Stage 3
The third stage is the tolerance stage and the desired state during the surgical procedure. The beginning of this stage is the end of involuntary muscle twitches. The cerebrum, midbrain and also the spinal cord are now completely inhibited.
This leads to the loss or strong inhibition of reflexes and muscle tone. The muscles slacken and thus offer good surgical conditions. The sensation of pain is completely eliminated.
Breathing is weakened and irregular, so that artificial help is required. The blood pressure and heart rate also drop. The pupils are initially narrow and become large again in the course of the third stage. This stage can be maintained for a long time by closely controlling the amount of gas and the patient can be awakened from this stage after the end of the procedure. Slippage into the fourth stage is avoided and is manifested by a complete cessation of autologous breathing.
Stage 4
The fourth stage of anesthesia after Guedel is poisoning. The beginning of this stage is marked by the failure to breathe. The regulatory centers for respiration and circulation, which are located in the brain stem, are paralyzed and both circulation and respiration are further reduced.The pupils are set as wide as possible and no longer react to light.
The muscle tone and reflexes are no longer present. The stage of poisoning ends with the breakdown of the circulation. In Guedel’s time this was a death sentence for the patient.
Today, artificial respiration and circulation-stabilizing drugs can still save the patient. There is no antidote to anaesthetic gases, but by strongly flooding the anaesthetic device with oxygen, the gas can be exhaled more quickly. Without intensive medical treatment, the brain and other organs are undersupplied with oxygen.
Late damage is also possible if the poisoning survives. The stage of poisoning is hardly ever reached today, since narcoses are carried out with drug mixtures and the gas can therefore be dosed less. At this point, the editors recommend that you also inform yourself about the possible risks of anesthesia.
