EMS Anatomy & Physiology - Mammalian Diving Response Syndrome

EMS Providers should be familiar with the Mammalian Diving Response Syndrome as it is a physiological reflex that can have critical implications during emergency scenarios, especially those involving drowning, cold-water immersion, or apnea. 

Here are some key points to know:

Definition:

The Mammalian Diving Response Syncdrome is a reflex primarily triggered by submersion in cold water or holding one’s breath. 

It is characterized by specific physiological changes that help conserve oxygen and protect vital organs during hypoxia. 

This response is more pronounced in children and is part of an evolutionary adaptation found in many mammals.

Physiological Mechanisms:

The diving response involves three primary components:

- Bradycardia: The heart rate slows down significantly to reduce oxygen consumption by non-essential tissues.

- Peripheral Vasoconstriction: Blood vessels in the extremities constrict, redirecting blood flow to vital organs like the brain and heart.

- Blood Shift (during deep dives): In humans, blood is directed away from the lungs and limbs to maintain pressure and prevent lung collapse during deep dives.

Triggers:

Submersion of the face in water, especially cold water.

Holding breath (apnea).

Psychological stress, such as fear or panic.

Clinical Implications for EMS: 

Understanding the diving response is crucial because it affects how a patient may present and how to manage their condition:

- Bradycardia Management: EMS providers might encounter significantly reduced heart rates in drowning or near-drowning victims.

Bradycardia could be misinterpreted as a sign of severe hypoxia, but it’s a protective mechanism rather than a sign of complete cardiac failure.

Avoid aggressive measures to increase heart rate unless the patient shows other signs of instability.

- Respiratory Considerations: The diving response may cause prolonged breath-holding, so patients might appear apneic or have delayed hypoxic symptoms.

Observe for hypoxia carefully and administer oxygen as indicated.

- Pediatric Considerations: The diving response is more prominent in children, which is why some drowning victims can survive prolonged submersion with relatively less neurological damage.

Cold water can extend the safe resuscitation window in pediatric patients.

- Cardiac Arrest in Cold Water: During cold water submersion, the body’s metabolic rate decreases significantly, which can potentially improve resuscitation outcomes even after prolonged submersion.

Follow hypothermia protocols and prolonged resuscitation efforts in cases of drowning in cold water.

Treatment and Management:

- ABC Approach: Focus on Airway, Breathing, and Circulation.

Hypothermia Management: Consider hypothermia treatment protocols as the mammalian diving response is often accompanied by cold water immersion.

Consider ECLS/ECMO in severe cases: In cases of cardiac arrest with diving reflex activation, specialized centers might use Extracorporeal Life Support (ECLS) or Extracorporeal Membrane Oxygenation (ECMO).

Key Takeaways:

Do not confuse bradycardia with imminent cardiac arrest. It can be a protective adaptation.

Cold-water submersion can improve survival outcomes—keep in mind for prolonged resuscitation in cold environments.

Children are more likely to benefit from the diving response due to their physiology.

Understanding this reflex allows EMS providers to better assess, treat, and manage patients exposed to cold water or other scenarios that can induce the diving response.

Who Discovered The Mammalian Diving Response Syndrome?

The mammalian diving response was first described by Edmund Goodwyn in 1786. However, it was extensively studied and popularized by Paul Bert and later Johan E. Severin Nilsson in the late 19th and early 20th centuries.

Goodwyn, a British physician, observed physiological changes in animals and humans during submersion. His initial work laid the foundation for understanding the reflex, but it was Paul Bert who made significant contributions by studying the effects of breath-holding and diving on the heart rate and blood flow.

Johan E. Severin Nilsson, a Swedish physiologist, further refined the concept, investigating how immersion and apnea affected circulation and oxygen usage in various mammals. His research solidified the understanding of the mammalian diving reflex as a protective adaptation seen across multiple species, including humans.

