Respiratory rates observed over 15 seconds compared with rates measured using the RRate app. Practice-based evidence from an observational study of acutely ill adult medical patients during their hospital admission

Background: counting respiratory rate over 60 seconds can be impractical in a busy clinical setting. Methods: 870 respiratory rates of 272 acutely ill medical patients estimated from observations over 15 seconds and those calculated by a computer algorithm were compared. Results: The bias of 15 seconds of observations was 1.85 breaths per minute and 0.11 breaths per minute for the algorithm derived rate, which took 16.2 SD 8.1 seconds. The algorithm assigned 88% of respiratory rates their correct National Early Warning Score points, compared with 80% for rates from 15 seconds of observation. Conclusion: The respiratory rates of acutely ill patients are measured nearly as quickly and more reliably by a computer algorithm than by observations over 15 seconds.

Upgrade of the CO2 Direct Absorption Method for Low-Level 14C Liquid Scintillation Counting

A new system for CO2 absorption and liquid scintillation counting (LSC) was designed and developed along with its inherent measurement protocol for radiocarbon analysis in gaseous emissions, fuels, and biobased products. CO2 is chemically trapped as a carbamate in a suitable absorbing solution (3-methoxy-propyl-amine), gravimetrically measured, and analyzed by LSC (using a QuantulusTM 1220) to determine the 14C content. The use of cryogenic traps and a pressure transducer in the system prevents the need for closed-loop recirculation or additional steps to maximize CO2 capture in a short amount of time. The choice of PTFE vials used both for CO2 pretreatment and subsequent LSC analysis provides the opportunity to significantly reduce the background counting down to 40% with respect to the low-40K glass vials. This upgrade resulted in improving the maximum detectable age back to 36,000 yr BP in routine measurements. This method therefore turns out to be flexible enough to be applied for 14C dating as well as to differentiate between modern and fossil carbon.