Prognostic indicators in colic horses 111 Ta bl e 1 . Clinical and laboratory variables in the study. Clinical variables Heart rate /min Respiratory rate /min Rectal temperature °C Mucous membranes (normal/abnormal) Capillary reﬁll time (CRT) sec Pain (no pain/moderate/severe) Abdominal activity (no sounds/decreased/normal/increased) Distended small intestine by rectal examination (yes/no) Pain by rectal examination (yes/no) Reﬂux through naso-pharyngeal tube (yes/no) Laboratory variables Packed cell volume (PCV) % Haemoglobin g/l Total protein g/l α-, ß- and γ-globulin g/l Albumin g/l Fibrinogen g/l Anion Gap (Na+ + K+-(Cl-+ HCO3)) mmol/l Na+ mmol/l K+ mmol/l Cl- mmol/l Total Ca mmol/l Mg++ mmol/l Lactate mmol/l HCO - mmol/l 3 Arterial pO2 kPa Arterial pCO2 kPa Standard Base Excess (SBE) mmol/l PH D-dimer mg/l peraemic or cyanotic as pallor and jaundice were not recorded). Abdominal paracentesis was not systematically performed, and the pro- tein content and cytology of the abdominal ﬂuid were therefore not used in the statistical analy- ses. Decisions whether the patients should be treated surgically or medically were primarily based on the clinical variables. The criteria for surgical treatment were: (i) Recurrent pain de- spite heavy analgesic treatment and/or (ii) Rec- tal ﬁndings of distended small intestines and/or (iii) Rectal ﬁndings corresponding to displace- ment of the large intestines. Non-responders to the medical treatment were continuously evalu- ated for surgical intervention. The different clinical variables used in this study are presented in Table 1. Laboratory analyses Packed cell volume (PCV) was analysed by a capillary micro centrifuge using venous blood from the jugular vein. Haematological variables were analysed on Technicon H 1 Analyser (Miles Inc., Tarrytown, NY, USA). For blood gas analysis approximately 1 ml of blood was collected from the transverse facial artery into a Pico 70 heparinised arterial blood sampler (Radiometer Medical A/S, Copenha- gen, Denmark) for immediate acid-base and blood gas evaluation on a Radiometer ABL 625 acid-base laboratory (Radiometer Medical A/S, Copenhagen, Denmark). Values were adjusted to body temperature. Total serum protein was measured with a re- fractometer (Atago SPR-NE, Atago Co LTD, Japan). Serum electrophoresis to measure albu- min, α-, ß- and γ-globulin fractions was per- formed using Paragon Electrophoresis System (Beckman Instruments Inc, Brea CA, USA). Fibrinogen was measured indirectly by calcu- lating the difference of total protein in EDTA- plasma and serum. Serum sodium was mea- sured with an ion-selective electrode,1 serum chloride was measured with a colorimetric method,2 and plasma lactate was measured en- zymatically.3 ––––––– 1 AVL 982 Electrolyte analyzer, AVL List GmbH, Graz, Austria. 2 Technicon RA-1000, Miles Inc., Tarrytown, NY. 3 Lactate fully enzymatic, Boehringer Mannheim, Germany. Acta vet. scand. vol. 45 no. 1-2, 2004