How do you undergo general anaesthesia and serious surgery if you have trouble breathing properly? The standard answer is simply that you don’t. Poor respiratory reserves or poor lung capacity can be one of the main reasons surgeons declare a traditional operation too risky, even if it’s something as life threatening as a heart related disorder. This doesn’t mean that you don’t have alternatives. One of them is ‘awake surgery’.
It’s exactly what it sounds like. A patient is conscious, and therefore able to breathe on their own throughout the surgery. This removes the need for a ventilator and reduces the risk of losing a patient on the operating table. This is simply done through the skilful use of a thoracic epidural. The injection ensures that a patient will not feel any sensation below the neck but allows the patient to remain conscious and breathe normally. So, in essence, you have a patient who may be able to hold a conversation even as surgeons operate on his beating heart.
|Pic courtesy sunseasurf.blogspot.com
Diagnosed with tuberculosis, obstructive sleep apnoea and poor respiratory reserves, the elderly gentleman lying on the table is undergoing a bypass surgery. Several blocks in his arteries will be cleared, new grafts placed and other irregularities looked into before they’re done. He’s conscious and perhaps nervous. If this had been a conventional surgery, the patient would have been under general anaesthesia and would have relied on a tube down his trachea and a ventilator to breathe.
His doctors decided that the conditions he suffered from made artificial ventilation too problematic. “If we had decided to go for a traditional surgery it would have been too high a risk,” says Dr. K. Kesava Dev, Consultant Cardiac Surgeon, who along with Dr. Anand Kumar, Consultant Cardiac Anaesthetist performed the surgery. “This way we can let the patient breathe on his own,” they explained, adding this process eliminated the possibility of the patient surviving the operation only to become ventilator dependent later.
When the two men recommended 'awake surgery' to their patient, they knew it would require trust and cooperation on the part of their patient. Though the procedure is painless and sedatives are prescribed to help the patient cope with anxiety, it can still be quite stressful. Patients cope in different ways, but doctors sometimes recommend earplugs and music to those who particularly wish to tune out.
The procedure is not without its challenges for the doctors themselves. Dr. Dev explains that as a surgeon he must cope with the movement generated by the expanding lungs and still beating heart as he works. Since breathing is under the control of the patient, doctors must be prepared for irregular patterns in the way the lungs fill and empty. For Dr. Kumar, maintaining exactly the right level of sedatives is crucial. Too much and he risks respiratory distress.
“You don’t want them to be aware of the general surroundings,” says Dr. Kumar, “and this way we remove the artificial ventilation component of the surgery.” Dr. Kumar is able to keep such a tight control over the sedation because the drug is administered in a trickle through a catheter and can be adjusted continuously. When the surgery is over, the concentration is gradually lowered. Within two to three hours a patient is able to move his or her limbs.
Such a procedure may have only been attempted once before in a Sri Lankan hospital, says a spokesperson for Durdans Hospital. And though the operation was completed successfully, 'awake surgery' is not necessarily for everyone, say the doctors. For starters, it is only suitable for adults. Secondly, the technical complexities of the procedure make it impractical to apply to all patients. Still for a small percentage of patients, particularly those with respiratory problems or obesity, the awake surgery method is their best option.
Awake surgery is also an option only when the “surgical procedure itself is reasonably short,” says Dr. Dev explaining that this is the case for those who need fewer grafts. The silver lining lies not only in a quick recovery but also in the fact that the procedure need not be more expensive than its more traditional counterparts.