To reduce pressure-related injuries resulting from pneumatic tourniquet use, the lowest possible inflation pressure is recommended. Arterial occlusion pressure (AOP) is a measure of the cuff pressure required to maintain a bloodless surgical field. However, its determination method is time consuming, requires operator skill, and is therefore seldom used in current practice. An AOP estimation can be made by knowing the pressure transmitted to the underlying soft tissues. We measured upper and lower extremity tissue pressures under the tourniquet cuff at 100, 200, and 300 mm Hg of tourniquet inflation pressures in 30 anesthetized living adult patients. All patients received general anesthesia with neuromuscular relaxation. A Stryker intra-compartmental pressure monitor was used to measure tissue pressures under the tourniquet cuff. In all patients, the soft tissue pressures were consistently lower than the applied tourniquet inflation pressures. Our results revealed tissue padding coefficients for extremities 20 to 75 cm in circumferences. An estimation method of AOP was developed [AOP = (systolic blood pressure + 10)/Tissue padding coefficient]. The new AOP estimation method may be a simple, rapid, and clinically practical alternative to the AOP determination method.

No abstract

IP pretreatment reduces lipid peroxidation and lung injury caused by lower limb IR.

Ischaemic preconditioning attenuates haemodynamic response and lipid peroxidation during lower-extremity surgery with unilateral tourniquet application.

Interscalene brachial plexus block (ISB) anaesthesia is widely used with or without general anaesthesia in patients undergoing shoulder surgery, which is generally done with the patient in a sitting position. This position affects haemodynamics, and supplementing ISB with general anaesthesia can exaggerate these haemodynamic changes. This study compared ISB combined with general anaesthesia, with ISB alone, in 29 patients undergoing elective shoulder surgery. Heart rate and oxygen saturation remained stable throughout the study in both groups. Mean arterial pressure was significantly decreased when the patient moved into the sitting position in those given combined anaesthesia, whereas in those given ISB alone mean arterial pressure did not change significantly. Neither pain scores nor patient satisfaction scores differed significantly between the two groups. All of the patients were either satisfied or entirely satisfied with their anaesthesia/analgesia. There were no significant differences in side-effects and no severe complications in either group. We advocate using ISB alone for patients undergoing shoulder surgery, but further larger studies are needed to confirm the present results.