increase DLCO

DLCO increased (NAKAMURA)
1. Supine position: increased perfusion to upper lobe
2. Exercise : increased pulmonary blood flow
3. Asthma: more uniform distribution of pulmonary blood flow
4. Obesity: increased pulmonary blood volume
5. Polycythemia
6. Intra-alveolar hemorrhage
7. Lt-Rt cardiac shunt : increased pulmonary blood volume

Residual volume

Residual volume
is determined by the balance of “expiratory muscle activity” and the “resistance” to volume decrease bythe lungs and chest wall

Pulmonary function testing in diaphragmatic paralysis

Pulmonary function testing in diaphragmatic paralysis

-MIP and MEP decrease (usually in early asymptomatic)
-MVV decrease next
-then Decrease in lung volume and FVC and FEV1
-DLCO may be decrease because of decrease in lung volume should use DLCO/VA

**VC in upright and supine
Measuring the vital capacity in the upright and supine positions is the most important pulmonary function test.

Normally, vital capacity in recumbency decreases by 10%. In unilateral paralysis, the vital capacity shows a decrease to 70-80% of the predicted level. The decrement is usually slightly more significant in the supine position.

In contrast, patients with bilateral diaphragmatic paralysis show a 50% decrease in vital capacity when they are supine. This decrease is from cephalad displacement of abdominal contents.

**MVV
Maximum Voluntary Ventilation (MVV) is a measure of the maximum amount of air that can be inhaled and exhaled within one minute. For the comfort of the patient this is done over a 15 second time period before being extrapolated to a value for one minute expressed as liters/minute. Average values for males and females are 140-180 and 80-120 liters per minute respectively.

can estimate MMV = 35xFEV1

PFT

TLC as follows:
● 80% to 120% predicted: normal;
● 70% to 80% predicted: mild restriction;
● 60% to 70% predicted: moderate restriction; and
● less than 60% predicted: severe restriction.

Slow VC and Force VC

SVC>FVCอย​่างsignificant แปลว่ามี airflow limitation
SVC > FVC 200

resectional thoracic surgery
preserved FEV1ต้อง>0.8L
FEV1 decrease 5%/segment resection (Rt.pneumonect. decrease55%, Lt.45%)
pneumonect. – preop.FEV1ควร>2L, lobec.>1.5L

Obesity and respiratory function

obesity and respiratory function
.The most sensitive indicator of obesity is a low ERV and FRC
.Restriction is seen in more severe obesity, with reductions in TLC and FVC
.RV is often preserved because of the relative high closing volume in relation to ERV
.IC was preserved
.Increase of RV/TLC
.DLCO normal or increase
.Although an increased prevalence of asthma has been reported in the obese, there are conflicting data on whether obesity causes AHR or airway inflammation
.Low MVV, low MIP