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The Best in FOAM Education

  • Tim Khowong, MD

The Zoll: What You Need to Know

The Zoll Series R is the defibrillator we use in the hospital and is an important part of ACLS management for unstable arrhythmias. It is important to be familiar with the use and commonly used functions of the Zoll for emergency situations. The front panel is below and the names and functions of the front panel buttons are listed below.

Mode Selector - Selects the mode of operation

  • OFF — Unit is powered off.

  • MONITOR — Physiological monitoring (ECG and other options)

  • DEFIB — Manual or advisory defibrillation

  • PACER — Noninvasive external pacing

ENERGY SELECT Buttons - Set of up-down arrow buttons control the selection of defibrillator energy.

CHARGE Button - Charges the defibrillator to the selected energy.

SHOCK Button - The SHOCK button illuminates when the device is charged and ready. Press to activate.

To use the Zoll, remember to put the pads on the patient first and connect them to the Zoll!

Take Away #1

To defibrillate:

  1. Turn the mode selector dial to defibrillate

  2. Set the appropriate energy (start with 120J)

  3. Press charge

  4. Clear the patient from anyone touching

  5. Press and hold shock button until the shock is delivered

  6. Repeat as necessary

Take Away #2

To perform synchronized cardioversion:

  1. Turn the mode selector dial to defibrillate

  2. Press the Sync On/Off key (one of the six softkeys)

  3. Ensure sync arrows appear on the display over the R waves

  4. Press charge

  5. Clear the patient

  6. Press and hold shock button until is delivered

  7. If repeat is necessary, remember to press the Sync button again, as it defaults to off after a shock is delivered

Take Away #3

To perform transcutaneous pacing:

  1. Turn the mode selector dial to Pacer

  2. Turn the output dial until the output is 70mA

  3. Turn the rate dial to about 30bpm above the patient’s intrinsic rate

  4. Keep turning the output dial until there is electrical and mechanical capture

  5. Set the final current to 5-10mA above the threshold current

  6. If there is failure to capture at 130mA, reposition pads and try again


Timothy Khowong, MD is a current third year resident at Stony Brook Emergency Medicine. He can be found @TimKhowong on Twitter.


  • Zoll Medical Corporation. (2019). Zoll R Series ALS Operator’s Guide (Rev. W ed., Vols. 9650-0912–01). ZOLL Medical Corporation.


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