Respiratory tract Surgery

1) Upper Respiratory tract

a) Rhinotomy and sinus trephination
Rhinotomy is used in the treatment of intranasal disease which cannot be managed medically, such as foreign bodies, some tumours and sometimes fungal disease. It is occasionally used in cats as treatment for chronic flu damaged nasal bones. It is not approached lightly , as there is a considerable blood supply to the nose,
Post - op complications: Haemorrhage, loss of sense of smell so difficulty with appetite and feeding
Sinus trephination is similar to rhinotomy, into the frontal sinuses which lie above the eyes just on either side of the mid line. This procedure is relatively bloodless, but results can be disappointing if the surgeon misses the mark and trephines into the brain!

b) Brachycephalic obstruction syndrome. This problem was covered in the diseases lecture. Surgery to improve breathing involves some or all of the following:
- Widening out the alar cartilages of the external nares.
- Shortening the soft palate
- Removing the tonsils
- Removing the laryngeal ventricles (small pieces of tissue which can balloon out from beside the vocal cords. )

c) Laryngeal Surgery
- Laryngeal tie-back is used to provide an airway in animals suffering from vocal cord paralysis. This condition (known as “roaring” in horses) is usually seen in older medium to large breed dogs; failure of the recurrent laryngeal nerve prevents the animal from retracting the vocal cords during breathing The tie-back procedure pulls a vocal cord back out of the way.
- Cricopharyngeal achalasia. Seen in young animals, a muscle across the entrance to the oesophagus fails to relax and the animal is unable to swallow solids, but is OK with liquids. Surgery to cut the muscle is curative.

d) Tracheal surgery
- Tracheal collapse. Miniature and toy breeds (particularly the Yorkshire Terrier) can have problems because their trachea flattens out as they age, causing the “collapsing drinking straw effect” and making inspiration difficult. Surgery to correct this is possible, but fairly risky, and involves the attachment of artificial rings to the outside of the trachea.
- Tracheotomy. The patient is clipped and prepped between the larynx and thoracic inlet in the ventral mid line. The incision is made longitudinally in the skin but then transversely through the tissue between two tracheal rings, usually the 2nd and 3rd or 3rd and 4th, the incision’s size should be judged based on the and the tracheotomy tube introduced pointing downward towards the lungs, and secured with supplied ties. Remember that tracheotomy tubes clog very quickly, often within an hour or two if unattended, and need flushing and / or cleaning hourly, often using a cannula and suction. Some tubes come with central linings which can be pulled out and cleaned or with stylets which can be used to clear secretions from the tube end. Pre-oxygenation is a good idea before any tracheal interference.

Problems with upper airway surgery:
The main problem with this type of surgery is swelling due to tissue damage. Normally swelling is a relatively unimportant side-effect of surgical trauma, but in the case of the airway, it can be life-threatening. Nursing care of these patients requires:
- close monitoring of anaesthesia, particularly oxygenation but also ensuring that the patient wakes up swiftly and quickly regains laryngeal and breathing reflexes.
- close post operative monitoring for pain and any restriction to the airway, for at least 6 hours post operatively.
- Advising owners on feeding suitable foods ( liquids such as milk may cause choking and inhalation pneumonia.) Also advising the owners on signs of dyspnoea to watch out for.

2) Thoracic Surgery
Thoracotomy is surgical entry into the chest.
The chest can be opened: Between the ribs (intercostal)
By removing a rib (rib resection)
By cutting straight along the middle of the sternum (median sternotomy).
During thoracic surgery, there is loss of the negative chest pressure necessary for respiration. This means that the patient must be ventilated by the anaesthetist, either by hand or mechanically. Sometimes muscle relaxing drugs are also used. These make surgery easier but also remove the ability to breathe.
After surgery of the thorax there will be loss of pressure within the chest and so pneumothorax is inevitable. Pneumothorax also occurs after road accidents and can be spontaneous. This is one of the many good reasons to become familiar with use of a stethoscope. In pneumothorax, the lungs are separated from the chest wall by a layer of air, so breathing sounds become quieter and quieter. If air continues to accumulate then the lungs are crushed inward and life-threatening tension pneumothorax develops. Pneumothorax is relieved by installing a chest drain. These are also used for drainage of fluid.
A Chest Drain is inserted through the skin on one side of the chest then tunnelled forwards and pushed though an intercostal space ahead of the skin incision. This arrangement means that when the tube is withdrawn, intact skin covers the hole in the chest wall. The drain tube is attached to a non-return valve (either a Heimlich, or a water bottle type trap. There are drawbacks to each - the Heimlich can stick closed, and the water bottle must be kept lower than the patient or water will run into the animal’s chest. One- way valves rely on the pressure changes during breathing to expel air from the chest. Chest drains are also used to suck air from the chest. By attaching the tube to a 3-way tap, a syringe can draw air from the chest then expel it. This can also be used for fluids.
Nursing care- Chest drains must be secure, otherwise there is risk of an opening into the chest. This means that most drains must be under a chest dressing when they are not being used so that they cannot be scratched out. A Chinese finger trap suture is used to secure the tube to the skin. This prevents the tube being pulled out of the chest. Great care must be taken in maintaining security of connections between tubes, taps, etc.

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