Canadian Health&Care Mall: Results of Pulmonary Function and Ventilatory Response

dynamic pulmonary volumeTable 1 summarizes the anthropometric characteristics of the patients and three normal subjects.

Table 2 shows the results of Pimax and PEmax. The reference value of the maximum static pressure for patients 2 and 3 is obtained from the equations of Gaultier and Zinman. For patient 1, the reference value of Leech and her associates is used. The measured results are expressed as a percentage of the reference value based on age, sex, and size of the individuals tested, as well as a percentage of the reference value based on vital capacity (VC) according to Gaultier and Zinman (Pim>vc and PEm,vc). Our results show that PEmax is slightly better preserved than Pimax, but this relation reversed for patients 1 and 3 when they are expressed as a percentage of predicted values based on VC.

Table 3 shows the static pulmonary volumes. The TLC and VC are significantly reduced for patients 1 and 2 but not for patient 3. In all three patients, when the values are expressed as a percentage of reference value, VC is decreased more than TLC. Values for FRC are within normal limits in all three patients. The RV is significantly elevated for patient 1, and the values are near the upper limit of the normal range for patients 2 and 3. The ratio of FRC/TLC is increased in all three, while the ratio of RV/TLC is significantly increased for patients 1 and 2 but not for patient 3.

Figure 2 summarizes the results of the observed maximum static pressures expressed as a percentage of reference values based on sex, size, and age, and the static pulmonary volumes as a percentile of reference values. This figure clearly shows a direct negative relation between the static maximum pressures and RV. Although limited data do not allow us to study the exact relation between them, since the maximal expiratory force is the major determinant in setting RV, we can infer that RV is related closely to PEmax. Although the values of VC and RV are clearly outside of the normal range, they cannot by themselves differentiate among functional disorders of muscular, restrictive, or obstructive origins. Figure 2 also shows that the observed values of static maximum pressures are better indicators of muscular disorder than are the static pulmonary volumes. Join or subscribe the canadian health and care mall news on plurk official group and become in touch with about what people are talking.

Table 4 shows measurements of dynamic pulmonary volume. All indices except for FEV/FVC are uscular disordersignificantly reduced. The PEFR is decreased less than MIFR. The FEV! is decreased slightly more than FEF25-75%. The MW is better preserved than VC of FEVj. Figure 3 summarizes the results of maximum static pressures based on VC, and dynamic pulmonary volumes as a percentage of reference values. Because the patient with either restrictive or obstructive disease may have a reduced VC, the observed values of maximum static pressures are corrected for the actual VC in order that the effect of reduced maximum static pressure on each dynamic pulmonary volume can be assessed more realistically. The relative position of various dynamic volume changes on a scale of percent of predicted allows us to differentiate three disease states: (1) muscular disorder; (2) restrictive disorder of pulmonary origin; and (3) obstructive disorder (see discussion).

Table 5 summarizes the results of V (inspired volume per minute [Vi] in case of carbon dioxide stimulus and expired volume per minute [Ve] in case of hypoxic stimulus) and its components, breathing frequency, and Vt, and Vi/Ti. Our patients generally had a smaller Vt and a larger breathing frequency than the control subjects, but the difference was significant only for Vt because of the large variability of patients breathing frequencies. In both tests, Vt failed to rise normally, whereas breathing frequency increased normally. In response to carbon dioxide stimulus, Vt/Ti increased by 113 percent of the base value when alveolar carbon dioxide tension (PaC02) reached 50 mm Hg, compared to a lb3 percent increase m normal subjects. In comparison, there was only a 40 percent increase in Vt/Ti among patients in response to hypoxic stimulus, whereas this index increased by 238 percent from the base value in the control subjects, when alveolar oxygen pressure (PaO*) dropped to the level of 42 mm Hg.

Table 6 shows Vos and ventilatory responses to hypoxia (AV*, and AV^/sq m) and hypercapnia (S and S/sq m). Oxygen consumption is within the limits of normal range in all three patients, but patient 1 had an improbably low Vo2, at times lasting up to three minutes on the spirometric tracing. The latter finding is similar to a case of OCS reported by Krieger and Hart. Both ventilatory response to hypercapnia and ventilatory response to hypoxia are significantly diminished (p=0.001), but the latter is more severely affected than the former in all three patients.

Figure-2

Figure 2. Maximum static inspiratory and expiratory pressures (based on sex, age, and size) and static pulmonary volumes expressed as percentage of predicted reference values. Symbols identify individual patients: x, patient 1; o, patient 2; and triangle$y patient 3.

Figure-3

Figure 3. Maximum static inspiratory and expiratory pressures (based on VC) and dynamic pulmonary volumes expressed as percentage of predicted values. Symbols identify individual patient: x, patient 1; o, patient 2; and triangles, patient 3.

