even though intradialytic hypotension is the most common acute complication. In this article, intradialytic hypotension is identified by means of signal analysis of data recorded at two clinics. The database consists of 30 treatments with concurrently acquired signals: the 12-lead electrocardiogram, continuous blood pressure, hematocrit, oxygen saturation, relative blood volume, and important hemodialysis variables. ⋯ These two types of information reflect different mechanisms of cardiac activity. It is essential that both types are used for the detection of hypotension, because HRV analysis is inappropriate when several ectopic beats are present. The proposed dynamic echocardiography-based method offers early identification of the cases with acute intradialytic hypotension of the database.