Usually, IV 0.9% saline is given slowly (sufficient only to keep an IV line open); vigorous volume replacement (crystalloid and colloid solutions, blood) is required only when arrest results from hypovolemia (see Intravenous Fluid Resuscitation), or as part of the management of cardiogenic shock after return of spontaneous circulation. Special Circumstances In accidental electrical shock, rescuers must be certain that the patient is no longer in contact with the electrical source to avoid shocking themselves.