Insulin resistance.
Authors: W. G. Oakley, V. E. Jones, A. C. Cunliffe
Journal: BMJ (1967)

of paradox and reduction in residual deformity.It reduces pain and allows humane sedation without fear of respiratory depression.If a trained medical and nursing staff and proper facilities-that is, a respiratory unit-are available, and they Should be, the hazards of I.P.P.V. are negligible.Though blood-gas analysis is not used as the main indication for I.P.P.V., it has been found to be of great value in the man- agement of a patient on a ventilator.This is particularly so in the " difficult " patient-that is, one with chronic lung disease or a low compliance from any other cause.Here frequent adjustments of inspiratory flow rates and inflation pressures may be necessary to achieve adequate ventilation, and the results of blood analysis are then invaluable.It is also very useful in the interpretation of certain clinical signs.For example, if varying levels of consciousness are occurring, are these due to a concurrent head injury or to hypoxia and acid- osis ?Or, if the patient's blood pressure is falling, is this due to excessive ventilation or hypovolaemia ?In the patient with renal failure is the restlessness respiratory or renal in origin ?In these situations blood-gas studies may be the only means of deciding.As the management of the respiatory problems improves the mortality rate will depend more and more on the severity of the associated injuries.For this reason patients in this series have been classified according to the sites of injury-that is, thoracic only or thoracic together with other major injuries.Furthermore, as patients die from dysfunctions rather than injuries, we have attempted to quantitate these dysfunctions.Ten patients died.In four of these (Cases 27, 31, 71, and 128) death resulted from dysfunctions which could not be influenced by I.P.P.V. Three deaths (Cases 125, 193, and 199) were due to failure of respiration with which I.P.P.V. with pure oxygen failed to cope.The remaining three deaths (Cases 57, 66, and 122) were due to multiple factors, of which respiratory dysfunction contributed its share.It is impossible to compare the results in this series with the results of current authors (Reid and Baird, 1965 ; Lloyd et al., 1965; Campbell, 1966).The indications for I.P.P.V. are different, and, furthermore, the mortality rate will, in part, depend on the presence of other serious injuries-for example, head or abdominal visceral injuries.However, if the results of this series are compared with those recorded by Griffiths in 1960 a marked improvement in the mortality rate is obvious.This is largely due to the efficient management of the respiratory problem. SummarySixty-four patients with severe crush injuries of the chest are reviewed.They have been classified according to the anatomical site of injury.The great majority of patients received I.P.P.V., the indications for this being on clinical rather than biochemical features-particularly the persistence of dyspnoea and paradoxical respiration after the correction of airway obstruction and collapse of the lung.Serious com- plications encountered included anaemia, gastrointestinal stasis, renal failure, electrolyte disorders, and respiratory infection.The overall mortality rate was 16%.The value of I.P.P.V. in abolishing respiratory effort, effecting internal splinting of the chest wall, and reducing pain is emphasized.