Further Reading

Alexander, M. & Belle, R. (2017) Advanced EMT: A Clinical Reasoning Approach (2nd Ed). Hoboken, New Jersey: Pearson Education

Bledsoe, B. E., Cherry, R. A. & Porter, R. S (2023) Paramedic Care: Principles and Practice (6th Ed) Boston, Massachusetts: Pearson

Godek, D., & Freeman, A. M. (2022) Physiology, Diving Reflex. Treasure Island, Florida: StatPearls Publishing

Mistovich, J. J. & Karren, K. J. (2014) Prehospital Emergency Care (11th Ed). Hoboken, New Jersey: Pearson Education

Panneton, W. M. (2013) The Mammalian Diving Response: An Enigmatic Reflex To Preserve Life? Physiology 28(5): 284-97. Accessed October 6, 2024

Peate, I. & Sawyer, S (2024) Fundamentals of Applied Pathophysiology for Paramedics. Hoboken, New Jersey:  Wiley Blackwell

EMS Medication Administration - Intravenous (IV) Catheter Gauges

Intravenous (IV) catheter gauges are critical tools for EMS (Emergency Medical Services) providers, and understanding their use is essential for effective patient care.

Here are the key points EMS Providers need to know about IV catheter gauges:

1. Gauge Size and Flow Rate

Gauge Number: The gauge number refers to the diameter of the IV catheter; a higher number indicates a smaller diameter.

Common Gauges Include:

• 14-16 gauge: Large bore for rapid fluid resuscitation or blood transfusions.
• 18 gauge: General use, including blood administration.
• 20 gauge: Suitable for most IV medications and fluids.
• 22-24 gauge: Smaller veins, pediatric patients, or the elderly.

Flow Rate: Larger catheters (lower gauge numbers) allow higher flow rates, essential in emergencies where rapid fluid or blood administration is required.

2. Clinical Indications

• 14-16 gauge: Trauma, major surgery, massive transfusion protocols.
• 18 gauge: Stable patients needing blood products, fluid resuscitation, or certain medications.
• 20 gauge: Routine IV access for medications and fluids.
• 22-24 gauge: Patients with fragile veins, such as children and the elderly, or when slower administration rates are acceptable.

3. Vein Selection

Larger Gauges: Preferable in larger, more central veins (antecubital fossa) to minimize complications and maximize flow rates.

Smaller Gauges: Suitable for smaller peripheral veins (hand, wrist) and for patients with fragile veins.

4. Insertion Technique

Skill and Experience: Proper insertion technique reduces complications like infiltration, phlebitis, and infection. Training and experience in venipuncture are crucial.

Stabilization: Secure the catheter to prevent dislodgement, especially in pre-hospital settings where patients may be moved frequently.

5. Complications

Infiltration and Extravasation: Fluid or medication leaks into surrounding tissue. Larger gauges have higher risks if not properly secured.

Phlebitis: Inflammation of the vein, more common with larger catheters or prolonged use.

Infection: Strict aseptic technique during insertion and maintenance is essential to prevent infections.

6. Special Considerations

Pediatric Patients: Use smaller gauges (22-24) to minimize trauma to delicate veins.

Geriatric Patients: Often have fragile veins; use smaller gauges and gentle techniques.

Medication Compatibility:

Some medications require specific gauge sizes to prevent damage to blood cells or ensure effective delivery.

7. Alternative Access

Intraosseous (IO) Access: In emergencies where IV access is difficult or impossible, intraosseous access may be used, particularly in cardiac arrest or severe trauma situations.

8. Documentation and Communication

Document the size of the catheter, insertion site, number of attempts, and any complications.

Communicate any issues encountered during IV insertion to the receiving medical facility.

9. Ongoing Education

Continuous education and practice are necessary to maintain proficiency in IV catheter insertion and management. This includes staying updated on the latest guidelines and best practices.

By understanding these key points, EMS Providers can make informed decisions about IV catheter selection and insertion, ultimately improving patient outcomes in emergency situations.

