Cardiorespiratory response to early rehabilitation in critically ill adults: A secondary analysis of a randomised controlled trial

Abstract

Introduction Early rehabilitation is indicated in critically ill adults to counter functional complications. However, the physiological response to rehabilitation is poorly understood. This study aimed to determine the cardiorespiratory response to rehabilitation and to investigate the effect of explanatory variables on physiological changes during rehabilitation and recovery. Methods In a prospectively planned, secondary analysis of a randomised controlled trial conducted in a tertiary, mixed intensive care unit (ICU), we analysed the 716 physiotherapy-led, pragmatic rehabilitation sessions (including exercise, cycling and mobilisation). Participants were previously functionally independent, mechanically ventilated, critically ill adults (n = 108). Physiological data (2-minute medians) were collected with standard ICU monitoring and indirect calorimetry, and their medians calculated for baseline (30min before), training (during physiotherapy) and recovery (15min after). We visualised physiological trajectories and investigated explanatory variables on their estimated effect with mixed-effects models. Results This study found a large range of variation within and across participants’ sessions with clinically relevant variations (>10%) occurring in more than 1 out of 4 sessions in mean arterial pressure, minute ventilation (MV) and oxygen consumption (VO2), although early rehabilitation did not generally affect physiological values from baseline to training or recovery. Active patient participation increased MV (mean difference 0.7l/min [0.4–1.0, p<0.001]) and VO2 (23ml/min [95%CI: 13–34, p<0.001]) during training when compared to passive participation. Similarly, session type ‘mobilisation’ increased heart rate (6.6bpm [2.1–11.2, p = 0.006]) during recovery when compared to ‘exercise’. Other modifiable explanatory variables included session duration, mobilisation level and daily medication, while non-modifiable variables were age, gender, body mass index and the daily Sequential Organ Failure Assessment. Conclusions A large range of variation during rehabilitation and recovery mirrors the heterogenous interventions and patient reactions. This warrants close monitoring and individual tailoring, whereby the best option to stimulate a cardiorespiratory response seems to be active patient participation, shorter session durations and mobilisation. Trial registration German Clinical Trials Register (DRKS) identification number: DRKS00004347, registered on 10 September 2012.

Identification and Quantification of Activities Common to Intensive Care Patients; Development and Validation of a Dual-Accelerometer-Based Algorithm

“…An assessment of activities is important as, until now, detailed information on the performed physical activity of IC patients during an ICU stay has been lacking. Furthermore, although IC patients are not highly active, a recent study found significant variations in physiological responses to different types of activities [ 2 ] indicating that an assessment of all types is immensely important. To enhance rehabilitation in IC patients, an appropriate amount of physical activity is essential [ 27 ], and objective measurements about the type, intensity, frequency, and duration of performed activity by IC patients are essential [ 6 ].…”

“…Being physically active as a form of rehabilitation, even in the early stages of recovery, is important for optimizing physical functioning and increasing autonomy [ 1 ]. Therefore, adequate physical activity in the IC setting is important for improving physical functioning [ 2 , 3 ]. However, what constitutes “adequate” physical activity has yet to be determined.…”

Mobilisation during mechanical ventilation: A qualitative study exploring the practice of conscious patients, nurses and physiotherapists in intensive care unit

“…The nurses might focus on patient's ventilation or wellbeing and perceive mobilisation to be sitting in a chair together with family even though this is done by hoist and categorised as passive mobilisation (Laerkner et al, 2019). However, there is a difference in the metabolic demands required of the patients which must be taken into account when planning mobilisation to match the capacity and condition of the patents as well as to allow sufficient time for recovery (Eggmann et al, 2022). Furthermore the need of planning and use of assisting devices varies along with a stepwise hierarchy of mobility intensity (Hodgson et al, 2015).This reflects a need for interprofessional communication to align expectations and support continuity whilst at the same time sustaining a situation-specific mobility plan to optimise mobilisation of conscious and mechanically ventilated ICU patients.…”

“…Recognising that mobilisation must be regarded situation‐specific, it might at times be beneficial to limit the actions; whereas other times to increase the effort to progress to the next level of physical function. Eggmann et al recommend shorter and more frequent mobilisation sessions to adapt duration, frequency, and intensity to the patients' actual conditions (Eggmann et al., 2022).…”

“…This study can contribute to HCPs' awareness towards the act of conditions (Eggmann et al, 2022) and safety concerns (Hodgson et al, 2022(Hodgson et al, , 2023 to optimise mobilisation of conscious and mechanically ventilated ICU patients. Future research is needed to support this individualised approach (Hodgson et al, 2023) this include ways of patient involvement as well as clarifying roles and responsibility between nurses and physiotherapist both bedside and on an organisational level.…”