Facts on File Encyclopedia of Health and Medicine

THE HEIMLICH MANEUVER

The HEIMLICH MANEUVER, an emergency procedure

for ejecting an inhaled object from the TRACHEA,

uses the DIAPHRAGMto generate a forceful exhala-

tion. Placing a sharp, upward thrust into the

diaphragm causes the diaphragm to rapidly con-

tract and relax, sending its dome higher into the

thoracic cavity than usual. The effect strongly

compresses the LUNGS, forcing them to propel air

outward. The force of the air dislodges the

object.

For further discussion of the diaphragm within
the context of pulmonary structure and function
please see the overview section “The Pulmonary
System.”
See also BREATHING EXERCISES.

dyspnea Difficulty BREATHING or shortness of
breath. There are numerous causes of dyspnea,
most of which relate to cardiovascular or pul-
monary disorders. Dyspnea occurs when the body
does not receive enough oxygen. As oxygen is the
fuel for cellular activity, lack of oxygen means
cells cannot function properly. When oxygen

insufficiency (HYPOXIA) is systemic (involves all the

body) the body begins to conserve oxygen for vital

uses. This concurrently slows activity of nonessen-

tial cells such as skeletal MUSCLEcells and sends

signals to the LUNGS and HEARTto increase their

productivity.

Dyspnea may occur as a result of intense physi-

cal activity, such as exercise, in which case it gen-

erally diminishes with improved AEROBIC FITNESS.

Dyspnea associated with cardiovascular or pul-

monary disease may lessen slightly with pul-

monary rehabilitation and improved physical

conditioning but typically does not improve sub-

stantially unless the underlying disease condition

improves. CHRONIC OBSTRUCTIVE PULMONARY DISEASE

(COPD) andHEART FAILUREare the two most com-

mon causes of dyspnea. Doctors assess clinical dys-

pnea according to the degree to which it interferes

with normal activities.

See also APNEA; ASPHYXIATION; DISABILITY AND

EXERCISE; INTERSTITIAL LUNG DISORDERS; LIVING WITH

CHRONIC PULMONARY CONDITIONS.

emphysema See CHRONIC OBSTRUCTIVE PULMONARY

DISEASE(COPD).

emphysema 203

GRADES OF DYSPNEA

Grade Severity Level of Impairment
grade 1 minimal shortness of breath with exertion such as climbing multiple flights of stairs, short running
such as to catch a bus, or walking uphill

grade 2 mild shortness of breath with moderate exertion such as climbing a single flight of stairs or
walking several blocks on the flat

grade 3 moderate shortness of breath with mild exertion such as walking one block on the flat; must pause
when climbing a single flight of stairs

grade 4 significant shortness of breath with everyday physical activity; must pause when walking on the flat;
must pause every few steps when climbing a flight of stairs

grade 5 incapacitating shortness of breath with any physical effort including dressing, undressing, showering or
bathing; cannot walk more than a few steps without pausing; cannot climb steps