The Bear 3 is similar to the Bear 1 with the following exceptions.

• Pressure Support - A button to the right of the airway pressure monitor labeled "Support" allows the operator to set the level of pressure support. The set pressure is machine pressure and is not automatically above PEEP. For example, if there is 5 cm H20 PEEP and 15 cm H20 of pressure support is desired, press the support button and adjust the pressure support knob until the airway pressure reads 20 cm H20. Since the airway pressure monitor normally reads proximal airway pressure, the setting just described will appear to be less than 20 cm H20 during a pressure supported breath. Pressing the button on the left to read machine pressure during a pressure supported breath will confirm that the level of pressure support is as desired. The pressure support level should be set prior to turning pressure support "ON".
• Stand-by Button - There is no Stand-by button on the Bear 3.
• High Respiratory Rate Alarm - An audiovisual alarm is triggered when the alarm rate is exceeded by any combination of machine or spontaneous breaths. The High Rate alarm can be set in A/C mode to warn of specific I:E ratios that may be detrimental to the patient. For example to warn of a 1:2 ratio for a patient with obstructive airway disease who may start to air-trap with that short of an expiratory time, the inspiratory time can be calculated and multiplied by 3. Sixty divided by that product will give the breaths/min setting for the High Rate Alarm. In the event the patient triggers enough breaths to set off the alarm, appropriate action can be taken such as increasing the peak flow or decreasing the tidal volume. In SIMV or CPAP, the High Rate Alarm can be set to warn of increases in respiratory rate that may lead to respiratory muscle fatigue or indicate that the patient's condition is deteriorating.
• Adjustable Apneic Period - like the Bear 2, the apnea alarm is adjustable from 2 - 20 seconds.
• Low Exhaled Volume Alarm Delay - a separate control allows a delay of 2 to 5 breaths before activating the Low Exhaled Volume Alarm. The delay detects all breath types and will activate the Low Exhaled Volume Alarm when the number of consecutive breaths less than the Low Exhaled Volume setting equals the Delay setting.
• Proximal Airway Temperature Display - Airway temperature is measured by an external temperature probe placed at the proximal airway. An audiovisual alarm is activated if the temperature exceeds 41 C or if the probe becomes disconnected from the circuit. If the probe is not connected to the machine, the temperature display is blank.
• No toggle switch to divide the Normal Rate by 10 - The breaths per minute range of the Normal Rate is from 1 breath every 2 minutes up to 60 BPM.