Pulmonary edema: new insight on pathogenesis and treatment

Safety of prehospital intravenous bolus dose nitroglycerin in patients with acute pulmonary edema: A 4-year review

Background

Intravenous nitrates are a primary therapy for hypertensive congestive heart failure (CHF) with acute pulmonary edema (APE) in the hospital setting. Historically, sublingual nitrates are the mainstay of emergency medical services (EMS) pharmacologic therapy for these patients. We aimed to evaluate the safety of prehospital bolus dose intravenous nitroglycerin in patients with APE.

Methods

This is a retrospective evaluation of EMS data between March 15, 2018, and March 15, 2022, where CHF with APE was suspected and bolus-dose intravenous nitroglycerin was administered. Protocol inclusion criteria were hypertension (systolic blood pressure [SBP] >160 mmHg) and acute respiratory distress, with a presumption of decompensated CHF with APE. These patients received 1 mg intravenous nitroglycerin, with the option to repeat once for ongoing distress if the SBP remained >160 mmHg. The primary outcomes were adverse events, defined as hypotension (SBP <90 mmHg), syncope, vomiting, or dysrhythmia.

Results

The final analysis included 235 patients. In patients receiving intravenous bolus nitroglycerin, the median (interquartile range [IQR]) initial and final EMS SBP values decreased from 198 mmHg (180-218) to 168 (148-187), respectively. The median (IQR) pulse decreased from 108 (92-125) to 103 (86-119), and the median oxygen saturation increased from 89% (82-95) to 98% (96-99). Three episodes (1.3%) of asymptomatic hypotension occurred, and none required intervention.

Conclusion

This study supports a favorable safety profile for prehospital bolus-dose intravenous nitroglycerin for decompensated CHF with APE. Blood pressure, heart rate, and oxygen saturation improvements are also demonstrated. Further, prospective studies are needed to confirm these findings.

Identification of a therapeutic interfering particle-A single-dose SARS-CoV-2 antiviral intervention with a high barrier to resistance

Viral-deletion mutants that conditionally replicate and inhibit the wild-type virus (i.e., defective interfering particles, DIPs) have long been proposed as single-administration interventions with high genetic barriers to resistance. However, theories predict that robust, therapeutic DIPs (i.e., therapeutic interfering particles, TIPs) must conditionally spread between cells with R0 >1. Here, we report engineering of TIPs that conditionally replicate with SARS-CoV-2, exhibit R0 >1, and inhibit viral replication 10- to 100-fold. Inhibition occurs via competition for viral replication machinery, and a single administration of TIP RNA inhibits SARS-CoV-2 sustainably in continuous cultures. Strikingly, TIPs maintain efficacy against neutralization-resistant variants (e.g., B.1.351). In hamsters, both prophylactic and therapeutic intranasal administration of lipid-nanoparticle TIPs durably suppressed SARS-CoV-2 by 100-fold in the lungs, reduced pro-inflammatory cytokine expression, and prevented severe pulmonary edema. These data provide proof of concept for a class of single-administration antivirals that may circumvent current requirements to continually update medical countermeasures against new variants.

Prehospital Treatment of Acute Pulmonary Edema with Intravenous Bolus and Infusion Nitroglycerin

OBJECTIVE

The study describes the implementation of a prehospital treatment algorithm that included intravenous (IV) bolus (IVB) nitroglycerin (NTG) followed by maintenance infusion for the treatment of acute pulmonary edema (APE) in a single, high-volume Emergency Medical Services (EMS) system.

METHODS

This is a retrospective chart review of patients who received IVB NTG for APE in a large EMS system in Minnesota and Wisconsin (USA). Inclusion criteria for treatment included a diagnosis of APE, systolic blood pressure ≥120mmHg, and oxygen saturation (SpO2) ≤93% following 800mcg of sublingual NTG. Patients received a 400mcg IVB of NTG, repeated every two minutes as needed, and subsequent infusion at 80mcg/min for transport times ≥10 minutes.

