626	S. Todi et al.

77.3Neurosurgery

Step 1: Maintain airway, oxygenation, and ventilation

¥Adequate oxygenation is mandatory for proper neuronal functioning. Hypercarbia is detrimental to the brain injury patient as it leads to rise in intracranial pressure (ICP), and therefore proper ventilation should be ensured (see Chap. 31).

¥Maintain arterial oxygen saturation of more than 94% and PaCO2 in the normocapnic range. Reserve hyperventilation for management of sudden increases in the ICP.

Step 2: Maintain adequate fluid balance while preventing brain swelling

¥Avoid hypotonic ßuids (like 5% dextrose) to prevent brain swelling. Note that lactated RingersÕ solution is also mildly hypotonic.

¥Use isotonic ßuid like normal saline to maintain euvolemia.

¥Fluid restriction and active diuresis should be avoided as it will lead to reduced circulating blood volume and hypoperfusion of the brain.

¥Either isotonic saline or colloids can be used as a volume replacement.

¥Maintain normal or slightly high serum sodium values (145Ð150 mEq/L).

Step 3: Maintain normoglycemia

¥Hyperglycemia is associated with worse outcome after brain injury. This is because during low oxygen supply state intracellular sugar is converted into lactate, which causes intracellular acidosis and is detrimental to neuronal cells.

¥On the other hand, for normal neuronal function, continuous supply of glucose is mandatory and hypoglycemia is equally detrimental.

¥Thus, a Þne balance of glucose control between 110 and 150 mg/dL should be maintained, with insulin infusion and ensuring adequate carbohydrate intake.

Step 4: Treat fever aggressively

¥Fever is detrimental to brain tissues, and on the other hand, mild hypothermia is beneÞcial.

¥Any febrile episode should be actively controlled with antipyretics and external cooling measure.

Step 5: Maintain blood pressure in the normal range

¥Excessive swings of blood pressure should be avoided as autoregulation of cerebral blood ßow is disrupted with the injured brain and ßow will increase or decrease with changes in blood pressure leading to hyperemia with increased ICP during hypertension or hypoperfusion leading to decreased cerebral blood ßow and neuronal injury during hypotension. Mean arterial pressure should be kept in the range of 65Ð75 mmHg in most patients.

Step 6: Decrease cerebral metabolic demand

¥Judicious use of sedatives (e.g., barbiturates and propofol) and analgesics is useful in these cases.

77 Specific Issues in Perioperative Care	627

Step 7: Prevent and treat convulsions aggressively (see Chap. 28)

¥Anticonvulsant prophylactic may be given perioperatively for cortical surgeries.

¥All episodes of new onset seizures should be actively managed to prevent secondary brain injury.

¥In patients with persistent or ßuctuating level of consciousness, nonconvulsive status should be ruled out.

Step 8: Monitor the patient for increases in ICP and neurological deterioration frequently (see Chap. 31)

¥Hourly Glasgow coma score, pupillary size and reaction

¥ICP monitoring where appropriate

¥Maintain CPP (MAP−ICP > 65 mmHg).

¥Measurement and management of raised ICP (refer to Chap. 31)

ÐBasics

¥Normal ICP is less than 15 mmHg.

¥Raised ICP is more than 15Ð20 mmHg for more than 1Ð5 min.

¥CPP = MAP − ICP.

¥Always measure cerebral perfusion pressure (CPP) along with ICP.

¥The ICP monitor (intraventricular drain or subarachnoid bolt) is inserted if indicated.

¥Transducer (without ßush system) has to be kept at midventricular level which is at the level of tragus in supine position.

¥Start treatment if ICP is more than 20Ð25 mmHg for more than 5 min.

ÐManagement of intraventricular drain (IVD)

¥Drain cerebrospinal ßuid (CSF) whenever ICP is more than 15Ð20 mmHg.

¥Drain CSF till ICP is 10Ð15 mmHg.

¥Measure daily CSF drain required to maintain ICP.

¥Examine CSF every day.

¥Take full sterile precautions.

¥Lumbar drain

ÐIf IVD is in situ, do lumbar puncture and compare opening and closing ventricular and lumbar pressures.

ÐIf there is comparable drop, IVD can be removed, and CSF is drained by Lumbar punctures (LPs).

ÐIf there is no fall in ventricular pressures, drain CSF from IVD and avoid further LPs.

¥Approach to an acute rise of ICP in a previously stable patient

ÐCheck the transducer level and rezero.

ÐConÞrm waveform of ICP trace.

ÐPosition the head, neck, and endotracheal tube tape properly to minimize increase in ICP.

ÐCheck ventilation, ABG, and X-rays and increase mechanical ventilation to decrease pCO2 if necessary.

ÐExclude anxiety, pain, or seizures.

ÐDrain CSF or give mannitol bolus.

ÐPerform a CT scan if appropriate.

628	S. Todi et al.

Suggested Reading

1.Behera BK, Puri GD. Patient-controlled epidural analgesia with fentanyl and bupivacaine provides better analgesia than intravenous morphine patient-controlled analgesia for early thoracotomy pain. J Postgrad Med. 2008;54(2):86Ð90.

Significantly less number of patients required rescue analgesia in PCEA group (P < 0.05). Pain relief was better both at rest and during coughing (P < 0.05) in PCEA group as compared to IVPCA. Patients in the PCEA group were less sedated and had fewer incidences of side effects, that is, nausea/vomiting and pruritus.

2.Venkataraman R. Vascular surgery critical care: perioperative cardiac optimization to improve survival. Crit Care Med. 2006;34(9 Suppl):S200Ð207.

Perioperative addition of statins to b-blockers in high-risk patients undergoing vascular surgery merits further evaluation. Preoperative coronary revascularization should be restricted to patients with unstable cardiac symptoms.

3.Karamichalis JM. Cardiovascular complications after lung surgery. Thorac Surg Clin. 2006; 16(3):253Ð60.

Although postoperative cardiac events cannot be completely eliminated from the thoracic surgery population, the prevention, treatment, and follow-up strategies outlined can attenuate these significant morbid and mortal events.

4.Soto RG, Fu ES. Acute pain management for patients undergoing thoracotomy. Ann Thorac Surg. 2003;75(4):1349Ð57.

This work provides a review of the literature and recommendations for the clinician.

Part XIII

General Issues

Yatin Mehta and Shirish Prayag