emt 31

The chest cavity boundaries

extends from the collarbones to the “dynamic lower border” framed by the diaphragm—dyanmic because it depends on the resp cycles current phase

Lower border of the chest

as high as the nipple line or as low as the umbilicus

Inhalation

active process diaphragm contacts + flattens, intercostal muscles flex, expanding chest wall outwards, increasing its size—negative pressure is created, pulling air from the trachea

Exhalation

passive process diaphragm + intercostal muscles relax and moves upward, chest wall returns to normal position, lung tissue is condensed, pressure inside the cavity increases, air is pushed out

Chest cavity characteristics

some hollow characteristics but packed with organs, major blood vessels, and lung tissue leaving little to no room

Chest cavity midline

houses the heart, larger vessels (aorta, vena cava), lung tissue takes up remaining space

Diaphragm

“umbrella shaped” at the bottom of the lungs, inferior part of the chest, separates chest from abdominal cavity

Vital chest organs

12 ribs, anterior sternum, thoracic spine vertebrae (forms chest, guards vulnerable lung tissue), 10 sets of ribs connected from vertebrae to sternum, 2 are “free-floating”, scapula rear protects organs

Center of the chest

heart beats, giving constant blood blow, large vessels enter/exit, houses a large portion of the body’s blood volume

Breathing mechanism

changes in chest cavity pressure push air in and out,

Serous fluid

clear, lubricating liquid that help lung tissue stick to the chest wall, allows lung expansion/contraction (changes pressure causing movement of air) and diaphragm contraction

Superior border of the abdomen

aka the diaphragm, abdominal organs extend inferiorly to the lower regions of the pelvis

Hollow organs

stomach, intestines, urinary bladder

Solid organs

 liver, spleen, kidneys, pancreas, cant stretch or compress, can cause massive hemorrhage

Abdominal organ location

dynamic, organs shift depending on diaphragm, 

Abdominal punctures

high pressure force can cause evisceration AND a-wall contains large blood volumes

Pediatric anatomy

kids <8 have pliable chests with less calcium, ribs are not as developed, abdominal organs are less protected

Three pathophysiological parts of chest/abdomen trauma

disruption of breathing, hemorrhage and shock, disruption of organ function

Disruption of breathing (pathophysiological trauma)

trauma, chest wall penetrations occupy space/displace lung tissue causing collapse, chest holes stop pressure generation, diaphragm injuries can inflame/impair breathing

Hemorrhage and shock (pathophysiological trauma)

largest threat in chest/abdomen injuries, internal bleeding can cause shock

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Infection

delayed but threatening, penetration, bacteria enters, hollow organ ruptures can spill contents into the thoracic/abdominal cavities inflaming them

Blunt trauma

an injury that does not penetrate the chest wall (ex. Motor vehicle crashes/falls), lungs/ribs, airway, great vessels, and heart may be seriously injured signs=bruising, shock symptoms, and resp problems

Penetrating trauma

injuries that violate the integrity of the chest wall, (ex. bullets, knives, glass) can damage internal organs and impair respirations

Compression and shearing injuries cause

severe blunt trauma where the chest is rapidly compressed (ex. chest hits steering column or reaped in trench-wall collapse)

Closed chest injury

chest wall is not penetrated, trauma is most likely blunt

Open chest injury

chest wall penetrations

Blunt chest injuries

most common, esp in sports; broken ribs (can cause blood vessel laceration and lung tissue damage), resp failure

Fail chest

2+ consecutive ribs in two or more places are fractured, leaving the chest wall unstable and free-floating ribs, reduces chest wall expansion + causes hypoventing

Paradoxical motion

caused by fail chest, free floating ribs move the opposite direction during breathing, give hi-flo O2 (PPV)

Penetrating chest wound

skin and chest wall are penetrated, may leave a small wound outside but cause massive internal injury, destroys pressure balance, injured lung may collapse, do not open the wound to check depth, O2+vent

Sucking chest wound

large chest holes, drawing in negative pressure with breathing symptoms include: chest wound, gasping, air bubbles in wound

Occlusive dressing

air tight dressing that prevents air from entering the chest cavity (open wound), may have one-way valve to allow air escape

DIY occlusive dressings

wrappers from an IV bag, NOT household plastic, leave one side of the dressing untapped to mimic flutter valves

Flutter valves

allow air to escape from the chest if pressure builds as pneumothorax develops

Pneumothorax

air trapped between the lung and chest wall, pushes tissue away from the chest causing lung collapse, caused by external injury or punctured lungs

Tension pneumothorax

air build up in the chest cavity becomes so severe it puts pressure on the heart/vena cava blood backs into the heart, dropping cardiac output and can cause shock + JV dissention

Pneumothorax symptoms

JV distention (low blood volume), diminished lung sounds, shock signs, trachea shifting to the opposite side (late stage)

Hemothorax

chest cavity fills with blood, caused by lacerations in the chest cavity (ex. penetrations, fractured ribs), may cause lung collapse or shock

Hemopneumothorax

chest cavity fills with blood and air, symptoms are signs of shock

Traumatic asphyxia

sudden chest compression causing sternum and ribs to exert severe pressure onto the heart and lungs, forces blood out of right atrium and into JV, pressure may rupture nearby vessels and cause neck/facial bruising

Cardiac tamponade

extra fluid builds up in the space around the heart, puts pressure on the heart and prevents it from pumping well.

Cardiac tamponade symptoms

beck’s triad: distended neck veins (blood cannot return to right atrium), signs of shock, narrowed pulse pressure, muffled heart sounds (fluid)

Aortic dissection

tear in the inner layer of aorta, blood rushes out causing inner and middle layers to split.

tearing pain may radiate to back/neck/abdomen

Aneurysm

weakened aortic walls becoming balloon-like which expands as pressure increases (may rupture), common w hypertension and smokers

Commotio cordis

bruising/fractures in the center of the chest when the heart is electrically vulnerable, can cause V-fib, immediate cardiac arrest

Evisceration

open wound abdominal trauma so large, organs fall out of the wounds opening

Hollow organ injury

organs spill their contents into the cavity causing inflammation, peritonitis, involuntary abdominal muscle contraction, and a rigid abdominal wall

Gunshot wounds

a bullets pathways within the body is seldom a  straight line, assess full body