Peripheral artery disease peripheral artery disease: If peripheral artery disease is suspected, the initial study is the ankle–brachial index (ABI). The ABI is a simple, non-invasive test, which measures the ratio of systolic blood pressure in the ankle to the systolic blood pressure in the upper arm. This is based on the idea that if blood pressure readings in the ankle are lower than those in the arm, a blockage in the arteries that provide blood from the heart to the ankle is suspected. An ABI range of 0.90 to 1.40 is considered normal. A person is considered to have PAD when the
Brachial plexus block represent the limit below which the needle must not be directed (the pleural cavity and uppermost part of the lung are located at this level). Palpation or ultrasound visualization of the subclavian artery just above the clavicle provides a useful anatomic landmark for locating the brachial plexus, which is lateral to the artery at this level. Proximity to the brachial plexus can be determined using by elicitation of a paresthesia, use of a peripheral nerve stimulator, or ultrasound guidance. Compared to the interscalene block, the supraclavicular block — despite eliciting a more complete block of the median, radial ulnar and