RESULTS

Forty-four patients were treated with IVB NTG. The median total bolus dose was 400mcg. Twenty patients were treated with NTG infusion following IVB NTG. The median infusion rate was 80mcg/min. For all patients, the initial median blood pressure was 191/113mmHg. Five minutes following IVB NTG, it was 160/94mmHg, and on arrival to the emergency department (ED) it was 152/90mmHg. Five minutes after the initial dose of IVB NTG, median SpO2 increased to 92% from an initial reading of 88% and was 94% at hospital arrival. One episode of transient hypotension occurred during EMS transport.

CONCLUSION

Patients treated with IVB NTG for APE had reduction in blood pressure and improvement in SpO2 compared to their original presentation. Prehospital treatment of APE with IVB appears to be feasible and safe. A randomized trial is needed to confirm these findings.

Treating acute hypertensive cardiogenic pulmonary edema with high-dose nitroglycerin

Acute pulmonary edema due to sympathetic surge and increased peripheral vascular resistance often present to the emergency department (ED) with markedly elevated blood pressure, severe dyspnea, and desaturation. This condition is known as “SCAPE” (sympathetic crashing acute pulmonary edema). We present three SCAPE patients who were successfully treated with high-dose nitroglycerin (NTG) and bilevel positive airway pressure (BiPAP) ventilation. All three patients presented with respiratory failure on arrival but rapidly improved after treatment and did not require endotracheal intubation or admission to the intensive care unit (ICU). SCAPE patients usually present to the ED with extreme respiratory distress associated with diaphoresis, restlessness, and high blood pressure. Emergency physicians must know how to manage SCAPE with high-dose nitrates and NIPPV (noninvasive positive pressure ventilation) because, when treated promptly, one will not only save a life but also obviate the need for endotracheal intubation and ICU admission.

Noninvasive Mechanical Ventilation in Acute Ventilatory Failure: Rationale and Current Applications

Noninvasive ventilation plays a pivotal role in acute ventilator failure and has been shown, in certain disease processes such as acute exacerbation of chronic obstructive pulmonary disease, to prevent and shorten the duration of invasive mechanical ventilation, reducing the risks and complications associated with it. The application of noninvasive ventilation is relatively simple and well tolerated by patients and in the right setting can change the course of their illness.

[Therapeutic strategies in acute decompensated heart failure and cardiogenic shock]

As the population of elderly people is increasing, the number of patients requiring hospitalization for acute exacerbations is rising. Traditionally, these episodes of hemodynamic instability were viewed as a transient event characterized by systolic dysfunction, low cardiac output, and fluid overload. Diuretics, along with vasodilator and inotropic therapy, eventually became elements of standard care. In a multicenter observational registry (ADHERE--Acute Decompensated Heart Failure National Registry) of more than 275 hospitals, patients with acute decompensated heart failure were analyzed for their characteristics and treatments options. These data have shown that this population consists of multiple types of heart failure, various forms of acute decompensation, combinations of comorbidities, and varying degrees of disease severity. The challenges in the treatment require multidisciplinary approaches since patients typically are elderly and have complex combinations of comorbidities. So far only a limited number of drugs is currently available to treat the different groups. Over the past years it was shown that even "standard drugs" might be deleterious by induction of myocardial injury, worsening of renal function or increasing mortality upon treatment. Therefore, based on pathophysiology, different types of acute decompensated heart failure require specialized treatment strategies.

Fenofibrate attenuates endothelial monocyte adhesion in chronic heart failure: an in vitro study

BACKGROUND

Inflammation is implicated in chronic heart failure (CHF). In this study, the potential inhibitory effect of peroxisome proliferator-activated receptor-alpha (PPARalpha) activator fenofibrate on monocyte adhesion in CHF patients was investigated in vitro.

MATERIALS AND METHODS

Isolated peripheral blood mononuclear cells (PBMCs) were collected from 36 patients (aged 65 +/- 8 years) with symptomatic CHF and from 12 healthy control subjects. The cultured human aortic endothelial cells (HAECs) were stimulated with or without 2 ng mL(-1) tumour necrosis factor-alpha (TNF-alpha) and the inhibitory effects of fenofibrate at 25, 50, 100 and 200 microM on endothelial mononuclear cell adhesion were tested. Furthermore, the HAECs were stimulated with 70% sera obtained from CHF patients and control individuals, respectively, with or without pretreatments with fenofibrate. The endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) was then confirmed by mRNA expression and Western blot.

