Early Mobilization in the ICU

Original Editor - Ashmita Patrao Top Contributors - Ashmita Patrao, Vidya Acharya and Kim Jackson

Introduction

Globally people recover from critical illnesses and get discharged from an ICU setup, however, it has been noticed that patients develop weakness, probably credited to their prolonged period of immobilization.[1] Post intensive care syndrome was the term used that describes the worsening of physical, mental, and cognitive problems.[2] Early mobilization of critically ill patients is a safe option with additional benefits of improving functional outcomes.[3] The term mobilization in the Intensive care unit is referred to as physical activity performed to the intensity that can bring about physiological changes.[4] Early mobilization is the application of physical activity as early as the 2nd to 5th day after the onset of critical illness or injury. [5]

Why Early Mobilization

Long term ICU care is always associated with complications in a high proportion of ICU survivors. Prolonged periods of immobility have often been associated with physical deconditioning, fatigue, loss of function and decreased quality of life have also been observed.[1] A systematic review and meta-analysis suggest early rehabilitation in the ICU reduces the incidence of developing Intensive care unit-acquired weakness (ICUAW)[6]. Another cross-sectional survey suggests patient unresponsiveness (n = 50; 24.4%) and hemodynamic instability (n = 42; 20.5%) are the most common barriers to early mobilization[7]. Also, the study infers a significant positive relationship between the type of ventilation and out-of-bed patient mobilization.

According to a retrospective cohort study in survivors of a prolonged ICU-stay, the ability to ambulate was related with a higher possibility of being discharged. Thus, emphasizing the importance of mobility training in long-term acute care hospitals[8].

Below is a gist of the system-wise complications of prolonged immobility.

  • Respiratory system it causes retention of secretions, reduced respiratory excursion, pneumonia, atelectasis.
  • Cardiovascular complications include orthostatic hypertension, deep vein thrombosis, hypovolemia, and embolization.
  • Gastrointestinal complications include decreased motility, constipation, ileus.
  • Musculoskeletal complications include muscle shortening, weakness, and wasting which would, in turn, cause functional denervation, joint contractures, bone demineralization, and heterotrophic ossification.[9] [10]
  • Neurological system is affected by polyneuropathies due to reduced microcirculation at the nerve.
  • Endocrine system-related complications include Hyperglycemia with insulin resistance and catabolism.
  • Integumentary system, it can cause pressure ulcers.
  • Psychology of the person is affected causing depression and delirium.[10]

Physiological Effects

The acute physiological effects of early mobilization are summarized below

Systems Physiological effects
Pulmonary system Increased Regional ventilation

Increased regional diffusion

Increased Regional perfusion

Increase tidal volume

Increase efficiency of respiratory mechanics

Reduce air flow resistance

Increase flow rates

Increase zone 2 (Area of ventilation perfusion matching)

Increase or decrease Breathing frequency

Increase floe rates

Increase strength and quality of a cough

Increase mucociliary transport and airway clearance

Increase distribution and function of pulmonary immune factors

Cardiovascular system Incraease venous return

Increase stroke volume

Increase heart rate

Increase myocardial cntractilty

Increase stroke volume, heart rate and cardiac output

Increase coronary perfusion

Increase circulating blood volume

Increase chest tube drainage

Peripheral circulatory effects Reduced peripheral vascular resistance

Increase blood flow

Increase peripheral tissue oxygen extractiion

Lymphatic system Increase pulmonary lymphatic flow

Increase pulmonary lymphatic drainage

Hematologic system Increase circulatory transit times

Reduce circulatory stasis

Neurological system Increase arousal

Increase cerebral electrical activity

Increase stimulus to breathe

Increase sympathetic stimulation

Increase postural reflexes

Endoricne system Increase release, distribution and degradation of catechoamines
Genitourinary system Increase glomerular filtration

Increase urinary output

Gastrointestinal system Increase gut motility

Reduce constipation

Integumentary system Increase cutaneous circulation for thermoregulation
Multisystemic effects Reduce effects of anesthesia and sedation

Reduce deleterious cardiopulmonary effects of surgery

Reduce the risk of loss of gravitational stimulus and exercise stimulus

There is an improved ventilation/perfusion matching, better lung compliance, mucociliary clearance, reduced work of breathing in upright positions. Movement of the lower limbs mainly the ankle prevented stasis of blood and hence prevents Deep vein thrombosis as well as pulmonary embolus formation.

