Research Article: Perioperative Anesthesiological Management of Patients with Pulmonary Hypertension

Date Published: October 12, 2012

Publisher: Hindawi Publishing Corporation

Author(s): Jochen Gille, Hans-Jürgen Seyfarth, Stefan Gerlach, Michael Malcharek, Elke Czeslick, Armin Sablotzki.

http://doi.org/10.1155/2012/356982

Abstract

Pulmonary hypertension is a major reason for elevated perioperative morbidity and mortality, even in noncardiac surgical procedures. Patients should be thoroughly prepared for the intervention and allowed plenty of time for consideration. All specialty units involved in treatment should play a role in these preparations. After selecting each of the suitable individual anesthetic and surgical procedures, intraoperative management should focus on avoiding all circumstances that could contribute to exacerbating pulmonary hypertension (hypoxemia, hypercapnia, acidosis, hypothermia, hypervolemia, and insufficient anesthesia and analgesia). Due to possible induction of hypotonic blood circulation, intravenous vasodilators (milrinone, dobutamine, prostacyclin, Na-nitroprusside, and nitroglycerine) should be administered with the greatest care. A method of treating elevations in pulmonary pressure with selective pulmonary vasodilation by inhalation should be available intraoperatively (iloprost, nitrogen monoxide, prostacyclin, and milrinone) in addition to invasive hemodynamic monitoring. During the postoperative phase, patients must be monitored continuously and receive sufficient analgesic therapy over an adequate period of time. All in all, perioperative management of patients with pulmonary hypertension presents an interdisciplinary challenge that requires the adequate involvement of anesthetists, surgeons, pulmonologists, and cardiologists alike.

Partial Text

Pulmonary hypertension represents an important risk factor for increased perioperative morbidity and mortality. Stress, pain, ventilation, and surgery-related inflammation can further increase pressure and resistance within the pulmonary arteries and cause right-sided heart failure. Ramakrishna et al. have described a number of independent factors leading to an increased perioperative risk for patients with pulmonary hypertension. Conditions that caused one or more perioperative complications in 42% of all patients were heart failure of NYHA class II or higher, a history of pulmonary embolism, high-risk surgery (e.g., thoracic or major abdominal surgery), and an anesthesia duration of more than 3 hours [1]. The literature reports a perioperative mortality of 7–24%—depending on the primary disease and the type of surgical intervention—with the highest risk for pregnant women and patients undergoing emergency interventions [1–5].

Pulmonary hypertension comprises a number of diseases, all of which have the common symptom of increased pressure in the pulmonary arteries. These diseases are characterized by a progressive course and a poor prognosis for the patient (Dana Point Classification; see Table 1) [7]. In order to diagnose pulmonary hypertension (PH), it is necessary to measure the mean pulmonary artery pressure (PAPm) during right-heart catheterization. PH is defined as PAPm > 24 mmHg at rest. Values of 20 ≤ PAPm ≤ 24 mmHg are referred to as borderline PH [8, 9]. Mean pulmonary artery pressure in healthy persons is 14 ± 3 mmHg [10].

There is no reliable data on the prevalence of patients with PH, for example, in an average anesthesiological patient population. An impression can be gained by considering the prevalence of individual entities of PH. In a major study in France, a prevalence of 15/1 million inhabitants (5–25/1 million including regional variations) has been observed for pulmonary arterial hypertension (PAH; → group 1, Tables 1 and 2), whereas the figure for idiopathic pulmonary arterial hypertension (IPAH) is about 5/1 million inhabitants [12]. Pengo et al. give a prevalence of 1–4% for pulmonary hypertension developing in patients who are survivors of pulmonary embolism (CTEPH; → group 4, Tables 1 and 2) [13].

The therapeutic approach is guided by the diagnosis of the PH type. In recent years, various new pulmonary vasodilators have been successively tested for their effects in clinical trials and launched on the market. However, these drugs are only approved for the therapy of PAH (→ group 1, Tables 1 and 2). They exert their effects using different signaling pathways, that is, the endothelin-signaling pathway (endothelin receptor antagonists: bosenthan, ambrisentan), the prostacyclin-signaling pathway (prostacyclin analogues: iloprost, epoprostenol, and treprostinil), and the NO-signaling pathway (phosphodiesterase-5 inhibitors: sildenafil, tadalafil). Table 4 gives an overview of all approved substances [8].

Given that pulmonary hypertension affects several organ systems simultaneously (lung, heart, and vascular system), preparations for the surgical procedure should be considered as the joint task of anesthesia, surgery, pulmonology, and cardiology [1, 26]. The purpose of these preparations should be, on one hand, to evaluate the functional state of the heart and lung organ systems as good as possible so that the probability of complications, including right-sided heart failure, can be properly estimated. On the other hand, experts should strive to optimize the patient’s initial condition as far as possible by adjusting the current specific medication and treatment of comorbidities, which minimizes the individual risk of complications [27]. In many cases, patients with pulmonary hypertension receive ongoing anticoagulant therapy, which necessitates the adaptation and preparation of anticoagulant medication prior to inpatient hospitalization. This includes establishing, prior to the surgical procedure, if postoperative recovery at home is an option and if the prerequisites for this option can be fulfilled (family environment, primary care physician, social services, outpatient services, and insurance providers) [27].

Pulmonary hypertension is a major reason for elevated perioperative morbidity and mortality, even in noncardiac surgical procedures. Patients should be thoroughly prepared for the intervention and allowed plenty of time for consideration. All specialty units involved in treatment should play a role in these preparations. After selecting each of the suitable individual anesthetic and surgical procedures, intraoperative management should focus on avoiding all circumstances that could contribute to exacerbating pulmonary hypertension (hypoxemia, hypercapnia, acidosis, hypothermia, and hypervolemia). A method of treating elevations in pulmonary pressure with selective pulmonary vasodilation by inhalation should be available intraoperatively, in addition to invasive hemodynamic monitoring. During the postoperative phase, patients must be monitored continuously and receive sufficient analgesic therapy over an adequate period of time. All in all, perioperative management of patients with pulmonary hypertension presents an interdisciplinary challenge that requires the adequate involvement of anesthetists, surgeons, pulmonologists, and cardiologists alike.

 

Source:

http://doi.org/10.1155/2012/356982

 

Leave a Reply

Your email address will not be published.