SummaryConcomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12patients randomly allocated to blinded air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation < 92%) and increased heart rate (> 90 beat.min-I). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease in heart rate ( p < 0.002). Thus, postoperative supplementary oxygen has a positive efect on the cardiac oxygen delivery and demand balance.

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16C. Gaarder et al. the prehospital careprovider with amoreorless obvious mechanismo fi njury,c omplaintsa nd symptoms, and with many uncontrolled factors making both diagnosis and triage achallenge.Vo lume loading results in adecrease in haemoglobin and clotting factors. Furthermore, the relative expansion with 500 ml of isotonic crystalloid is greater in as hocked person than in ah ealthy individual. The optimal volume of intravenous fluid to administer is abalance between avoiding hypovolaemia and not increasing systolic blood pressure(SBP) causing disruption of clots and further bleeding. To what extent this is moret han at heoretical worry in patients with blunt trauma, is not well documented. Several animal models of penetrating injury,h owever,h ave documented the relationship between increasing blood pressure, increased bleeding and fatal outcome.AS BP <90m mH gi su sed extensively to assess volume status in trauma patients, both for triage, treatment and study protocols. How well aSBP <90 mm Hg defines the presence of uncontrolled bleeding, the need for intravenous fluid resuscitation and later surgical interventions is still not clear.T herei s also some evidence to support the use of only manual SBP for pre-hospital, or hospital, triage decisions (1).In EMS (Emergency Medical Services) systems wherep re-hospital fluid therapy is used, the incidence of hypotension at hospital admission is lower than 10% and the need for immediate haemostatic surgery is low (5). Recent publications have reinforced the impression that fluid resuscitation and blood transfusion in the Emergency Department still aree ssential elements of early management in most critically injured patients. Hence, providing the same therapy earlier,i fn ot exaggerated, seems logical. A major concern with prehospital fluid therapy is that infusing cold fluids will cause hypothermia in the patients, afactor known to reduce clotting activity.Patients with severeT BI (traumatic brain injury) do not tolerate even short periods of hypotension. Hence, theu se of volume therapy to counteract hypovolaemia and hypotension is considered standard treatment by most authors. The discussion has been focused moreonwhat systolic blood pressuretoaim for and what fluid to use. RECOMMENDATIONS

We have compared impingement of the tracheal tube against the larynx using a standard preformed tube, warmed preformed tube or two flexible spiral-wound tracheal tubes with different tip designs, in 100 adult patients undergoing orotracheal fibreoptic intubation under general anaesthesia, in a prospective, randomized study. The rates of impingement were 20 of 30 with the standard tube, 12 of 30 with the warmed standard tube (P = 0.07) and eight of 20 with both spiral tubes. However, impingement with the spiral tubes took longer to overcome if a sharp tipped rather than an obtuse tipped tube was used. Manipulations after impaction led to oesophageal intubation in one patient, and in one patient fibreoptic intubation failed. We conclude that resistance to the tracheal tube occurred frequently when the spiral-wound tubes were used.