Further Reading:

Alexander, M. & Belle, R. (2017) Advanced EMT: A Clinical Reasoning Approach (2nd Ed). Hoboken, New Jersey: Pearson Education

Bledsoe, B. E., Cherry, R. A. & Porter, R. S (2023) Paramedic Care: Principles and Practice (6th Ed) Boston, Massachusetts: Pearson

Mistovich, J. J. & Karren, K. J. (2014) Prehospital Emergency Care (11th Ed). Hoboken, New Jersey: Pearson Education

Peate, I. & Sawyer, S (2024) Fundamentals of Applied Pathophysiology for Paramedics. Hoboken, New Jersey:  Wiley Blackwell

EMS Emergencies - Pediatric Patients

EMS providers need to be well-prepared to handle pediatric emergencies as they require specialized knowledge and skills due to the unique needs of children.

Here are some key points they should know:

1. Respiratory Distress: Children commonly present with respiratory distress due to conditions such as asthma, bronchiolitis, or croup. EMS providers should be proficient in assessing respiratory status, administering oxygen, and managing airway obstructions.

2. Febrile Seizures: Febrile seizures are common in young children and are often frightening for caregivers. EMS providers should know how to assess and manage febrile seizures, including ensuring adequate ventilation and preventing injury during the seizure.

3. Trauma: Children are at risk for various types of trauma, including falls, burns, and motor vehicle accidents. EMS providers should be skilled in assessing and managing pediatric trauma, including immobilization techniques and pain management.

4. Sepsis: Sepsis can be challenging to recognize in children, as symptoms may be nonspecific. EMS providers should be vigilant for signs of sepsis, such as fever, tachycardia, and altered mental status, and be prepared to initiate early treatment.

5. Anaphylaxis: Allergic reactions, including anaphylaxis, can occur in children due to food allergies, insect stings, or medications. EMS providers should be trained in recognizing anaphylaxis and administering epinephrine as needed.

6. Dehydration: Children are at increased risk for dehydration due to factors such as vomiting, diarrhea, or fever. EMS providers should be skilled in assessing hydration status and administering fluids as needed, especially in cases of severe dehydration.

7. Seizures: Seizures can occur in children due to various causes, including epilepsy or febrile illnesses. EMS providers should know how to assess and manage seizures, including protecting the child from injury and administering appropriate medications if necessary.

8. Poisoning: Accidental poisoning is a common pediatric emergency. EMS providers should be familiar with common toxins and their effects on children, as well as appropriate decontamination and treatment measures.

9. Cardiac Arrest: While less common in children than in adults, cardiac arrest can still occur due to various causes, including congenital heart defects or respiratory failure. EMS providers should be proficient in pediatric CPR and advanced life support techniques.

10. Communication & Family Support: Effective communication with caregivers is essential in pediatric emergencies. EMS providers should be skilled in providing clear and compassionate communication, as well as offering support to families during stressful situations.

By being knowledgeable about these common pediatric emergencies and having the necessary skills to assess and manage them effectively, EMS providers can play a crucial role in providing optimal care for children in emergency situations.

Further Reading:

Alexander, M. & Belle, R. (2017) Advanced EMT: A Clinical Reasoning Approach (2nd Ed). Hoboken, New Jersey: Pearson Education

Bledsoe, B. E., Cherry, R. A. & Porter, R. S (2023) Paramedic Care: Principles and Practice (6th Ed) Boston, Massachusetts: Pearson

Mistovich, J. J. & Karren, K. J. (2014) Prehospital Emergency Care (11th Ed). Hoboken, New Jersey: Pearson Education

Peate, I. & Sawyer, S (2024) Fundamentals of Applied Pathophysiology for Paramedics. Hoboken, New Jersey:  Wiley Blackwell

EMS Emergencies - Special Populations (4)

This article will explore the healthcare implications for a range of special populations, each facing its own unique set of challenges and considerations. 

From children born prematurely, infants or small children with congenital heart disease, patients with neurologic diseases, individuals with congenital or acquired diseases, to patients with sensory deficits, and geriatric patients with chronic ailments, we will examine how these diverse groups require tailored care approaches

By acknowledging the unique needs and challenges encountered by special populations, EMS providers can effectively serve as advocates for their patients' health and well-being. 