RESULTS

We found that the increased adhesion of PBMCs to TNF-alpha-stimulated HAECs in CHF patients was reduced when the HAECs were pretreated with fenofibrate (31% inhibition, P = 0.0121). However, pretreatment of the isolated PBMCs collected from CHF patients with fenofibrate failed to suppress their adherence to TNF-alpha-stimulated HAECs. Furthermore, stimulation of cultured HAECs with CHF patient sera significantly increased VCAM-1 and ICAM-1 expression, which could also be inhibited by fenofibrate.

CONCLUSIONS

The fenofibrate directly inhibits monocyte binding by TNF-alpha-activated HAECs, probably through preventing up-regulation of cell adhesion molecules by endothelial cells in response to inflammatory stimuli. This PPARalpha activator may have the potential to ameliorate vascular inflammation in patients with CHF.

Pulmonary edema prognostic score predicts in-hospital mortality risk in patients with acute cardiogenic pulmonary edema

BACKGROUND

Congestive heart failure is a common cardiac disorder associated with a high mortality. There are a limited number of prognostic scales predicting in-hospital outcomes after an acute episode of congestive heart failure.

OBJECTIVES

The goal of this investigation was to develop a simple prognostic score predicting in-hospital outcome in patients with acute cardiogenic pulmonary edema.

METHODS

We retrospectively studied 276 consecutive patients hospitalized with acute pulmonary edema from the years 1998 to 2000.

RESULTS

During the initial hospitalization, 58 patients (21%) died and 218 patients (79%) were discharged. Statistical analyses revealed that the most significant predictors of inhospital mortality were acute myocardial infarction, heart rate greater than 115/beats/min, systolic blood pressure of 130 mm Hg or less, and white blood cell count greater than 11,500/mm3 on presentation. The presence of each factor was scored as 1 point, and the absence was scored as 0 points. The Pulmonary Edema Prognostic Score (PEPS) was defined as a sum of all points. Patients with a PEPS of 0 had good short-term prognosis with a 2% in-hospital mortality rate, whereas mortality in patients with a PEPS of 4 was 64%.

CONCLUSIONS

The PEPS is a simple tool that can be easily calculated using common clinical diagnostic tests (electrocardiogram, blood pressure, heart rate, and white cell count) to determine in-hospital mortality risk in patients with an acute episode of cardiogenic pulmonary edema.

Increased endothelial monocyte adhesiveness is related to clinical outcomes in chronic heart failure

BACKGROUND

Vascular inflammation and endothelial dysfunction are evident in patients with chronic heart failure (CHF). We hypothesized that circulating peripheral blood mononuclear cells (PBMCs) may be activated and the resultant increased endothelial monocyte adhesion may be functionally and pathophysiologically relevant in CHF. In the present study, we investigated the clinical significance of the activity of PBMCs in patients with CHF.

METHODS

PBMCs were isolated from 34 CHF patients, from 10 healthy volunteers (normal control group) and from 17 patients admitted for investigation of suspected coronary artery disease (disease control group). In each patient, the adhesiveness of PBMCs to cultured human aortic endothelial cells (HAECs) with or without tumor necrosis factor-alpha (TNF-alpha) stimulation was determined. Major adverse cardiac events (death, heart transplantation or hospitalization with worsening heart failure) were determined in the 34 CHF patients during a median follow-up period of 182 days.

RESULTS

Compared with those from both control groups and from mild CHF patients, PBMCs isolated from severe CHF patients adhered more to the HAECs. The endothelial adhesiveness of PBMCs correlated positively with the circulating levels of CAMs and can supply prognostic information in CHF patients. The difference between event-free curves based on the median levels of endothelial-PBMC adhesion was significant (log rank test, p=0.0139).

