It is the purpose of the researchers to identify the variation in intravascular deficits which can have relevance in high risk patients for minor and medium sized surgery.

The investigators will also estimate fluid deficit in healthy, non-fasting subjects for comparison.

Intravascular volume optimization has shown to improve outcome after surgery. In minor and medium surgery , however, the preoperative volume deficit has not been estimated with functional parameters. Patient scheduled for minor surgery are included. After the patient is anesthetized the intravascular volume is optimized by stroke volume maximization by colloid boluses. Stroke volume is obtained by esophageal Doppler technique which is a minimally invasive method.

The volume estimated for optimization is considered as the functional volume deficit.

In the healthy subjects the probe will be placed in the awake subject. A standardized meal and fluid intake secures that the subjects are in a non-fasting state.

Inclusion Criteria:

• Planned minor or medium sized surgery

Exclusion Criteria:

• Oesophageal pathology
• Age >90 yr or < 18 yr
• Alcohol abuse,
• Insulin dependent DM

Patients for surgery in 3 procedures:

• mastectomy
• rad. prostatectomy
• open adb. surgery

And 20 healthy subjects