Hemodynamic and catecholamine responses associated with extracorporeal shock wave lithotripsy

Area of Science:

• Anesthesiology
• Nephrology
• Cardiovascular Physiology

Background:

• Nephrolithiasis treatment with extracorporeal shock wave lithotripsy (ESWL) is associated with hypertension and tachycardia.
• The cause of these hemodynamic changes during ESWL was hypothesized to be adrenal medullary release of catecholamines.

Purpose of the Study:

• To investigate the effects of ESWL on cardiovascular variables.
• To determine if ESWL influences circulating epinephrine and norepinephrine levels.

Main Methods:

• Nine anesthetized patients undergoing ESWL for nephrolithiasis were studied.
• Cardiovascular variables (cardiac output, mean arterial pressure, total peripheral resistance) and plasma catecholamine levels were measured at various time points during and after ESWL.
• Patients received isoflurane, nitrous oxide, and oxygen anesthesia, with end-tidal CO2 maintained at 34 +/- 2 mmHg.

Main Results:

• ESWL treatment led to a significant decrease in cardiac output and significant increases in mean arterial pressure and total peripheral resistance.
• These hemodynamic changes returned to baseline when ESWL was discontinued.
• Plasma epinephrine and norepinephrine concentrations did not change significantly throughout the study.

Conclusions:

• The study concludes that ESWL-associated hemodynamic alterations are likely not mediated by epinephrine or norepinephrine.
• Alternative mechanisms should be investigated to explain the observed cardiovascular changes during ESWL for nephrolithiasis.