Alteration of anion gap during almost total plasma replacement with synthetic colloids in piglets.

In ten piglets (body weight 8.2-11.6 kg), acid base, electrolyte and anion gap changes were investigated during almost total plasma replacement with hydroxyethyl starch (HES) and modified fluid gelatin (GEL) in saline solution using a cell saver autotransfusion technique. During the study, there were only moderate acid base changes, but marked disturbances in anion balance. At study end, the mean chloride concentration was significantly higher (mmol/l: normal values 97-108, HES 116 +/- 1.5, GEL 108 +/- 1.1, p < 0.01) and the mean anion gap was significantly lower in the HES group in comparison to the GEL group (mmol/l: normal values 5-14, HES 3 +/- 1.7, GEL 11.9 +/- 0.9, p < 0.01). It is concluded that plasma replacement with electroneutral HES, but not with negatively charged GEL, can lower the anion gap irrespective of the underlying disease. This can be misleading when the anion gap is used for differential diagnosis of metabolic acidosis in patients after large volume infusion of synthetic colloids.

[The visibility of a central venous catheter using digital luminescence radiography in intensive care radiology]. / Erkennbarkeit zentralvenöser Katheter bei Einsatz der digitalen Lumineszenzradiographie in der intensivmedizinischen Radiologie.

The aim of the following study was to assess the impact of dose alterations on the detection of catheters. We compared the performance of well-exposed conventional and digital portable chest radiographs in the detection of thin catheters and tested the influences of dose alterations. Portable chest radiographs of 20 patients were obtained with conventional film/screen (FR) and with storage phosphors at 50% (SRL), 100% (SRN), and 250% (SRH) of the conventionally required exposure dose. The region of the mediastinum was subdivided into an average of 18 fields, 50% of which were superimposed with thin catheter segments. ROC analysis of 11,600 observations by 8 readers found only SRH equivalent to FR in catheter visualisation. Performance decreased significantly with SRN and SRL. Detection of low contrast catheters was found to be significantly decreased in storage phosphor radiographs obtained with standard exposure dose. A dose reduction is not feasible with current equipment if performance equivalent to conventional radiography is to be achieved.

Acid-base, electrolyte and metabolite concentrations in packed red blood cells for major transfusion in infants.

METHODS: Acid-base, electrolyte and metabolite concentrations were determined in 100 U of packed red blood cells (RBC) preserved in extended-storage media to be used for major transfusion in paediatric and cardiac surgery. RESULTS: In fresh RBC, low pH, bicarbonate (cHCO3-), base excess (BE) and high glucose values were observed all outside the physiological range. With lengthening storage duration, values of pH, cHCO3-, BE, sodium and glucose decreased and carbon dioxide, potassium and lactic acid concentrations increased [mean +/- SD (range): storage duration 6.7 +/- 3.8 (1-17) days, pH 6.79 +/- 0.1 (6.53-6.99); mmol.l-1: cHCO3- 11.1 +/- 1.5 (6.2-14.5), BE - 29.2 +/- 4.1 ([-39.4] - [-20.9]), potassium 20.5 +/- 7.8 (4.2-43.6), glucose 24.1 +/- 6.1 (16.7-29.2), lactic acid 9.4 +/- 4 (4.3-21.4)]. CONCLUSION: Massive and rapid transfusion of RBC may lead to a severe burden of hydrogen ions, carbon dioxide, potassium, glucose and lactic acid and this can be avoided by cell saver blood processing, when autologous erythrocytes from the operative field are saved and substrate load and storage lesions from packed red blood cells are minimized in one step by washing.

Haemodynamic, acid-base and electrolyte changes during plasma replacement with hydroxyethyl starch or crystalloid solution in young pigs.

We investigated haemodynamic, acid-base and electrolyte changes during almost total plasma replacement with hydroxyethyl starch (HES) and physiological balanced electrolyte solution (PBE) by using a cell saver in ten young pigs. In the PBE group an additional 3550 (444) ml crystalloid solution [Mean (SD)] was infused over the course of the study in order to maintain pulmonary capillary wedge pressure. Plasma protein levels decreased in both groups and the colloid osmotic pressure increased in HES and decreased in PBE. At the end of the study, body weight [HES 10.4 (1), PBE 13.1 (1.4) kg, P < 0.01] and lactic acid concentration [HES 0.9 (0.3), PBE 2.9 (1. 3) mmol.l -1, P < 0.01] was higher and tissue oxygen delivery [HES 327 (22), PBE 89 (29) ml.min.m2, P < 0.01] was lower in the PBE group. There were only moderate acid-base changes in both groups, but at the end, anion gap was significant lower in HES. In conclusion, maintenance of colloid osmotic pressure close to the physiological range of infants seems to be advantageous during major paediatric surgery.