Delivery of high-quality chest compressions by trained rescuers is crucial for the success of cardiopulmonary resuscitation (CPR). Performing chest compressions appropriately is physically demanding and tiring for rescuers. Therefore, current guidelines recommend that it should be performed by pairs of rescuers, who rotate every two minutes [1,2]. During the COVID-19 pandemic, the guidelines were updated to incorporate the use of personal protective equipment (PPE) including well-sealed respirators (such as N95 face masks) by rescuers performing CPR [1,3,4]. The use of PPE and N95/FFP2 masks is recommended in other contagious environments also [5,6]. Chest compressions have been shown to be more tiring for rescuers wearing N95 masks than otherwise [7,8]. A recent meta-analysis showed that chest compression rate, as well as depth, were significantly compromised when rescuers used PPE, including N95 masks [9]. This adverse impact on resuscitation quality is most likely due to rescuer fatigue [[10], [11], [12]].

Various solutions have been proposed to overcome the problem of rescuer fatigue (while wearing N95 masks) and its impact on chest compression quality. They include decreasing the cycle time by more frequent rescuer rotations, increasing the number of personnel in the CPR team for performing chest compressions or using mechanical chest compression devices [9]. Among these options, more frequent rescuer rotation appears to be the most feasible solution as both mechanical compressors, or increasing the number of personnel, involve additional cost and logistic challenges. However, decreasing the cycle time by more frequent rescuer rotations raises a potential concern whether chest compression quality could be compromised during the switch between rescuers. There is limited literature that has evaluated the benefits and harm of decreasing the cycle time during chest compressions with rescuers wearing PPE. In a randomized controlled trial (RCT) on manikins, Cekman et al. [13] observed better depth of chest compressions when rescuers rotated at 1-min intervals instead of the recommended 2-min intervals. However, they did not observe a decrease in rescuer fatigue with 1-min rescuer rotations. Therefore, it is unclear whether rescuers wearing N95 masks should be rotated more frequently than recommended, to reduce rescuer fatigue and maintain the quality of chest compressions.

We hypothesized that rescuer pairs wearing N95 masks would provide better quality chest compressions if they were rotated every 1 min instead of the current standard practice of 2-min rotations. We conducted a randomized controlled crossover trial in manikins, to evaluate whether rescuer rotations at 1-min intervals are superior to rotations at 2-min intervals when rescuers perform CPR wearing N95 masks.