Insensible water loss from the Jostra Quadrox D oxygenator: an in vitro study

Extracorporeal membrane oxygenation (ECMO) has been shown to improve outcomes in neonatal patients with respiratory and/or cardiac failure. Insensible water loss is defined as water loss via evaporation from the skin and respiration. Fluid and electrolyte balance are a primary concern and very challenging in the neonatal patient population. Hypernatremia can result from untreated insensible water loss, leading to possible cerebral complications. A new type of fiber used in the Jostra Quadrox D oxygenator has recently been approved for use in the United States of America. This oxygenator uses a polymethylpentene closed hollow-fiber technology and has been approved for six hours of continuous use by the Federal Drug Administration. The closed hollow-fiber technology may be advantageous for extended use due to the fact that it is a true membrane and plasma leakage will not occur across its surface. The Jostra Quadrox D is an adult-sized oxygenator with a surface area of 1.8 M(2). The aim of this study is to discover what the insensible water loss will be from the Jostra Quadrox D when used at blood flows which would mimic those used for a neonatal ECMO patient. The median insensible water loss from the Quadrox D oxygenator at a gas flow rate of two liters per minute(LPM) was 4.0 +/- 0.2 ml/hour, at five LPM was 9.8 +/- 0.4 ml/hour and at 10 LPM was 20.6 +/- 0.7 ml/hour. The daily evaporative water loss from the Jostra Quadrox D can be estimated to be 48.0 +/- 2.1 ml for each LPM of sweep gas with a normal saline pump flow rate of 500 ml/min.