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SUBJECT: Ventilator Circuit Changes

PURPOSE: The objectives of the ventilator circuit change procedure as described are:

To limit the occurrence of nosocomial infection acquired as a consequence of endotracheal intubation or tracheostomy and ventilatory support.

To assure that the ventilator-circuit system maintains its physical integrity and proper function.

To provide a circuit that is clean in appearance.

To minimize the risk of harm to the patient and health care personnel during the process of changing the circuit.


  1. Adult ventilator circuit and in-line suction catheter changes are performed PRN. The PRN ventilator circuit change may take place when circuit is not clean in appearance, tubing leaks are suspected (after connections are secured), or when in-line filters have significant increased resistance.
  2. When changing ventilator circuit the entire ventilator circuit including the humidifier circuit components, filters, suction catheter, and aerosol delivery devices (nebulizer, MDI holding chamber) should be changed simultaneously. In-line suction catheter may be changed alone (without change out of entire circuit).


Patient's condition (e.g hemodynamic instability) may predispose him or her to harm or injury during the changing process.

Hypo- or hyperoxia or Hyper or hypocapnia

Artificial airway displacement or airway obstruction

Contamination or transmission of pathogens to patient or staff.

Patient may not be safely maintained during disconnection from the ventilator (inappropriate or inadequate ventilation (f and/or VT), inappropriate or inadequate oxygenation (FI02 and/or PEEP), inappropriate increase in work of breathing, airway obstruction).

Inability to assure that the replacement circuit has been satiety and effectively disinfected and that it is operationally sound.

Malfunctioning or suboptimally functioning ventilator or circuit

Failure to assure proper ventilator function with patient reconnection (ie, correct settings, absence of leaks, functioning alarms, proper valve placement)

Manipulation and disconnection of the ventilator tubing can cause contaminated ventilator condensate to spill into the patient's airway, exposing the patient to further risk of infection.

Changing ventilator circuits more frequently than is necessary may increase the risk of nosocomial pneumonia.


There should be no presence of conditions in the patient's cardiopulmonary or neurologic status that might make tolerance of disconnection from mechanical ventilation hazardous to the patient.

Assure patient is safely and effectively ventilated or maintained during the ventilator circuit change. This can be accomplished with a second RCP or nurse manually ventilating patient with manual resuscitator in same fashion as mechanical ventilator. Patients on PEEP should be ventilated with manual resuscitator with PEEP valve as set on ventilator.

  1. Perform patient/ventilator system check.
  2. Assemble new circuit (with same type components as the old circuit) in clean fashion as much as possible prior to disconnection of existing circuit.
  3. Place new circuit (in clean fashion) in a position allowing quick connection to ventilator and then to patient.
  4. Place manual rescuscitator in convienient position with its oxygen supply adequately running (e.g. 15 LPM).
  5. Disconnect patient from ventilator and have second person apply adequate support using manual resuscitator.
  6. Disconnect old circuit from ventilator and connect new circuit. Assure proper function of new circuit (on 840 ventilator a "SST" should be performed, on Servo 900C use a clean test lung to check function).
  7. When new circuit is completely connected and checked out place the patient back on the ventilator.
  8. Observe patient, circuit, and ventilator looking for leaks, incomplete circuit connection or other problems.
  9. Perform patient/ventilator system check and compare to previous patient/ventilator system check to assure significant changes have not occured.


Evidence suggests that routine circuit changes (more frequently than every 48 hours) do not provide any advantage in controlling infections acquired by patients while being mechanically ventilated.

Controversy exists concerning the frequency at which ventilator circuits should be changed to minimize patient infection.

Controversy exists concerning the influence that circuit design and the presence of various circuit components have on the safe interval of circuit change.

The type of humidification device used may influence circuit change interval.

Use of heated vs non-heated circuits may influence circuit change interval.

Use of disposable vs reusable circuits may influence circuit change interval.

Use of aerosol generators (nebulizers) may influence circuit change interval.

Changing ventilator circuits too frequently may incur added patient or institutional expense and deliver no additional infectious disease protection to the patient.


AARC Clinical Practice Guideline - Ventilator Circuit Changes. Respir Care 1994; 39(8):797-802 ( )

Centers for Disease Control (CDC) Recommendations for Prevention of Nosocomial Bacterial Pneumonia ( ).

Fink JB. Krause SA. Barrett L. Schaaff D. Alex CG. Extending ventilator circuit change interval beyond 2 days reduces the likelihood of ventilator-associated pneumonia. Chest. 113(2):405-11, 1998 Feb.

Kollef MH. Prentice D. Shapiro SD. Fraser VJ. Silver P. Trovillion E. Weilitz P. von Harz B. St John R. Mechanical ventilation with or without daily changes of in-line suction catheters. American Journal of Respiratory & Critical Care Medicine. 156(2 Pt 1):466-72, 1997 Aug.