Early Out-of-Bed Rehabilitation in Severe Psittacosis to Enhance Recovery in Critical Care: A Case Report

Introduction

Early mobilization (EM) in critical care patients improves prognosis, shortens intensive care unit (ICU) stays, and improves quality of life after discharge. Recently, EM has received increasing attention in critical care management and is now considered part of rehabilitation in critical care (RIC). However, there is still a lack of established norms and guidelines for RIC and EM [1,2]. In general, rehabilitation therapy prioritizes patients’ mobilization out of bed (OB), encouraging them to perform exercises and training at the bedside to achieve rehabilitation goals. Thus, OB activity is a critical component of rehabilitation, including RIC. Owing to various factors, EM is predominantly focused on in-bed activities, while OB activities in RIC remains insufficiently used [3]. Weaknesses, cardiopulmonary failure, sedation and analgesia, and safety concerns regarding medical tubing (eg, ventilator circuits, deep venous catheters, arterial catheters) impede their ability to engage in OB activities.

This study presents the RIC process of a patient with severe psittacosis pneumonia. Chlamydia psittaci, the causative organism, has a distinct pulmonary tropism. Severe cases of this disease often require ICU admission and treatments such as artificial airways and shock correction, with a prolonged recovery period [4]. The characteristics of this case are similar to the obstacles to high-quality RIC. During the RIC process, we actively implemented OB and observed its role in RIC. Through this case report, we explore the role of OB in RIC while reviewing the relevant literature, aiming to provide valuable clinical insights for RIC.

Case Report

ADMISSION CONDITIONS AND THERAPIES:

A 75-year-old man was admitted to the Department of Critical Care Medicine at the First Affiliated Hospital of Xi’an Jiaotong University due to a fever lasting 5 days and behavioral abnormalities for 3 days. Five days before admission, he developed a fever, peaking at 39.5°C, accompanied by a cough and frequent nocturnal symptoms. Three days before admission, he had intermittent hallucinations, babbling speech, and behavioral changes, particularly during fever or at night. He did not report headaches, dizziness, nausea, vomiting, loss of consciousness, or limb twitching. He visited the hospital 5 days after symptom onset and was admitted to the Neurology Department. He was treated with cefoperazone and sulbactam sodium for infection, and received normal care. Additional physical signs and blood test results are presented in Table 1. He had a history of cerebral infarction 2 years prior without sequelae and had been confined to bed for 20 days due to a left greater trochanteric fracture after a fall. A computed tomography (CT) scan showed an infection in the inferior lobe of the left lung (Figure 1A).

DETERIORATION:

On hospital day 2, he developed respiratory failure and was transferred to the Intensive Care Unit (ICU) with nasal high-flow oxygen therapy at 50 L/min and a fraction of inspired oxygen (FiO2) of 70% (pulse oxygen saturation of 96%). Additional physical signs and blood test results are presented in Table 1. The Acute Physiology and Chronic Health Evaluation version 2 score was 33, and his Sequential Organ Failure score was 9.

Due to worsening respiratory failure, tracheal intubation and mechanical ventilation were performed. Fiberoptic bronchoscopy revealed a large amount of thick sputum in the left lung and submucosal bleeding spots in the inferior lobe of the left lung (Figure 1E). Considering the possibility of infection with an atypical pathogen, moxifloxacin was administered as an empirical anti-infective agent.

ETIOLOGIC DIAGNOSIS:

On hospital day 4, a chest CT showed more aggravated inflammation than before (Figure 1B), and metagenomic next-generation sequencing (mNGS) results of bronchoalveolar lavage fluid revealed Chlamydia psittaci (sequence number 3559, gene coverage 24.95%, mean depth 1.18 X). The pneumonia antibody test revealed immunoglobulin G of 41.10 AU/mL (normal <24.00) and immunoglobulin M of 0.01 COI (normal <1.00). Complementary medical history noted that he had contact with pigeons 2 weeks before presentation, leading to a diagnosis of Chlamydia psittaci pneumonia. This was treated with moxifloxacin and minocycline.

