Continuous Monitoring in an Inpatient Medical-Surgical Unit: A Controlled Clinical Trial

Published:December 16, 2013DOI:



      For hospitalized patients with unexpected clinical deterioration, delayed or suboptimal intervention is associated with increased morbidity and mortality. Lack of continuous monitoring for average-risk patients has been suggested as a contributing factor for unexpected in-hospital mortality. Our objective was to assess the effects of continuous heart rate and respiration rate monitoring in a medical-surgical unit on unplanned transfers and length of stay in the intensive care unit and length of stay in the medical-surgical unit.


      In a controlled study, we have compared a 33-bed medical-surgical unit (intervention unit) to a “sister” control unit for a 9-month preimplementation and a 9-month postimplementation period. Following the intervention, all beds in the intervention unit were equipped with monitors that allowed for continuous assessment of heart and respiration rate.


      We reviewed 7643 patient charts: 2314 that were continuously monitored in the intervention arm and 5329 in the control arms. Comparing the average length of stay of patients hospitalized in the intervention unit following the implementation of the monitors to that before the implementation and to that in the control unit, we observed a significant decrease (from 4.0 to 3.6 and 3.6 days, respectively; P <.05). Total intensive care unit days were significantly lower in the intervention unit postimplementation (63.5 vs 120.1 and 85.36 days/1000 patients, respectively; P = .04). The rate of transfer to the intensive care unit did not change, comparing before and after implementation and to the control unit (P = .19). Rate of code blue events decreased following the intervention from 6.3 to 0.9 and 2.1, respectively, per 1000 patients (P = .02).


      Continuous monitoring on a medical-surgical unit was associated with a significant decrease in total length of stay in the hospital and in intensive care unit days for transferred patients, as well as lower code blue rates.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The American Journal of Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • McGloin H.
        • Adam S.K.
        • Singer M.
        Unexpected deaths and referrals to intensive care of patients on general wards. Are some cases potentially avoidable?.
        J R Coll Physicians Lond. 1999; 33: 255-259
        • Hravnak M.
        • Edwards L.
        • Clontz A.
        • Valenta C.
        • Devita M.A.
        • Pinsky M.R.
        Defining the incidence of cardiorespiratory instability in patients in step-down units using an electronic integrated monitoring system.
        Arch Intern Med. 2008; 168: 1300-1308
        • DeVita M.A.
        • Smith G.B.
        • Adam S.K.
        • et al.
        “Identifying the hospitalised patient in crisis” – a consensus conference on the afferent limb of rapid response systems.
        Resuscitation. 2010; 81: 375-382
        • Ben-Ari J.
        • Zimlichman E.
        • Adi N.
        • Sorkine P.
        Contactless respiratory and heart rate monitoring: validation of an innovative tool.
        J Med Eng Technol. 2010; 35: 393-398
        • Zimlichman E.
        • Szyper-Kravitz M.
        • Unterman A.
        • Goldman A.
        • Levkovich S.
        • Shoenfeld Y.
        How is my patient doing? Evaluating hospitalized patients using continuous vital signs monitoring.
        Isr Med Assoc J. 2009; 11: 382-384
        • Zimlichman E.
        • Szyper-Kravitz M.
        • Shinar Z.
        • et al.
        Early recognition of acutely deteriorating patients in non-intensive care units: assessment of an innovative monitoring technology.
        J Hosp Med. 2012; 7: 628-633
        • Knaus W.A.
        • Draper E.A.
        • Wagner D.P.
        • Zimmerman J.E.
        APACHE II: a severity of disease classification system.
        Crit Care Med. 1985; 13: 818-829
        • Chambrin M.
        • Ravaux P.
        • Calvelo-Aros D.
        • Jaborska A.
        • Chopin C.
        • Boniface B.
        Multicentric study of monitoring alarms in the adult intensive care unit (ICU): a descriptive analysis.
        Intensive Care Med. 1999; 25: 1360-1366
        • Lawless S.
        Crying wolf: false alarms in a pediatric intensive care unit.
        Crit Care Med. 1994; 22: 981-985
        • Görges M.
        • Markewitz B.
        • Westenskow D.
        Improving alarm performance in the medical intensive care unit using delays and clinical context.
        Anesth Analg. 2009; 108: 1546-1552
        • Siebig S.
        • Kuhls S.
        • Imhoff M.
        • Gather U.
        • Schölmerich J.
        • Wrede C.
        Intensive care unit alarms – how many do we need?.
        Crit Care Med. 2010; 38: 451-456
        • Wiklund L.
        • Hok B.
        • Stahl K.
        • Jordeby-Jonsson A.
        Postanesthesia monitoring revisited: incidence of true and false alarms from different monitoring devices.
        J Clin Anesth. 1994; 67: 182-188
        • Larson T.S.
        • Brady W.J.
        Electrocardiographic monitoring in the hospitalized patient: a diagnostic intervention of uncertain clinical impact.
        Am J Emerg Med. 2008; 26: 1047-1055
        • Schull M.J.
        • Redelmeier D.A.
        Continuous electrocardiographic monitoring and cardiac arrest outcomes in 8,932 telemetry ward patients.
        Acad Emerg Med. 2000; 7: 647-652
        • Pedersen T.
        • Dyrlund Pedersen B.
        • Møller A.M.
        Pulse oximetry for perioperative monitoring.
        Cochrane Database Syst Rev. 2003; (3):CD002013. Review. Update in: Cochrane Database Syst Rev. 2009;(4):CD002013
        • Taenzer A.H.
        • Pyke J.B.
        • McGrath S.P.
        • Blike G.T.
        Impact of pulse oximetry surveillance on rescue events and intensive care unit transfers: a before-and-after concurrence study.
        Anesthesiology. 2010; 112: 282-287
        • Hutton P.
        • Clutton-Brock T.
        The benefits and pitfalls of pulse oximetry.
        BMJ. 1993; 307: 457-458
        • Lynn L.A.
        • Curry J.P.
        Patterns of unexpected in-hospital deaths: a root cause analysis.
        Patient Saf Surg. 2011; 5: 3
        • Waugh J.B.
        • Epps C.A.
        • Khodneva Y.A.
        Capnography enhances surveillance of respiratory events during procedural sedation: a meta-analysis.
        J Clin Anesth. 2011; 23: 189-196
      1. Anesthesia Patient Safety Foundation. Conclusions and recommendations from June 08, 2011 Conference on electronic monitoring strategies. Available at: Accessed July 19, 2012.

