GASEOUS EXCHANGE IN HUMAN BEINGS
• Be able to trace the flow of air from the environment to the alveoli. Identify the structure
of each area, i.e. ringed cartilage, smooth moist surface, etc.
• Understand where gas exchange occurs In the body Understand the role of oxygenated
verses un-oxygenated blood in the process of gas exchange
• Understand the process of simple diffusion and how it impacts gas exchange
• Understand the role of mucous and cilia in the respiratory system.
• what happens when cilia are damaged Understand the role that smoking
• plays in health and wellness . what damage does smoking cause
• Be able to calculate cigarette pack years for your patient
• It is calculated by multiplying the number of packs of cigarettes smoked per day by the
number of years the person has smoked. For example, 1 pack-year is equal to smoking 20
cigarettes (1 pack) per day for 1 year, or 40 cigarettes per day for half a year, and so on
o 2 packs per day for 30 years?
o 20 cigarettes per day (2 packs = 40
o cigarettes per day) has smoked for
o 30 years. What is the pack years?
o Answer: 60 pack years
o Number of cigarettes smoked per
o day / 20 (# in a pack)
o times the number of years smoked.
o 40/20=2 x 30 years= 60 pack years
• You need to demonstrate clinical judgment in patients with excessive
tracheobronchial secretions
• Understand how an IVC filter works
• Understand heparin vs. warfarin in Anticoagulation. Dosing, routes, Antidotes,
discharge teaching
• Understand the oxyhemoglobin Desaturation curve. Be able to identify factors that shift
the curve to the right or to the left.
• Understand oxygen’s affinity for HGB and for Carbon Monoxide
• Be able to assess for hypoxemia and prioritize nursing intervention
• Understand the diagnostic quality of labs such as D-dimer, Pao2, INR, troponins
• Make nursing assessments and decisions regarding patients with chest tube including
equipment, problem solving, leaks, disconnects, etc.
• You WILL be asked to interpret Arterial Blood Gasses. You may be given just the
results to interpret or you may be given Aapatient scenario that includes ABG results, (or
both)
• With ABG’s expect to identify if the cause is respiratory, metabolic, if it is acidosis
or alkalosis and if it is fully, partially or non-compensated
• Know what is normal:
o pH: 7.35-7.45
o pCo2: 35-45 mm Hg
o HCO3: 22-26 mm Hg
,• Problem 1:
o pH: 7.43, PaCO2: 28, HCO3: 18
o pH is normal, PaCO2 is (less than 35) alklotic and
o HCO3 is (less than 22) Acidic We don’t have a tic tac toe so values are
representing either partial or fully compensation. pH is normal, therefore fully
compensated. Which value is furthest from normal? in this case, PaCo2 is 7
points from normal vs. HCO3 which is 4 points from normal therefore it is
(respiratory) Aakalosis fully compensated by means of metabolic acidosis
o Remember: we learned that when the body enters into respiratory alkalosis it will
try to COMPENSATE/CORRECT the body making the metabolic system keep
acids within the kidneys. This will hopefully bring down the blood pH level
• Problem 2:
o pH: 7.50
o PaCO2: 49
o HCO3, 30
o Partially compensated metabolic
o Alkalosis Tic tac toe shows metabolic alkalosis the pH is abnormal so look
at system that is trying (PaCO2) to correct. It is abnormal so it is trying to
compensate but pH is still abnormal so full compensation has not occurred
o Now you may be asking yourself what if the PaCO2 was normal? Then it
would be uncompensated because the respiratory system isn’t attempting
to correct the metabolic alkalosis
• Know about discharge teaching as well as questions from patient/parent that indicate
they do or do not understand
• When anti-coagulating a patient know control and therapeutic times
• You will have one or more questions where you are given patient scenarios at shift
report. You must prioritize the order in which you round on those Patients Read the
question
and scenarios carefully!
• Study up on the chambers In a chest tube
• Describe the process of breathing. What form of energy is required?
• Understand the role of alveoli in gas exchange include surfactant In your studies. What
happens Physiologically when fluid fills alveoli Or when alveoli collapse?
• Review the role of the brain in respiration
• Understand the role of Hgb In buffering the blood
• Be able to differentiate between the various lung disorders that we discussed in lecture.
• What is Homer’s Sign and how do you elicit it? Does it continue to be the gold
Standard for diagnosing DVT?
• What instructions are you going to provide to your patient who is going home on
anticoagulation therapy?
• ARDS à acute respiratory distress syndrome (adult resp.
Distress syndrome, as well)
o What is it?
, ▪ Acute respiratory distress syndrome is a medical condition occurring and
critically ill patients characterized by widespread inflammation in the
lungs.
• ARDS is not a particular disease, rather it is a clinical phenotype
which may be triggered by various pathology such as trauma,
pneumonia and sepsis.
▪ Also known as “shock lung.”
▪ Non cardiac pulmonary edema
▪ Characterized by refractory hypoxemia
▪ Severe form of acute respiratory failure
•
▪ Not a primary process, but results from lung injury due to:
• Septic shock
• pneumonia
• Near drowning
o Common cause of ARDS
• O2 toxicity
o Inhalation injury
• Aspiration
• Multiple transfusions
• Open heart surgery with cardiopulmonary bypass
• embolism
▪ Thought of as a spectrum
▪ Mild form (acute lung injury) to most severe form that’s life-threatening
▪ Characterized by a severe inflammatory process causing diffuse
alveolar damage that results in sudden and progressive pulmonary
edema,
increasing bilateral infiltrates on chest x-ray, hypoxemia, unresponsive
to oxygen supplementation regardless of the amount of PEEP (positive
end- expiratory pressure deals with ventilation), and the absence of an
elevated left atrial pressure
▪ Major cause of death is from non-pulmonary multi-organ
dysfunction syndrome, often with sepsis
▪ SIRS (systematic inflammatory response syndrome)à damaged
Alveolar capillary membraneà fluid fills alveoli à lungs become less
compliantà Hypoxemia, Respiratory acidosis, metabolic acidosis
o Risk Factors
, ▪ Aspiration
▪ Drug ingestion and overdose
▪ Hematologic disorders
• Disseminated intravascular coagulopathy
• Massive transfusions
• Cardiopulmonary bypass
▪ Prolonged inhalation of high concentrations of oxygen, smoke, or
corrosive substances
▪ Localized infection
• Bacterial
• Fungal
• Viral pneumonia
▪ Metabolic disorders
• Pancreatitis
• Uremia
▪ Shock
▪ Blood transfusion
▪ Inhalation injury
▪ burns
▪ Trauma
• Pulmonary contusion
• Multiple fractures
• Head injury
▪ Major surgery
▪ Fat or air embolism
▪ Sepsis
o Patho
▪ Inflammation causes the release of cellular and chemical mediators that
lead to injury to the alveolar capillary membrane and additional
structural damage to the lungs
▪ Severe V/Q mismatching occurs
▪ Alveoli collapses from infiltrates, blood, fluid, and bronchial obstruction
that lead to the narrowing of the small airways
▪ The blood returning to the lung for gas exchange is pumped through the
non-ventilated, non-functioning areas of the lung, causing shunting -->
meaning the alveoli are impaired causing severe, refractory hypoxemia