Cardiorespiratory impact of intrathoracic pressure overshoot during artificial carbon dioxide pneumothorax: a randomized controlled study

Table 2 The profiles of intrathoracic pressure overshoot and its impact on the circulatory and respiratory functions

	STR group (n = 100)	STO group (n = 100)	P
Pressure overshoot frequency (times.hour⁻¹)	38 ± 7.4	32 ± 9.9	0.238
Pressure overshoot duration (second)	5.3 ± 0.86	1.2 ± 0.31	0.000
Pressure overshoot value (mmHg)^a	8.9 ± 1.60	9.8 ± 3.13	0.551
Maximum pressure overshoot (mmHg)	58	51	NULL
Increase of peak airway pressure (cmH₂O)^b	4.8 ± 1.17	0.9 ± 0.41	0.000
Increase of central venous pressure (cmH₂O)^c	8.2 ± 2.86	4.9 ± 2.35	0.000
Decrease in SBP (mmHg)	5.6 ± 1.47	1.1 ± 0.39	0.000
Percentage of patients with significant SBP drop^d	51%	9%	0.000
Decrease in heart rate (beats per minute)	0 ± 1.4	0 ± 1.3	0.534
SpO₂ reduction percentage	0%	0%	1.000

^aPressure overshoot value: defined as the maximum thoracic pressure minus eight mmHg during each pressure overshoot period
^bIncrease of peak airway pressure (cmH₂O): defined as the maximum peak airway pressure in each pressure overshoot minus the baseline in the pre-overshoot period
^cIncrease of central venous pressure: defined as the maximum CVP during each pressure overshoot minus the baseline in the pre-overshoot period
^dPercentage of patients with significant SBP drop: defined as the percentage of patients who suffered at least once the SBP drop magnitude was more than 10 mmHg during pressure overshoot

ISSN: 1471-2253