[Noninvasive monitoring]

For a number of reasons, invasive and non-invasive measuring procedures for monitoring purposes must not be considered to be mutually exclusive alternatives. The transitions between the two are fluid, and their respective advantages and disadvantages frequently complement one another. The complication rate characteristic of a given procedure is the greater, the more invasive this procedure is. For this reason, a non-invasive technique should always be given preference over an invasive method provided it is capable of recording the parameter to be monitored at least as reliably and accurately as the latter. For minimal monitoring during anaesthesia, non-invasive procedures are applied exclusively. These include the monitoring of ventilation (FIO2, pressures, volumes, flows), ECG, measurement of blood pressure employing the cuff method, temperature measurement, and a nerve stimulator for establishing the degree of relaxation. In addition, pulse oximetry and capnography are increasingly becoming accepted elements of basic monitoring. The question as to whether further monitoring procedures need to be employed will depend upon the condition of the patient and the nature and duration of the surgical operation and anaesthesia. Here, preferential use is made of invasive methods of recording pressures and flows (cardiac output) within the circulatory system and of various blood parameters (for example, blood gas analysis). To an increasing extent, they are being supplemented, expanded or replaced by newly developed non-invasive methods. Thus, for example, the time and material requirement for non-invasive blood pressure measurement in the finger by means of servomanometry (Finapres) is reduced as compared with intra-arterial pressure recording.(ABSTRACT TRUNCATED AT 250 WORDS)