We examine nursing documentation on a newly implemented electronic flowsheet in medical resuscitations to identify the temporal patterns of documentation and how the recorded information supported time-critical teamwork. To determine when the information was documented, we compared timestamps from 58 flowsheet logs to those of verbal communications derived from video review. We also drew on observations of 95 resuscitations to understand the behaviors of nurse documenters. We found that only 8% of the verbal reports were documented in near real-time (one minute within the verbal report), while 42% of reports were not documented in the electronic flowsheet. In addition, 38% were documented early (before the verbal report) and 12% were documented with a delay, ranging from one to 58 minutes after the report. Our study showed that the electronic flowsheet design posed many challenges for realtime documentation, leading to paper-based workarounds and the use of free-text fields on the flowsheet to visualize and keep track of time, and to communicate temporal information to the team. These findings suggest that documenters shape the temporal rhythms of not only their own work but also the rhythms of the electronic record and medical process. We discuss the implications of these rhythms for EHR redesign to support real-time documentation in high-risk, safety-critical settings. CCS CONCEPTS • Human-centered computing~Field studies • Humancentered computing~Empirical studies in HCI