Respiratory rate has been shown to be an important predictor of cardiac arrest, respiratory adverse events and intensive care unit admission and has been designated a vital sign. However it is often inadequately monitored in hospitals. We test the hypothesis that RespiraSense, a piezoelectric-based novel respiratory rate (RR) monitor which measures the differential motion of the chest and abdomen during respiratory effort, is not inferior to commonly used methods of respiratory rate measurement. Respiratory rate was compared between the developed RespiraSense device and both electrocardiogram and direct observation by nursing staff. Data was collected from 48 patients admitted to the post-anaesthesia care unit in a tertiary level hospital. The primary outcome measure was difference in average RR calculated over a 15 min interval between (1) RespiraSense and ECG and (2) RespiraSense and nurses’ evaluation. The secondary outcome measure was the correlation between the respiratory rates measured using these three methods. The 95 % confidence interval for the difference in average RR between RespiraSense and ECG was calculated to be [−3.9, 3.1]. The 95 % confidence interval for the difference in average RR between RespiraSense and nurses’ evaluation was [−5.5, 4.3]. We demonstrate a clinically relevant agreement between RR monitored by the RespiraSense device with both ECG-derived and manually observed RR in 48 post-surgical patients in a PACU environment.
This is a preview of subscription content, log in to check access.
The research project would not have occurred without the patient and professional assistance of the nursing staff in the post anaesthesia care unit of Cork University Hospital. This work was funded by PMD Solutions.
Conflict of interest
P.L. has no financial interest in the RespiraSense device or PMD Solutions.
Hillman K, Chen J, Cretikos M, et al. MERIT study investigators. Introduction of the medical emergency team (MET) system: a cluster randomised controlled trial. Lancet. 2005;365:2091–7.CrossRefPubMedGoogle Scholar
Hodgetts TJ, Kenward G, Vlachonikalis IG, et al. The identification of risk factors for cardiac arrest and formulation of activation criteria to alert a medical emergency team. Resuscitation. 2002;54:125–31.CrossRefPubMedGoogle Scholar
McBride J, Knight D, Piper J, et al. Long-term effect of introducing an early warning score on respiratory rate charting on general wards. Resuscitation. 2005;65:41–4.CrossRefPubMedGoogle Scholar
Ryan H, Cadman C, Hann L. Setting standards for assessment of ward patients at risk of deterioration. Br J Nurs. 2004;13:1186–90.CrossRefPubMedGoogle Scholar
Fieselmann JF, Hendryx MS, Helms CM, et al. Respiratory rate predicts cardiopulmonary arrest for internal medicine patients. J Gen Intern Med. 1993;8:354–60.CrossRefPubMedGoogle Scholar
Goldhill DR, McNarry AF, Mandersloot G, et al. A physiologically-based early warning score for ward patients: the association between score and outcome. Anaesthesia. 2005;60:547–53.CrossRefPubMedGoogle Scholar
Subbe CP, Davies RG, Williams E, et al. Effect of introducing the Modified Early Warning score on clinical outcomes, cardio-pulmonary arrests and intensive care utilisation in acute medical admissions. Anaesthesia. 2003;58:797–802.CrossRefPubMedGoogle Scholar
Cretikos M, Chen J, Hillman K, et al. The objective medical emergency team activation criteria: a case–control study. Resuscitation. 2007;73:62–72.CrossRefPubMedGoogle Scholar
Overdyk FJ, Carter R, Maddox RR, et al. Continuous oximetry/capnometry monitoring reveals frequent desaturation and bradypnea during patient-controlled analgesia. Anesth Analg. 2007;105:412–8.CrossRefPubMedGoogle Scholar
Taenzer AH, Pyke JB, McGrath SP, et al. Impact of pulse oximetry surveillance on rescue events and intensive care unit transfers: a before-and-after concurrence study. Anesthesiology. 2010;112:282–7.CrossRefPubMedGoogle Scholar
Edmonds ZV, Mower WR, Lovato LM, et al. The reliability of vital sign measurements. Ann Emerg Med. 2002;39:233–7.CrossRefPubMedGoogle Scholar
Folke M, Cernerud L, Ekström M, et al. Critical review of non-invasive respiratory monitoring in medical care. Med Biol Eng Comput. 2003;41:377–83.CrossRefPubMedGoogle Scholar
Lovett PB, Buchwald JM, Stürman K, et al. The vexatious vital: neither clinical measurements by nurses nor an electronic monitor provides accurate assessments of respiratory rate in triage. Ann Emerg Med. 2005;45:68–76.CrossRefPubMedGoogle Scholar
Ouchterlony J, Arvidsson S, Sjöstedt L, et al. Peroperative and immediate postoperative adverse events in patients undergoing elective general and orthopaedic surgery: the Gothenburg study of perioperative risk (PROPER). Part II. Acta Anaesthesiol Scand. 1995;39:643–52.CrossRefPubMedGoogle Scholar
Rose D, Cohen M, Wigglesworth D, et al. Critical respiratory events in the postanesthesia care unit: patient, surgical, and anesthetic factors. Anesthesiology. 1994;81:410–8.CrossRefPubMedGoogle Scholar
Friesen RH, Alswang M. End-tidal PCO2 monitoring via nasal cannulae in pediatric patients: accuracy and sources of error. J Clin Monit. 1996;12:155–9.CrossRefPubMedGoogle Scholar