**1. Introduction**

Pulmonary hypertension (PH) is a devastating and potentially life-threatening condition that results from a heterogeneous group of diseases. PH is characterized by a sustained increase of mean pulmonary artery pressure (PAP) of 25 mmHg or greater due to any etiology [1]. PH is the manifestation of abnormal pulmonary vascular bed anatomy, abnormal vasoconstrictive status, and pulmonary parenchymal abnormalities which result in obstruction to pulmonary blood flow, cardiac diseases which may impede venous return from the lungs, or a combina‐ tion of the above. Although many different causes exist, hypertension in the pulmonary circulation is the result of increased vascular resistance, increased vascular bed flow, or a coexistence of both. Initially the signs and symptoms of PH are usually subtle and nonspecific, often ignored by the patients. If left untreated, however, these patients with PH will develop progressive symptoms of dyspnea, fatigue, poor exercise tolerance and right heart failure culminating in a markedly shortened survival [2]. The mechanism for the pathogenesis of pulmonary arterial hypertension (PAH) is not completely understood. There is a conceptual transition in recent decades from the traditional view of mechanical obstruction of blood flow leading to elevated pressure in the pulmonary circulation to cellular growth and vascular remodeling causing increased resistance in pulmonary vasculature resistance [3][4]. Though uncommon, there are patients with PH scheduled for various surgical procedures and requiring anesthetic care perioperatively. In recent years some emerging strategies in the management of PH are potentially applicable to anesthesia practice intraoperatively. From the

© 2013 Liu et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Liu et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

clinical anesthesia standpoint, although mild or transient PH won't considerably complicate anesthetic management, moderate or severe PH surely can dramatically deteriorate intrao‐ peratively or postoperatively and potentially lead to acute right heart failure (RHF), cardio‐ genic shock and even death. The perioperative management of patients with PH varies depending upon the pathological features present, functional clinical classification, hemody‐ namic status, and success of current medical therapy. This chapter will review the epidemi‐ ology, etiologies, the mechanisms, especially cellular growth-related remodeling mechanisms, preoperative evaluation, intraoperative considerations and anesthetic management strategies, and postoperative management of patients with PH.

pulmonary hypertension; Group V: Others (Tumor obstruction, fibrosing mediastinitis,

Pre-capillary mPAP ≥25 mmHg PCWP ≤15 mmHg CO normal or reduced+

Perioperative Considerations of Patients with Pulmonary Hypertension

http://dx.doi.org/10.5772/56056

197

Post-capillary, mPAP ≥25 mmHg PCWP "/>15 mmHg CO normal or reduced+

Pre-capillary mPAP ≥25 mmHg PCWP≤15 mmHg CO normal or reduced+ Passive: TPG≤12 mmHg Reactive: TPG"/>12 mmHg

Pre- capillary mPAP ≥25 mmHg PCWP ≤15 mmHg CO normal or reduced+

Pre-capillary mPAP ≥25 mmHg PCWP ≤15 mmHg CO normal or reduced+

**Subcategory of pulmonary hypertension Hemodynamics**

chronic renal failure on dialysis). [5] [6], and is presented in Table-2.

I Pulmonary arterial hypertension (PAH): idiopathic or inheritable PAH

II Pulmonary (venous) hypertension because of left-heart disease (PH

III Pulmonary hypertension associated with lung diseases and/or

IV Pulmonary hypertension associated with chronic thrombotic and/or embolic disease (PH with thromboembolic diseases)

> multifactorial mechanisms. Functional versus pathophysiologic considerations are important issue in classification. A more detailed description of PH Classification is available in other chapters of the

PAH: Pulmonary arterial hypertension; PH: Pulmonary hypertension; mPAP: mean pulmonary artery pressure; PCWP: pulmonary artery wedge pressure; TPG: transpulmonary pressure gradient (P¯pa - P¯pcw). #: all values measured at rest; +: high CO can be present in cases of hyperkinetic conditions such as systemic-to-pulmonary shunts (only in the pulmonary

A review of a large U.S. database by Memtsoudis *et al* was undertaken to identify mortality in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA).[7] The authors studied 1359 THA and 2184 TKA patients who also carried the diagnosis of PH. In

V Pulmonary hypertension associated with unclear and/or

**Table 2.** DANA POINT Classification of Pulmonary Hypertension [5] [6]

**3. Epidemiology of pulmonary hypertension**

A. Idiopathic B. Infectious

book

circulation), anemia, hyperthyroidism, etc.

C. Connective tissue disorders D. Congenital heart diseases

hypoxemia (PH with lung diseases)

with left-heart diseases)
