How to enhance experience and skill of non invasive ventilation: suggestions from the literature

Abstract

19 have seen an iron lung, yet sixty years ago these medical mechanical monsters would have been a common sight in most hospital throughout the world. Through the late 1920’s and into 50’s the iron lung was considered to be state of the art, high-tech, life support technology. Indeed medical physician of the time would have learn about such devices as a recommended treatment for respiratory paralysis, used to maintain life for those whose breathing capabilities had been impaired or destroyed by poliomyelit is (1).They were non invasive in the sense that no part of the device penetrated the patient. In truth, it was the patient who was inside the machine. The whole body was enclosed within the air tight chamber of the device, apart from the head which protruded through a tight seal around the neck (Figure 1). For each inspiration a large set of leather bellows mounted in a separate pump unit would expand causing the pressure within the cabinet to be lowered to below that of the surrounding atmosphere. The sub-atmospheric pressure in turn acted upon the chest, causing it to expand, thereby drawing fresh air into the lungs through the patients’ mouth. During expiration, the pressure equalise to atmospheric and the patient exhals passively. This method of artificial respiration was known as external negative pressure ventilation (ENPV). The first description of ventilator support via mouthpiece was described by Dr.Affeldt of Rancho Los Amigos in 1953 (Figure 2), to assist patients when the iron lung was open for patient care (1, 2). He observed that intermittent positive pressure administered by a circuit with a mouthpiece could be used to relieve dyspnea in patients with polio ventilator-dependence when negative pressure ventilation had been interrupted for transfers, nursing or physical therapy (1, 2). However, intermittent positive pressure breathing (IPPB) machine became available even earlier than 1951 and a positive pressure blower caller was used to deliver occasional deep breaths as well. Patients used mouthpiece NIV in a wheelchair as well as use an intermittent abdominal pressure ventilator (IAPV) or other portable negative pressure ventilators. Since IPPV via mouthpiece Bantam became available and since the IPPV via mouthpiece was able to provides much larger volumes of air directly to the lungs than the IAPV, it became the principal mode of ventilatory support during lung infections and other conditions of lung impairment. The mouthpieces were mounted on the controls of powered Mini-review