Download MBBS Pulmonary Medicine Presentations 6 Respiratory Failure Lecture Notes

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