Nursing Case Study: Acute Respiratory Distress Syndrome and Severe Sepsis

Nursing Case Study Acute
Respiratory Distress Syndrome
arterial blood cardiac output
sepsisgas

Case study:
Billy, a 32-year-old male, was admitted to the Intensive Care Unit (ICU) with a suspected
overdose of tricyclic antidepressants. He is obese (weight 160kg, height 172cm) and has a
history of depression and chronic back pain for which he takes oxycodone.
On admission to the emergency department, paramedics were maintaining Billy’s airways
with a combination of jaw thrust, head tilt and guedel airway. Billy was obtunded with
evidence of vomitus on his clothing. There was an attempted intubation enroute which was
unsuccessful.
Billy’s initial observations were:
 Temperature 35.5 degrees Celsius
 Heart rate 140bpm
 Blood pressure 100/50mmHg
 Respiratory Rate 22 beats/ min, shallow and laboured
 Oxygen saturation 92% breathing spontaneously via a bag valve mask with oxygen at
15L/min
 Auscultation of lung sounds revealed decreased air entry bilaterally and expiratory
wheezes
 Arterial blood gas: pH 7.21, PaCO2 68mmHg, PaO2 90mmHg, HCO3 26mEq/L,
SaO2 94%
 GCS 8 (E1, V3, M4)
Question One
PART A)
Describe the pathophysiology of Acute Respiratory Distress Syndrome, including a
systematic interpretation of the arterial blood gas (Consider PaO2/ FiO2 – P/F ratio, assume
PEEP is 5cmH2O). Interpret the ABG, including determining the PaO2/FiO2 ratio. What do
these results indicate for Billy?
Pathophysiology of Acute Respiratory Distress Syndrome: An Acute Respiratory
Distress Syndrome is generally a multifaceted syndrome of acute lung damage specifically
foremost to a non-cardiogenic pulmonary oedema from various reasons which is
heterogeneous within its medical demonstration and are also linked with the 40% death rate.
An Acute Respiratory Distress Syndrome is significantly marked by an inflammation-
medicated disruption within the alveolar-capillary permeability, edema formation, decreased
alveolar clearance as well as collapse/derecruitment, decreased obedience, enhanced
pulmonary vascular resistance as well as a resulting interchange of gases. Within this, an
understanding of ARDS physiology, that can include a key characteristics consisting
exchange of gas abnormalities can frequently need ventilator encouragement as well as
reduced compliance with the specific regional heterogeneity, generally has inferences for the
ventilator encouragement strategies (Ali and Lamont, 2019). A positive pressure ventilation
consisting with the positive as well as an expiratory pressure generally decreases the
breathing work as well as can prevent atelectasis of a nearly collapsed lung units in order to
enhance the interchange of gases. In this, a positive pressure of the airways generally helps to
decrease further ongoing edema synthesis within various oedematous states, consisting the

enhanced alveolar penetrability of the Acute Respiratory Distress Syndrome. Within acute
respiratory distress syndrome, the damaged lung is generally believed to go via the specific
three phases such as exudative, fibrotic and a proliferative, but the course of every part as
well as entire illness development is quite variable. While talking about exudative phase,
injury towards the alveolar epithelium as well as vascular endothelium creates leakage of
water, inflammatory, protein as well as the red blood cells within the interstitium and an
alveolar lumen. In addition, these such alterations are effectively induced by a complex
interplay of a pro-inflammatory as well as an anti-inflammatory mediator. The specific type 1
alveolar cells are generally irreversibly injured as well as the denuded space is replaced by
the protein deposition, cellular debris, fibrin and can produce a hyaline membrane, while
damage to the type 2 cells produced by surfactant mainly contributes towards an alveolar
collapse. In context with the proliferative phase, type 2 cells generally proliferate with
regeneration of some of the epithelial cells, remodelling and a fibroblastic reaction as well.
Among some of the patients, such things can advance towards a permanent fibrotic phase
consisting the deposition of collagen within alveolar, interstitial beds and vascular with the
advancement of microcyst.
ABG is generally an Arterial Blood Gas that can include various steps. Within this, the
initial step in an interpretation of ABG is to visualise the pH. The standard range of blood pH
is 7.4, minus or plus 0.05, mainly developing the range of 7.35 to 7.45. If the pH falls from
the normal range such as below 7.35 then it can be considered as acidic. Whereas, if the
blood pH increased above 7.45, then it can be considered as alkalotic (Byrne, 2021). The pH
range of Billy’s is about 7.21 is normal but slightly acidic. In addition to this, the another step
is to determine the pCO2 level. A standard pCO2 levels are about 35 to 45 mmHg. An
underneath from the normal range such as >35 is alkalotic and <45 is quite acidic. In context
with provided case scenario, the pCO2 level is 68 mmHg that is quite acidic. The third step
within the interpretation of Arterial Blood Gas is to aspect at the HCO3 level. In this, a
standard range of HCO3 is about 22 to 26 mEq/L. And, if the HCO3 is above the level of 26,
the patient is alkalotic and below of 22 then the patient is acidotic in nature. Within the
provided case scenario, a HCO3 level is given about 26 mEq/L which is normal. Next will
match either the HCO3 or the pCO2 with the pH in order to measure the acid-base disorders.
Such that, if the pH is acidotic, and the CO2 is acidotic, then the acid-base disturbance is
generally being caused by the respiratory system. Therefore, if the pH is alkalotic and the
HCO3 is alkalotic, then the acid-base disturbance is being caused by the metabolic or the
renal system. However, it will be a metabolic alkalosis. In the case of Jelly, while comparing
the normal range of pCO2 or HCO3 with the pH, in his case pH is slightly acidotic and the
CO2 is also acidotic, then the acid-base disturbance that is being caused by the respiratory
system (6 Easy Steps to ABG Interpretation, 2019). The partial arterial pressure of O2 and the
fraction of an inspired oxygen ratio such as PaO2/FiO2 is broadly used within the Intensive
Care Units as an indicator of the oxygenation status. A PaO2/FiO2 ratio is mainly subdivided
using the threshold of about 100-200-300 as per the Berlin criteria of Acute Respiratory
Distress Syndrome. PaO2< 60 and>100 mmHg versus PaO2 60-100. A partial pressure level
of oxygen in Jelly’s case is 90 mmHg.
PART B)
In view of Billy’s current clinical condition, outline the proposed ventilation parameters you
would suggest including rationales.