CONCLUSIONS

Endothelial adhesiveness of PBMCs is increased and correlated to clinical outcomes, and may be pathophysiologically relevant to the progression of CHF.

Treatment of Severe Decompensated Heart Failure With High-Dose Intravenous Nitroglycerin: A Feasibility and Outcome Analysis

STUDY OBJECTIVE

We perform a feasibility and outcome assessment of the treatment of severe decompensated heart failure with high-dose nitroglycerin.

METHODS

This study was designed as a nonrandomized, open-label, single-arm study of high-dose nitroglycerin. Patients with hypertension (systolic blood pressure > or = 160 mm Hg or mean arterial pressure > or = 120 mm Hg) who were refractory to initial therapy were eligible for inclusion. Enrolled patients began receiving a titratable nitroglycerin infusion and were given a bolus of high-dose nitroglycerin (2 mg). Repeated administration of high-dose nitroglycerin was allowed every 3 minutes, up to a total of 10 doses. Predefined effectiveness and safety outcomes were tracked throughout hospital admission. To provide a frame of reference for these outcomes, data were retrospectively compiled for similar patients with severe decompensated heart failure who did not receive high-dose nitroglycerin.

RESULTS

Twenty-nine patients received high-dose nitroglycerin. Endotracheal intubation was required in 13.8% of patients, bilevel positive airway pressure (BiPAP) ventilation in 6.9%, and ICU admission in 37.9%. Symptomatic hypotension developed in 1 patient (3.4%), and biomarker evidence of myocardial infarction was found in 17.2% of patients. The mean dose of high-dose nitroglycerin was 6.5 mg (+/-3.4). For patients who were treated without high-dose nitroglycerin (n=45), endotracheal intubation occurred in 26.7%, BiPAP in 20.0%, and ICU admission in 80.0%. None of these patients developed symptomatic hypotension, and biomarker evidence of myocardial infarction was observed in 28.9% of patients.

CONCLUSION

In this nonrandomized, open-label trial, high-dose nitroglycerin was associated with endotracheal intubation, BiPAP, and ICU admission less frequently than expected to occur without high-dose nitroglycerin, and adverse events were uncommon. Treatment of hypertensive, severely decompensated heart failure patients with high-dose nitroglycerin seems promising, but a randomized, blinded study is needed to more completely define its clinical utility. According to this trial, such a study seems feasible.

Competition for intrathoracic space reduces lung capacity in patients with chronic heart failure: a radiographic study

BACKGROUND

The purpose of this study was to determine the influence of changes in cardiac size on total lung volume in patients with chronic heart failure compared to control subjects.

METHODS

Forty-four patients and age-, gender-, and height-matched control participants were recruited. All participants underwent posteroanterior and lateral chest radiography for volumetric estimations of the total thoracic cavity (TTC), diaphragm, heart, and lungs. To assess the relationship between chronic heart failure severity and cardiac enlargement, patients with chronic heart failure were classified into groups based on New York Heart Association class, as follows: class I and II, n = 26 (group A); class III and IV, n = 18 (group B).

RESULTS

There was no difference between the groups for TTC volume (TTCV) [p = 0.56]. Cardiac volumes were significantly different between all groups for both the absolute volumes (p < 0.001) were calculated as a percentage of TTCV (p < 0.001), with the largest cardiac volumes in group B (twice the volume of healthy control subjects). When expressed as a percentage of TTCV, there also was a clear reduction in lung volumes as a function of disease severity (p < 0.001).

CONCLUSIONS

The present study demonstrates a close relationship between the severity of heart failure and cardiac size. These changes in cardiac size within a closed thoracic cavity may pose significant constraints on the lungs, resulting in reductions in lung volumes that likely play a major role in the restrictive breathing patterns often reported in patients with chronic heart failure.

