Power is the probability that a study will reject the null hypothesis. difference between the null and alternative hypotheses. level of significance, and the null vs. alternative difference. a numeric example of power and sample size estimation for the one-sample case.
During the procedure the patient is unconscious and unaware of the need to urinate. After the procedure, however, it may not be safe for the patient to walk. They may be too sick to take care of their own bathroom needs or their surgeon may feel that a catheter is best for their particular recovery.
Once the need for the catheter is done, careful attention to removal of the line is still needed to prevent complications for the patient such as bleeding, infection, air embolism, and catheter embolism. Key elements of this practice include knowledge of how an air embolism can occur.