Fiberoptic bronchoscopy on hospital day 8 indicated significant improvement (Figure 1F). However, he was still unable to be weaned off invasive ventilation, with multiple failed attempts at spontaneous breathing.

REHABILITATION INTERVENTION:

Following early aggressive management (eg, targeted antibiotics after mNGS diagnosis, bronchoscopic clearance, ventilator adjustments, and nutrition), the patient’s condition exhibited initial improvement, with hemodynamic and respiratory mechanics parameters achieving basic stability. On hospital day 6, early rehabilitation intervention (as RIC) was considered.

After experiencing a left greater trochanteric fracture from a fall, the OB RIC could not be carried out; all EM were performed in bed, including breathing exercises and muscle strength training, combined with traditional Chinese medicine (TCM) treatment (Table 2). However, his overall condition had not improved. On hospital day 9 (30 days after the fracture), OB RIC was initiated.

The OB RIC training (Figure 2A) was performed to enhance motor and respiratory functions. The RIC was adjusted to include transfer training (bed and chair), bedside occupational therapy, endurance training (limb and ventilatory muscles), and respiratory training with a simple trainer during weaning.

Daily OB sessions were initiated, gradually increasing OB time (OBT) (Figure 3A), while occupational therapy and daily living activities exercises promoted functional recovery. The OBT proportion (OBTP) (defined in Table 3) to ambulation was 0.101.

After extubation on hospital day 14, the patient had a choking cough without hoarseness. The water swallow test (WST) scored grade 4, and the functional oral intake scale (FOIS) was grade 2, indicating apraxic oropharyngeal swallowing dysfunction. Rehabilitation for dysphagia included physiotherapy (ice stimulation), physical therapy (mandibular motor and orofacial muscle training), and acupuncture (Figure 2B–2D, Table 2). By hospital day 16 (2 days after extubation), the WST improved to grade 2, and the FOIS increased to grade 5. On hospital day 17, the WST was grade 1, the FOIS was grade 6, and the gastric tube was removed.

OUTCOMES:

Upon retrospective analysis of the diagnostic and therapeutic course, the patient received emergency resuscitation. Following definitive etiological confirmation, the anti-infective regimen was adjusted, ventilator parameters were optimized, nutritional therapy was administered, and RIC and EM were actively implemented. A slight decrease in P0.1 (oral closure pressure 0.1 seconds) was noted on the first day after invasive ventilation (hospital day 3), which later increased and fluctuated at a higher value (Figure 3B). This indicated a good respiratory drive reserve, which is favorable for future weaning and extubation. While the fraction of inspired oxygen (FiO2) and P/F ratio (arterial partial pressure of oxygen to FiO2, PO2/FiO2) improved (Figure 3E), they reached a plateau before hospital day 9 (the P/F ratio was 140 mmHg and FiO2 was 50%). Following the OB, the P/F ratio continued to increase to around 180 mmHg on hospital day 12, when he was successfully weaned (continuous weaning for more than 24 hours). The endotracheal tube was removed on hospital day 14, when the P/F ratio was 204 mmHg and FiO2 was 40%.

After OB RIC sessions, improvements were observed in protein synthesis, inflammatory parameters, pulmonary function, and motility index compared to in-bed training (Figure 3C–3F). Although these changes had the same trend as before the OB sessions, when he had been receiving antibiotic treatment, nutritional therapy, ventilator optimization, and in-bed training, the trend became more obvious after the OB sessions, suggesting that the OB training helped promote the improvement.

DISCHARGE AND FOLLOW-UP:

The patient’s condition improved, and he was discharged on hospital day 19 (a brief treatment course is summarized in Figure 1G). At discharge, he was fully conscious, no longer required oxygen, and scored 725 points on the quality of life short-form 12-item scale (out of 1200 points) and 164 points on the discharge preparation scale (out of 220 points). Follow-up chest CT scans at discharge (Figure 1C) and on the 14th day after discharge (Figure 1D) revealed gradual absorption of inflammation.

