- many surgeon use 30 mm Hg as the cut off for performing fasciotomy;
- diastolic pressure: (Whiteside' Theory):
- development of a compartment syndrome depends not only on intra-compartment pressure but also depends on systemic blood pressure;
- DBP - CP should be greater than 30
- references:
- Diastolic blood pressure in patients with tibia fractures under anaesthesia: implications for the diagnosis of compartment syndrome.
- Diagnostic techniques in acute compartment syndrome of the leg.
- compartment measurements within 20 mm Hg of diastolic pressure is an indication for fasciotomy (hence DBP - compartment pressure is a relative indicator of tissue perfusion);
- some authors cite a difference of 20-30 as a relative indication for compartment syndrome;
- in contrast, differences (DBP-CP) of greater than 30, tend to indicate that compartment syndrome is not present;
- compartment pressure measurements should be taken as close to the fracture site as possible (since these will give the highest readings);
- influence of vascular injury: (see vascular trauma)
- while pulses are usually present in compartment syndromes, the absence of a pulse (eg. from associated fracture or trauma) raises the probability that a compartment syndrome could occur;
- for instance loss of the anterior tibial artery following a tibial fracture, places anterior compartment at high risk for compartment syndrome;
- which type of needle is best?
- Moed and Thorderson (1993) compared three methods of measurement methods: (the simple-needle technique, use of the slit catheter, and use of the side-ported needle.)
- the side-ported needle appeared to be as accurate as the slit catheter for the measurement of compartment pressures (p = 0.355, 1-beta = 0.9);
- the values obtained with use of simple needle were consistently higher than those obtained with other 2 methods (p < 0.001): an average of 18.3 millimeters of mercury
higher than the values measured with slit catheter and 19.3 millimeters of mercury higher than those measured with the side-ported needle;
- use of the simple 18-gauge needle is not recommended for this purpose.
- references:
- Measurement of intracompartmental pressure: a comparison of the slit catheter, side-ported needle, and simple needle.
- Intracompartmental pressure, PO2, PCO2 and blood flow in the human skeletal muscle.
- Tibial Compartment Pressures Measurements:
- most common finding is isolated elevation in the deep posterior compartment followed by isolated elevation in the anterior compartment;
- be sure to measure pressure in the deep posterior compartment as well as anterior & superficial compartments;
- compartment pressure measurements should be taken as close to the frx site as possible (since these will give the highest readings);
- peak compartment pressures will be located within 5 cm of frx;
- measurements away from the frx site may underestimate compartment pressure;
- sterile technique is a must when compartments are measured, otherwise the frx hematoma may become infected;
- references:
- Compartment monitoring in tibial fractures. The pressure threshold for decompression.
- Compartment pressures after closed tibial shaft fracture. Their relation to functional outcome.
- Intramuscular pressure varies with depth. The tibialis anterior muscle studied in 12 volunteers.
- Compartment pressure in association with closed tibial fractures. The relationship between tissue pressure, compartment, and the distance from the site of the fracture.
- Compartment pressure monitoring during intramedullary fixation of tibial fractures.
- Compartmental pressure in adults with tibial fracture.
- Elevated intramuscular compartment pressures do not influence outcome after tibial fracture.
- Compartment pressure in nailed tibial fractures. A threshold of 30 mmHg for decompression gives 29% fasciotomies.
- Normal compartment pressures of the lower leg in children.
Acute compartment syndromes: diagnosis and treatment with the aid of the wick catheter.
Intramuscular pressure varies with depth. The tibialis anterior muscle studied in 12 volunteers.
Diagnostic techniques in acute compartment syndrome of the leg.
Survey of management of acute, traumatic compartment syndrome of the leg in Australia
Continuous compartment pressure monitoring vs. clinical monitoring in tibial diaphyseal fractures.
The Estimated Sensitivity and Specificity of Compartment Pressure Monitoring for Acute Compartment Syndrome