Korean J Anesthesiol.  1993 Dec;26(6):1254-1264. 10.4097/kjae.1993.26.6.1254.

Clinical Study of the Changes in End tidal PCO2 Arterial Blood Gas and Vital Signs by Increased Minute Ventilation After Deflation of Tourniquet

• Wie HW
• Kim TS
• Kil HY
• Yoon YJ
• Jin SH

• KMID: 1933963
• DOI: http://doi.org/10.4097/kjae.1993.26.6.1254

Abstract

Tourniquets are often used for surgery on the extremities to provide a bloodless surgical field. However, tourniquets may cause nerve and other tissue injuries.While the tourniquet is inflated, metabolic changes occur in the ischemic limb, chages that include increased PaCO2, lactic acid and pottasium, and decreased levels of PaO2 and pH. Deflation of the tourniquet results in the release of these products of ischemia into the general circulation. The resultant decreases in arterial pH and PaO2 and increased in arterial lactic acid, potassium, PaCO2 and P(ET)CO2 are associated with significant decrease in mean arterial and central venous pressure and increase in heart rate. Since Pa is one of the important factor to control the cerebral blood flow and intracranial pressure, a sudden increase in PaCO2 immediately after toumiquet deflation may cause detrimental effects in head injured patients with elevated intracranial pressure. The purpose of this study was investigate the effect of the degree of hyperventilation by means of increased minute ventilation by 25%, 50% and 75% respectively, after deflation of toumiquets to keep P(ET)CO2 at former levels, for twenty minutes period, with arterial blood gas analysis, endtidal PaCO2 and vital signs was monitored serially. We compared normal minute ventilation group I with increased minute ventilation groups(II, III and IV) before and after deflation of tourniquet. In summary, we calculated from our data that increasing minute ventilation by more than 50% for 5 minutes following tourniquet deflation could prevent P(ET)CO2 from increasing more than 1.5-6.5 mmHg in all patients.

MeSH Terms

Blood Gas Analysis
Central Venous Pressure
Extremities
Head
Heart Rate
Humans
Hydrogen-Ion Concentration
Hyperventilation
Intracranial Hypertension
Intracranial Pressure
Ischemia
Lactic Acid
Potassium
Tourniquets*
Ventilation*
Vital Signs*
Lactic Acid
Potassium