Physiological Effects of 38°C vs. 22°C Fluid Therapy in Critically Ill Patients

Physiological Effects of 38°C vs. 22°C Fluid Therapy in Critically Ill Patients: A Randomized Controlled ICU Study

A randomized controlled clinical trial. 24 adult ICU patients will be recruited upon decision to administer fluid bolus of 500ml of crystalloid. The fluid will then be randomized to be infused at controlled room temperature or warmed to body temperature. Hemodynamic measurements will be made for 2 hours following the bolus, and laboratory values will be noted. The hypothesis is that part of the hemodynamic response will differed in response to cooling, and be larger in the cold group.

A randomized controlled clinical trial of the influence of fluid temperature on hemodynamic effects of fluids. 24 adult ICU patients meeting objective criteria of circulatory impairment (hypotension, tachycardia, lactatemia etc) will be recruited upon decision to administer fluid bolus of 500ml of crystalloid. The fluid will then be randomized to be infused at controlled room temperature of 22 degrees or warmed to body temperature at 38 degrees. All patients will be monitored with either calibrated or uncalibrated pulse contour analysis. Hemodynamic measurements (Heart rate (HR), Systolic blood pressure (SBP), Diastolic blood pressure (DBP), Mean arterial pressure (MAP), Cardiac output (CO), Cardiac index (CI), Stroke volume (SV), Stroke volume variation (SVV), Extravascular lung water (EVLW) etc) will be registered for 2 hours following the bolus, and laboratory values such as lactate, creatinine will be noted, as well as fluid balances. Confounders such as levels of vasopressors, sedation, switches in positioning och or ventilation will be registered. The hypothesis is that part of the hemodynamic response will differed in response to cooling, and be larger in the cold group.

Inclusion Criteria:

• Admission to the ICU
• Age 18 years or older
• Clinical decision to administer a fluid bolus of at least 500 ml of crystalloid over 15 minutes.
• Monitoring with either an arterial line in an extremity that can be used for pulse contour analysis (Vigileo, FloTrac or equivalent system) or a central venous catheter and a femoral arterial line that can be used for pulse contour analysis calibrated by thermodilution (EV1000, PiCCO or equivalent system)
• At least one of the following criteria for fluid administration must be met:
• MAP < 65 mmHg
• HR >100
• Urine output < 0,5ml/kg/h
• Lactate levels of > 3 mmol/l
• CI < 2.5L/min/m2
• SVV or PPV > 12% if mechanically ventilated with tidal volumes > 7 ml/kg
• ScvO2 or SvO2 < 65%

Exclusion Criteria:

• Active bleeding requiring transfusion
• Haemoglobin level <70 g/L
• Arrhythmia disturbing monitoring of cardiac output
• Patients in whom death is considered imminent (within 24 hours)
• CRRT
• Known pregnancy
• Active temperature control, either active warming or cooling
• Medical issue of pathological thermoregulation, such as malignant hyperthermia, thyroid storm, NMDA overdose, serotonin syndrome, malignant neuroleptic syndrome, or delirium.
• Planned exit from the ICU during the 2-hour monitoring period (planned surgical procedure, radiology, change of department etc.)