Development of test methods for evaluating the effectiveness of manual resuscitation devices.

Manual resuscitation devices are widely available but there are currently no standards which define minimum performance criteria or which describe test methods for assessing performance. This report describes test methods developed at the Institute of Occupational Medicine to (i) assess the degree of protection afforded to the first aider from the risk of contracting diseases from resuscitatees (by measuring valve leakage and filter penetration), (ii) measure the breathing resistance imposed on the first aider’s lungs and (iii) determine the magnitude of any leakages between devices and resuscitatees’ faces. This latter method would demonstrate the effectiveness of the device during resuscitation attempts.The test methods were applied to nine commercially available resuscitation devices; these included three types which rely upon the first aider’s exhalate to inflate the resuscitatee’s lungs (ie. airway, facepiece, flat sheet) and manual pumps.Of seven exhalation devices tested, six relied on one-way valves to protect the first aider. Leakages of at least 100 ml min””1 were observed for these valves. The remaining device relied on a filter; penetration of the filter by standard sodium chloride aerosol and water exceeded 20 per cent and 50 per cent respectively. These valve leakage and filter penetration results are considered to be sufficiently high to provide inadequate protection to the first aider. Also, all but three of the exhalation devices gave exhalation resistances considered to be high (exceeding 125 Pa at 50 Q. min-1) to the extent that undue stresses may be imposed on the first aiders’ lungs. One of the seven exhalation devices could not be tested for face-seal leakage; of the six which were, only two gave leakages (consistently below 10 per cent) considered to provide adequate fit.Both pump devices tested gave face-seal leakage results up to 30-40 per cent; neither is considered to provide adequate fit between the device and the resuscita tee’s face.Comparison of the results obtained for the resuscitators with the performance achieved by available respirators indicates that resuscitator performance could be improved by design modifications. “”