Discussion

EM AND RIC:

Although the importance of RIC was acknowledged in the mid-20th century [5], it still lacks relative assessment, intervention, and implementation strategies after half a century of development. Although the concept of RIC based on EM has gained popularity in critical care management, the efficacy and safety of EM in this context remain unclear [6–8]. While several recent studies have attested to the safety and efficacy of EM [9–11], and some preliminary strategies and guidelines have been established [12,13], the translation of EM into clinical practice remains challenging, possibly due to the variability in studies and clinical strategies [14–16].

ICU conditions differ significantly from those in general wards, with patients being in more critical condition and unstable. General rehabilitation interventions can increase oxygen consumption in patients, which can aid recovery from a rehabilitation perspective. However, critically ill patients may not tolerate such training and exercise due to their physical condition, which presents a higher risk of further deterioration. A study demonstrated that EM is safe and effective in patients after cardiac surgery aged 65 years and older [17]. However, challenges remain in current RIC practices, complicating implementation. Therefore, appropriate bed rest to conserve physical strength before formal rehabilitation training, along with low-intensity pre-rehabilitation exercises, is recommended [18].

To maintain a balance between “reduced exercise tolerance in the critical patient” and “promoting functional recovery through exercise intensity”, we recommend an individualized RIC. This approach dynamically assesses the patient’s condition, functional reserve, and safety risks at various stages of severe illness, allowing for a stratification of RIC intensity, in which various rehabilitation strategies are applied and gradually intensified based on the patient’s condition and tolerance.

We recommend a stage 4 evaluation of the patient’s condition and exercise endurance during RIC (Table 4). Patients in the lo- or re-capability periods may display clear or unconscious behaviors, while those in the gro-capability period or rehab-capability period should exhibit clear responses, possibly affected by cognitive dysfunction but not arousal disorder. These periods can occur sequentially or out of order. For example, a patient with stable vital signs after resuscitation might progress from the lo-capability to the gro-capability period.

OB AND EM:

At the end of the 19th century, scholars began to recognize the issues of skeletal muscle atrophy, weakness, and incapacity associated with prolonged bed rest, challenging the traditional view [19]. With the advent of RIC and an understanding of EM, EM has emerged as a crucial component of RIC [20], but there is still no consensus on the content of EM. In clinical practice, in-bed activities are often favored over OB activities for several reasons, with some therapists viewing bed training as a substitute for OB exercises.

A University of Minnesota team has developed the ICU EM protocol [21] and promoted its implementation. This protocol aims primarily at enabling patients to engage in high-quality OB activities as much as possible, and has shown that the incidence of adverse events in patients undergoing EM is less than 1% [22]. However, concerns regarding the safety of OB, particularly for patients with high-danger tubing (HDT), such as endotracheal intubation, deep venous catheterization, and mechanical ventilation, pose significant barriers to participation [23]. A study in Saudi Arabia found that even minimal staff training could improve EM practices involving mechanical ventilation [24]. Patients with HDT have significantly less OB activity compared to those classified as low-risk without HDT, as seen in studies from the UK, Germany, and Brazil [25–27].

We recommend that the safety criteria for OB should include hemodynamic stability (receiving low-dose or no vasoactive agents), clear consciousness, and able to cooperate with treatment. HDT should not be regarded as a barrier to OB, but enhanced training on safety is warranted.

OB IN THIS CASE:

At admission, our patient was in a very unstable condition and in the lo-capability period, receiving only body position management. By hospital day 4, he had advanced to the gro-capability period. However, due to a fracture, the RIC strategy primarily involved in-bed exercises, with muscle and ventilator impedance training. Once the fracture stabilized, OB exercise was encouraged, gradually increasing OBT and the complexity of exercises (assisted bed-chair transfer to independent sitting, and gradually increasing occupational therapy). On hospital day 16, more OB training was considered, as the patient transitioned into the “rehab-capability period”.

Our patient received continuous active in-bed training. While there was a noticeable improvement in nitrogen utilization, anabolism, inflammation, and respiratory function, the progress plateaued, and MI did not improve significantly (Figure 3). Although in-bed exercises can play a role in EM, as the initial measure of RIC, their overall impact is limited, and they cannot replace OB RIC.

