Haemoglobin and other data from perioperative goal directed fluid protocols in total knee arthroplasty surgery patients (RCT)

We prospectively studied patients undergoing total knee arthroplasty (TKA). As part of a revised GDT (revGDT) protocol, the mini volume loading test (mVLT) was applied before induction of anaesthesia and surgery (pre-operative) and also 24-h later (post-operative). The mVLT implies mini fluid challenges consisting of acetated Ringer’s boluses followed by 5-min periods without fluids. Three 5 mL kg-1 boluses were used in mVLT for 36 TKA patients, and six 2.5 mL kg-1 boluses in other 48 TKA patients. Haemoglobins - invasive (aHb, arterial; and vHb, venous) and non-invasive (SpHb, capillary), as well as stroke volume (SV) deviation from baseline (%), perfusion index (PI) and its deviation from baseline (PID), mean arterial pressure (MAP). They were measured before and after each mini fluid challenge and also 20 min after the last bolus. We present our records of raw data. Several variables were obtained by mathematically processing haemoglobin values: plasma dilution (PD), plasma dilution efficacy (PDE), arterio-capillary plasma dilution efficacy difference (acPED) as well as relative difference between the paired invasive and non-invasive haemoglobin measurements (RD) and absolute RD (ARD) and some other parameters. We post the related math.