Treatment of Total Spinal

Although rare, total spinals can occur with frightening rapidity and result in the death of the patient if not quickly recognised and treated. They are more likely to occur when a planned epidural injection is, inadvertently, given intrathecally. The warning signs that a total spinal block is developing are:

• Hypotension - treat as detailed above. Remember that nausea may be the first sign of hypotension. Repeated doses of vasopressors and large volumes of fluid may be necessary.
• Bradycardia - give atropine. If this is not effective give ephedrine or adrenaline.
• Increasing anxiety - reassure.
• Numbness or weakness of the arms and hands, indicating that the block has reached the cervico-thoracic junction.
• Difficulty breathing - as the intercostal nerves are blocked the patient may state that they can't take a deep breath. As the phrenic nerves (C3,4,5) which supply the diaphragm become blocked, the patient will initially be unable to talk louder than a whisper and will then stop breathing.
• Loss of consciousness.

Call for help - several pairs of hands may be useful!

• ABC Resuscitation
• Intubate and ventilate the patient with 100% oxygen.

Treat hypotension and bradycardia with intravenous fluids, atropine and vasopressors as described earlier. If treatment is not started quickly the combination of hypoxia, bradycardia and hypotension may result in a cardiac arrest.

• Ventilation will need to be continued until the spinal block recedes and the patient is able to breathe again unaided. The time this will take will depend on which local anaesthetic has been injected.
• Once the airway has been controlled and the circulation restored, consider sedating the patient with a small dose of a benzodiazepine as consciousness may return before muscle power and the patient will find it distressing to be unable to breathe properly. 

General Postoperative Care

The patient should be admitted to the recovery room as with any other anaesthetised patient. In the event of hypotension in the recovery room, the nurses should elevate the patients' legs, increase the rate at which intravenous fluids are being administered, give oxygen and summon the anaesthetist. Further doses of vasoconstrictors or fluids may be required, as previously discussed. Patients should be advised as to how long their spinal block will last and be told to remain in bed until full sensation and muscle power has returned. 

Complications of Spinal Anaesthesia

Headache. A characteristic headache may occur following spinal anaesthesia. It begins within a few hours and may last a week or more. It is postural, being made worse by standing or even raising the head and relieved by lying down. It is often occipital and may be associated with a stiff neck. Nausea, vomiting, dizziness and photophobia frequently accompany it. It is more common in the young, in females and especially in obstetric patients. It is thought to be caused by the continuing loss of CSF through the hole made in the dura by the spinal needle. This results in traction on the meninges and pain.

The incidence of headache is related directly to the size of the needle used. A 16 gauge needle will cause headache in about 75% of patients, a 20 gauge needle in about 15% and a 25 gauge needle in 1-3%. It is, therefore, sensible to use the smallest needle available especially in high-risk obstetric patients. As the fibres of the dura run parallel to the long axis of the spine, if the bevel of the needle is parallel to them, it will part rather than cut them and therefore, leave a smaller hole. Make a mental note of which way the bevel lies in relation to the notch on the hub and then align it appropriately. It is widely considered that pencil-point needles (Whiteacre or Sprotte) make a smaller hole in the dura and are associated with a lower incidence of headache (1%) than conventional cutting-edged needles (Quincke) (figure 7).

Treatment of spinal headache. Patients with spinal headaches prefer to remain lying flat in bed as this relieves the pain. They should be encouraged to drink freely or, if necessary, be given intravenous fluids to maintain adequate hydration. Simple analgesics such as paracetamol, aspirin or codeine may be helpful, as may measures to increase intra-abdominal and hence epidural pressure such as lying prone. Sumatriptan, normally used in the treatment of migraine, is said to be effective. Caffeine containing drinks such as tea, coffee or Coca-Cola are often helpful. Prolonged or severe headaches may be treated with epidural blood patch performed by aseptically injecting 15-20ml of the patient's own blood into the epidural space. This then clots and seals the hole and prevents further leakage of CSF.

It used to be thought that bedrest for 24 hours following a spinal anaesthetic would help reduce the incidence of headache, but this is now no longer believed to be the case. Patients may get up once normal sensation has returned, if surgical considerations so allow.

Urinary retention. As the sacral autonomic fibres are among the last to recover following a spinal anaesthetic, urinary retention may occur. If fluid pre-loading has been excessive, a painful distended bladder may result and the patient may need to be catheterised.

Permanent neurological complications are extremely rare. Many of those that have been reported were due to the injection of inappropriate drugs or chemicals into the CSF producing meningitis, arachnoiditis, transverse myelitis or the cauda equina syndrome with varying patterns of neurological impairment and sphincter disturbances. Damage to an epidural vein can lead to the formation of an epidural haematoma that compresses the spinal cord. This is most unlikely in a patient with a normal clotting profile. If inadequate sterile precautions are taken, bacterial meningitis or an epidural abscess may result although it is thought that most such abscesses are caused by the spread of infection in the blood. Finally, permanent paralysis can occur due to the "anterior spinal artery syndrome". This is most likely to affect elderly patients who are subjected to prolonged periods of hypotension and may result in permanent paralysis of the lower limbs. 

(Continued ...)

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