Download Guideline for Mobilising Critically Ill Patients

Guidance for the Mobilisation of Critically Ill Patients
Guidance for the Mobilisation of Critically Ill
Patients
Introduction
Research developments have lead to improvements in the diagnosis and
management of critically ill patients. With these improvements, the survival
rate of critically ill patients is increasing [6].
As impaired mobility is an almost inevitable sequelae for patients who are
admitted to hospital with an acute life threatening illness, the physiotherapy
management of these patients will often include treatment aimed at increasing
mobility and independence [9].
The aims of mobilisation include:
 Improving respiratory function by optimising ventilation/perfusion
matching, increasing lung volumes, and improving secretion clearance
 Reducing the detrimental effects of immobility
 Increasing levels of consciousness
 Increasing functional independence
 Improving cardiovascular fitness
 Improving psychological well being [8]
Additionally, for critically ill patients, mobilisation may reduce the incidence of
respiratory complications, hasten recovery, decrease the duration of
mechanical ventilation, and reduce the length of ICU or hospital stay [8].
For the purposes of this guideline, the generic term mobilisation may refer to
any of the following:
 Active/active assisted limb exercises
 Turning in bed
 Bed → chair transfers via mechanical lifting machines or slide boards
 Lie → sit transfers
 Sitting at edge of bed
 Sit → stand
 Standing transfers
 Walking
Aim of Guideline
The aim of this guideline is to provide Greater Glasgow & Clyde Trust
Physiotherapists with a reference tool regarding safety issues that should be
considered prior to and while mobilising critically ill patients to minimise the
risk of detrimental effects. The guideline covers safety factors intrinsic and
extrinsic to the patient.
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Guidance for the Mobilisation of Critically Ill Patients
Medical Background
Prior to mobilisation, the patient’s current and past medical history should be
obtained. This may provide practitioners with information that can help identify
how well the patient is likely to tolerate mobilisation. In particular, it can
indicate which system is likely to limit exercise tolerance and therefore provide
clues as to what parameters to monitor during mobilisation [9].
The types of diagnoses that may affect a patient’s ability to tolerate
mobilisation include:
 Cardiovascular disease – MI, cardiac surgery, angioplasty, angina,
cardiac arrest, hypertension, peripheral arterial disease
 Respiratory disease – COPD, asthma, restrictive lung disease
 Cancer – bony metastases
 Metabolic – diabetes, renal failure, liver failure
 Neurological disorders – stroke, ataxia, MS
 Musculoskeletal disorders - osteoporosis
 Psychiatric conditions
In conjunction with a patient’s past medical history, the history of the patient’s
presenting condition and current symptoms should also be obtained. This
should also include a review of current medications, since drugs such as beta
blockers, peripheral vasodilators and sedatives may affect a patient’s
response to mobilisation or prevent mobilisation altogether. Information on a
patient’s previous level of mobility and exercise tolerance will provide clues as
to their pre-morbid function, the degree of deconditioning and the need for
mobility equipment to assist in the safe mobilisation of the patient [9].
Cardiovascular Considerations
Heart Rate
The usual heart rate (HR) response to exercise in normal subjects is an
incremental increase in HR, dependent on the person’s underlying fitness and
the intensity of exercise [3]. Current literature suggests that mobilisations of
any form result in an increase in HR, however, it is not clear by how much and
the possible implications of such an increase.
There is little published clinical research concerning resting HR’s when
determining the safety of mobilising critically ill patients before an intervention
[9]. Calculations of age predicted maximal HR can aid the clinician in
estimating the patient’s cardiac reserve [10]. The formula for calculating
maximal HR is 220 – age of patient. It is recommended to express each
patient’s resting HR as a percentage of his or her age predicted maximal HR.
Stiller & Phillips suggest that in critically ill patients, it would seem appropriate
to aim for an exercise HR either below or at the very low end of the range
used for increasing the fitness of stable outpatients (60 – 90% of maximal
HR). Therefore in critically ill patient’s, this would be approximately 50-60% of
maximal HR.