Once OB activities were introduced, our patient showed significant improvements in the aforementioned outcomes, including MI. While these changes may be influenced by multiple factors (such as antibiotic effect, natural disease recovery, accumulated nutrition, or ventilator optimization) and not entirely driven by OB, the OB sessions significantly amplified their effects. One plausible hypothesis is that OB requires patients to recruit additional bodily functions – including neural regulation, muscle contraction, and cardiovascular responses – to address the challenges posed by gravity and postural changes. This may enhance the body’s demand for protein synthesis, improve motor performance, augment cardiopulmonary function, and activate specific anti-inflammatory pathways. It is plausible that the effects elicited by OB RIC in combination with other interventions can synergistically increase the overall treatment efficacy.

We hypothesize that OB RIC exerted a promoting role in this. However, its actual efficacy warrants further rigorous and comprehensive research for evaluation in future studies. The specific efficacy of OB RIC warrants quantitative assessment and analysis in subsequent research. It is important to note that our patient had advanced age, bed rest due to fracture, psittacosis pneumonia, and invasive mechanical ventilation, and it remains unclear whether OB RIC can have the same effect on other critically ill patients and ICU patients.

FUTURE OUTLOOK:

To review the case, an elderly patient with psittacosis pneumonia and recent fracture-related bed rest was admitted to the ICU. Following acute treatment, once hemodynamic stability was achieved, and the patient demonstrated clear consciousness with the ability to cooperate with treatment, a rehabilitation assessment was promptly initiated. Through a cycle of evaluation, rehabilitation, and reevaluation, the RIC strategy was adjusted, EM was actively implemented, and early OB training was emphasized, particularly focusing on the quality of RIC.

We believe that improving staff understanding of EM and OB, even though brief training sessions, along with personal encouragement and coordination of relevant tasks, could enhance the quality of RIC. Currently, research on OB RIC lacks structured and quantifiable metrics, which hinders further elucidation of the role and efficacy of OB training in RIC, particularly regarding the assessment of whether a dose–effect interaction exists between OB and clinical outcomes.

To promote the high-quality development of RIC, we recommend the following conceptual and exploratory metrics for assessment, which should be prioritized in future research (see calculation formula inTable 3).

OB Percentage (OBP) measures the percentage of OB days during ICU stay. For the population, it can be used analogously to calculate the “pop-OBP”, which is the ratio of total OB days to the total ICU days for a specific population, as well as the OBP with endotracheal intubation (endo-OBP), which assesses the percentage of total OB days with endotracheal intubation compared to total endotracheal intubation days, and the “OBP with mechanical ventilation”, which measures the percentage of the total OB days with mechanical ventilation relative to total mechanical ventilation days.

OBT represents the absolute time spent on OB activities. This indicator can calculate the daily and weekly OBT for individuals or populations, although it may vary due to differences in ICU stays.

OBTP provides the ratio of OBT to total ICU stay. This indicator can be used to describe the relative intensity of OB activities for individuals or populations and accounts for variations in ICU length of stay compared to OBT.

Conclusions

This case report shows the feasibility of structured OB with invasive ventilation in a patient with a complex infection, and proposes quantifiable descriptors for OB RIC that need validation in larger cohorts.

In this case, we developed an individualized RIC strategy tailored to the patient’s condition, actively increasing OBP and OBT to improve prognosis. Following the OB activities, the improvement rate of anabolism accelerated; respiratory function and inflammation resumed a trend of improvement, and MI started to improve. However, the actual magnitude of this effect and its confounding associations with other factors remain to be verified. It is unclear whether the effect of OB is equally pronounced in other ICU patients who do not present with the characteristics of this case, including advanced age, bed rest due to fracture, mechanical ventilation, and psittacosis. Further research is needed on OB RIC, with a particular focus on early RIC in critical patients.

We recommend that future research investigate the efficacy of OB RIC, with a specific focus on verifying whether OBT/OBP/OBTP can serve as valid indicators for evaluating the quality and effectiveness of OB interventions.