Comparison of Two Potassium Targets Within the Normal Range in Intensive Care Patients (GRIP-COMPASS)

• Potassium regulation within 3.5 to 5.0 mmol/L. [ Time Frame: From Intensive Care Unit admission to hospital discharge. ] [ Designated as safety issue: Yes ]
  Participants will be followed for the duration of hospital stay, an expected average of 2 weeks.
• AFib or AFl in other patients, i.e. patients who did not undergo CABG or valvular surgery. [ Time Frame: First 7d after ICU-admission or hospital discharge, whichever is earlier. ] [ Designated as safety issue: No ]
  Post-surgery AFib and AFl typically occur within days after surgery. AFib and AFl can only be reliably assessed during ICU stay and hospital stay. Therefore this outcome measure is not determined after hospital discharge.
• Biochemical disturbances including electrolytes (Na, K, Mg, Ca), blood gas analysis, lactate, renal function (creatinine, urea). [ Time Frame: From ICU-admission to hospital discharge. ] [ Designated as safety issue: No ]
• Cumulative fluid balance. [ Time Frame: During ICU-stay. ] [ Designated as safety issue: No ]
• Mortality and (ICU) length of stay. [ Time Frame: ICU-mortality and hospital-mortality as well as 90-day mortality. ] [ Designated as safety issue: Yes ]
• Glucose regulation [ Time Frame: During ICU-admission. ] [ Designated as safety issue: No ]
  The relation with glucose levels and insulin administration

• Potassium regulation within 3.5 to 5.0 mmol/L. [ Time Frame: From ICU-admission to hospital discharge. ] [ Designated as safety issue: Yes ]
• AFib or AFl in other patients, i.e. patients who did not undergo CABG or valvular surgery. [ Time Frame: First 7d after ICU-admission or hospital discharge, whichever is earlier. ] [ Designated as safety issue: No ]
  Post-surgery AFib and AFl typically occur within days after surgery. AFib and AFl can only be reliably assessed during ICU stay and hospital stay. Therefore this outcome measure is not determined after hospital discharge.
• Biochemical disturbances including electrolytes (Na, K, Mg, Ca), blood gas analysis, lactate, renal function (creatinine, urea). [ Time Frame: From ICU-admission to hospital discharge. ] [ Designated as safety issue: No ]
• Cumulative fluid balance. [ Time Frame: During ICU-stay. ] [ Designated as safety issue: No ]
• Mortality and (ICU) length of stay. [ Time Frame: ICU-mortality and hospital-mortality as well as 90-day mortality. ] [ Designated as safety issue: Yes ]
• Glucose regulation [ Time Frame: During ICU-admission. ] [ Designated as safety issue: No ]
  The relation with glucose levels and insulin administration

Rationale: It is well known that distinctly abnormal blood potassium values can cause serious complications such as cardiac arrhythmias. Although potassium regulation is generally considered important, hardly any research has been done about potassium regulation in intensive care patients. The investigators hypothesize that different potassium target-values, within the as normal accepted range, may have different effects in critically ill patients.

Study design: A prospective trial comparing two different potassium target-values. Potassium will be tightly regulated with the already fully operational GRIP-II computer program.

Study population: 1200 adult patients admitted at the thoracic intensive care unit of the University Medical Center Groningen.

Intervention: Comparison between two variations of standard therapy: potassium target-value of 4.0 mmol/L versus 4.5 mmol/L.

Main study parameters/endpoints: The primary endpoint is the incidence of atrial fibrillation or atrial flutter from ICU-admission to hospital discharge. Secondary endpoints are serum levels of potassium and the other main electrolytes, renal function and renal potassium excretion, the relation with insulin and glucose, the cumulative fluid balance, (ICU) length of stay and mortality.

• Thoracic Surgery
• Cardiac Surgery
• Critically Ill

• Drug: Potassium Chloride
  KCl is continuously administered and titrated towards a Normal-high Potassium (4.5 mmol/L)
• Drug: Potassium Chloride
  KCl is continuously administered and titrated towards a Normal-low Potassium (4.0 mmol/L)

• Active Comparator: Normal-high potassium (NHP)
  A potassium target of 4.5 mmol/L.
  Intervention: Drug: Potassium Chloride
• Active Comparator: Normal-low potassium (NLP)
  A potassium target of 4.0 mmol/L.
  Intervention: Drug: Potassium Chloride

• Vogelzang M, Zijlstra F, Nijsten MW. Design and implementation of GRIP: a computerized glucose control system at a surgical intensive care unit. BMC Med Inform Decis Mak. 2005 Dec 19;5:38.
• Vogelzang M, Loef BG, Regtien JG, van der Horst IC, van Assen H, Zijlstra F, Nijsten MW. Computer-assisted glucose control in critically ill patients. Intensive Care Med. 2008 Aug;34(8):1421-7. Epub 2008 Apr 4.
• Hoekstra M, Vogelzang M, Verbitskiy E, Nijsten MW. Health technology assessment review: Computerized glucose regulation in the intensive care unit--how to create artificial control. Crit Care. 2009;13(5):223. Epub 2009 Oct 16.
• Hoekstra M, Vogelzang M, Drost JT, Janse M, Loef BG, van der Horst IC, Zijlstra F, Nijsten MW. Implementation and evaluation of a nurse-centered computerized potassium regulation protocol in the intensive care unit--a before and after analysis. BMC Med Inform Decis Mak. 2010 Jan 25;10:5.

Inclusion Criteria:

• All adult patients admitted to the thoracic and surgical ICU of the University Medical Center Groningen.
• Computerized potassium regulation with GRIP-II

Exclusion Criteria:

• Patients who are not potassium regulated with GRIP-II (patients who take their own meals).