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Guidance for the Mobilisation of Critically Ill Patients
For Example, a 45 year old patient:
Maximal HR = 220 – 45 = 175bpm
50-60% HR = 87 – 105bpm
As can be seen from the example above, it is likely that a large proportion of
critically ill patients will have a resting HR already at or above the suggested
exercise limits. In these circumstances, it is essential that the clinician
consider HR in conjunction with other safety issues raised in this guideline, to
support clinical decision making.
Blood Pressure
As with HR, the usual blood pressure (BP) response to exercise in normal
subjects is an initial rise in systolic BP [5]. In contrast diastolic BP tends to
remain stable or only slightly increase at higher levels of exercise intensity
[3,5]. Several studies have documented an increase in BP of approximately
10% during active and/or passive limb movements in critically ill patients
[7,11].
As with HR, there is no published data concerning safe levels of resting BP
when deciding whether to mobilise critically ill patients. When interpreting BP
prior to mobilisation to assess whether it is safe to proceed, the absolute
values may not necessarily be indicative of haemodynamic stability for acutely
ill inpatients [9]. Instead a recent change in BP (systolic, diastolic, or mean) is
most relevant [4]. However an acute increase or decrease in BP, in the order
of at least 20%, is indicative of haemodynamic instability and is likely to delay
mobilisation [4].
If a critically ill patient requires inotropic medication (e.g. adrenaline or
noradrenaline) to maintain adequate BP, in most cases, this is indicative of
haemodynamic instability. Although it may be safe to gently mobilise patients
who have stable BP on low levels of inotropes, in many instances where
inotropes are required to maintain BP, mobilisation will have to be deferred
[9].
Cardiac Status
The following are a list of cardiac conditions that should be considered as
relative contra-indications to mobilisation in critically ill patients:
 Recent significant change in the resting ECG, suggesting significant
ischaemia, recent myocardial infarction, or other acute cardiac event
 Unstable angina
 Uncontrolled cardiac arrhythmia causing symptoms or haemodynamic
compromise
 Severe symptomatic aortic stenosis
 Uncontrolled symptomatic heart failure
 Acute pulmonary embolus
 Acute myocarditis or pericarditis
 Suspected or known dissecting aneurysm [3]
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Guidance for the Mobilisation of Critically Ill Patients
During mobilisation, ECG monitoring is strongly advised in critically ill patients
as it provides an immediate measurement of HR and allows for the detection
of arrhythmias. Additionally, all patients should be observed carefully for signs
and symptoms of cardiac stress (e.g. clamminess, chest/arm/neck pain, and
shortness of breath).
Respiratory Considerations
Oxygenation
When assessing a patient’s suitability for mobilisation, the inspired fraction of
oxygen (FiO2) should be taken into account when interpreting PaO2 as this
more accurately reflects oxygenation and thus the patient’s respiratory
reserve [9]. The ratio of PaO2/FiO2 is a valid measure and easily calculable at
the bedside. Various authors have suggested that a PaO2/FiO2 ratio of
greater than 300 is a strong indicator for suitability for mobilisation. A ratio of
200-300 indicates marginal respiratory reserve and values less than 200
indicate virtually no respiratory reserve. Despite these recommendations,
there is no published data to provide safety limits for interpreting values for
PaO2/FiO2 prior to attempting mobilisation.
For Example:
Patients
Normally fit
100
and well
patient on
room air
COPD patient 60
on room air
Post-Op
90
patient
spontaneously
breathing on
face mask at
8L/min
PaO2
FiO2
0.21
PaO2/FiO2
Ratio
476
Respiratory
Reserve
High
0.21
286
Low
0.55
164
Very Low
Patients should always be mobilised receiving the same FiO2 as is being
delivered at rest, and preferably, with an oximeter to monitor SpO2
throughout. Stiller & Phillips 2003 suggest that a SpO2 of more than 90% is
likely to reflect oxygenation that would allow for patient mobilisation. It is also
recommended that SpO2 should be maintained at or above 90% during
mobilisation to avoid pulmonary vasoconstriction. If a patient’s oxygenation
deteriorates during mobilisation, the activity should be modified to a lower
intensity that reduces the demand on the patient, or the FiO2 increased to
improve oxygenation. If these measures do not improve oxygenation rapidly,
mobilisation should be ceased.