Pharmacological therapy of acute cardiogenic pulmonary oedema in the emergency department

This paper critically reviews the major drug types that are currently used in the management of acute cardiogenic pulmonary oedema. As decompensated heart failure becomes an increasingly common problem in emergency departments in the developed world, optimization of emergency drug therapy for these critically ill patients is essential. The evidence base for 'routine therapy' in the ED is considered. The review also briefly considers emerging pharmacological therapies that may have an impact on future management of cardiogenic pulmonary oedema.

The role of cardiac power and systemic vascular resistance in the pathophysiology and diagnosis of patients with acute congestive heart failure

OBJECTIVE

Conventional hemodynamic indexes (cardiac index (CI), and pulmonary capillary wedge pressure) are of limited value in the diagnosis and treatment of patients with acute congestive heart failure (CHF).

PATIENTS AND METHODS

We measured CI, wedge pressure, right atrial pressure (RAP) and mean arterial blood pressure (MAP) in 89 consecutive patients admitted due to acute CHF (exacerbated systolic CHF, n=56; hypertensive crisis, n=5; pulmonary edema, n=11; and cardiogenic shock, n=17) and in two control groups. The two control groups were 11 patients with septic shock and 20 healthy volunteers. Systemic vascular resistance index (SVRi) was calculated as SVRi=(MAP-RAP)/CI. Cardiac contractility was estimated by the cardiac power index (Cpi), calculated as CIxMAP.

RESULTS AND DISCUSSION

We found that CI<2.7 l/min/m(2) and wedge pressure >12 mmHg are found consistently in patients with acute CHF. However, these measures often overlapped in patients with different acute CHF syndromes, while Cpi and SVRi permitted more accurate differentiation. Cpi was low in patients with exacerbated systolic CHF and extremely low in patients with cardiogenic shock, while SVRi was increased in patients with exacerbated systolic CHF and extremely high in patients with pulmonary edema. By using a two-dimensional presentation of Cpi vs. SVRi we found that these clinical syndromes can be accurately characterized hemodynamically. The paired measurements of each clinical group segregated into a specific region on the Cpi/SVRi diagnostic graph, that could be mathematically defined by a statistically significant line (Lambda=0.95). Therefore, measurement of SVRi and Cpi and their two-dimensional graphic representation enables accurate hemodynamic diagnosis and follow-up of individual patients with acute CHF.

RITZ-5: randomized intravenous TeZosentan (an endothelin-A/B antagonist) for the treatment of pulmonary edema: a prospective, multicenter, double-blind, placebo-controlled study

OBJECTIVES

The objective of this study was to evaluate the addition of intravenous (IV) tezosentan to standard therapy for patients with pulmonary edema.

BACKGROUND

Tezosentan is an IV nonselective endothelin (ET)-1 antagonist that yields favorable hemodynamic effects in patients with acute congestive heart failure (CHF).

METHODS

Pulmonary edema was defined as acute CHF leading to respiratory failure, as evidenced by an oxygen saturation (SO(2)) <90% by pulse oxymeter despite oxygen treatment. All patients received oxygen 8 l/min through a face mask, 3 mg of IV morphine, 80 mg of furosemide, and 1 to 3 mg/h continuous drip isosorbide-dinitrate according to their blood pressure level and were randomized to receive a placebo or tezosentan (50 or 100 mg/h) for up to 24 h.

RESULTS

Eighty-four patients were randomized. The primary end point, the change in SO(2) from baseline to 1 h, was 9.1 +/- 6.3% in the placebo arm versus 7.6 +/- 10% in the tezosentan group (p = NS). The incidence of death, recurrent pulmonary edema, mechanical ventilation, and myocardial infarction during the first 24 h of treatment was 19% in both groups. Reduced baseline SO(2), lower echocardiographic ejection fraction, high baseline mean arterial blood pressure (MAP), and inappropriate vasodilation (MAP reduction at 30 min of <5% or >30%) correlated with worse outcomes. A post-hoc analysis revealed that the outcome of patients who received only 50 mg/h tezosentan was better than patients in the placebo group whereas patients receiving 100 mg/h had the worst outcomes.

CONCLUSIONS

In the present study, tezosentan (an ET-1 antagonist) did not affect the outcome of pulmonary edema, possibly because of the high dose used.