Perioperative hypertension

BACKGROUND Perioperative hypertension is a situation whose management is suggested by the clinical judgement much more than clinical evidences. JNC 7 guidelines give a classification of blood pressure (BP), without any mention specifically dedicated to patients undergoing surgery. The ACC/AHA guidelines recommend deferring surgery if diastolic BP is above 110 mmHg and systolic BP is above 180 mmHg.
AIM OF THE STUDY In this review we considered pathogenetic, clinical and therapeutic factors related to perioperative management of hypertensive patients.
DISCUSSION In actual trend of the preoperative evaluation, alone hypertension is considered as a minor risk factor. BP values ‰¤ 180/110 mmHg do not influence the outcomes in patients who underwent noncardiac surgery. Therefore, in these conditions it's not necessary to delay surgery. Hypertensive picks are possible during the operation, mostly because of the intubation, but, much more dangerous, falls of pressure are possible. The intraoperative arterial pressure should be maintained within 20% of the best estimated preoperative arterial pressure, especially in patients with markedly elevated preoperative pressures. After surgery the arterial BP can increase for stress factors, pain, hypoxia and hypercapnia, hypothermia and infusional liquids overload. For all these reasons a careful monitoring is mandatory. Anti-hypertensive medication should be continued during the postoperative period in patients with known and treated hypertension, as unplanned withdrawal of treatment can result in rebounded hypertension. The decision to give anti-hypertensive drugs must be made for each patient, taking into account their normal BP and their postoperative BP. With regard to the optimal treatment of the patient with poorly or uncontrolled hypertension in the perioperative evaluation, recent guidelines suggest that the best treatment may consider cardioselective β-blockers therapy, but also clonidin by transdermic way. ACE-ihinibitors and angiotensin- II-antagonists are allowed, but with caution, like as dihydropiridinic calcium-antagonists. Sublingual nifedipin is not recommended, owing to the evidence of an increased morbidity and mortality. Diuretics can lead to dangerous liquids depletions and would not be used in absence of specific indications (such as congestive heart failure, etc.). In hypertensive crisis the most used drugs remain NPS, nitrates, i.v. β-blockers (labetalol, esmolol), fenoldopam.
CONCLUSIONS Postoperative BP should always be reviewed with reference to the preoperative and intraoperative assessments.