PREOPERATIVE ASSESSMENT FOR

CARDIOTHORACIC SURGERY

Group 4

Muhammad Arsalan Khan

Said Khitab Shah

Liaqat Ali

Gauhar Rahman

KMU, IPMS, 3rd batch

Department of Anesthesiology.

Key Points

• Patients for pulmonary resection

• Three pulmonary areas observed

• Lung mechanical function

• Pulmonary parenchymal function

• Cardio pulmonary reserve

• Pulmonary resection surgery

• Patient extubated provided AWaC (alert warm and

comfortable)

• Geriatric patient are at high risk for cardiac complications

i.e. arrhythmias etc.

• Assessment for malignancy done by 4 M’s i.e. mass

effect, metabolic effect, metastases and medication.

Introduction

• Thoracic anesthesia

• Wide variety of diagnostic and therapeutic procedures.

• Involves lungs and other thoracic structures.

• Anesthetic technique have changed as the population of

patient presenting for cardiothoracic surgery have

changed.

• Major causes of morbidity and mortality of thoracic

surgeries are

• Respiratory complications 15-20% i.e. atelectasis, pneumonia etc.

• Cardiac complications 10 -15% morbidity i.e. Ischemia etc.

Initial Preoperative Assessment

• Respiratory complication are the major cause of morbidity

and mortality.

• Following are the initial preoperative assessment for

thoracic surgeries:

Pulmonary Assessment

• Best assessment for respiratory function is done by

• Detailed history of patient quality of life.

• Simple baseline spirometery preoperatively to measure FEV1 and FVC.

• Three legged assessment of lungs• Respiratory mechanics

• Pulmonary parenchymal function

• Cardio respiratory interaction

• Basic functional units for extracellular respiration which get atmospheric O2.

• Into alveoli

• Into the blood

• To the tissue ( reserved for CO2 removal).

Lung mechanical Function

•Spirometery:• Test for respiratory mechanics and volume.• FEV1, FVC, mechanical voluntary ventilation (MVV),

RV/TLC.

• Most valid single test for post thoracotomy respiratory complication is ppoFEV1%.• ppoFEV1%= preop. FEV1x (1- % functional lung tissue

removal /100)

• ppoFEV1% > 40% no or minor complications.

• ppoFEV1% <40% have complication but not in all.

• ppoFEV1% <40% are operated with acceptable morbidity and mortality.

Pulmonary Parenchymal Function• Arterial blood gas data

• PaO2 < 60mmHg

• PaCO2 > 45mmHg

• Pulmonary resection contraindicated.

• Cancer resection can successfully performed under the

above situation.

• Most useful test for gas exchange capacity of lungs is the

diffusing capacity of carbon mono oxide i.e. DLCO

• DLCO is non invasive.

• ppoDLCO% same as ppoFEV1% (<40%) have both

respiratory and cardiac complications.

• DLCO% < 20% unacceptable because of preoperative

mortality rate.

Cardiopulmonary Interactions

• Laboratory exercise testing is gold standard.

• Max. oxygen consumption (VO2) is best predictor of post

thoracotomy outcomes.

• Resting measurement is for 3 to 5 minutes.

• Max. working capacity is reached normally at 8 to 15 min.

• After that limitations are initiated i.e. severe dyspnea,

significant ECG abnormalities.

• Estimation of VO2 is based on age, sex and height.

• Predicted VO2 max (mL/min)= [(height – age)X20] whole divided by weight.

• If VO2 is <15 mL/kg/min , the morbidity and mortality is highly unacceptable.

• Few patients having VO2 max. >20 mL/kg/min have respiratory complications.

• Poor exercise tolerance test is due to pulmonary versus cardiac etiologies.

• Anaerobic threshold 55% of VO2 max. observed in untrained person while it exceeds >80% in trained athletes.

• Repeated blood lactate analysis documents the increase in threshold of CO2production above the initial respiratory quotient (ratio of CO2 production/O2 consumption).

Regional Lung Function

• Assessment of preoperative contribution of lung or lobe to

be resected by imaging of regional lung function.

• For any potential pneumonectomy who has ppo <40%

predicted for 80% of FEV1 and/or DLCO.

• Three techniques done.

• Radionuclide ventilation/perfusion V/Q lung scanning.

• Pulmonary quantitative CT-scanning

• MRI

Combination Of Tests

Final Assessment

• Assessment just prior to the admission of the patient to

the operating room.

Difficult Endobronchial Intubation

• Factors leading to suspicion of difficult endobronchial

intubation are:

Previous radiotherapy

Infections

Pulmonary or airway surgery

• Assessment are made:

Bronchoscopy report

X –Ray, CT- Scan preoperatively

Preoperative chest X-ray of a patient with a

history of

previous tuberculosis, right upper

lobectomy, and recent hemoptysis

presenting for right thoracotomy possible

completion pneumonectomy.

The potential problems positioning a left-

sided double-lumen

tube in this patient are easily appreciated

by viewing the X-ray but

are not mentioned in the Radiologist’s

report. The Anesthesiologist

must examine the chest imaging

him/herself preoperatively to anticipate

problems in lung isolation.

Prediction of Desaturation During

One-Lung Ventilation• Most patients suffer desaturation during OLV.

• Factors correlating are:

• High percentage of ventilation or perfusion to the

operative lung on preoperative

• V/Q scan

• Poor PaO2 during two-lung ventilation, particularly in the

lateral position intraoperatively

• Right-sided thoracotomy

• Normal preoperative spirometery (FEV1 or FVC) or

restrictive lung disease

• Supine position during one-lung ventilation

References

• Preanesthetic Assessment for Thoracic Surgery by Peter Slinger and Gail

Darling (pdf)

• Slinger P, Suissa S, Triolet W. Predicting arterial oxygenation during one-lung

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• Kempainen RR, Benditt JO. Evaluation and management of patients with

pulmonary disease before thoracic and cardiovascular surgery. Semin Thorac

Cardiovasc Surg. 2001;13:105–15.

• Liu SS, Mulroy MF. Neuraxial anesthesia and analgesia in the presence of

standard heparin. Reg Anesth Pain Med. 1998;23(6 Suppl 2):157–63.

• Licker M, Widikker I, Robert J, et al. Operative mortality and respiratory

complications after lung resection for cancer: impact of chronic obstructive

pulmonary disease and time trends. Ann Thorac Surg. 2006;81:1830–8.

• British Thoracic Society. Guidelines on the selection of patients with lung

cancer for surgery. Thorax. 2001;56:89–108.

• Patterson AG. Pearson’s thoracic and esophageal surgery. 3rd ed.

Philadelphia, PA: Elsevier; 2008. p. 1168.