Mechanical ventilation weaning issues can be counted on the fingers of just one hand: part 1

The Ultrasound Journal

Table 1 Most common bias to consider before an ultrasound assessment of diaphragmatic function

	Affected parameters
	DE	DTF
Poor echographic transthoracic window
Obesity	Ø	Ø
Splenectomy (left hemidiaphragm)	Ø	Ø
Altered starting position of hemidiaphragm
Downward: COPD, asthma, PLEFF	Ø
Upward: abdominal hypertension, ascites, supine position	Ø
Iatrogenic impaired function
Drugs (sedative, myorelaxants, etc.)	Ø	Ø
Mechanical ventilation
Inspiratory positive pressure	Ø
PEEP	Ø
Operator-dependent factors
a angle other than 90°	Ø
ZOA identification^a		Ø

DE diaphragmatic excursion, DTF diaphragm thickening fraction, COPD chronic obstructive pulmonary disease, PLEFF pleural effusion, PEEP positive end-expiratory pressure, a angle angle between M-Mode and hemidiaphragm examined, ZOA zone of apposition
^aThe further away from the ribs, the smaller the DTF will be