In patients undergoing resuscitation from shock three groups were defined on the basis of the responses of arterial blood lactate (ABL) concentrations. The first group had hyperlactataemia which corrected following therapy which achieved significant increases in mean arterial blood pressure (MAP: p<0.01) and DO<SUB>2</SUB> (p<0.005). Group two had similar lactate levels, but vigorous therapy, which increased MAP significantly (p<0.05) did not increase DO<SUB>2</SUB>. ABL concentrations remained elevated, and mortality was high. These differences emphasise the importance of simultaneous reversal of hypotension and attainment of adequate DO<SUB>2</SUB>. In the third group, despite severe cardio-respiratory abnormalities hyperlactataemia was not seen. Shock may occur with normal ABL concentrations. In patients with shock and adult respiratory distress syndrome (ARDS) an elevated ABL has been proposed as a marker of delivery dependent VO<SUB>2</SUB>, a potential indicator of tissue hypoxia. Septic shock and ARDS patients were classified on the basis of normal or elevated ABL concentrations. The level of ABL had no value in predicting the response of VO<SUB>2</SUB> to changing DO<SUB>2</SUB> in either the grouped data, or in individual patients. The absence of hyperlactataemia in ARDS does not preclude the presence of delivery dependent VO<SUB>2</SUB>, and by implication tissue hypoxia. The anaesthetic induction agent propofol has been used for sedation in adult critically ill patients. In a group of ventilated, invasively monitored patients its effects on cardiorespiratory function were documented. Heart rate and MAP fell significantly (p<0.05) but DO<SUB>2</SUB> and VO<SUB>2</SUB> were unchanged despite a significant increase in the sedation score (p<0.01), suggesting there was no improvement in overall oxygen supply/demand balance.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:660010 |
| Date | January 1996 |
| Creators | Nimmo, Graham R. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/21447 |
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