We'll discuss strategies ranging from tailored treatment plans to multidisciplinary care approaches, aimed at optimizing outcomes and enhancing the overall quality of care for these populations

Premature Neonates:

Premature infants may experience a range of medical complications related to their immature organ systems, including respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis.

Healthcare providers should monitor growth and development closely, address nutritional needs, and provide early intervention services to support developmental milestones.

Premature infants may require specialized follow-up care from neonatologists, pediatricians, and developmental specialists to optimize long-term outcomes.

Infants or Small Children with Congenital Heart Disease:

Children with congenital heart disease may require lifelong cardiac monitoring and management to prevent complications and optimize cardiac function.

Healthcare providers should be aware of potential signs and symptoms of cardiac decompensation, such as cyanosis, poor feeding, and failure to thrive.

Collaborate with pediatric cardiologists and cardiac surgeons to develop individualized treatment plans tailored to the specific type and severity of congenital heart disease.

Patients with Neurologic Disease:

Patients with neurologic diseases, such as epilepsy, cerebral palsy, or traumatic brain injury, may require comprehensive care to address their unique medical, cognitive, and functional needs.

Healthcare providers should assess for neurological deficits, monitor for disease progression or complications, and provide interventions to optimize neurological function and quality of life.

Multidisciplinary care teams, including neurologists, physiatrists, physical therapists, occupational therapists, and speech therapists, can provide coordinated care and support for patients with neurologic diseases.

Patients with Congenital or Acquired Diseases:

Patients with congenital or acquired diseases, such as cystic fibrosis, sickle cell disease, or cancer, may require specialized medical management and supportive care throughout their lifespan.

Healthcare providers should tailor treatment plans to address the specific needs and challenges associated with each disease, including symptom management, disease monitoring, and preventive interventions.

Collaborate with specialists in the management of specific diseases, as well as supportive care services such as palliative care and rehabilitation, to optimize patient outcomes and quality of life.

Patients with Sensory Deficits:

Patients with sensory deficits, such as vision or hearing impairment, may require accommodations to facilitate communication, navigation, and access to healthcare services.

Healthcare providers should use alternative communication methods, assistive devices, and sensory-friendly environments to ensure effective communication and equitable access to care.

Collaborate with vision and hearing specialists, as well as community resources and advocacy organizations, to address the unique needs of patients with sensory deficits.

Geriatric Patients with Chronic Ailments:

Geriatric patients with chronic diseases, such as hypertension, diabetes, and heart failure, may require comprehensive management to address age-related changes in physiology and multimorbidity.

Healthcare providers should assess for geriatric syndromes, such as frailty, cognitive impairment, and functional decline, and incorporate preventive interventions and supportive care services into treatment plans.

Multidisciplinary geriatric care teams, including geriatricians, nurses, pharmacists, and social workers, can provide holistic and patient-centered care for geriatric patients with chronic diseases.

As EMS providers, our commitment to delivering high-quality care extends to all individuals, including those belonging to special populations with unique healthcare needs. 

In our ever-evolving healthcare landscape, it's essential for EMS providers to be well-informed and sensitive to the implications of various special populations we may encounter in the field.

Further Reading:

Alexander, M. & Belle, R. (2017) Advanced EMT: A Clinical Reasoning Approach (2nd Ed). Hoboken, New Jersey: Pearson Education

Bledsoe, B. E., Cherry, R. A. & Porter, R. S (2023) Paramedic Care: Principles and Practice (6th Ed) Boston, Massachusetts: Pearson

Mistovich, J. J. & Karren, K. J. (2014) Prehospital Emergency Care (11th Ed). Hoboken, New Jersey: Pearson Education

Peate, I. & Sawyer, S (2024) Fundamentals of Applied Pathophysiology for Paramedics. Hoboken, New Jersey:  Wiley Blackwell

EMS Particular Patient Populations - Special Considerations

In the prehospital setting, EMS providers encounter a diverse range of special populations, each with unique needs and considerations.

