**5.1 Nonoperative factors**

Hyperlactatemia could be present in a critically ill patient due to multiple factors that are either secondary to increased production (shock, sepsis, or respiratory failure) or because of reduced lactate clearance (liver or renal failure). Shock was the most common cause for non-surgical hyperlactatemia, followed by respiratory and renal failures in one study (Juneja et al., 2011). Patients with or without shock who had higher blood lactate levels on admission to the ICU were also found to have higher APACHE II scores, and a greater need for vasopressors or renal replacement therapy and mechanical ventilation, (Juneja et al., 2011).
