Date Published: March 5, 2019
Publisher: Public Library of Science
Author(s): Hyun Ju Min, Hyung-Jun Kim, Dong Seon Lee, Yun Young Choi, Miae Yoon, Dayoon Lee, Jun Yeun Cho, Jong Sun Park, Young-Jae Cho, Ho Il Yoon, Jae Ho Lee, Choon-Taek Lee, Yeon Joo Lee, Chiara Lazzeri.
This study aimed to determine the occurrence rate and risk factors of cardiopulmonary arrest (CPA) during intra-hospital transport (IHT) among critically ill patients, accompanied by a rapid response team (RRT).
We performed a retrospective cohort study in a 1300-bed tertiary-care teaching hospital. Data of all admitted patients transported within the hospital and accompanied by the RRT from October 2012 to May 2016 were included. We compared patients with CPA (+) and patients without CPA (-) to identify risk factors for CPA during transport.
Among 535 patients, CPA occurred in eight (1.5%) patients during IHT. There were no significant differences in age, sex, and comorbidities between groups. More patients in the CPA (+) group than in the CPA (-) group received manual ventilation during IHT (75% vs. 23.0%, p = 0.001). An increased risk of CPA (p<0.001) corresponded with a higher number of vasopressors used during IHT. In univariate logistic regression analysis, history of myocardial infarction (OR 10.7, 95% CI 2.4–50.5, p = 0.005), manual ventilation (OR 10.1, 95% CI 2.0–50.5, p = 0.005), and use of three or more vasopressors (OR 11.1, 95% CI 2.5–48.9, p = 0.001) were significantly associated with risk of CPA during RRT-led IHT. Despite accompaniment by a specialized team such as the RRT, CPA can occur during IHT. History of myocardial infarction, manual ventilation with bag-valve mask, and the use of three or more vasopressors were independent risk factors of CPA during IHT of critically ill patients accompanied by the RRT.
In practical guidelines on the transport of critically ill patients, published in 2004 , four components of intra-hospital transport (IHT) were suggested as essential for safe patient transport: “pre-transport coordination, accompanying personnel, equipment, and monitoring during transport”. Ideally, these guidelines recommend that all critical care transports be performed by specially trained individuals, as qualified personnel in critical care can adequately cope with at-risk patients and intervene in the event of serious adverse events (AEs), such as hypoxia, hypotension, etc. as well as minor AEs . Nevertheless, even when accompanied by specially trained teams, cardiopulmonary arrest (CPA)—one of the most serious AEs—can occur during IHT despite the care provided by a dedicated transport team  or specially trained intensive care unit (ICU) staff .
During the study period of 40 months, 558 critically ill patients were transported with the RRT. Of these, data from the following sets of patients were excluded: 11 patients due to the lack of information, seven patients who were admitted despite having no CPA event and five patients who were under 18 years of age. A final total of 535 patients were included in this study, of which eight (1.5%) developed CPA. Patients’ baseline demographics are described in Table 1. There were no significant differences in age, sex, and comorbidities between the CPA (+) and CPA (-) groups, but there were more patients with previous myocardial infarction (MI) in the CPA (+) group. ICU survival was significantly higher in the CPA (-) group than in the CPA (+) group (67.2% vs. 25.0%, p = 0.015). Origins of departure and transport destinations for included patients are depicted in Fig 1. Computed tomography rooms were the most frequent destination of ICU departures, while the ICU was the most frequent destination of ward departures.
In this study, we aimed to determine the occurrence rate of CPA during IHT among patients accompanied by the RRT, and to identify risk factors for CPA during transport. We determined that 1.5% of critically ill patients transported with an RRT developed CPA during transport, and that history of MI, manual ventilation with a bag-valve mask, and the use of three or more vasopressors were independent risk factors for developing CPA during transport. Age and APACHE-II score appeared to be significant also, but each OR was near 1.0, and there were two young patients in their 20’s among the eight CPA patients (Table 5). Thus the OR value, which indicated that the risk of CPA increased as the age decreased, should be interpreted along with other clinical findings.
This is the first study to report the incidence rate of CPA in critically ill patients during IHT accompanied by the RRT. The occurrence rate of CPA was 1.5%. Furthermore, we determined that history of MI, manual ventilation with a bag-valve mask, and the use of three or more vasopressors were independent risk factors of CPA during IHT of critically ill patients who were accompanied by the RRT. Despite the use of this type of specialized team, CPA still occurred during IHT, and special attention should be devoted to high-risk, critically ill patients, particularly those with the risk factors determined by this study. Further prospective studies with larger sample sizes are needed to clarify when and how a portable ventilator should be used in the transport of critically ill patients, and to confirm the cutoff point for number of vasopressor use during transport.