Lactate/pyruvate ratio as a marker of tissue hypoxia in circulatory and septic shock.

In this prospective, observational study, we measured arterial lactate and pyruvate concentrations within the first four hours of shock and at four hour intervals during the first 24 hours in 26 patients with septic and 13 with cardiogenic shock. We also studied 10 intensive care unit patients with normal lactate levels as controls. Seven patients (18%) died during the first 24 hours of shock, 12 (31%) patients died later in the intensive care unit and 21 (54%) were discharged alive from the intensive care unit. Blood lactate values were higher at shock onset in the non-survivors than in the survivors (P=0.02) and remained significantly elevated throughout the study. The lactate/pyruvate ratio at shock onset was significantly higher in the non-survivors (24 [17 to 34] vs 15 [10 to 19], P=0.01) than in the survivors. All patients with cardiogenic shock had hyperlactataemia at the onset of shock, and 69% had a high lactate/pyruvate ratio. Only 65% of patients with septic shock had hyperlactataemia at the onset of shock and 76% of these also had a high lactate/pyruvate ratio. In conclusion, the lactate/pyruvate ratio confirms that hyperlactataemia is frequently, but not solely, due to hypoxia, especially at the onset of shock.

Survival and quality of life after prolonged intensive care unit stay.

There are few data on long-term outcomes in mixed groups of intensive care unit (ICU) patients with prolonged stays. We evaluated the relationship between length of stay in the ICU and long-term outcome in all patients admitted to our 31-bed department of medico-surgical intensive care over a one-year period who stayed in the department for more than 10 days (n = 189, 7% of all ICU admissions). Mortality increased with length of stay from 1 to 10 days (1 day 5%, 5 days 15%, 9 days 24%, 10 days 33%) but remained stable at about 35% for longer ICU stays. In the long-stay patients, the most common reasons for ICU admission were intracranial bleeding (23%), polytrauma (14%), respiratory failure (13%) and septic shock (11%). The main reasons for prolonged ICU stay were ventilator dependency (40%), infectious complications (23%) and coma (16%). Long-stay patients had a 65% ICU survival, 55% hospital survival and 37% one-year survival. At one-year follow-up, 73% of surviving patients reported no or minor persistent physical complaints compared to before the acute illness; 27% had a major functional impairment, including 8% who required daily assistance. In conclusion, in ICU patients, mortality increases with length of stay up to 10 days. Patients staying in the ICU for more than 10 days have a relatively good long-term survival. Most survivors have an acceptable quality of life.