Cardiogenic pulmonary edema: mechanisms and treatment - an intensivist's view

Negative pressure pulmonary edema (Review)

Negative pressure pulmonary edema (NPPE) is a complication resulting from acute or chronic upper airway obstruction, often posing challenges in recognition and diagnosis for clinicians. If left untreated, NPPE can lead to hypoxemia, heart failure and even shock. Furthermore, the drug treatment of NPPE remains a subject of controversy. The primary pathophysiological mechanism of NPPE involves the need for high inspiratory pressure to counteract upper airway obstruction, subsequently causing a progressive rise in negative pressure within the pleural cavity. Consequently, this results in increased pulmonary microvascular pressure, leading to the infiltration of pulmonary capillary fluid into the alveoli. NPPE exhibits numerous risk factors and causes, with laryngospasm following anesthesia and extubation being the most prevalent. The diagnosis of NPPE often presents challenges due to confusion with conditions such as gastroesophageal reflux or cardiogenic pulmonary edema, given the similarity in initial factors triggering both diseases. Upper airway patency, positive pressure non-invasive ventilation, supplemental oxygen and re-intubation mechanical ventilation are the foundation of the treatment of NPPE. The present review aims to discuss the etiology, clinical presentation, pathophysiology and management of NPPE.

Pulmonary oedema in the course of severe maternal outcome in South Africa: A cohort study combined with clinical audit

OBJECTIVES

To describe the incidence and outcomes of pulmonary oedema in women with severe maternal outcome during childbirth and identify possible modifiable factors through audit.

METHODS

All women with severe maternal outcome (maternal deaths or near misses) who were referred to Tygerberg referral hospital from health facilities in Metro East district, South Africa, during 2014-2015 were included. Women with severe maternal outcome and pulmonary oedema during pregnancy or childbirth were evaluated using three types of critical incident audit: criterion-based case review by one consultant gynaecologist, monodisciplinary critical incident audit by a team of gynaecologists, multidisciplinary audit with expert review from anaesthesiologists and cardiologists.

RESULTS

Of 32,161 pregnant women who gave birth in the study period, 399 (1.2%) women had severe maternal outcome and 72/399 (18.1%) had pulmonary oedema with a case fatality rate of 5.6% (4/72). Critical incident audit demonstrated that pre-eclampsia/HELLP-syndrome and chronic hypertension were the main conditions underlying pulmonary oedema (44/72, 61.1%). Administration of volumes of intravenous fluids in already sick women, undiagnosed underlying cardiac illness, administration of magnesium sulphate as part of pre-eclampsia management and oxytocin for augmentation of labour were identified as possible contributors to the pathophysiology of pulmonary oedema. Women-related factors (improved antenatal care attendance) and health care-related factors (earlier diagnosis and management) would potentially have improved maternal outcome.

CONCLUSIONS

Although pulmonary oedema in pregnancy is rare, among women with severe maternal outcome a considerable proportion had pulmonary oedema (18.1%). Audit identified options for prevention of pulmonary oedema and improved outcome. These included early detection and management of preeclampsia with close monitoring of fluid intake and cardiac evaluation in case of suspected pulmonary oedema. Therefore, a multidisciplinary clinical approach is recommended.

Protective effects of Descurainia sophia seeds extract and its fractions on pulmonary edema by untargeted urine and serum metabolomics strategy

Background: Descurainia sophia seeds (DS) is a herbal medicine in traditional Chinese medicine (TCM) for treating lung diseases. We aimed to evaluate the therapeutic effect of DS and five of its fractions upon pulmonary edema (PE) through metabolomics analysis (MA) of urine and serum samples of rats. Methods: A PE model was established by intrathoracic injection of carrageenan. Rats were pretreated with DS extract or its five fractions (polysaccharides (DS-Pol); oligosaccharides (DS-Oli); flavonoid glycosides (DS-FG); flavonoid aglycone (DS-FA); fat oil fraction (DS-FO)) for seven consecutive days. Forty-eight hours after carrageenan injection, lung tissues were subjected to histopathology. MA of urine and serum was done by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry, respectively. Principal component analysis and orthogonal partial least squares-discriminant analysis were operated for the MA of rats and potential biomarkers related to treatment. Heatmaps and metabolic networks were constructed to explore how DS and its five fractions act against PE. Results: DS and its five fractions could all attenuate pathologic lung injury to different degrees, and DS-Oli, DS-FG, and DS-FO had a more potent effect compared with DS-Pol and DS-FA. DS-Oli, DS-FG, DS-FA, and DS-FO could regulate the metabolic profiles of PE rats, but DS-Pol was less potent. According to MA, the five fractions could improve PE to some degree due to their anti-inflammatory, immunoregulatory, and renoprotective activities by mediating the metabolism of taurine, tryptophan, and arachidonic acid. However, DS-Oli, DS-FG, and DS-FO had more important roles in edema-fluid reabsorption, and reduction of vascular leakage through regulating the metabolism of phenylalanine, sphingolipid and bile acid. Finally, heatmaps and hierarchical clustering analysis indicated DS-Oli, DS-FG, and DS-FO to be more efficacious than DS-Pol or DS-FA against PE. The five fractions of DS had a synergistic effect on PE from different aspects, thereby constituting the entire efficacy of DS. DS-Oli, DS-FG, or DS-FO could be used as an alternative to DS. Conclusion: MA combined with use of DS and its fractions provided novel insights into the mechanism of action of TCM.

