Resuscitation Devices Research Articles

Mechanical ventilation with the esophageal tracheal combitube (ETC) in the intensive care unit.

Mechanical ventilation in critically ill patients is usually performed with the conventional endotracheal airway. The esophageal tracheal combitube (ETC) is a new device for cardiopulmonary resuscitation, conceived to bridge the gap between hospital and prehospital phases. The ETC may be used in esophageal and endotracheal positions. The authors report six patients who were ventilated with the ETC in the esophageal obturator position for 2-8 h after emergency ventilation. Blood gas data showed adequate ventilation with the ETC during the observation period. Data suggest that mechanical ventilation with the ETC is possible for several hours after cardiopulmonary resuscitation. This might be helpful during the initial post-arrest period, when replacement of the ETC by a conventional endotracheal airway might destabilize a vulnerable patient.

Esophageal Tracheal Combitube (ETC): Tierexperimentelle Ergebnisse mit einem neuen Notfalltubus

Prompt and effective ventilation, essential for patients with cardiopulmonary arrest, may be provided by a new airway for emergency resuscitation. The "Esophageal Tracheal Combitube (ETC)" offers endotracheal or esophageal obturator ventilation according to choice. Ventilation is therefore always possible after blind intubation. Experimental studies in dogs showed encouraging results during oesophageal placement of the ETC; blood gas analyses and cardiovascular parameters, in particular, were comparable to conventional endotracheal ventilation. Satisfying results were achieved during routine surgical operations in humans. We intend to use the ETC as a device for emergency cardiopulmonary resuscitation in humans. It is especially suitable for medical personnel not trained in endotracheal intubation. The ETC has been conceived to bridge the gap of the prehospital phase.

A simple device for respiratory resuscitation of newborn calves and lambs.

The neonatal death of calves and lambs is responsible for a heavy financial loss to the farming industry; respiratory failure accounts for 6 per cent of the post parturient deaths in lambs. A simple method of pulmonary resuscitation with expired air is described employing a device portable and simple enough for emergency use by herdsmen and shepherds. The rationale of the use of the equipment is explained.

Investigation of an outbreak of infection with Acinetobacter calcoaceticus in a special care baby unit

During a period of 6 months, an ‘epidemic strain’ of Acinetobacter calcoaceticus was isolated from 10 pre-term neonates in a special care baby unit (scbu). Of these, nine had pulmonary infections. The tenth was found to have conjunctival colonization only. The ‘epidemic strain’ was characterized by serotyping, biotyping, bacteriocin typing and antibiograms. An identical strain was isolated from an ‘Ambu’ resuscitation device but not from other environmental samples or from staff on the unit. The outbreak ceased after the colonized resuscitator was removed and an appropriate disinfection policy implemented for the replacement resuscitators.

THE EFFICACY OF FACE MASK RESUSCITATION

Although the physical characteristics of hand-held face mask resuscitation devices used by most units in the first line therapy for asphyxia at birth are well known, there have been no studies published on their efficacy. We have, therefore, measured inflation pressure and tidal exchange using a Laerdal Resuscitator in 9 babies asphyxiated at birth (L). Their birth weight ranged from 1.96 to 3.8 Kg (mean, 3.26) and gestational ages from 34 to 40 weeks (mean, 39.0). Results were compared with a matched group of 9 babies (I) resuscitated by intubation. The Apgar scores immediately prior to resuscitation were 5.0 (L) and 3.3 (I). Tidal exchange and inflation pressures were measured using the same pneumotachograph/pressure transducer systems. Only expiratory volumes could be analysed with the Laerdal system due to leak around the face mask. Both systems produced similar first inflation pressures (L, 31.4; I, 28.2 cm/H2O) but expiratory volumes were strikingly different (L, 2.7 ml; I, 14.3 ml). Similar results were in the next two breaths. Throughout resuscitation the Laerdal system rarely produced adequate exchange (deadspace X 2). The failure appears to be due to the short duration of the inflation pressure (L, .3 to .5 sec; I, >1.0 sec) in a situation where the airway is fluid-filled and highly viscous. We conclude that face mask resuscitation does not produce adequate tidal exchange but relies on stimulating the baby to commence spontaneous respiration. Performance could be improved by prolonging the inflation time.

CLOSED CIRCUIT ANAESTHESIA: A new approach

A logical development of the closed circuit is described, from a basic resuscitation device, through various modifications, to a circle system incorporating an oxygen demand valve, adsorbers for both carbon dioxide and halothane, and some specific safety features. The behaviour of the circuits has been investigated in relation to elimination of nitrogen, concentrations of halothane and circuit leaks.

Electrical and mechanical aspects of left atrial activity.

<b>Background:</b> The Lund University Cardiopulmonary Assist System (LUCAS) is a gas-driven mechanical cardiopulmonary resuscitation device. If oxygen is used as the driving gas in a confined environment, there is a potential fire hazard. 24% oxygen is considered the threshold for increased risk. <b>Objective and methods:</b> Three trials were conducted using different cabin ventilation settings to determine the rise in oxygen concentration in an MD902 helicopter during use of the LUCAS. <b>Results:</b> The oxygen concentration rose rapidly with the aircraft at rest, but during flight, using realistic cabin ventilation settings and durations of use, the oxygen concentration failed to reach 24%. <b>Conclusion:</b> The LUCAS is safe for normal-duration flights in an MD902 helicopter. It is potentially unsafe in a static MD902 and, by extrapolation, in other static aircraft of similar or smaller size such as the EC135 or Bolkow 105.

Expansion of the lungs of newborn infants.

The normal newborn infant is able to expand his lungs so easily that he seems not to struggle at all, and in a few minutes the oxygen saturation of his blood is over 90%. In the operating room, the anesthesiologist can maintain pulmonary ventilation during chest operations on newborn infants with ease. In the delivery room, however, one encounters, fortunately rather rarely, infants who cannot breathe adequately, and in such infants, artificial positive-pressure respiration is much less successful than in the operating room where normal lungs are dealt with. The difficulty seems to arise from three possible causes: 1. The lungs may be obstructed by debris. 2. The lungs may be too immature to expand well. 3. The normal neonatal lung may require more than the 15 cm. H 2 O (11.5 mm. Hg) permitted on most positive-pressure resuscitation devices. Since the first two difficulties are discussed by others (see