Leveling when monitoring central blood pressures: an alternative method

Monitoring central hemodynamic pressures is an important part of total assessment by those who assume responsibility for total care of those critically ill patients in need of invasive monitoring. In such patients frequent measurements are required during the course of the several days, on a 24 hour basis. If the data are to be highly reliable and valid, particular attention must be given to the important aspects of leveling the two reference points by the several nurses who assume such responsibility. The two methods of leveling now in use, sighting and use of the spirit level, leave the question of such consistent accuracy in doubt. This alternative method of using water in a closed loop of tubing for leveling, with its definite and necessary steps, may seem to be time consuming to the already busy critical care nurse. The ability to master the necessary technique after a few practices and to gain speed and confidence in performing the steps has been demonstrated clearly by those nurses who have received instruction and supervision in this approach to leveling and monitoring central blood pressures. The loop of tubing used for this alternative method is easily made from materials readily available in each critical care unit. Its looped construction allows it to be placed for convenience and accessibility to the patient undergoing frequent hemodynamic monitoring, and can be used for a number of similarily placed patients.