Research Progress on the Mechanism of Right Heart-Related Pulmonary Edema

Objective. To investigate the mechanisms underlying the development of right heart-associated PE. Background. Right heart-related pulmonary edema (PE) refers to PE resulting from impaired right heart function caused by primary or secondary factors, which is common in critically ill patients. Although the clinical manifestations of different types of right heart-related PE are similar, the pathophysiological changes and treatment methods are significantly different. According to the hemodynamic mechanism, right heart-related PE is primarily classified into two types. One is the increase of right heart flow, including extravascular compression, intravascular compression, cardiac compression, and cardiac decompression. The other type is the abnormal distribution of pulmonary circulation, including obstruction, resistance, pleural decompression, or negative pressure. With the development of hemodynamic monitoring, hemodynamic data not only help us understand the specific pathogenesis of right heart-related PE but also assist us in determining the direction of therapy and enabling individualized treatment. Summary. This article presents a review on right heart-associated PE, with a perspective of hemodynamic analysis, and emphasizes the importance of right heart function in the management of circulation. Understanding the mechanism of right heart-associated PE will not only aid in better monitoring right heart function but also help intensivists make a more accurate identification of various types of PE in the clinic.

Preoperative nutritional evaluation of prostate cancer patients undergoing laparoscopic radical prostatectomy

Background and objective

Prostate cancer (PCa) is one of the most common malignant tumors in men. Geriatric Nutritional Risk Index (GNRI) is an objective index for evaluating nutritional status of elderly people over 65 years old. The aim of the current study was to explore the correlation and predictive value between GNRI and postoperative recovery and complications in PCa patients undergoing laparoscopic radical prostatectomy (LRP).

Methods

Taking 98 as the GNRI boundary value, 96 PCa patients (aged≥65 y) undergoing LRP in the Department of Urology, Affiliated Hospital of North Sichuan Medical College from January 2018 to December 2020 were grouped into malnutrition group (MNg, 34 patients, 35.4%) and normal nutrition group (NNg, 62 patients, 64.6%). Basic information, laboratory examination indexes, operation conditions, postoperative complications and postoperative recovery indexes of patients were recorded and retrospectively analyzed. Clavien-Dindo Classification System (CDCS) was used to assess postoperative complications. T-test was used to analyze differences between the two groups. ROC curve was generated to determine the predictive value of GNRI for postoperative complications.

Results

Percentage of complications was significantly higher in MNg group compared with that in NNg group (P < 0.01). The average grade based on CDCS was significantly lower in NNg group compared with that in MNg group (P < 0.01). Body weight, Body Mass Index (BMI), preoperative hemoglobin value (HGB), serum albumin (ALB) values of MNg and NNg were significantly positively correlated with GNRI (P<0.01). Incidence and severity of postoperative complications of MNg patients were significantly higher compared with those of NNg patients (P<0.05). Average hospitalization cost of MNg patients was higher in MNg patients compared with that of NNg patients (P<0.05). Duration of post-anesthesia care unit (PACU), duration of antibiotic use and duration of indwelling drainage tube were longer in MNg patients compared with those in NNg patients (P<0.05). Furthermore, volume of indwelling drainage tube was higher in MNg patients compared with that in NNg patients (P<0.05).

Conclusion

GNRI is an effective and reliable tool for evaluation of preoperative nutritional status of prostate cancer patients. The findings showed that GNRI is correlated with postoperative recovery and complications, and is an effective predictive marker.

Mechanical ventilation in cardiogenic shock

PURPOSE OF REVIEW

Mechanical ventilation is frequently needed in patients with cardiogenic shock. The aim of this review is to summarize and discuss the current evidence and the pathophysiological mechanism that a clinician should consider while setting the ventilator.

RECENT FINDINGS

Little attention has been placed specifically to ventilatory strategies in patients with cardiogenic shock undertaking mechanical ventilation. Lung failure in patients with cardiogenic shock is associated with worsening outcome as well as a delay in mechanical ventilation institution. The hemodynamic profile and cardiogenic shock cause, considering the preload dependency of the failing heart, must be defined to adjust ventilatory setting.

SUMMARY

Evidence is growing regarding the role of lung failure as adverse prognostic factor and beneficial effect of positive pressure ventilation as part of first-line treatment in patients with cardiogenic failure.

Pulmonary Manifestations of Congenital Heart Disease in Children

This review addresses how anomalous cardiovascular anatomy imparts consequences to the airway, respiratory system mechanics, pulmonary vascular system, and lymphatic system. Abnormal formation or enlargement of great vessels can compress airways and cause large and small airway obstructions. Alterations in pulmonary blood flow associated with congenital heart disease (CHD) can cause abnormalities in pulmonary mechanics and limitation of exercise. CHD can lead to pulmonary arterial hypertension. Lymphatic abnormalities associated with CHD can cause pulmonary edema, chylothorax, or plastic bronchitis. Understanding how the cardiovascular system has an impact on pulmonary growth and function can help determine options and timing of intervention.