Hypertension is caused by a variety of mechanisms including but not limited to pain, anxiety, delirium, hypothermia, hypercarbia, hypoxia, emergence excitement, and other triggers of catecholamine release. Treatment of the hypertension must be immediate and patient specific, and should target its often multifactorial etiology. A balanced approach
to analgesics to reduce perioperative pain while avoiding excessive sedation, maintaining normothermia, and ensuring adequate oxygenation and ventilation is imperative and can help in the management of postoperative hypertension. Medical treatment of hypertension often includes intravenous administration of β-blocking agents (e.g., labetalol) or calcium channel blockers (e.g., nicardipine), both of which are readily found in the infusion formulation.

As in any postsurgical patient, hypotension is also a common finding after neurosurgical procedures and may require optimization of the volume status or administration of vasopressors. Common causes include large perioperative blood loss and hypovolemia from other volume losses such as vomiting (seen often with brain tumors) and urinary losses associated with diabetes insipidus or cerebral salt wasting. If volume resuscitation is required, it is important to avoid hypotonic solutions (e.g., 0.45% saline), which could worsen the intracranial swelling and raise the intracranial pressure (ICP). Isotonic crystalloids (normal saline or lactated ringers) are typically used, but hypertonic saline and colloids are also sometimes used, with the aim to minimize the risk of worsening edema and intracranial hypertension.

Similar to other postsurgical patients, tachycardia after neurosurgery can be a response to hypovolemia, pain, and withdrawal from medications (most notably benzodiazepines, nodal agents). It may be managed by treating the underlying cause or through pharmacologic rate control with β-blockers or calcium channel blockers. Given the prolonged time of immobility and inability to use deep venous thrombosis prophylaxis during the immediate postoperative period, it is important to consider pulmonary embolism as a potential etiology, particularly in patients with associated hypoxemia or chest pain. In the setting of an acute stress response, patients with underlying cardiac disease and electrolyte abnormalities (i.e., secondary to excessive diuresis or after brain relaxation therapy) are at higher risk for developing dysrhythmias and should be managed carefully through correction of the underlying conditions and administration of antiarrhythmic agents.

Postoperative nausea and vomiting (PONV) is common, especially following infratentorial craniotomies and resection of acoustic neuromas. In the general population, the predictors of PONV include female gender, history of motion sickness or PONV, duration of surgery, use of postoperative opioids, and a nonsmoking status. In the case of neurosurgical procedures, this complication may be augmented by the stimulation of the chemoreceptor trigger zone, which is located in the infratentorial compartment. In addition to the usual antiemetic agents such as ondansetron, prochlorperazine, and low-dose haloperidol, prophylactic dexamethasone has been reported to reduce the incidence of PONV.

Postoperative neurosurgical patients usually stay in the ICU for a few hours to a few days depending on the pathophysiology of their underlying disease, intervention performed, intraoperative or immediate postoperative events, their comorbid conditions, and the efficacy of their pharmacologic treatment. An accurate and comprehensive baseline medical and neurologic evaluation is important to minimizing the ICU time and improving patient outcome. An accurate and timely medication reconciliation and reintroduction of the patient’s home regimen is also important to the postoperative hemodynamic management.