Clinical Trial: Incidence of Postoperative Ketosis and Metabolic Acidosis

Study Status: Completed
Recruit Status: Unknown status
Study Type: Observational

Official Title: Incidence of Postoperative Ketosis and Metabolic Acidosis

Brief Summary: The aim of this study is to define the incidence and nature of acidosis after major surgery using Figge's equations to directly measure acidosis. This study will also aim to compare the ability of indirect measures (base deficit, anion gap,corrected anion gap and lactate) to identify the presence of tissue acids in this population. The incidence of postoperative ketoacidosis as a contributor to tissue acidosis will be assessed through the use of point of care urinalysis.

Detailed Summary: Metabolic acidosis is a frequent occurrence following major surgery. Monitoring acid base disturbances and in particular diagnosing the aetiology of the acidosis are important parts of assessing a patient's cardiovascular status following surgery. The presence of a metabolic acidosis is frequently attributed to anaerobic metabolism leading to the generation of lactic acid due to hypovolaemia and poor tissue perfusion. This commonly results in clinicians treating postoperative patients with a metabolic acidosis by administering intravenous fluids containing 0.9% saline or Hartmann's solution (compound sodium lactate). If the cause of the metabolic acidosis is not hypovolaemia, treatment with intravenous fluids may actually exacerbate the acidosis by causing hyperchloraemia. An often overlooked cause of metabolic acidosis after surgery is starvation leading to ketoacidosis. All patients are starved for a minimum of six hours prior to general anaesthesia due to the potential risk of aspiration of gastric contents into the bronchial tree. Many patients are in fact fasted for much longer periods than this. There is, however, little data describing the incidence of ketoacidosis following surgery. In addition, there may be other causes of acidosis after surgery which often overlooked but can be determined using equations and mathematical models. The aim of this study is to define the incidence and nature of acidosis after major cancer surgery using using equations to directly determine acids. This study will also aim to compare the ability of commonly used indirect measures (base deficit, anion gap, corrected anion gap and lactate) to identify the presence of tissue acids in this population. The incidence of postoperative ketoacidosis as a contributor to tissue acidosis will be assessed through the use of point of care urinalysis.
Sponsor: Royal Marsden NHS Foundation Trust

Current Primary Outcome: Incidence of tissue acidosis, defined as tissue acids > 5mEq/L (Figge's equation) within one hour of completion of surgery [ Time Frame: 31/08/13 ]

Original Primary Outcome: Same as current

Current Secondary Outcome: Incidence of metabolic acidosis, defined by base deficit . 2 mEq/L (Henderson-Hasselback) within one hour of completion of surgery. [ Time Frame: 31/08/13 ]

Original Secondary Outcome: Same as current

Information By: Royal Marsden NHS Foundation Trust

Dates:
Date Received: May 20, 2013
Date Started: October 2012
Date Completion: August 2013
Last Updated: May 20, 2013
Last Verified: May 2013