Extended monitoring | Monitoring

Extended monitoring

The extension of the basic monitoring may be indicated for certain procedures and patients. This is especially true for patients with pre-existing cardiovascular diseases or patients requiring intensive care. The EEG records the brain waves.

This provides information on the depth of anaesthesia and the blood flow in the brain. The EEG is used in addition to the normal monitoring, if particularly endangered persons are operated on or if interventions are performed on blood vessels supplying the brain. In contrast to non-invasive blood pressure measurement, this method is more accurate because a measuring probe is placed directly into an artery on the wrist to determine the blood pressure.

This probe continuously registers the blood pressure, so that even small fluctuations can be noticed directly. The invasive blood pressure measurement is used especially for patients with circulatory instability, a high risk of bleeding or major vascular surgery. The central venous catheter represents an alternative access route to the patient’s venous vascular system.

It is usually placed in a large vein in the patient’s neck. The central venous pressure can be determined by the central venous catheter, which provides information about pressure conditions in the pulmonary circulation and thus indirectly about the patient’s heart function and volume status. In addition, infusions and nutrient solutions can be administered via the CVC, which would lead to irritation of the veins if the access to the extremities were smaller.

Patients who are particularly at risk for myocardial insufficiency or a heart attack are monitored by a special ECG. In addition, the so-called ST segment is closely monitored, which enables the anesthetist to detect early on whether the patient’s heart is undersupplied with blood. Cardiac output is the volume of blood that the heart pumps through the body in a given period of time.

It is a measure of the functional efficiency of the heart muscle and is particularly reduced in a state of shock. The cardiac output is measured using a so-called thermodilution method. For this purpose, a temperature probe is placed in a vein in the groin.

Then a cold saline solution (approx. 20°C) is injected – usually into a vein in the neck area. The distribution of the cold solution leads to a change in the temperature of the blood, which can also be measured in the groin after a certain time.

The time required to transport the cold solution to the groin depends on the cardiac output.Thus this can be calculated indirectly. This method is used especially for patients in shock and for patients with sepsis (blood poisoning).