Pulmonary hypertension: a review of pathophysiology and anesthetic management

A 1-month-old infant with pulmonary hypertensive crisis after cardiac surgery was successfully rescued with connection of left atrial and right ventricular pressure measurement tubes: a case report

Background

Pulmonary hypertensive crisis is a complication with extremely high mortality after surgery of congenital heart disease. However, there are still no treatment guidelines or expert consensus on the standard treatment of pulmonary hypertensive crisis, and the effect of conventional treatment is still unsatisfactory. We present a case of a patient who developed pulmonary hypertensive crisis after cardiac surgery, and was successfully rescued with a pioneering method, which has never been reported so far.

Case summary

An infant with congenital heart disease had undergone cardiac surgery successfully. Due to obvious myocardial oedema, sternal closure was delayed. The left atrial and right ventricular pressure monitoring tubes, both of which were connected through a triplet, were inserted into right pulmonary vein and pulmonary artery, respectively, and the triplet was in closed condition. On the night of the surgery, pulmonary hypertensive crisis occurred. Emergency bedside thoracotomy was given, and the triplet was turned on urgently to make the left atrial and right ventricular pressure monitoring tubes connected. Meantime, conventional treatment was performed. Eventually, the pulmonary hypertensive crisis was quickly relieved, and the infant was discharged 9 days later.

Discussion

The left atrial and right ventricular pressure monitoring tubes are placed intraoperatively in patients who both need delayed sternal closure and have high risk factors for pulmonary hypertensive crisis, by which could not only monitor the pressure of left atrium and right ventricle in real time but also effectively relieve the right ventricular pressure instantaneously when pulmonary hypertensive crisis occurs, as well as remedy ischaemia of systemic and coronary circulation.

The incidence and risk factors of perioperative cardiac complications in noncardiac major surgery in high-altitude areas: A prospective trial in Tibet autonomous region, China

Background

The risk of perioperative cardiac complications (PCCs) in patients living in high-altitude areas may increase with more adverse clinical outcomes due to the special geographical environment, which has not yet been studied. We aimed to determine the incidence and analyze risk factors for PCCs in adult patients undergoing major noncardiac surgery in the Tibet Autonomous Region.

Methods

This prospective cohort study enrolled resident patients from high-altitude areas receiving major noncardiac surgery in Tibet Autonomous Region People's Hospital in China. Perioperative clinical data were collected, and the patients were followed up until 30 days after surgery. The primary outcome was PCCs during the operation and within 30 days after the surgery. Logistic regression was used to build the prediction models for PCCs. A receiver operating characteristic (ROC) curve was used to evaluate the discrimination. A prognostic nomogram was constructed to generate a numerical probability of PCCs for patients undergoing noncardiac surgery in high-altitude areas.

Results

Among the 196 patients living in high-altitude areas involved in this study, 33 (16.8%) suffered PCCs perioperatively and within 30 days after surgery. Eight clinical factors were identified in the prediction model, including older age (P = 0.028), extremely high altitude above 4,000 m (P = 0.442), preoperative metabolic equivalent (MET) < 4 (P = 0.153), history of angina within 6 months (P = 0.037), history of great vascular disease (P = 0.073), increased preoperative high sensitivity C-reactive protein (hs-CRP) (P = 0.072), intraoperative hypoxemia (P = 0.025) and operation time >3 h (P = 0.043). The area under the curve (AUC) was 0.766 (95% confidence interval: 0.785–0.697). The score calculated from the prognostic nomogram predicted the risk of PCCs in high-altitude areas.

Conclusion

The incidence of PCCs in resident patients living in high-altitude areas who underwent noncardiac surgery was high, and the risk factors included older age, high altitude above 4,000 m, preoperative MET < 4, history of angina within 6 months, history of great vascular disease, increased preoperative hs-CRP, intraoperative hypoxemia, and operation time >3 h. The prognostic nomogram of this study could help to assess the PCCs for patients in high-attitude areas undergoing noncardiac surgery.

Clinical Trial Registration

ClinicalTrials.gov ID: NCT04819698.

Right Heart Catheterization in Pediatric Pulmonary Arterial Hypertension: Insights and Outcome from a Large Tertiary Center