Prescription of Early Mobilization

To assist in the clinical decision-making process, you can follow the steps below:

Step 1: Identifying the contributing factors towards oxygen transport deficits

  • Understanding the pathophysiology of the condition or disease
  • Extrinsic factors that affect patient care
  • Intrinsic factors related to the patient
  • Relative immobility

Step 2: Determining the specific need for mobilization and subsequently the form of mobilization or exercise that will address the oxygen transport deficiency.

Step 3: Matching the selected mobilization technique or exercise type to the patient’s oxygen-carrying capacity.

Step 4: Set the dosage, i.e. the intensity to match the safe limits of oxygen transport of the patient.

Step 5: Combining body positions with these maneuvers

  • Thoracic mobility exercises
  • ROM exercises (Active, passive and active-assisted)
  • Coordinating breathing control with body movements
  • Coughing, supported by self or others

Step 6: Use oxygen transport and its indices to monitor the dosage of mobilization, not a fixed duration of time.

Step 7: Repeat this mobilization as frequently and safely as the beneficial effects are tolerated by the subject or patient.

Step 8: The intensity of the mobilization stimulus can be increased as long as the patient capacity permits the effects of the mobilization stressor, keeping the oxygen transport as the benchmark, constantly monitoring vitals.[11]

Early Mobilization Intervention

The frequency of early mobilization can be conducted every day of the week or five days a week.[1] Although active techniques are preferred more than passive and attribute more to the prevention of complications, these are some of the listed techniques that come under the scope of early mobilization:

  • Passive and active range of motion
  • Active side-to-side turning
  • Exercising in the bed
  • Bedside sitting
  • Transfers from the bed to the chair and vice versa
  • Ambulation
  • Hoist therapy
  • Tilt table
  • Resistance exercises
  • Electrical stimulation [12]

References

  1. 1.0 1.1 Castro-Avila AC, Serón P, Fan E, Gaete M, Mickan S. Effect of early rehabilitation during intensive care unit stay on functional status: systematic review and meta-analysis. PloS one. 2015;10(7).
  2. Harrold ME, Salisbury LG, Webb SA, Allison GT, Australia and Scotland ICU Physiotherapy Collaboration. Early mobilisation in intensive care units in Australia and Scotland: a prospective, observational cohort study examining mobilisation practises and barriers. Crit Care. 2015 Dec 1;19(1):336.
  3. Needham DM, Davidson J, Cohen H, Hopkins RO, Weinert C, Wunsch H, Zawistowski C, Bemis-Dougherty A, Berney SC, Bienvenu OJ, Brady SL. Improving long-term outcomes after discharge from intensive care unit: report from a stakeholders' conference. Crit Care Med. 2012 Feb 1;40(2):502-9.
  4. Stiller K. Physiotherapy in intensive care: an updated systematic review. Chest 2013;144:825–47.
  5. Castro-Avila AC, Serón P, Fan E, Gaete M, Mickan S. Effect of early rehabilitation during intensive care unit stay on functional status: systematic review and meta-analysis. PloS one. 2015;10(7).
  6. Anekwe DE, Biswas S, Bussières A, Spahija J. Early Rehabilitation Reduces the Likelihood of Developing Intensive Care Unit-Acquired Weakness: A Systematic Review and Meta-Analysis. Physiotherapy. 2019 Dec 19.
  7. Tadyanemhandu C, van Aswegen H, Ntsiea V. Organizational structures and early mobilization practices in South African public sector intensive care units—A cross‐sectional study. Journal of Evaluation in Clinical Practice. 2020 Mar 6.
  8. Tran DH, Maheshwari P, Nagaria Z, Patel HY, Verceles AC. Ambulatory Status Is Associated With Successful Discharge Home in Survivors of Critical Illness. Respiratory Care. 2020 Mar 31.
  9. Morris PE, Herridge MS. Early intensive care unit mobility: future directions. Crit Care Clinics. 2007 Jan 1;23(1):97-110.
  10. 10.0 10.1 Amidei C. Mobilisation in critical care: a concept analysis. Intens Crit Care Nur. 2012 Apr 1;28(2):73-81.
  11. Frownfelter D, Dean E. Principles and practise of Cardiopulmonar Physical Therapy. 3rd ed. Missouri: Mosby; 1996
  12. Gosselink R, Bott J, Johnson M, Dean E, Nava S, Norrenberg M, et al. (2008) Physiotherapy for adult patients with critical illness: recommendations of the European Respiratory Society and European Society of Intensive Care Medicine Task Force on Physiotherapy for Critically Ill Patients. Intensive Care Med 34: 1188–1199.