Respiratory Mechanics and Diaphragmatic Dysfunction in COPD Patients Who Failed Non-Invasive Mechanical Ventilation

Figures & data

Figure 1 Flow chart for study population.

Table 1 Demographics and Relevant Clinical Features of the Patients On Admission

Feature	Value
Patients (n)	12
Age (years)	69 (8.4)
Male (n)	9 (75%)
Pneumonia (n)	6 (50%)
Diabetes (n)	6 (50%)
GCS	12 (3.4)
APACHE II	27 (6.5)
SAPS II	46 (6.3)
SOFA	6.1 (2.1)
pH	7.21 (0.06)
pCO2 (mmHg)	88 (10.3)
Blood lactate (mg/dL)	9 (4.5)
P/F	168 (20.4)

Note: Data are presented as number and percentage for dichotomous values or mean value and standard deviation for continuous values.

Abbreviations: APACHE II, Acute Physiology and Chronic Health Evaluation II; GCS, Glasgow Coma Scale; P/F, PaO₂/FiO₂ ratio; SAPS, Simplified Acute Physiology Score; SOFA, Subsequent Organ Failure Assessment.

Table 2 Physiological Characteristics of Enrolled Patients

Patient	Pdisniff (cmH2O)	Pdi/Pdisniff	Static EELV (mL)	iPEEP Stat (cmH2O)	iPEEP Dyn (cmH2O)	Elast Tot (cmH2O/L)	Elast Lung (cmH2O/L)	Elast Chest Wall (cmH2O/L)	Airway Resistance (cmH2O/L*sec)
1	6	0.83	2300	5	9	8.6	2.9	5.7	40
2	14	0.64	1925	10	8	17.5	7.5	10.0	40
3	0	–	4219	14	14	16.7	6.7	10.0	40
4	88	0.28	2468	1	1	20.9	9.3	11.6	25
5	0	–	2956	14	14	17.1	5.7	11.4	50
6	0	–	3000	7	22	13.2	3.8	9.4	30
7	22	0.72	3000	0	6	19.6	4.9	14.7	40
8	9	0.88	2900	3	6	15.4	12.3	3.1	12
9	45	0.33	1300	0	3	11.1	8.9	2.2	26
10	21	1	5000	7	8	24.0	8.0	16.0	30
11	5	0.79	3200	8	10	12.3	2.5	9.8	26
12	70	0.38	2520	4	5	16	8	8.0	39
Mean (IQR)	23.3 (29)	0.64 (0.3)	2900 (975)	6.3 (4.8)	8.8 (5.7)	16 (4.3)	6.7 (2.9)	9.3 (4.1)	33 (10.2)

Note: In the bottom line data are presented as mean and interquartile ranges.

Figure 2 (A) Linear regression analysis showing correlation between dynamic intrinsic PEEP and maximal transdiaphragmatic pressure. (B) Linear regression analysis showing correlation between static lung elastance and maximal transdiaphragmatic pressure. (C) Linear regression analysis showing inverse correlation between Pdi/Pdisniff and Pdisniff.

Figure 3 (A) Linear regression analysis showing correlation between static intrinsic PEEP and maximal transdiaphragmatic pressure. (B) Linear regression analysis showing correlation between static elastance of the respiratory system and maximal transdiaphragmatic pressure. (C) Linear regression analysis showing correlation between chest wall elastance and maximal transdiaphragmatic pressure. (D) Linear regression analysis showing correlation between airway resistance and maximal transdiaphragmatic pressure.

Data Availability of Data and Materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.