Air stacking (v no intervention) on lung volumes in people with SCI who have respiratory muscle weakness | SCI Physiotherapy Clinical Practice Guidelines

	Air stacking (v no intervention) on lung volumes in people with SCI who have respiratory muscle weakness
P	People with SCI who have respiratory muscle weakness	Evidence recommendation No evidence recommendation Reason: No recommendation due to insufficient or inconclusive evidence.		Weak opinion statement FOR Air stacking may be taught to improve lung volume in people with SCI who have respiratory muscle weakness. Clinical note: Air stacking involves the use of any positive pressure inspiratory device. These should be provided by a mouthpiece and nose peg rather than a face mask because of the risk of pneumothorax if a facemask is provided.
I	Air stacking
C	No intervention	Consensus-based opinion statement Weak for (100%)
O	Lung volume (L)	Consensus-based opinion statement Weak for (100%)
	SUMMARY	1 RCT (see reference)		Mean difference (95% CI): Lung volume in litres 0 (-0.6 to 0.6) Favours air stacking
	GRADE Very low certainty ⨁◯◯◯	Risk of bias Very Serious	Inconsistency Serious	Imprecision Serious	Indirectness Serious	Publication bias Serious

AIR STACKING ON LUNG VOLUME: GRADE Evidence to Decision
PROBLEM	No	Probably no	Probably yes	Yes		Don't know
DESIRABLE EFFECTS	Trivial	Small	Moderate	Large		Don't know
UNDESIRABLE EFFECTS	Large	Moderate	Small	Trivial		Don't know
CERTAINTY OF EVIDENCE	Very low	Low	Moderate	High		No included studies
HOW MUCH PEOPLE VALUE THE MAIN OUTCOME	Important uncertainty or variability	Possibly important uncertainty or variability	Probably no important uncertainty or variability	No important uncertainty or variability
BALANCE OF EFFECTS	Favours the Control	Probably favours the Control	Does not favour either the intervention (I) or the comparison (C)	Probably favours the I	Favours the I	Don't know
RESOURCES REQUIRED	Large costs	Moderate costs	Negligible costs and savings	Moderate savings	Large savings	Don't know
CERTAINTY OF EVIDENCE OF REQUIRED RESOURCES	Very low	Low	Moderate	High		No included studies
COST EFFECTIVENESS	Favours the comparison	Probably favours the comparison	Does not favour either the intervention or the comparison	Probably favours the intervention	Favours the intervention	No included studies
EQUITY	Reduced	Probably reduced	Probably no impact	Probably increased	Increased	Don't know
ACCEPTABILITY	No	Probably no	Probably yes	Yes		Don't know
FEASIBILITY	No	Probably no	Probably yes	Yes		Don't know

AIR STACKING FOR LUNG VOLUME: Randomised Controlled Trial Details
STUDY	COMPARISON	DOSAGE/DETAILS	PARTICIPANTS	N (Rx/C)	OUTCOME	ROB 2 PEDRo
JEONG 2015	Air stacking V Incentive spirometry	20 reps air stacking 2 x per day 5 days per week for 6 weeks	tetaplegia	14/12	Lung volume (FVC)	High Risk of Bias PEDro = 6/10

The Australian and NZ SCI Physiotherapy guideline committee recommends air stacking may be taught to improve lung volume in people with SCI who have respiratory muscle weakness. This is a consensus-based opinion statement supported by the opinions of the experts even though there are randomised controlled trials related to this topic. The results of these randomised controlled trials are either contradictory or inconclusive preventing an evidence recommendation. The guideline states:

Air stacking may be taught to improve lung volume in people with SCI who have respiratory muscle weakness.

This statement was formed by considering the balance between benefits and harms, values and preferences, resource use, personal experience, equity, accessibility, feasibility and personal experience. The results of the two randomised controlled trials were also taken into consideration.

This is a consensus-based opinion statement. Consensus-based opinion statements are less robust than evidence-based recommendations. They can be strong or weak. This is a weak consensus-based opinion statement which means that the guideline panel is confident they can probably recommend that air stacking may be taught to improve lung volume in people with SCI who have respiratory muscle weakness based on opinion.

To learn more about the this intervention go to the research evidence.

Jeong, JH, Yoo WG. Effects of air stacking on pulmonary function and peak cough flow in patients with cervical spinal cord injury. Journal of Physical Therapy Science 2015 Jun;27(6):1951-1952.