General issues with anesthesia for thoracic surgery

NEET PG Anaesthesia
#1

GENERAL ISSUES WITH ANESTHESIA FOR THORACIC SURGERY

Anesthetists assigned to the Thoracic list know all too well how challenging it can be. It is a list often filled with challenging of cases and the most complex of surgery.

The patients are often fraught with a multitude of intercurrent ailments ranging from Chronic Obstructive Airway Disease to Malignancies and some of them have folders as thick as telephone directories lol😥.

The anesthetic itself is just as challenging since thoracic epidurals and para vertebral blocks are the mainstay of the balanced analgesic plan.

Fortunately most patients are slim and landmarks are easily delineated.

The double lumen tube is often used with the challenging lung isolation techniques thereafter.

Team work is very essential considering the fact that major vessels and the conducting airway are within striking distance.

Anyways I have compiled a bulleted summary of some salient issues that we must take into consideration when embarking to provide anesthesia for such surgery.

I. PRE-OPERATIVE
II. INDUCTION
III. SURGERY
IV. POST- OPERATIVE

I. PRE-OPERATIVE
A. TEAMWORK
This is of paramount significance as this is one field where anesthetist/surgeon interaction is key to a good outcome. Also a collaborative discussion is needed with the surgeon and intensivist as for what is being done with respect to
:black_small_square: The bed availability in ICU for post op management.
:black_small_square: The appropriate investigations & whether optimization is necessary prior to surgery.
:black_small_square: Whether Bronchoscopy will precede a thoracotomy etc.

B. ASSESS CHRONIC DISEASE STATUS

  1. #MALIGNANCY
    :black_small_square: Remember The 4 M’s
  • Mass
  • Metastasis
  • Metabolic
  • Medication,
    :black_small_square: Superior Vena Caval Syndrome
    Check for features of CONGESTION in the upper body ie swelling of the face , headaches, and the presence of lower collaterals on the torso.

••• Check for
PARANEOPLASTIC EFFECTS ie…
• SIADH,
• Pancoast’s Syndrome or
• Eaton Lambert’s Syndrome

2.#COAD
(Chronic Obstructive Airway Disease)
:black_small_square: Bronchitis/emphysema
:black_small_square: Pulmonary hypertension
:black_small_square: Cor Pulmonale

  1. #INFECTION
    :black_small_square: Tuberculosis
    Check Chest X-ray, ESR, if MDR /XDR need to take necessary precautions with respect to circuit, use of N95 Masks and scheduling of the patient as per order of the list.
    :black_small_square: Bronchiectasis, Lung Abscess
    Check degree of lung involvement optimisation as per Antibiotics etc
    :black_small_square: Hydatid Cyst
    See how circumscribed the Lesion is and plan for
    Possible lung isolation techniques.

C #COMPLICATIONS
:black_small_square: Cachexia - These patients are often wasted and thus check on Albumin levels .
:black_small_square: Pulmonary Hypertension - Check for loud P2 or pruning of lung vessels
:black_small_square: Hemoptysis - Check on hemoglobin, immediate lung isolation techniques should be planned
:black_small_square: Atrial fibrillation - issues with warfarin etc
:black_small_square:Infection - Bronchiectasis, Empyema, TB, Fungal, Hydatid etc

D. #VIABILITY for Surgery
i. Lung function tests
ii. DLCO for gaseous exchange
iii.Cardiorespiratory reserve

:black_small_square: Assess If One Lung ventilation is possible
:black_small_square: Airway obstruction - by tumor
:black_small_square: Check perfusion status of diseased lung

E. #OPTIMISATION
:black_small_square: Stop smoking,
:black_small_square: Antibiotics,
:black_small_square: Chest physiotherapy

II. INDUCTION
A. Invasive lines, put femoral lines with superior vena cava syndrome
B. Epidural or Paravertebral block
C. Rapid lung isolation to prevent soiling vs elective intubation
D. Fibre optic confirmation of ETT placement
E. Lateral positioning - protect brachial plexus

III. SURGERY
Challenging
:black_small_square: Shared airway and the task of being able to control the two lungs independently
:black_small_square: Promote hypoxic pulmonary vasoconstriction to improve V/Q matching

A. AIRWAY & VENTILATION
:black_small_square: Bleeding & Soiling (Pus or Hydatid cyst) from the Surgery
:black_small_square: Bronchospasm - have on line nebulizer, change ventilator settings to large tidal volumes and prolonged expiratory times.
:black_small_square: Protective ventilation (low tidal volumes; high respiratory rate ) with a restrictive infiltrative condition
:black_small_square: Atelectasis - This presents with high Plateau Pressures and is treated with a lung recruitment manoeuvre.
:black_small_square: BRONCHIAL STUMP
IT IS ABSOLUTELY IMPORTANT TO CHECK FOR AN AIRWAY LEAK AT THE END
This is done through assessment of the bronchial stump at conclusion whereby warm saline is poured into the operative field. thereafter bagging is done to see if there are any bubbles in the saline coming out of the stump.

B. CARDIOVASCULAR
:black_small_square: Hypotension
Compression of the great vessels by

  • Surgeon
  • Moving mediastinum in right lateral position
    :black_small_square: Blood loss
  • very vascular area
  • more blood loss with superior vena cava syndrome
    :black_small_square: Arrhythmias
  • irritation of the heart by surgery etc

IV. POST- OPERATIVE
A. Extubate as post op ventilation causes stress resulting in an air leak or chest infections
B. Good Analgesia - Epidural, keep Warm, Alert & Comfortable
C. 40 % Oxygen to compensate for VQ mismatch
D. Encourage coughing, incentive spirometry and chest physiotherapy to improve lung function.