Changes in respiratory efficiency and dynamics in experimental pulmonary congestion

Southern As the patient’s

thyrotoxicosis

propylthiouracil,

first

the

Society

improved

filtration

with

rate

and

finally the renal plasma flow became

normal but

the renal plasma flow was decreased.

The latter

increased

as the

patient’s

for Clinical

thyrotoxicosis

im-

proved with propylthiouracil. Thus further

evidence

ism for reduction filtration even above

of the renal plasma

for the metabolic

though

the cardiac

the accepted

vasoconstriction reduced that

average

and edema

normal

renal

cardiac

needs of the tissues, normal.

occurs.

with

this will produce

filtration

One

at rest

depression

flow and filtration

When

failure

had

and

inadequate

were produced

congestion

in dogs by rapid venous

infusion of saline and buffer solutions. ous determinations

pressure

per

and

minute

animals

experiments

Continu-

were made of tidal exchange,

intrapleural Eighteen

and

fluctuations,

of jugular

ventilation

venous

pressure.

were utilized in all. In several

comparative

made

at rest (nembutal

after

the

hyperpnea

determinations anesthesia)

induced

were

as well as

by

rebreathing

CO, and oxygen, or by experimental

congestion.

The rapid infusion produced congestion mortem

and

edema,

examination.

marked pulmonary

confirmed

Generalized

progressive

by

visceral

expiratory

pressures

changes

pressure develpressure

level,

even three

it rose above this level.

The average tidal air increased CO2 administration ventilation

(often

per minute

maximum decreased while

hyperpnea,

slightly increased

Total

congestion

markedly, the

tidal

even with gross

ventilation

was

either

or decreased.

exchange

(cm.3/meter2) -. presssure change

as an index of efficiency

tion. This index rose abruptly stration

after

and the

rose even more sharply.

intrapleural

was utilized

markedly

doubling),

pulmonary

and decreased

of respira-

after CO2 admini-

sharply

after pulmonary

congestion

was produced.

Vagotomy

slowed the

respiratory

rate, but did not abolish

the shift in

intrapleural

pressure to levels above atmospheric,

nor did it prevent tory efficiency of

expiratory

severe

the rapid decline

after congestion. muscle

pulmonary

cervical

cord

groups

congestion.

abolished

these

failed to cause expiratory to drop

to subatmospheric

The authors increased lung,

efficiency

whereas

congestion

failure

with of the

movements?

intrapleural

but

pressures

levels in all cases. produces

hyperpnea

of pulmonary

mainly

by a marked decrease The latter to

toward

positive

lungs are also causative.

in

the

values

explainable by muscles, but the

and cord section

indicates

phenom-

changes

tissues. The shift in

is partially of expiratory

of vagotomy

these changes

Section

in the normal

of respiration.

(with congestionj increased activity

activity

occurred

of breathing

the

is ascribed

in respira-

Marked

that hyperpnea

is accompanied

in efficiency enon

conclude

pressure

of venous

pressure

in the remaining

intrapleural

Intrapleural pressures were levels prior to infusion, but

congestion

hyperpnea;

con-

to over 500 mm. of saline were noted

,narked

intrapleural

post-

and

levels.

caused

atmospheric

of pulmonary

pressure

with increasing

animals

the

changes

intrapleural

In five of eight animals

given CO?, the expiratory below

atmospheric

atmospheric

in the negative

distensibility

gestion

in all experiments. below atmospheric

elevation

toward

oped during inspiration.

more nega-

mean

in total intrapleural

Tidal

the Department of Medicine, Southwestern Medical College, Dallas, Tex.

and

hyperpnea

and an increase

here.

pulmonary

deviated

all cases.

in

pressure

increases

exchange

duced by Morton F. Mason, M.D.)

toward

dioxide

of the renal plasma

M.D. and GEORGE T. SHIRES, M.D. (intro-

slightly

Carbon

During

types of heart

levels

intrapleural

markedly

with marked

HOWARD E. HEYER, M.D., JAMES HOLMAN,

edema

increased

rate

to suppose that a similar

would operate

Experimental

shifted Total

remained

are

atmospheric

pressures either became

this

CHANGES IN RESPIRATORY EFFICIENCY AND DYNAMICS IN EXPERIMENTAL PULMONARY CONGESTION

From

or

We have shown that

rate in other

failure and it is logical

tive

may surmise

less severe

studies

be well

the filtration

outputs on exertion.

mechanism

may

salt and water

the patients

flow and

output becomes

output

is extreme,

and consequently

Inspiratory

pressures

is found of a mechan-

rate when the cardiac

inadequate

rose well above

levels.

503

Research

to abolish

that local changes

in the