The management of critically ill patients in the intensive care unit (ICU) requires investigations leading to numerous transports outside the unit.1 Intrahospital transportation (IHT), defined as the movement of a patient from one physical location within the hospital to another, is one of the most frequently performed tasks in the care of ICU patients.2,3 An emerging issue is the safety during IHT in ICU patients, especially those subjected to invasive mechanical ventilation (MV). Patients under MV are among the high-risk populations for IHT, with reported worsening of respiratory and other essential organ functions.3–6 Various adverse events, including cardiopulmonary arrest, have been described during IHT.2 During COVID-19 management, IHT is indicated in many situations, including radiologic images that could potentially change their management.7 Conducting safe transportation of COVID-19 patients is therefore fundamental. The main objective of this study was to evaluate the incidence of major adverse event (AE) in IHT of severe COVID-19 patients, as well as the modifications in clinical parameters post-procedure.

A cohort study was conducted using retrospective data collected from June 2020 to April 2021 in an 800-bed tertiary hospital, including four clinical-surgical ICUs. All IHTs for diagnostic computerized tomography (CT) of patients who were hospitalized in ICUs and required transport to the diagnostic unit were analyzed. The study was approved by the local Ethics Committee (Plataforma Brasil number 66240017.0.0000.5530) and the requirement for informed consent was waived, and the confidentiality of individual patient data was preserved. All transports were carried out by a transport team consisting of an intensivist, nurse, and nursing technician, in a predefined transport protocol, that consists of the use of a transport monitor, a period of ventilatory stabilisation, a FiO2 of 100% during transport, the assessment of the need for additional doses of sedatives, analgesics, or neuromuscular blockers (NMB), transport through the patient’s own bed, and exclusive use of the transport route and elevator. Transport for the CT scan consists of a move between two floors, with the patient being transferred via their own ICU bed and using their own ventilator (Servo-air© or Servo-i© ventilator, Getinge AB, Sweden) or a transport ventilator (Drager Oxylog 3000 Transport Ventilator, Drager Germany). The total time between leaving the ICU and returning the patient was approximately 30min.

Data were collected on the oxygenation index through the PaO2/FiO2 ratio; use of vasopressors before and after transport; need to start, combine, or increase sedatives, analgesics, or NMBs after transport; need for increased vasopressors after transport; and presence of an AE related to transport. AEs were divided into major and minor. Major AEs included death, cardiorespiratory arrest during transport or up to 6h after the failure of devices involved with transport (MV, infusion pumps), and inadvertent removal of devices (tracheal tube, tracheostomy cannula, central venous access, arterial line, indwelling urinary catheter, or enteral tube). Minor AEs included desaturation (SaO2 <90%), agitation, hypotension (new vasopressor or increase in vasopressor dose), or cardiac arrhythmias during or after transport. Continuous variables are presented as median and interquartile range, and categorical variables are presented as frequency and percentage. To compare continuous variables, the Wilcoxon test or Student's t-test was used for paired samples. Statistical significance was defined as p<0.05. We used Jamovi 2.3.21.0 for all analyses.

In total, 170 patients were included in this study. The median SAPS 3 score was 68 points (56–77), and the SOFA score on the day of CT was 6 points.4–8 The median age was 60 years (range, 50–67 years), and the male:female ratio was 63%:37%. Seventy transports (41%) were carried out in the time range between 11:59 pm and 8 am.

A total of 155 patients did not develop any AE. One patient had a major AE: mechanical ventilator malfunction during transport, requiring manual ventilation with the aid of an appropriate device. There were no occurrences of cardiorespiratory arrest, death, accidental extubation, or the pulling of other devices. As shown in Table 1, 15 patients (8.8%) presented with minor AEs, which were reversed with the established treatment.

The use of noradrenaline, as well as the PaO2/FiO2 ratio pre- and post-transport are described in Table 1. There was no difference in the median norepinephrine dose between pre- and post-transport, with a mean difference (MD) of 0μg/kg/min (95% CI: -0.02, 0.02; p=0.84). Patients who developed pre-transport AEs did not have a higher dose of noradrenaline compared to those who did not develop AEs: MD 0.01μg/kg/min (95% CI −0.03–0.05; p=0.62). Also, there was no difference in the PaO2/FiO2 ratio before and after transport (MD=2; 95% CI −6–10; p=0.58).

It is particularly challenging as patients move to an environment with a changed care setting, which carries the potential risk of deterioration of clinical parameters, equipment and facilities malfunction, and tubes and lines malfunction.8 Despite this risk,3 we demonstrated the safety of IHT with a relatively low incidence of AEs. Different definitions regarding a serious AE secondary to IHT, however, may lead to different incidences in the literature.6 Our definition of AE is quite specific and may be one of the reasons for the incidence of AEs found. As it is a retrospective study, the incidence of AEs may be underestimated when compared to prospective studies. Our study was carried out in a population at risk for AEs, due to the high incidence of hypoxemia, the need for vasopressors, and the need for multiple infusions of sedatives, analgesics, and continuous neuromuscular blockers. However, our cohort presents data similar to another study in the literature on oxygenation stability in patients undergoing IHT.5 The IHT process requires an interdisciplinary approach, in an established protocol.2 This fact may be a protective factor that minimises AE related to transport, such as equipment checks, patient preparation, and an experienced transport team.1,4 Our results corroborate this hypothesis, suggesting that IHT is a safe procedure in this context, when carried out under the best patient safety practices, through structured preparation management for the procedure.