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Guidance for the Mobilisation of Critically Ill Patients
Hypercapnia
While a chronically increased PaCO2 does not on its own affect the ability of
acutely ill patients to mobilise, any associated decreased level of
consciousness can obviously influence the patient’s ability to cooperate with
mobilisation. An acute rise in PaCO2 is indicative of respiratory failure and, if
accompanied by inadequate oxygenation, will most likely limit mobilisation [9].
Respiratory Pattern
As with oxygenation, observing a patient’s respiratory pattern can provide
additional information regarding respiratory reserve [8]. This observation
includes respiratory rate, the presence of asynchronous or paradoxical
movement of the chest wall an abdomen, overactivity of the accessory
muscles of respiration, and unduly prolonged expiration or wheezing [8].
If a patient is maintaining adequate oxygenation, but is only able to do this at
the expense of an increased work of breathing, then mobilisation should be
deferred, or caution taken when attempting mobilisation. Respiratory pattern
should be monitored throughout the procedure.
Mechanical Ventilation
The need for a critically ill patient to be mechanically ventilated is not in itself a
reason to prevent mobilisation. However, the need for high levels of
ventilatory support to maintain adequate gas exchange indicates that the
patient’s underlying respiratory reserve is likely to be poor.
It is recommended that the patient’s level of ventilatory support should be
maintained throughout mobilisation, and the least demanding method of
mobilisation should be used, at least initially [9].
Patients who are being weaned from mechanical ventilation are particularly
vulnerable if mobilised during times of reduced ventilatory support. It is
advisable to mobilise such patients during periods of higher ventilatory
support to ensure that excessive demand is not being placed on the patient.
Once mobilisation has been safely undertaken in this manner, the intensity
can be increased to place higher demands on the patient or the same level of
mobilisation can be attempted during periods of lower ventilatory support [9]
Haematological & Metabolic Considerations
Prior to mobilisation, the patient should be reviewed regarding haematological
and metabolic considerations. This includes the following:
Haemoglobin (Hb)
The oxygen carrying capacity of the blood is proportional to the Hb level.
Normal Hb ranges from 12-18 grams/dL. While there are no absolute lower
values for Hb precluding mobilisation, an acute fall in Hb may delay
mobilisation [9]
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Guidance for the Mobilisation of Critically Ill Patients
Platelet Count
Patients with a very low platelet count are at higher risk of microvascular
trauma and bleeding which has the potential to result from mobilisation. A
count of 20,000 cells/mm³ may be considered a safe lower limit [1].
White Cell Count (WCC)
An abnormally high (> 10,800 cells/mm³) or low (< 4,300 cells/mm³) WCC can
indicate the presence of infection [1]. This in itself does not preclude
mobilisation, but as infection can increase a patient’s oxygen utilisation,
caution is required if undertaking activities that may further increase a
patient’s oxygen demand [8].
Blood Glucose Level
Normally ranges from 3.8 – 5.8 mmol/L [12]. Mobilisation and exercise have
the potential to increase any hypo / hyperglycaemia, which could lead to an
altered level of consciousness and increased risk to the patient [9].
Subjective Considerations
In addition to the factors already discussed, there are numerous other factors
that should be taken into account before mobilising patients to ensure the
safety of the intervention to be carried out. These factors include:
 Appearance (cyanosis, clamminess, anxiety, and muscle bulk).
 Conscious state
 Level of pain (visual analogue scale)
 Rate of perceived exertion
 Shortness of breath (Borg scale)
 Level of fatigue
 Emotional status
Other Considerations





Neurological status
Orthopaedic conditions
Skin conditions
Deep vein thrombosis & pulmonary embolism
Nutritional status
Attachments
During patient mobilisation, it is extremely important to ensure that all
attachments are considered. Prior to mobilisation, seek advice from the
patient’s nurse as to which attachments can be safely disconnected for the
activity. It may also be beneficial to give individual clinicians roles during the
mobilisation e.g. responsibility for the patient, ventilator tubing, catheter, etc.
Endotracheal (ET) or tracheostomy tube
Patients who are ventilated via an ET or a tracheostomy tube can be
mobilised, however care should be taken to avoid dislodgement of the tube
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Guidance for the Mobilisation of Critically Ill Patients
[2]. Excessive tube movement may traumatise the larynx or other areas of the
upper respiratory tract [9].