Aim: To define the clinical characteristics, hemodynamics, and adverse events for pediatric patients with pulmonary arterial hypertension (PAH) undergoing right heart catheterization (RHC). Methods: The large referral single center data of 591 diagnostic RHC procedures performed between 2005 and 2020 on pediatric PAH patients was retrospectively collected and analyzed. Results: A total of 591 RHC procedures performed on 469 patients with congenital heart disease (CHD)-PAH (median age 8.8 years, 7.9% New York Heart Association (NYHA) class > II, 1.5% with syncope) and 122 patients with idiopathic PAH (median age of 9.0 years, 27.0% NYHA class > II, 27.0% with syncope) were included. Of those, 373 (63.1%) procedures were performed under general anesthesia. Eighteen patients (18/591, 3.0%) suffered adverse events (mainly pulmonary hypertensive crisis, PHC, n = 17) during the RHC procedure, including 14 idiopathic pulmonary arterial hypertension (IPAH) patients and 4 CHD-PAH patients, and one IPAH patient died in hospital 63 hours after RHC. The risk of developing PHC was significantly increased in patients with IPAH (OR = 14.02, 95%CI: 4.49−43.85, p < 0.001), atrial blood gas pH < 7.35 (OR = 12.504, 95%CI: 3.545−44.102, p < 0.001) and RAP > 14 mmHg (OR = 10.636, 95%CI: 3.668−30.847, p < 0.001). Conclusions: RHC is generally a low-risk procedure in pediatric patients with PAH. However, PHC occur in approximately 3% of patients. Therefore, RHC should be performed in a large, experienced referral pediatric cardiology center, especially in pediatric patients with IPAH requiring general anesthesia.

Pulmonary hypertensive crisis in children with pulmonary arterial hypertension undergoing cardiac catheterization

Pediatric patients with pulmonary arterial hypertension (PAH) are considered to be at risk for pulmonary hypertensive crisis (PHC) or even death during right heart catheterization (RHC). This retrospective study was designed to identify the risks and clinical characteristics associated with PHC in pediatric PAH patients. We included 163 consecutive procedures from 147 pediatric patients diagnosed with PAH who underwent diagnostic RHC in Beijing Anzhen Hospital between January 2007 and December 2020. The average patient age was 9.0 ± 4.7 years and 84 (51.5%) were females. Before RHC, over 20% of patients were in New York Heart Association (NYHA) class III-IV. Sedation or general intravenous anesthesia was used in 103 procedures (63.2%), with spontaneous breathing in 93.2%. PHC occurred in 19 patients (11.7%), 5 (3.1%) required cardiac compression, and 1 died (0.6%). Compared to patients without PHC, those who experienced PHC were more likely to be in NYHA class III-IV (p = 0.012) before RHC, require sedation (p = 0.011), had echocardiographic indices of higher peak tricuspid regurgitation velocity (p = 0.018), and right ventricle (RV) to left ventricle (LV) ratio (p < 0.001). Multivariate logistic regression for PHC identified the need for sedation and a higher RV/LV ratio as independent predictors. In conclusion, the risk of RHC remains significant in children with PAH, particularly in those with severe RV dilation who require sedation during cardiac catheterization. Comprehensive evaluation, close monitoring, and appropriate treatment before and during the procedure are essential for reducing mortality.

"HIDE AND SEEK" NEUROSENSORY RETINAL DETACHMENTS IN PERIPAPILLARY PACHYCHOROID SYNDROME ASSOCIATED WITH PULMONARY ARTERIAL HYPERTENSION

PURPOSE

To report the case of a patient with peripapillary pachychoroid syndrome and recurrent and spontaneous resolving peripapillary neurosensory retinal detachments associated with pulmonary arterial hypertension.

METHODS

Case report imaged with spectral-domain optical coherence tomography, swept-source optical coherence tomography angiography, fundus autofluorescence, and fluorescein and indocyanine green angiography.

RESULTS

A 47-year-old woman presented with unilateral blurred vision and metamorphopsia in her left eye and was diagnosed with peripapillary serous retinal detachments associated with peripapillary pachychoroid syndrome. Cardiologic examination was remarkable for heart failure secondary to severe pulmonary arterial hypertension. Neurosensory detachments spontaneously resolved after 1 day but recurred again three days from baseline. Fluorescein and indocyanine green angiography illustrated choroidal hyperpermeability associated with pachyvessels, whereas optical coherence tomography angiography displayed numerous areas of choriocapillaris nonperfusion, more severe in the left eye of the patient.

CONCLUSION

In pulmonary arterial hypertension, hemodynamic changes caused by increased central venous pressure and endothelin-1 may explain the development of exudative retinal detachment and choroidal ischemia. The pathophysiological mechanisms explaining the peripapilary location of the fluid and the thick choroid, as with the peripapillary pachychoroid syndrome, are explored and discussed.

Effect of Prostanoids on Human Platelet Function: An Overview

Prostanoids are bioactive lipid mediators and take part in many physiological and pathophysiological processes in practically every organ, tissue and cell, including the vascular, renal, gastrointestinal and reproductive systems. In this review, we focus on their influence on platelets, which are key elements in thrombosis and hemostasis. The function of platelets is influenced by mediators in the blood and the vascular wall. Activated platelets aggregate and release bioactive substances, thereby activating further neighbored platelets, which finally can lead to the formation of thrombi. Prostanoids regulate the function of blood platelets by both activating or inhibiting and so are involved in hemostasis. Each prostanoid has a unique activity profile and, thus, a specific profile of action. This article reviews the effects of the following prostanoids: prostaglandin-D₂ (PGD₂), prostaglandin-E₁, -E₂ and E₃ (PGE₁, PGE₂, PGE₃), prostaglandin F_2α (PGF_2α), prostacyclin (PGI₂) and thromboxane-A₂ (TXA₂) on platelet activation and aggregation via their respective receptors.

