Download Update 11 - Update in Anaesthesia - WFSA

Update in Anaesthesia 55OperationAt operation, a large clot is found under high pressure.Once released, the blood pressure falls to normal levels.The bleeding point is identified and secured. The brainwhich was compressed, is pulsating with each heart beatand respiration. If an Intensive Care (ICU) bed is availableand it is decided to ventilate the patient for a periodpostoperatively, an ICP monitor is inserted. As describedbelow, a catheter is inserted subdurally and connected toan arterial transducer.Postoperative careThe patient is now taken to ICU to allow the anaestheticdrugs to wear off with an intracranial pressure monitor insitu. After some hours he is opening his eyes, coughing onthe ET tube and breathing well. His ICP is 12 mmHg andhe is allowed to wake up and is extubated.An inexpensive ICP monitorIf an arterial pressure transducer is available this can bedone simply with a neonatal umbilical catheter. The catheteris inserted either subdurally or intraventricularly and filledwith saline by the surgeon. A 1-2 cm subcutaneous tunnelis formed to reduce the risk of the catheter being pulledout. Care must be taken to avoid kinking the catheter.Under aseptic conditions it is connected to a transducerwithout the usual pressure heparin flush system. Adampened looking pressure trace is seen with pressurefluctuations with each cardiac cycle. It will rise withcoughing and will be flat if it is blocked or ICP is veryhigh. It does not often block, but if this happens only thesurgical team should attempt to unblock it. Intraventricularcatheters are less likely to block but have greater risk ofinfection, their use being limited to 5 daysConclusion1 The initial assessment and resuscitation is vital andmust be carried out: a scheme is described.2 A method of anaesthesia is described based onsimple physiological and pharmacological principleswhich, when used, will reduce the risk of addeddamage.An unconscious patient with an extraduralhaematoma will die or be permanently severelydamaged unless treated quickly and correctly.Urgent surgical decompression is required. ItALONE is not enough. Attention to basic simpleclinical details will prevent additional irreversibledamage occurring before the intracranial pressurecan be reduced by releasing the haematoma.Teaching PointAt the end of surgery the anaesthetist should achievethe following aims1 Prevent further damage from physiologicalfactors which will cause brain swelling.2 Observe the patient to detect anydeterioration.3 Provide adequate analgesia.Deterioration postoperatively may occur from brainswelling or accumulation of a further haematoma. Thebest method of detecting any deterioration inneurological status postoperatively is observation ofthe conscious patient, looking for a change in consciouslevel and new or changed neurological signs. Thereforewhen a simple haematoma without bruising or contusionto the brain is removed early from an otherwise fitpatient who has no other trauma, as in this case, it isbetter to wake the patient up immediately after surgery.Anaesthesia is stopped and the patient extubated. Incontrast, when there is significant brain contusion orother systems are damaged by the accident, wakingand extubation are delayed if an ICU bed is available.ICU availableThe patient is taken to the ITU where ventilation andsedation are continued. BP, pulse and ICP aremonitored. When the ICP remains normal, the patientis allowed to wake up and be extubated.ICU not availableAnaesthesia is stopped in theatre and the patientallowed to wake up. Neuromuscular block is reversedand spontaneous respiration allowed to start.Extubation should be carried out when theendotracheal tube is seen to be irritating the trachea.Initially the patient lies in the recovery (lateral) positionuntil airway reflexes have returned. The patient is thensat up at about 30° to reduce cerebral venouscongestion. The patient should be given the best nursingcare that the hospital can provide with Glasgow ComaScore or AVPU recordings started, recorded andrepeated at 15 minute intervals. Any deterioration inconscious level or appearance of new neurologicalsigns is reported to the surgical team immediately.