[Experimental and clinical study of safe prolongation of tourniquet time by hypothermia of an upper limb (author's transl)].

UNLABELLED: In order to establish a practical method by which the tourniquet can be safely kept on for more than 2 hours, i.e., the safe limit in the conventional method, the author initially made an experimental and then a clinical investigation as follows. EXPERIMENT: Thirty-five adult mongrel dogs were used including a control group. One hour immersion of hind limb in ice water lowers the temperature of leg muscles from ca. 38 degrees C to 16 degrees--18 decrees C. Thereafter, maintenance of tourniquet exsanguination of the cooled hind limb for 5 hours elevates the muscle temperature several degrees, but still keeps it much lower than in the control group. Edema and limping appeared after release of the tourniquet and subsided much faster in the cooled group than in the control group. Result in 12 CASES: Cooling of an upper limb after general anesthesia or nerve block with ice bags for 30 minutes lowers the temperature of the forearm muscles from 30 degrees--35 degrees C to 16 degrees--25 degrees C. Tourniquet applied thereafter at the upper arm was kept inflated maximally for four hours and 7 minutes. An average of 3 hours and 30 minutes did not cause any serious side effects but only temporary dysesthesia at the finger tips in 2 cases and a Tinel's sign at the site where tourniquet was applied in one case. CONCLUSION: These results proved that tourniquet time could be safely prolonged for 4 hours. The most important problem in the future is to clarify how far it can be safely prolonged.

Gross errors made by routine blood sampling from two sites using a tourniquet applied at different positions.

Tourniquet application in routine blood sampling procedures may induce considerable haemoconcentration and thereby augment the concentration of serum protein and protein-bound substances. To evaluate this effect serum protein, calcium and magnesium were measured in 31 healthy persons before and after 3-min venous stasis induced by a standardized tourniquet. Four sites of tourniquet and two sampling sites on the arm were compared. The concentration of measured serum constituents rose after the stasis period (5--13% rise in serum protein), the changes being similar at all tourniquet positions. However, blood sampled from a cubital arm vein showed significantly larger haemoconcentration than samples obtained simultaneously more distally on the arm. Taking three samples in a series, the serum concentration of protein, calcium and magnesium rose from tube to tube (5--10% change). The study demonstrates that neither use of a standardized tourniquet nor release of the tourniquet before blood sampling eliminates the errors inherent in routine venepuncture. Adjustment to a constant serum protein level minimizes these errors.

Plasma lidocaine concentrations after different methods of releasing the tourniquet during intravenous regional anaesthesia.

Different methods of tourniquet release have been proposed to decrease the concentrations of local anaesthetic released into the systemic circulation at the end of intravenous regional anaesthesia. The effect of releasing the tourniquet intermittently with 5 seconds (group I) and 30 seconds (group II) deflation periods or at once (group III) was studied in 25 adult patients after intravenous regional anaesthesia with 40 ml of 0.5% lidocaine. The venous plasma lidocaine concentrations from the contralateral arm were measured by gas chromatography. There was no leakage of lidocaine from the occluded arm into the systemic circulation. The mean maximum plasma lidocaine concentration in group I 1.99 +/- 1.45 (SD) microgram/ml, in group II 1.33 +/- 0.54 microgram/ml and in group III 1.56 +/- 0.88 microgram/ml (P greater than 0.05) was below the toxic concentrations reported in the literature. There were subjective complaints such as dizziness and ringing in the ears in 4 out of the 7 patients in group I, in 2 out of the 9 patients in group II and in one of the 9 patients in group III (P greater than 0.05). There was no correlation between the duration of tourniquet time (range 12-87 minutes) and the maximum plasma lidocaine concentration. The intermittent release of the tourniquet did not decrease the venous plasma lidocaine concentrations in the contralateral arm; neither did comparing the lidocaine pharmacokinetics in 5 patients of group II after tourniquet release and in the 5 healthy volunteers after a single 100 mg intravenous lidocaine injection reveal any differences.

[Diagnosis of incompetent communicating veins in contrast medium-sensitive patients]. / K diagnostike nesostoiatel'nykh kommunikatsionnykh ven u kontrastno-chuvstvitel'nykh bol'nykh.

A new functional method of phlebotonometry was used by the authors in 36 contrast--sensitive patient with postthrombophlebitic syndrome and varicosis for the purpose of diagnosing incompetent calf communicants. The determination of venous pressure in the superficial veins in these patients should be carried out between tourniquets three times at rest and against the backgrounds of the Valdman's test with the patient in a horizontal position by means of Valdman apparatus with elongated capillary tubes.

Electromyographic changes in postmeniscectomy patients. Role of the pneumatic tourniquet.

Delayed rehabilitation in postmeniscectomy patients may be due to a slowly resolving axonal compression syndrome secondary to the use of the pneumatic tourniquet. Twenty-five patients who underwent meniscectomy were examined to determine whether the pneumatic tourniquet used during the procedure caused a neurological dificit detectable by electromyography (EMG). Of these, 18 had postsurgical EMG changes that eventually resolved. Analysis of the data suggests a relationship between the occurrence of EMG abnormalities, the duration of the tourniquet inflation during surgery, and patient's recovery time. Quadricep muscle weakness after knee surgery has generally been attributed to disuse atrophy. In an attempt to prevent this problem, patients participate in a quadriceps exercise program, if possible, before surgery, with continuation after surgery. The persistence of weakness has been believed to be secondary to inadequate exercise.

Repair of the quadriceps apparatus following patellectomy in recent fractures of the patella: a new technique, with results.

The importance of "double tourniquet" technique in repair of the quadriceps mechanism after total patellectomy in recent fractures of the patella is described and its advantages are discussed. The results following this method of repair in 17 total patellectomies have been studied and discussed.

The use of tourniquets in podiatric surgery--a review.

The purpose, types, advantages, disadvantages, and clinical application of tourniquets is reviewed. Special emphasis is given to the pneumatic tourniquet as it is used today in podiatric surgery. A discussion of its possible complications as well as a method of using a double thigh and ankle cuff is presented.