The International Journal of Artificial Organs

Transfer of severely hypoxic patients is a high-risk procedure. Extracorporeal Membrane Oxygenation (ECMO) allows safe transport of these patients to tertiary care institutions. Our ECMO transportation program was instituted in 2004; here we report results after 5 years of activity.

This is a clinical observational study. Criteria for ECMO center activation were: potentially reversibile respiratory failure, PaO₂ <50 mmHg with FiO₂ >0.6 for >12 hours, PEEP >5 cmH₂0, Lung Injury Score (LIS) ≥3 or respiratory acidosis with pH <7.2, no intracranial bleeding, and no absolute contraindication to anticoagulation. If eligible, a skilled crew applied ECMO at the referral hospital. Transportation was performed with a specially equipped ambulance.

Sixteen patients were possible candidates for ECMO transfer. Two patients were excluded while 14 (mean±SD, age 35.4±18.6, SOFA 8.4±3.7, Oxygenation Index 43.7±13.4) were transported to our institution (distance covered 102±114 km, global duration of transport 589±186 minutes). Two patients improved after iNO-trial and were transferred and subsequently managed without ECMO. The remaining 12 patients were transferred on veno-venous ECMO with extracorporeal blood flow 2.7±1 L·min⁻¹, gas flow 3.8±1.8 L·min⁻¹, and FiO₂ 1. Data were recorded 30 minutes before and 60 minutes after initiation of ECMO. ECMO improved PCO₂ (75±23 vs. 53±9 mmHg, p<0.01) thus improving pH (7.28±0.13 vs. 7.39±0.05, p<0.01) and allowing a reduction in respiratory rate (35±14 vs. 10±4 breaths/min, p<0.01), minute ventilation (10.1±3.8 vs. 3.7±1.7 L·min⁻¹, p<0.01), and mean airway pressure (26±6.5 vs. 22±5 cmH₂O, p<0.01). No major clinical or technical complications were observed.

ECMO effectively enabled high-risk ground transfer of severely hypoxic patients.

The choice of vascular access catheter may affect filter life during continuous renal replacement therapy (CRRT); specifically, a new surface-modified catheter has been reported to possibly prevent thrombosis and catheter malfunction.

A sequential, controlled study in a tertiary ICU.

To compare circuit life when CRRT was performed with a Bard®Niagara™ catheter or the surface-modified GamCath™ Dolphin® Protect 1320 catheter.

We studied 50 patients with acute kidney injury requiring CRRT, all delivered with catheters in the femoral position. We obtained information on age, gender, disease severity score (APACHE II and APACHE III), filter life, total heparin dose, hemoglobin concentration, platelet count, INR, and aPTT during CRRT.

We studied 341 circuits in 50 patients; 30 patients (140 circuits) used the Niagara and 20 patients (201 circuits) used the Dolphin catheter. Mean of circuit life in two groups was 14.9 hours and 13.1 hours, respectively (p=0.22). Patients using Niagara catheters had a more prolonged APTT (p<0.01) and lower platelet count (p=0.05), while heparin dose (p=0.22), and other anticoagulant treatment (p=0.73) were not significantly different. On Kaplan-Meier survival analysis, circuit life was not significant different between the two catheters (p=0.15).

The Niagara and Dolphin catheters appear to be broadly equivalent in terms of their impact on circuit life.

Oritavancin is an investigational lipoglycopeptide antibiotic under clinical development for the treatment of gram-positive bacterial infections. The impact of hemodialysis on plasma concentrations of oritavancin is unknown and may be important in making dosage adjustments in such patients. The present study sought to determine the clearance of oritavancin from human blood by various commercially available dialyzers in an in vitro hemodialysis model.

Three types each of low-flux (Dicea 130, F6, and Polyflux 14L) and high-flux (Revaclear, Exeltra 150, and Optiflux F160NR) dialyzers and one type of continuous renal replacement therapy (CRRT) dialyzer (Prismaflex M100) were studied. Heparinized human blood containing oritavancin (200 mg/L) was circulated from a reservoir to the dialyzers and back to the reservoir. Fresh dialysate was pumped through the dialyzers in a countercurrent manner. Blood samples from each side of the dialyzers and contaminated dialysate samples were collected at periodic intervals. Oritavancin levels were analyzed by a liquid chromatography/mass spectrometry method with a limit of quantification of 12.5 ng/mL and plasma clearances of oritavancin were calculated.

The mean dialytic clearance of oritavancin was insignificant for each of the low-flux, high-flux and CRRT dialyzers. Clinically significant amounts of oritavancin were not detected in dialysate during any of the experimental dialysis sessions.

The clearance of oritavancin from human blood by the dialyzers used in this study is insignificant. Further clinical studies would be required before making changes in dosage of oritavancin in hemodialysis patients.

This phase I study was performed to evaluate the feasibility and toxicity of a new method of extracorporeal perfusion-induced whole body hyperthermia (WBHT) in patients with advanced sarcoma avoiding the need of intubation and general anesthesia.

One double-lumen femoral venous access was inserted by Seldinger's technique to obtain WBHT (41.8°C for 120 minutes) via an extracorporeal circuit. No concomitant chemotherapy was applied. Up to 4 treatments of WBHT were performed under moderate sedation in 6 spontaneously breathing patients. Invasive hemodynamic monitoring was performed by use of a pulmonary artery catheter.

After their first WBHT session, 2 patients were excluded from further treatment due to transient liver toxicity or catheter-related complication, so a total of 12 cycles remained for analyses. In all patients, conscious sedation resulted in sufficient spontaneous respiration without the need for mandatory ventilation. Median time to reach the target temperature was 84 minutes (range 60–142). Hemodynamic changes revealed the expected hyperdynamic state: heart rate, cardiac index, and stroke volume index significantly increased (p<0.05), whereas blood pressure and systemic and pulmonary vascular resistance index significantly decreased (p<0.05). A net fluid balance of 5822+1766 mL as well as norepinephrine (mean; 0.062 μg·kg¹·min⁻¹) were necessary to maintain the mean arterial blood pressure >60 mmHg.

Our data demonstrate the feasibility of this method of extracorporeal WBHT without mandatory ventilation. Hemodynamic side effects in spontaneously breathing patients during perfusion-induced WBHT seem less severe than those observed in radiant heat WBHT.

The present study evaluated in vitro and in vivo the effects of quercetin (QC), a major ingredient in various flavonoids, on peripheral nerve regeneration.

In the in vitro study, we found that QC at concentrations of 0.1, 1, and 10 μg/mL could significantly promote the survival and outgrowth of cultured Schwann cells as compared with the controls treated with culture medium only. In the in vivo study, we evaluated peripheral nerve regeneration across a 15-mm gap in the sciatic nerve of the rat, using a silicone rubber nerve chamber filled with the QC solution. In the control group, the chambers were filled with normal saline only.

At the end of 8 weeks, morphometric data revealed that all 3 QC groups significantly increased the count and density of myelinated axons as compared with the controls. Electro-physiological measurements showed that the QC-treated group at 1 μg/mL had a significantly larger area of evoked muscle action potential (MAP) compared with the controls. In addition, the amplitude of the MAP in the QC-treated groups at 0.1 and 1 μg/mL was significantly larger than that in the controls.

All of these results indicate that QC treatment has nerve growth–promoting effects which may lead to a promising herbal medicine for the recovery of regenerating peripheral nerves.