        • Buist M.D.
        • Jarmolowski E.
        • Burton P.R.
        • Bernard S.A.
        • Waxman B.P.
        • Anderson J.
        Recognising clinical instability in hospital patients before cardiac arrest or unplanned admission to intensive care. A pilot study in a tertiary-care hospital.
        Med J Aust. 1999; 171: 22-25
        • Schein R.M.
        • Hazday N.
        • Pena M.
        • Ruben B.H.
        • Sprung C.L.
        Clinical antecedents to in-hospital cardiopulmonary arrest.
        Chest. 1990; 98: 1388-1392
        • Franklin C.
        • Mathew J.
        Developing strategies to prevent in hospital cardiac arrest: analyzing responses of physicians and nurses in the hours before the event.
        Crit Care Med. 1994; 22: 244-247
        • Hillman K.M.
        • Bristow P.J.
        • Chey T.
        • et al.
        Duration of life-threatening antecedents prior to intensive care admission.
        Intensive Care Med. 2002; 28: 1629-1634
        • Goldhill D.R.
        • White S.A.
        • Sumner A.
        Physiologic values and procedures in the 24 h before ICU admission from the ward.
        Anaesthesia. 1999; 54: 529-534
        • Jacques T.
        • Harrison G.A.
        • McLaws M.L.
        • Kilborn G.
        Signs of critical conditions and emergency responses (SOCCER): a model for predicting adverse events in the inpatient setting.
        Resuscitation. 2006; 69: 175-183
        • Kause J.
        • Smith G.
        • Prytherch D.
        • Parr M.
        • Flabouris A.
        • Hillman K.
        A comparison of antecedents to cardiac arrests, deaths and emergency intensive care admissions in Australia and New Zealand, and the United Kingdom – the ACADEMIA study.
        Resuscitation. 2004; 62: 275-282
        • Young M.P.
        • Gooder V.J.
        • McBride K.
        • James B.
        • Fisher E.S.
        Inpatient transfers to the intensive care unit: delays are associated with increased mortality and morbidity.
        J Gen Intern Med. 2003; 18: 77-83
        • Cretikos M.A.
        • Bellomo R.
        • Hillman K.
        • Chen J.
        • Finfer S.
        • Flabouris A.
        Respiratory rate: the neglected vital sign.
        Med J Aust. 2008; 188: 657-659
        • Peberdy M.A.
        • Kaye W.
        • Ornato J.P.
        • et al.
        Cardiopulmonary resuscitation of adults in the hospital: a report of 14720 cardiac arrests from the National Registry of Cardiopulmonary Resuscitation.
        Resuscitation. 2003; 58: 297-308
        • Buist M.
        • Bernard S.
        • Nguyen T.V.
        • Moore G.
        • Anderson J.
        Association between clinically abnormal observations and subsequent in-hospital mortality: a prospective study.
        Resuscitation. 2004; 62: 137-141