Overview of the Respiratory System

Respiratory System Overview

• The respiratory system involves inhalation (oxygen intake) and exhalation (carbon dioxide expulsion).
• The airway includes the nose, mouth, throat, voice box, and windpipe (trachea). Air travels through this system to and from the lungs.
• The lungs are elastic organs with thousands of tiny air spaces (alveoli). The bronchial tree is part of the lungs.
• The rib cage is formed by connected ribs, the spine, and breastbone. The diaphragm is a dome-shaped muscle separating the abdominal cavity from the bottom part of the rib cage.
• The diaphragm and rib muscles automatically contract and relax to control breathing. Contraction increases the rib cage and atmospheric pressure, causing air to move in and out.
• Breathing cycles occur approximately 12-18 times per minute.

Upper Respiratory Tract

• The nasal cavity warms, filters, and humidifies air before it reaches the lungs.
• Mucus and cilia trap particles in the nasal cavity to help prevent infection.
• The pharynx is a passageway for both food and air. It branches into the esophagus (for food) and the trachea (for air).
• The larynx houses the vocal cords, plays a role in breathing, sound production, and protecting the trachea from food aspiration.

Lower Respiratory Tract

• The trachea (windpipe) carries air from the larynx to the bronchi.
• Bronchi branch into smaller bronchioles that lead to the alveoli.
• Alveoli are tiny air sacs where inhaled air exchanges oxygen for exhaled carbon dioxide. A network of capillaries surrounds the alveoli for gas exchange.

Diaphragm

• The diaphragm is a large muscle at the base of the lungs.
• Contraction of the diaphragm expands the chest cavity, drawing air into the lungs.
• Relaxation of the diaphragm expels air from the lungs.

Air Passages

• The respiratory system's air pathways include the nose, throat (pharynx), windpipe (trachea), air tubes (bronchi), bronchioles, and alveoli.

Mechanism of Respiration

• Breathing involves inhaling and exhaling.
• Muscles (diaphragm and ribs) contract and relax, expanding and reducing the chest cavity, creating low and high pressure to move air, respectively.

Inspiration (Breathing In)

• The diaphragm flattens, increasing chest capacity from downwards.
• Ribs move upward and forward, further expanding chest capacity.
• Lungs expand, drawing air in.

Expiration (Breathing Out)

• The diaphragm relaxes, reducing chest capacity.
• Ribs move downward, decreasing chest capacity.
• Lungs contract, forcing air out.

Small Blood Vessels (Capillaries)

• Capillaries surround the alveoli.
• Oxygen and carbon dioxide exchange happens through blood circulating in these capillaries.
• Oxygen is absorbed, and carbon dioxide and water vapor are expelled into the alveoli.
• The lungs are also supplied with nerves connected to the respiratory center in the brain, which controls breathing.

No Breathing or Difficult Breathing

• Asphyxia is when the lungs do not receive enough air.
• Without breathing or a beating heart, survival is limited to a few minutes.

Causes of No Breathing in a Dental Setting

• Common causes include airway obstruction, anaphylaxis, sedation/anesthesia complications, vasovagal syncope, cardiac arrest, asthma attacks, hyperventilation, or trauma to the airway.

How to Recognize No Breathing in Patients

• Look for cyanosis (blue lips, face, or nails), absence of chest movement/gas exchange, gasping/choking sounds, unresponsiveness or unconsciousness, and/or struggling/high-pitched breathing called stridor.

Syncope (Fainting)

• Causes include a decrease in blood pressure.
• Symptoms are pale skin, dizziness, sweating, loss of consciousness , lightheadedness, nausea.
• Immediate action includes positioning the patient flat with legs elevated to improve blood flow to the brain, ensure a clear airway, monitor vital signs, and administer oxygen if needed.

Airway Obstruction in Dentistry

• Causes include inhaling dental tools, fragments, or materials.
• Signs are gagging, choking, cyanosis, inability to speak.
• Treatment involves encouragement of coughing (if conscious), Heimlich maneuver (if choking persists), calling for emergency help, and possibly CPR if not responsive.

Anaphylaxis

• A severe allergic reaction causing difficulty breathing, hives, facial/throat swelling, breathing difficulties, abdominal pain, shock, and wheezing.
• Immediate action includes administering epinephrine (auto-injector), positioning the patient lying down with elevated legs, providing oxygen, and calling emergency services.

Sedation or Anesthesia Complications

• Causes include overdose or adverse reaction to medications.
• Symptoms include slow or absent breathing, cyanosis, unconsciousness.
• Immediate action includes ensuring a clear airway, administering oxygen, CPR if necessary, and calling emergency services.

