The defibrillator on a crash cart is fundamental rescue equipment used to deliver a therapeutic electrical shock during sudden cardiac arrest. It terminates life-threatening arrhythmias like ventricular fibrillation by depolarizing myocardial cells simultaneously. Given its purpose in time-sensitive emergencies, the operational status of this device is directly linked to patient outcomes. A machine that fails to deliver energy transforms a chance for survival into a preventable safety incident. Therefore, rigorous and routine verification is a non-negotiable requirement for patient safety.
Pre-Shift Readiness Verification
The first action at the start of any shift involves a rapid visual assessment of the defibrillator unit. This initial check confirms the physical presence of the device on the crash cart and verifies its general state of readiness. The unit should be immediately visible and free from any external signs of damage, such as cracked casings or frayed power cords.
A primary concern is the device’s power source, which must be immediately available for use. The machine should be plugged into an external alternating current (AC) power outlet to maintain a full battery charge. If the unit is operating solely on battery power, the charge indicator must display a full charge, often symbolized by a green light or a specific percentage readout. This ensures the internal battery can supply the high electrical current required for defibrillation.
The quick visual check also extends to the ancillary components necessary for immediate monitoring. Ensure that the patient monitoring leads, such as the three- or five-lead electrocardiogram (ECG) cables, are correctly attached to the machine and are not tangled or damaged. If reusable paddles are used, they should be securely docked in their appropriate storage wells on the machine.
Similarly, the thermal printer must have an adequate supply of specialized paper to generate a record of the patient’s rhythm and device activity. Running out of paper mid-resuscitation can impede accurate documentation. Finally, the display screen should power on clearly with no pixelation or lines, confirming the operator can accurately view the patient’s heart rhythm.
Detailed Functional Testing Procedures
After confirming external readiness, the next phase involves systematic verification of the defibrillator’s electrical components. Many modern devices are equipped with an internal self-test function, which should be initiated first. This automated process checks the integrity of the internal circuitry and may flag issues with capacitors or energy delivery pathways.
The most important functional test is confirming the ability to charge and deliver the maximum programmed energy level. The operator must select the highest energy setting available (200 to 360 Joules) and activate the charging sequence. The time taken to reach the maximum charge must be within manufacturer’s specifications, usually less than ten seconds. A slow charge time indicates a potential fault in the capacitor or power supply system.
It is helpful to also test a lower energy setting, such as 50 Joules, to confirm the capacitor bank can accurately store and release varying energy amounts. Once the maximum charge is reached, the energy must be safely discharged to prove the delivery mechanism works correctly. This is achieved by using the machine’s internal testing load or a dedicated paddle-check feature, which simulates the electrical resistance of the human chest wall.
The monitor screen should display the confirmed energy delivered, verifying successful transfer through the cables. This discharge step is essential to confirm the integrity of the high-voltage circuit and the safety release mechanism. Failure to discharge the full amount or any delay is a failure of the functional test.
A final check involves engaging the synchronization (SYNC) mode, used for synchronized cardioversion to treat specific arrhythmias. When activated, the device must display a marker on the ECG waveform, showing it is prepared to deliver a shock timed precisely with the patient’s R-wave. Verification ensures the machine can correctly identify the R-wave and that the SYNC function can be reliably engaged and disengaged.
Essential Accessory and Supply Checks
Beyond the electrical function of the defibrillator itself, the readiness of all patient-interface accessories requires focused attention. The disposable defibrillation pads, which are the most common method of energy delivery, must be immediately inspected. This includes checking the expiration date printed on the packaging, as the conductive gel can dry out over time, leading to ineffective energy transfer and potential skin burns.
The crash cart must contain both adult-sized pads and smaller, attenuated pediatric pads, ensuring a proper surface area for patients of all sizes. If reusable external paddles are part of the system, their conductive surfaces must be completely clean and free of any residual gel or dried debris. Any residue can interfere with the connection to the skin or the test load.
The presence of fully charged spare batteries or external battery packs must be confirmed, providing a backup power source if the main internal battery fails or AC power is unavailable during transport. All monitoring cables and sensors, such as pulse oximetry or blood pressure cuffs, must be present and correctly organized.
Documentation and Malfunction Reporting
The final step in the readiness protocol is the meticulous documentation of the completed checks. Every facility maintains an official crash cart checklist, which must be signed, dated, and timed upon completion of the verification process. This log serves as a legal record, providing evidence that the machine was confirmed operational at the beginning of the shift.
Adherence to this documentation process is necessary for maintaining compliance with regulatory bodies, which mandate strict maintenance and operational logs. Failure to accurately log a successful check can create a liability risk, even if the machine was fully functional.
If any part of the defibrillator check uncovers a fault, immediate corrective action is mandatory. The unit must be removed from patient service without delay and clearly tagged with a “DO NOT USE” or “OUT OF SERVICE” label. The designated department, typically biomedical engineering, must be notified instantly to begin the repair process. Placing a non-functional defibrillator back on a patient floor is a breach of safety protocol.