What are the hemodynamic and respiratory effects of passive limb exercise for mechanically ventilated patients receiving low-dose vasopressor/inotropic support?

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

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.

Respiratory Support Adjustments and Monitoring of Mechanically Ventilated Patients Performing Early Mobilization: A Scoping Review

Supplemental Digital Content is available in the text.

Objectives:

This scoping review is aimed to summarize current knowledge on respiratory support adjustments and monitoring of metabolic and respiratory variables in mechanically ventilated adult patients performing early mobilization.

Data Sources:

Eight electronic databases were searched from inception to February 2021, using a predefined search strategy.

Study Selection:

Two blinded reviewers performed document selection by title, abstract, and full text according to the following criteria: mechanically ventilated adult patients performing any mobilization intervention, respiratory support adjustments, and/or monitoring of metabolic/respiratory real-time variables.

Data Extraction:

Four physiotherapists extracted relevant information using a prespecified template.

Data Synthesis:

From 1,208 references screened, 35 documents were selected for analysis, where 20 (57%) were published between 2016 and 2020. Respiratory support settings (ventilatory modes or respiratory variables) were reported in 21 documents (60%). Reported modes were assisted (n = 11) and assist-control (n = 9). Adjustment of variables and modes were identified in only seven documents (20%). The most frequent respiratory variable was the Fio₂, and only four studies modified the level of ventilatory support. Mechanical ventilator brand/model used was not specified in 26 documents (74%). Monitoring of respiratory, metabolic, and both variables were reported in 22 documents (63%), four documents (11%) and 10 documents (29%), respectively. These variables were reported to assess the physiologic response (n = 21) or safety (n = 13). Monitored variables were mostly respiratory rate (n = 26), pulse oximetry (n = 22), and oxygen consumption (n = 9). Remarkably, no study assessed the work of breathing or effort during mobilization.

Conclusions:

Little information on respiratory support adjustments during mobilization of mechanically ventilated patients was identified. Monitoring of metabolic and respiratory variables is also scant. More studies on the effects of adjustments of the level/mode of ventilatory support on exercise performance and respiratory muscle activity monitoring for safe and efficient implementation of early mobilization in mechanically ventilated patients are needed.

Physiotherapy in the neurotrauma intensive care unit: A scoping review

PURPOSE

This scoping review summarizes the literature on the safety and effectiveness of physiotherapy interventions in patients with neurological and/or traumatic injuries in the intensive care unit (ICU), identifies literature gaps and provides recommendations for future research.

MATERIALS AND METHODS

We searched five databases from inception to June 2, 2018. We included published retrospective studies, case studies, observation and randomized controlled trials describing physiotherapy interventions in ICU patients with neurotrauma injuries. Two reviewers reviewed the databases and independently screened English articles for eligibility. Data extracted included purpose, study design, population (s), outcome measures, interventions and results. Thematic analysis and descriptive numerical summaries are presented by intervention type.

RESULTS

12,846 titles were screened and 72 met the inclusion criteria. Most of the studies were observational studies (44 (61.1%)) and RCTs (14 (19.4%)). Early mobilization, electrical stimulation, range of motion, and chest physiotherapy techniques were the most common interventions in the literature. Physiotherapy interventions were found to be safe with few adverse events.

CONCLUSIONS

Gaps in the literature suggest that future studies require assessment of long term functional outcomes and quality of life, examination of homogenous populations and more robust methodologies including clinical trials and larger samples.

Short-term effects of passive mobilization on the sublingual microcirculation and on the systemic circulation in patients with septic shock

Background

Active mobilization is not possible in patients under deep sedation and unable to follow commands. In this scenario, passive therapy is an interesting alternative. However, in patients with septic shock, passive mobilization may have risks related to increased oxygen consumption. Our objective was to evaluate the impact of passive mobilization on sublingual microcirculation and systemic hemodynamics in patients with septic shock.

Methods

We included patients who were older than 18 years, who presented with septic shock, and who were under sedation and mechanical ventilation. Passive exercise was applied for 20 min with 30 repetitions per minute. Systemic hemodynamic and microcirculatory variables were compared before (T0) and up to 10 min after (T1) passive exercise. p values <0.05 were considered significant.

Results

We included 35 patients (median age [IQR 25–75%]: 68 [49.0–78.0] years; mean (±SD) Simplified Acute Physiologic Score (SAPS) 3 score: 66.7 ± 12.1; median [IQR 25–75%] Sequential Organ Failure Assessment (SOFA) score: 9 [7.0–12.0]). After passive mobilization, there was a slight but significant increase in proportion of perfused vessels (PPV) (T0 [IQR 25–75%]: 78.2 [70.9–81.9%]; T1 [IQR 25–75%]: 80.0 [75.2–85.1] %; p = 0.029), without any change in other microcirculatory variables. There was a reduction in heart rate (HR) (T0 (mean ± SD): 95.6 ± 22.0 bpm; T1 (mean ± SD): 93.8 ± 22.0 bpm; p < 0.040) and body temperature (T0 (mean ± SD): 36.9 ± 1.1 °C; T1 (mean ± SD): 36.7 ± 1.2 °C; p < 0.002) with no change in other systemic hemodynamic variables. There was no significant correlation between PPV variation and HR (r = −0.010, p = 0.955), cardiac index (r = 0.218, p = 0.215) or mean arterial pressure (r = 0.276, p = 0.109) variation.

Conclusions

In patients with septic shock after the initial phase of hemodynamic resuscitation, passive exercise is not associated with relevant changes in sublingual microcirculation or systemic hemodynamics.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0318-x) contains supplementary material, which is available to authorized users.