Angina and Myocardial Infarction (Heart Attack)

• Causes include underlying heart conditions, stress, or medication reactions.
• Angina symptoms include chest pain/pressure (often relieved by rest), pain radiating to arm/jaw.
• Heart attack symptoms include severe chest pain, shortness of breath, nausea, sweating, or dizziness.
• Immediate action involves administering aspirin, oxygen, placing the patient upright, calling emergency services, monitoring, and preparing for transport to the hospital.

Hypoglycemia (Low Blood Sugar)

• Causes include low blood sugar levels.
• Symptoms include shakiness, confusion, sweating, dizziness, or loss of consciousness.
• Immediate action involves administering oral glucose (glucose tablets, juice), monitoring blood glucose levels, calling emergency services if not responding, and ensuring full medical evaluation if recurrent.

Seizures

• Symptoms include uncontrolled muscle contractions, loss of consciousness, and possible confusion.
• Immediate action involves removing objects around patient, supporting head with soft cushion, placing patient on their side for clear airway, timing seizure, and seeking medical help.
• Follow-up includes monitoring the patient closely, seeking medical attention if necessary, protecting from injury, and ensuring a safer environment .

Respiratory Distress

• Causes include various underlying conditions.
• Symptoms include difficulty breathing, shortness of breath, cyanosis, or wheezing.
• Immediate action includes administering supplemental oxygen, positioning patient upright, continuous monitoring if necessary, calling for immediate emergency services if condition worsens, and ensuring a thorough medical evaluation.

Asthma Attack

• Causes include exposure to allergens, stress, colds, upper airway infections, pet dander, insect bites/stings, foods, or pollen, paint, or smoke.
• Symptoms include shortness of breath, coughing/wheezing, fast/shallow breathing, bluish coloration of the face, anxiety, tightness in the chest, rapid pulse, shock, and restlessness with subsequent fatigue.
• First aid involves a scene survey and primary survey, positioning the patient comfortably for breathing, providing care (ex. administering medication), CPR if necessary, and monitoring for improvement or calling emergency services.

Hyperventilation

• Causes include anxiety or panic attacks.
• Symptoms include rapid breathing, dizziness, tingling, and fainting.
• First aid involves instructions for slow deep breaths, breathing into cupped hands, reassuring, and assessing anxiety levels; stress management techniques.

Trauma to the Airway

• Trauma-related breathing emergencies are caused by procedural trauma (leading to bleeding or swelling).
• Symptoms include difficulty breathing, coughing up blood, and cyanosis.
• Immediate action includes positioning the patient upright, administering oxygen, and calling emergency services.

Pneumothorax (Collapsed Lung)

• Cause: Air leaks into the space between the lung and chest wall (e.g., broken rib).
• Symptoms include Sudden chest pain, shortness of breath, reduced breath sounds on one side.
• First Aid: Call for emergency help immediately. Keep the patient calm and in a comfortable position (usually sitting upright) to assist breathing.

Basic Life Support (BLS) and Airway Management

• For adults, chest compressions of at least 2 inches deep at a rate of 100-120 per minute.
• Rescue breaths after 30 compressions, ensuring the airway is open (head-tilt, chin-lift).
• If the airway is blocked (e.g., tongue, foreign object), ensure proper airway management.
• Automated External Defibrillator (AED) can be used if the heart has stopped and to restore a heart beat.

CPR Steps

• Details for performing chest compressions and rescue breaths.

Recovery Position

• A position for unconscious breathing patients to prevent the tongue from blocking the airway, and keeps the head and neck extended to allow for the airways to widen.
• Allows for vomit or fluids to drain out of the mouth.

Signs of Asphyxia

• Difficulty breathing, restlessness, increased breathing rate, shortness of breath, swollen neck veins, bluish discoloration of face, lips, nails, fingers, and toes, rapid pulse, and feebleness.

Gas Inhalation

• Common symptoms include difficulty breathing/shortness of breath, dizziness/confusion, nausea or vomiting, coughing/irritation of the throat/lungs, and unconsciousness.
• First aid steps involve ensuring safety, moving the person to fresh air, checking breathing and responsiveness, loosening tight clothing, providing oxygen if available, positioning in the recovery position, monitoring symptoms, seeking medical attention, and being prepared to perform CPR.

Respiratory System Pathologies Relevant to First Aid

• Chronic Obstructive Pulmonary Disease (COPD) and Pneumonia are common lung conditions that can affect airflow and lead to breathing problems.

Preparedness in the Dental Clinic

• Maintain emergency equipment for no breathing or other emergencies.
• Staff training in BLS and CPR.
• Regular performance of emergency drills and evaluating patient's medical history.