OUT-OF-HOSPITAL CONTROL OF ET TUBE PLACEM ENT AND VENTILATION

Oesophageal malposition of an endotracheal tube is among the leading c auses of anaesthesia incidents. While clinical manoeuvres for detectio n of tube malposition are unreliable, monitoring (i.e. capnography) ca n prevent such incidents. The problem is particularly important in pre hospital care, where capnography is not (yet) widely available. We tes ted three devices used for differentiating oesophageal from endotrache al intubation: 1. Non-CO2-dependent Oesophageal Detector Device (ODD) as described by Pollard and Wee, 2. Semi-quantitative chemical disposa ble capnometer EasyCAP (Nellcor), 3. Non-quantitative infrared miniatu rised capnometer MiniCAP (MSA). Methods. 50 anaesthetised minipigs wer e intubated with a Magill tube. An identical additional tube was place d in the oesophagus. The cuffs of both tubes were inflated. Unexperien ced personel (students, laborary technicians) were asked to determine the position of one of the tubes by using one of the devices according to the randomisation plan. The decision had to be taken within 30 s. Using the ODD, the proband first injected 100 ml air into the lung (or stomach) and then tried to aspirate the same volume. EasyCAP and Mini CAP were used according to manuals. Results. Each device was used 25 t imes with a tracheal tube and 25 times with an oesophageal tube. All t ube position identifications were correct. When ventilating the oesoph agus/stomach for capnometric control, regurgitation into the tube occu rred six times (five times with the EasyCAP and once with the MiniCAP) . In these cases, the decision was based on this occurrence and not on the display of the device. While using the ODD no regurgitation occur red. Conclusion. These devices are useful for preclinical practice. Ac cording to the literature and our experience, the ODD is superior for the initial control of tube position, especially in cardiac arrest. Ca pnometry is needed, however, for continuous control of ventilation.