Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Pulmonary Medicine 6 Respiratory Failure PPT-Powerpoint Presentations and lecture notes
Approach to a case of
Respiratory failure - Acute
and Chronic
Pulmonary medicine
A 55 years old, smoker male having
exertional breathlessness, cough with scanty
expectoration since 4-5 years. Now
presented with worsening dyspnea since 4
days following upper respiratory tract
infection.
History
HOPI
Cough
Expectoration
Breathlessness
Systemic symptoms
History
Past History
Allergic History
Medication History
Family History
Personal History
Examination
General Physical Examination
Drowsy, oriented to person but not to
time and place
Vitals:
PR ? 100, BP ? 90/60 mmHg, RR- 30/min
Spo2 ? 89 % RA
Systemic Examination:
Inspection :
Barrel shaped chest,
tracheal descent present,
widened intercostal space,
intercostal retraction present,
apex impulse shifted downward
Palpation:
Widened intercostal space,
apex beat shifted downward
Percussion:
B/L hyperresonant note,
Liver shifted downward
Auscultation:
B/L wheezing present
Investigation
ABG
Chest X-ray PA View
Routine investigations
ABG
pH ? 7.208
pCO2 ? 67.3
pO2 ? 47.5
SO2 ? 72.1
HCO3 ? 27.1
Chest Xray
Complete Hemogram
Management
Respiratory failure
Respiratory failure is a condition in which the
respiratory system fails in one or both of its gas-
exchanging functions; that is,
Oxygenation, and
Carbon dioxide elimination
Patho-physiology
Classification of Respiratory failure
Type I (hypoxemic) respiratory failure:
Type II (hypercapnic) respiratory failure:
? COPD
COPD
Severe asthma
? Pneumonia
Drug overdose
? Pulmonary edema
Poisonings
? Pulmonary fibrosis
Myasthenia gravis
? Asthma
Polyneuropathy
? Pneumothorax
Poliomyelitis
? Pulmonary embolism
Primary muscle disorders
? Pulmonary arterial hypertension
Porphyria
Cervical cordotomy
? Pneumoconiosis
Head and cervical cord injury
? Granulomatous lung diseases
Primary alveolar hypoventilation
? Cyanotic congenital heart disease
Obesity-hypoventilation syndrome
? Bronchiectasis
Pulmonary edema
? Acute respiratory distress syndrome (ARDS)
ARDS
? Fat embolism syndrome
Myxedema
Tetanus
? Kyphoscoliosis
? Obesity
ABG
pH ? 7.411
pH ? 7.208
pCO2 ? 32.8
pCO2 ? 67.3
pO2 ? 31.0
pO2 ? 47.5
SO2 ? 49.6
SO2 ? 72.1
HCO3 - 20.5
HCO3 ? 27.1
The presence of markers of chronic hypoxemia (e.g.,
polycythemia or cor pulmonale) provides clues to a long
-standing disorder, whereas abrupt changes in mental
status suggest an acute event.
Marker of chronic hypercapnia ? Bicarbonate levels
Hypoxemic Respiratory failure
Alveolar hypoventilation
Normal alveolar?arterial oxygen gradient
Ventilation?perfusion mismatch,
Shunt, and
Diffusion limitation
Hypercapnic Respiratory failure
Ventilatory supply Versus demand
Ventilatory supply : maximal spontaneous ventilation that
can be maintained without development of respiratory
muscle fatigue. AKA maximal sustainable ventilation
(MSV)
Ventilatory demand : spontaneous minute ventilation,
which, when maintained constant, results in a stable
PaCO2
A 70-kg adult has an MVV of about 160 L/ min, an MSV
of 80. L/min, and, under basal conditions, a Ve of
approximately 6 to 7 liters per minute (90 mL/kg/ min).
Normal y, therefore, there is a 10- to 15-fold difference
between resting V.e and MSV.
In disease states, the V. e requirement may approach a
markedly reduced MSV.
Further reductions in MSV result in ventilatory demand
exceeding supply, and hypercapnia occurs.
Approach to the patient
Clinical suspicion:
Signs of
underlying disease process ? pneumonia, pulmonary edema,
asthma, COPD, cor pulmonale etc
Hypoxemia- restlessness, anxiety, tachycardia, dyspnea, cyanosis,
use of accessory muscles, arrhythmias, seizures etc
Hypercapnia ? Confusion, drowsiness, somnolence, asterixis,
tachycardia etc
ABG :
PaO2
PaCO2
AaDO2
pH
HCO3
O2 saturation
Difference between Acute & Chronic
Principles of Management
1. Triage decision
OPD
Ward
HDU
ICU
? At one end of the spectrum is the patient with fulminant hypoxemic
respiratory failure, metabolic acidosis, and imminent cardiovascular
collapse, who needs emergent intubation, mechanical ventilation,
and admission to a critical care unit.
? At the other end of the spectrum is the patient with COPD and
chronic, compensated hypercapnic respiratory failure, who
requires observation in an intermediate care unit.
2. Airway Management:
Intubation and mechanical ventilation
Non invasive ventilation (Pros & Cons)
3. Correction of Hypoxemia and Hypercapnia
Hypoxemia : most life-threatening aspect of acute respiratory
insufficiency
Goal is ? assure adequate oxygen delivery to tissues (Generally
PaO2 > 60 mmHg),
Coronary or cerebrovascular disease (a slightly higher level)
Hypercapnia:
NIV/Invasive
4. Search of an underlying cause
Monitoring patients with acute respiratory
failure
Simple observation of respiratory rate, tidal volume.
Use of accessory muscles, and presence of paradoxical
breathing movements provides evidence of worsening
respiratory failure and the need for intubation and
mechanical ventilation
On mechanical ventilation, the patient must be care-
ful y monitored for ventilator-associated complications.
In addition, placement of indwel ing arterial and venous
catheters, patient immobilization, and use of a broad
range of pharmacologic agents present additional
potential threats to the acutely il patient
Thank you
This post was last modified on 08 April 2022