Special populations refer to groups of individuals who may require specific attention or modifications in their care due to factors such as age, medical conditions, cultural differences, or social circumstances.

Here are some key considerations for several special populations, along with examples:

1. Pediatric Patients:

Considerations:

Children have unique anatomy, physiology, and psychological needs.

Communication should be age-appropriate.

Equipment and drug dosages may need adjustments.

Examples:

Pediatric respiratory distress or failure.

Pediatric trauma.

Febrile seizures.

2. Geriatric Patients:

Considerations:

Aging-related physiological changes.

Increased susceptibility to certain medical conditions.

Polypharmacy and medication interactions.

Examples:

Falls with fractures.

Altered mental status.

Cardiovascular events.

3. Pregnant Patients:

Considerations:

Pregnancy-induced physiological changes.

Special attention to maternal and fetal well-being.

Potential complications such as pre-eclampsia or premature labor.

Examples:

Pregnancy-related bleeding.

Maternal trauma.

Severe morning sickness.

4. Patients with Disabilities:

Considerations:

Mobility, sensory, or cognitive impairments.

Adaptations needed for communication and transportation.

Addressing unique health needs.

Examples:

Spinal cord injuries.

Developmental disabilities.

Neurological disorders.

5. Patients with Mental Health Conditions:

Considerations:

Unique behavioral and communication challenges.

Potential for self-harm or harm to others.

Medication management and interactions.

Examples:

Psychiatric emergencies.

Suicidal ideation.

Aggressive behavior.

6. Cultural and Linguistic Minorities:

Considerations:

Respect for diverse cultural practices and beliefs.

Language barriers and the need for interpreter services.

Awareness of cultural factors influencing health behaviors.

Examples:

Language barriers in obtaining medical history.

Cultural preferences in end-of-life care.

Religious considerations affecting care decisions.

7. Homeless or Vulnerable Populations:

Considerations:

Limited access to healthcare resources.

Increased risk of communicable diseases.

Addressing social determinants of health.

Examples:

Exposure-related illnesses.

Substance abuse-related emergencies.

Malnutrition and dehydration.

8. Non-English Speaking Patients:

Considerations:

Language barriers in communication.

Use of interpreter services.

Cultural sensitivity in care delivery.

Examples:

Difficulty obtaining medical history.

Misunderstandings about medication instructions.

Challenges in explaining the nature of the emergency.

9. Patients with Chronic Medical Conditions:

Considerations:

Medication adherence and management.

Recognition of exacerbations or complications.

Collaboration with primary care providers.

Examples:

Diabetic emergencies.

Asthma exacerbations.

Chronic obstructive pulmonary disease (COPD) exacerbations.

10. Bariatric Patients:

Considerations:

Unique physiological challenges, such as obesity-related comorbidities.

Specialized equipment and resources for lifting and moving.

Attention to skin integrity and the potential for pressure ulcers.

Examples:

Difficulty with airway management and ventilation.

Musculoskeletal issues and joint pain.

Metabolic complications, including diabetes.

EMS providers must be adaptable and responsive to the unique needs of special populations.

Training, cultural competence, and a patient-centered approach are crucial in providing effective and compassionate care across diverse groups in the prehospital setting.

Additionally, ongoing education and collaboration with community resources can enhance the ability of EMS providers to meet the specific needs of special populations.

Further Reading:

Alexander, M. & Belle, R. (2017) Advanced EMT: A Clinical Reasoning Approach (2nd Ed). Hoboken, New Jersey: Pearson Education

Bledsoe, B. E., Cherry, R. A. & Porter, R. S (2023) Paramedic Care: Principles and Practice (6th Ed) Boston, Massachusetts: Pearson

Mistovich, J. J. & Karren, K. J. (2014) Prehospital Emergency Care (11th Ed). Hoboken, New Jersey: Pearson Education

Peate, I. & Sawyer, S (2024) Fundamentals of Applied Pathophysiology for Paramedics. Hoboken, New Jersey:  Wiley Blackwell