Pulmonary vasodilators: Latest evidence and outcomes in the perioperative setting

Numerous conditions give rise to pulmonary arterial hypertension (PAH), with most of them being idiopathic. Signs and symptoms are generally difficult to recognize initially because they present as nonspecific and typically are mistaken for age-related physiological processes or alternate medical conditions. Many advances have been made toward PAH-specific therapies that have led to advanced clinical management of the disease. The present investigation describes new pulmonary vasodilator agents that are currently available or under development that could impact perioperative management. The 6-min walk test is the gold standard in assessing the efficacy of any pulmonary hypertension treatment, and the only drug to show any mortality benefit in pulmonary hypertension is epoprostenol. The present investigation also describes the latest evidence on using these medications in the perioperative period, including clinical trials and practice guidelines. Future direction for research and clinical management of pulmonary hypertension is described.

Mortality among infants with evolving bronchopulmonary dysplasia increases with major surgery and with pulmonary hypertension

OBJECTIVE

To assess whether mortality in patients with evolving bronchopulmonary dysplasia (BPD, defined as ⩾28 days of oxygen exposure with lung disease) is independently associated with pulmonary arterial hypertension (PAH) and surgery.

STUDY DESIGN

Single institution retrospective birth cohort of preterm infants with gestational age (GA) 23^0/7 to 36^6/7 weeks, and evolving BPD delivered between 2001 and 2014. Surgery was classified as minor or major using published criteria. Mortality was analyzed by stepwise logistic regression analysis.

RESULTS

Among 577 patients with evolving BPD, 33 (6%) died prior to discharge. Mortality decreased with GA (adjusted odds ratio (aOR): 0.69; 95% confidence interval (CI): 0.55, 0.87), birth weight Z-score (aOR: 0.69, 95% CI: 0.47, 0.996) and increased with PAH (aOR: 30, 95% CI: 2.1, 415), major surgery (aOR; 2.8, 95% CI: 1.3, 6.3), and PAH and surgery (aOR: 10.3, 95% CI: 2.5, 42.1).

CONCLUSION

Among preterm patients with evolving BPD, PAH and surgery are independently associated with mortality.

Pulmonary Vasodilators and Anesthesia Considerations

Pulmonary hypertension (PH) is a complex disease process of the pulmonary vasculature system characterized by elevated pulmonary arterial pressures. Patients with PH are at increased risk for morbidity and mortality, including intraoperatively and postoperatively. Appreciation by the clinical anesthesiologist of the pathophysiology of PH is warranted. Careful and meticulous strategy using appropriate anesthetic medications, pulmonary vasodilator and inotropic agents, and careful fluid management all increase the likelihood of the best possible outcome in this challenging patient population.

Pulmonary veno-occlusive disease: a misnomer?

Pulmonary veno-occlusive disease (PVOD) is a rare entity with non-specific signs and symptoms and is nearly always associated with a dismal prognosis. This review will first consider pulmonary hypertension in general and then will focus on PVOD specifically with particular attention to the pathophysiology of the disease. Classically PVOD is described as a disease primarily involving obstructed venules, with the arterial side of the circulation involved to a lesser degree. This article discusses the demographics of affected individuals; the ways in which an accurate diagnosis can be made, including imaging features; predisposing diseases and associated disorders; and potential treatment.

Ondine's curse: anesthesia for laparoscopic implantation of a diaphragm pacing stimulation system

PURPOSE

Central alveolar hypoventilation syndrome (CAHS) is a rare disease characterized by the loss of autonomic control of breathing. This condition causes hypoventilation and obstruction during sleep. Throughout their lives, these patients require ventilatory assistance by means of positive pressure ventilation to their lungs via mask, tracheotomy, or other means, such as phrenic nerve pacers. The diaphragm pacing stimulation system (DPSS) is a new treatment where electrodes are implanted into the diaphragm and cause contraction on stimulation. The DPSS has been used successfully in tetraplegic patients and patients suffering from amyotrophic lateral sclerosis (ALS). It has been shown to improve quality of life and to extend survival in patients with advanced respiratory muscle weakness. In our case, we describe the perioperative management of an adult patient with acquired CAHS who presented for laparoscopic DPSS insertion.

CLINICAL FEATURES

Our patient was a 50-yr-old female who developed CAHS at age thirteen after contracting encephalitis. Since the onset of her disease, she had been managed with positive pressure ventilation to her lungs via mask. Due to her longstanding disease, she presented with pulmonary hypertension and cor pulmonale and was scheduled for laparoscopic DPSS implantation. Our anesthetic technique included a total intravenous technique with remifentanil and propofol, and her trachea was intubated without the use of muscle relaxants. The pacemakers were switched on when the patient emerged from anesthesia, which provided her with ventilatory support and allowed us to extubate her trachea.

CONCLUSION

We present the successful anesthetic management of an adult patient with CAHS undergoing laparoscopic DPSS insertion.