Underwater sealed drain
When mobilising patients with an underwater sealed drain, care should be
taken to ensure the tubing is not kinked or dislodged and that the drain
remains below the level of the tube’s insertion in the chest [9].
Dialysis tubing
The mobilisation of patients receiving continuous haemodialysis may be
dependent on the patient’s dialysis line site. Patients with a neck line can be
sat up in a chair, but great care must be taken to avoid dislodgement of the
dialysis line during the transfer. However, patients with a femoral line are often
unable to be sat up as this may interfere with blood flow and lead to occlusion
of the dialysis line.
Epidural
Patients with an epidural for pain relief can be mobilised once it has been
ascertained that there is no motor (normal power in legs) or sympathetic block
(BP within normal limits) [8].
Sengstaken tubes
Patients with bleeding gastroesophageal varices may be treated with a
Sengstaken tube. Mobilisation of these patients should be avoided due to the
potential risk of dislodgement of the tube and perforation of the oesophagus.
Environment
Prior to mobilising any critically ill patient, a thorough assessment of the
environment should be carried out. This is to ensure that the environment is
safe and uncluttered, patient attachments are sufficiently long and positioned
appropriately, the bed height is optimal, and the appropriate equipment
required for the mobilisation is at hand.
Staffing
When mobilising critically ill patients, it is essential that there are sufficient
staff available to assist with the activity. Additionally, appropriate staff should
be available to review the patient in the event of deterioration during
mobilisation. Attention should also be given to ensure that the patient is kept
informed about what is going to happen and when. Clear, concise, and calm
instructions will ensure patient confidence and the overall safety of the
mobilisation.
Selecting the Intervention
For critically ill patients, the most appropriate mode, intensity, frequency and
duration of mobilisation will reliant on the patient’s degree of debilitation,
current medical condition, dependency, and their response to previous
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Guidance for the Mobilisation of Critically Ill Patients
mobilisation attempts. Initially mobilisation may start with tasks at a low
intensity such as a bed exercises or mechanically assisted transfers to sitting
out of bed. This may then be progressed to bed mobility and sitting on the
edge of the bed. Once basic independence has been achieved and has been
tolerated well by the patient, mobilisation can progress to the more complex
tasks of standing and walking [8]. Keep in mind, that it is always far safer to
increase the intensity of mobilisation slowly as each treatment is tolerated,
rather than setting the patient back if too much is attempted too soon.
References
1. Braunwald E, Fauci A, Kasper D et al. Harrison’s principles of internal
medicine 15th edition. New York; McGraw-Hill 2001.
2. Ciesla N, Murdock K. Lines, tubes, catheters and physiologic
monitoring in ICU. Cardiopulmonary Physical Therapy Journal 2000;
11(1): 16-25.
3. Franklin B, Whaley M, Hawley E. ACSM’s guidelines for exercise
testing and prescription 6th edition. Philadelphia: Lippincott Williams
and Wilkins 2000.
4. MacIntyre N. Evidence-based guidelines for weaning and discontinuing
ventilatory support. Chest: 2001, 120; 375-395.
5. MacArdle W, Katch F, Katch V. Exercise physiology 4th edition.
Baltimore: Williams and Wilkins; 1996.
6. Morris P. Moving our critically ill patients: mobility barriers and benefits.
Critical Care Clinics: 2007, 23: 1-20.
7. Norrenberg M, De Backer D, Moraine J et al. Oxygen consumption can
increase during passive leg mobilisation. Intensive care medicine:
1995, 21: 177.
8. Stiller K. Safety issues that should be considered when mobilising
critically ill patients. Critical Care Clinics: 2007, 23: 35-53.
9. Stiller K, Phillips A. Safety aspects of mobilising acutely ill inpatients.
Physiotherapy Theory and Practice: 2003, 19: 239-257.
10. Stiller K, Phillips A, Lambert P. The safety of mobilisation and its effect
on haemodynamic and respiratory status of ICU patients.
Physiotherapy Theory and Practice: 2004; 20(3): 175-185.
11. Weissman C, Kemper M, Dansk M et al. Effect of routine intensive care
interactions on metabolic rate. Chest: 1984; 86(6): 815-818.
12. Worthley L. Synopsis of intensive care medicine. Edinburgh: Churchill
Livingstone; 1994.
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