A prospective randomised trial of tourniquet in varicose vein surgery.

A prospective randomised trial of 50 patients was carried out to assess the autoclavable Lofquist cuff (Boazal, Sweden) as a tourniquet in varicose vein surgery and determine the effect on bleeding, bruising, cosmesis and patient pain and activity. Patients undergoing unilateral long saphenous vein ligation, stripping and avulsions were randomised to tourniquet or no tourniquet. Lofquist cuffs were applied after inflation to 120 mmHg to the upper thigh for the duration of the surgery. Varicose vein grade, duration of surgery, blood loss, extent of bruising at 7 days, pain and activity scores over the first week, and wound complications and cosmetic result at 6 weeks were recorded. Patients' age, sex, and varicose vein grade were similar in the two groups. Peroperative blood loss (median, range) was significantly reduced in the tourniquet group (0 ml, 0-20 ml) compared to the no tourniquet group (125 ml, 20-300; P < 0.01). Operative time and thigh bruising (median, range) were also reduced in the tourniquet group (30 min, 11-47 min; 72 cm2, 30-429 cm2), respectively, compared to the no tourniquet group (37 min, 18-50 min; 179 cm2, 24-669 cm2) both (P < 0.01). There was no difference in pain and activity scores in the two groups and cosmetic results were also similar. The use of the Lofquist cuff tourniquet during varicose vein surgery reduces peroperative blood loss, operative time and postoperative bruising without any obvious drawbacks.

Thrombophilia, polymorphisms, and vascular disease.

Thrombophilia traditionally refers to rare inherited defects leading to enhanced coagulation, especially of the venous system. In recent years, a broader search for genetic polymorphisms of prothrombotic genes has been carried out to determine the relative impact on venous and arterial thrombosis. The bulk of evidence is drawn from numerous, often small, heterogeneous, case control association studies, with a variety of end points (deep venous thrombosis, myocardial infarction, or stroke). The data are often conflicting and inconclusive with only factor V Leiden and prothrombin polymorphisms having clear associations with venous thrombosis. Many of the polymorphisms interact with established cardiovascular risk factors, in particular smoking, to increase greatly the risk of a thrombotic episode. Future studies will need to consider the confounding factors of sample size, race, and clinical end points as well gene-environment interactions.

Sodium pentobarbitone enhances responses of thalamic relay neurones to GABA in rat brain slices.

1. In rat isolated thalamic slices, intracellular recordings were made of responses to electrophoretically applied gamma-aminobutyric acid (GABA) in the absence and presence of sodium pentobarbitone (NaPb). 2. Responses to electrophoretically applied GABA were biphasic in the majority of neurones studied. They consisted of an early, negative-going and later, positive-going phase, when recorded close to reversal potential. 3. An increase in the GABA ejection current caused an enhancement of the late positive-going phase, along with a shift in the reversal potential of the whole response to a more positive value. These changes were accompanied by an increase in GABA-induced conductance (decrease in resistance) and an increase in the duration of the response. 4. Application of NaPb to the GABA response produced similar effects, namely an enhancement of the late positive-going phase, a shift in the reversal potential to a more positive value, an increase in conductance and an increase in duration. 5. GABA-mediated inhibitory postsynaptic potentials (i.p.s.ps) were evoked by electrical stimulation of the nucleus reticularis thalami. Application of NaPb caused an increase in the duration of the i.p.s.p. and a shift in its reversal potential to a more positive value.