Table 1—Anthropometric Characteristics of Patients and Normal Control Subjects

Croup and Subject Age,yr Sex Height,cm Weight,kg BSA, sq m*
Patients
1 16 F 154.0 41.8 1.35
2 13 F 164.5 48.5 1.50
3 10 F 135.5 36.6 1.15
Controls
4 31 F 164.0 56.2 1.60
5 25 F 166.0 55.6 1.60
6 23 F 157.5 50.8 1.50

Table 2—Maximum Static Inspiratory and Expiratory Pressures

Patient Pimax (cm H20) Observed Percent PEmax (cm H20) Observed Percent P Im.vc(cm H20) Observed Percent Px Em, vc(cm H.O): Observed Percent
123Mean ± SE 25 (80) 30.3 45 (108) 41.7 69 (86) 77.7 50.0± 11.7 28 (95) 48(126)81 (108) 47.5 28.738.7 95.0±11.5 25 (70) 35.7 45 (85) 52.9 69 (64) 107.8 65.5 ±17.8 28 (76) 36 48(90) 53 81 (70) 98 62.9+15.1

Table 3—Static Pulmonary Volumes

Patient TLC, Lt VC, Lt FRC, Lt RV, Lt FRC/TLC,percent RV/TLC,percent
1 3.19 (76) 1.76 (57) 1.86 (109) 1.27 (151) 59.9 40.8
2 3.66 (73) 2.22 (59) 2.07 (98) 1.34 (129) 56.6 36.5
3 2.37 (88) 1.66 (78) 1.34 (116) 0.74 (130) 55.4 30.5
Mean ± SE 79 ±4 65±6 108 ±4 13 ±6 54.4± 1.3 36.6 ±2.1

Table 4—Dynamic Pulmonary Volumes

Patient MIFR, L/sect PEFR, L/mint FEVj, Lt FEV/FVC,percent FEF25-75%,L/sect MW, L/mint
1 2.19 (53.3) 223(58.7) 1.42 (51.2) 80.9 1.82 (55.0) 56.9 (58.9)
2 2.68 (56.2) 268 (62.7) 1.87 (57.6) 84.5 2.47 (64.3) 74.5 (66.8)
3 2.60 (86.4) 254 (88.8) 1.42 (73.3) 85.3 1.82 (75.6) 53.0 (78.3)
Mean± SE 69.3 ±8.6 70.1 ±7.7 60.7 ±5.4 83.6±1.1 65.0±4.9 68.0±4.6

Table 5—Ventilation and Its Components

Variable and Group PaCO* mm Hg Pa02, mm Hg
39-42 49-52 >120 81-79 43-41
V, L/mint
Controls 8.77 ±0.42 23.8± 1.1 8.14 ±0.35 10.52 ±0.46 27.68 ±1.32
Patients 7.83 ±0.31$ 16.36 ±0.93$ 7.33 ±0.29$ FG7.40±0.26$ 10.85 ±0.41$
Breathing frequency
Controls 16.2 ± 1.3 23.8 ±1.1 16.0± 1.2 18.1 ±1.6 22.7± 1.7
Patients 17.9± 1.9 24.0±1.9 16.8± 1.6 18.2±2.2 19.9± 1.2
Vt, Lt
Controls 0.54 ±0.04 1.25 ±0.07 0.51 ±0.02 0.58 ±0.03 1.22 ±0.05
Patients 0.44 ±0.08$ 0.68 ±0.06$ 0.43 ±0.06$ 0.41 ±0.08$ 0.51 ±0.07$
Vt/Ti
Controls 0.38 ±0.05 1.00 ±0.06 0.34 ±0.03 0.44 ±0.04 1.15 ±0.08
Patients 0.32 ±0.08 0.68 ±0.04$ 0.30 ±0.06 0.30 ±0.07$ 0.42 ±0.06$

Table 6—Ventilatory Responses to Hypercapnia and Hypoxia and Vot

Group and Subject ДУ*» L/min AV«/sq m, L/min/sq m s,L/mm Hg COt S/sq m,L/mm Hg COj/sq m Vo* ml*
Patients
1 2.5 ±0.1 1.9 0.6 ±0.03 0.4 133 ±2
2 4.7±0.2 3.1 0.9 ±0.05 0.6 147 ±3
3 4.5 ±0.2 3.8 1.3±0.1 1.2 156 ±3
Mean±SE 3.9±0.3 3.0 ±0.5 0.9 ±0.1 0.8 ±0.2 145 ±4
Controls
4 23.8 14.9 2.7 1.7
5 31.5 19.7 2.1 1.3
6 26.3 17.5 2.0 1.4
Mean±SE 27.2 ±1.9 17.4 ±1.1 2.3 ±0.2 1.5±0.1

Category: Pulmonary Function

Tags: Familial Myopathy, neuromuscular diseases, ventilatory response, Wright peak flowmeter.