Clinical Presentation

• 63 yo man

• Hemicolectomy (right) cecal carcinoma

• Past History:– Anemia, chronic stable angina, GERD

• Medications:– Diltiazem, Losec

• No allergies, non-smoker

Post-Operative Course

• Uneventful operation – laparoscopic

• Post-extubation dyspnea + cough + wheeze

• Respiratory distress with desaturation

• RR 36/min

• SpO2 80’s – FiO2 increased to 0.4

Investigations

• Chest X-ray

• Spirometry

• ABG’s on 0.28

• Sputum g/s + C&S

• ECG/troponin

• Bilateral opacities

• FEV 1.46 (44%)

• FVC 1.98 (52%)

• 7.38/38/56/24

• Few pus cells

• Non-specific, normal

Diagnosis

• Asthma

• Aspiration

• Cardiogenic pulmonary edema

• Non-cardiogenic pulmonary edema

• Fluid overload

• Pulmonary embolism

• Hospital acquired pneumonia

Management

• Pulmonary edema – Mueller manoeuvre– Negative pressure pulmonary edema– Forced inspiration with closed glottis– Associated with stridor post-extubation– Rx oxygen, diuretic

• Aspiration– Rx antibiotics, oxygen,

Follow-Up

• Diuresis 1.2 L post furosemide 40 mg iv

• At 4 hours, SpO2 94% on room air

• Admitted for observation, serial troponins

• Chest X-Ray next day - clear

Case Presentation II

• 53 yo woman undergoing elective hysterectomy• Pre-operative assessment:

– Hypertension, – Allergies to HDM, pollens – Hay fever treated with anti-histamines

• At induction – severe increase in inspiratory pressures, difficult to ventilate, bagged

• OR cancelled

Issues

• “negative” medical history – had asthma as a child and young adult – no problem in recent years – no inhaler use

• Medications used for induction -

• Uneventful intubation, no trauma, no aspiration

More Issues

• No risk factors for cardiovascular disease other than treated hypertension

• No recent URTI

• No asymmetry in chest findings (that might suggest pneumothorax)

• Bilateral wheezes, no crackles

Diagnosis

• Asthma

• Aspiration

• Cardiogenic pulmonary edema

• Non-cardiogenic pulmonary edema

• Pulmonary embolism

• Hospital acquired pneumonia

Management

• Chest X-Ray normal

• Rx salbutamol 4 puffs via Aerochamber– SoluMedrol 40 mg iv– Symbicort 200/6 2 puffs BID

• D/C – to be seen in clinic

Follow-Up

• Well, no symptoms

• Normal examination, no wheezes

• Spirometry normal

• Does she have asthma?

Follow-Up II

• Asthma – variable airflow obstruction– Airway inflammation– Bronchoconstriction

• May have normal airflow – if well-treated or no exposure to irritants/stimuli

• Variable airflow obstruction documented by– Baseline AFO improved acutely by B-agonist– Inducible AFO – methacholine challenge – PC20

Follow-Up III

• PC20 – 1.25 mg/ml (Normal >16 mg/ml)

– severe increase in bronchial responsiveness

• Rx Symbicort 200/6 2 puffs BID + prn

• OR re-scheduled and completed uneventfully

Post-operative Day 4

Atelectasis

Atelectasis

• Duggan M, Kavanagh BP. Pulmonary Atelectasis. Anesthesiology 2005;102:838-54.

• 90% of patients undergoing GA• Alveolar collapse, reduced lung compliance,

impaired gas exchange (O2)– Compression– Absorption of alveolar air– Impaired surfactant function

Atelectasis

• Compression– Diaphragm dysfunction - reduced transmural Pr– Reduced FRC– Intercostal muscles and inhalational agents

• Absorption– Trapped pocket of gas – increases with FiO2

– Areas of low VA/Q + high FiO2 + duration

• Surfactant impairment (=least relevant)– Physical or chemical factors

Atelectasis

• Effect of position– Upright – supine reduces FRC 0.5-1L– Greater reduction if Trendelenburg

• Atelectasis reduced by– Avoiding 100% Oxygen, use >30% Nitrogen– Lung recruitment manoeuvers– cPAP– Any incentive to deep breath and cough– ?Laparoscopic surgery instead of open?– ?with better pain control?

Complications

• Hypoxemia

• Tachypnea, low tidal volume

• Reduced cough and mucociliary clearance

• Acute lung injury – cytokine release– Physical, ARDS

• Lobar collapse

• Pneumonia

Treatment

• Sit up

• Move

• Encourage or force deep breathing– Breathing exercises, IPPV/cPAP,

physiotherapy, incentive spirometry

• Sternal traction