Efficacy, Safety, and Medication Errors Associated with the Use of Inhaled Epoprostenol for Adults with Acute Respiratory Distress Syndrome: A Pilot Study

A Narrative Review on the Administration of Inhaled Prostaglandins in Critically Ill Adult Patients With Acute Respiratory Distress Syndrome

OBJECTIVE

To describe the effect of inhaled prostaglandins on both oxygenation and mortality in critically ill patients with acute respiratory distress syndrome (ARDS), with a focus on safety and efficacy in coronavirus disease 2019 (COVID-19)-associated ARDS and non-COVID-19 ARDS.

DATA SOURCES

A literature search of MEDLINE was performed using the following search terms: inhaled prostaglandins, inhaled epoprostenol, inhaled nitric oxide, ARDS, critically ill. All abstracts were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language reports and studies conducted in humans between 1980 and June 2023 were considered.

DATA SYNTHESIS

Data regarding inhaled prostaglandins and their effect on oxygenation are limited but show a benefit in patients who respond to therapy, and data pertaining to their effect on mortality is scarce. Concerns exist regarding the formulation of inhaled epoprostenol (iEPO) utilized in addition to modes of medication delivery; however, the limited data surrounding their use have shown a reasonable safety profile. Other avenues and beneficial effects may exist with inhaled prostaglandins, such as use in COVID-19-associated ARDS or non-COVID-19 ARDS patients undergoing noninvasive mechanical ventilation or during patient transport.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

The use of inhaled prostaglandins can be considered in critically ill patients with COVID-19-associated ARDS or non-COVID-19 ARDS who are experiencing difficulties with oxygenation refractory to nonpharmacologic strategies.

CONCLUSIONS

The use of iEPO and other inhaled prostaglandins requires further investigation to fully elucidate their effects on clinical outcomes, but it appears these medications may have a potential benefit in COVID-19-associated ARDS and non-COVID-19 ARDS patients with refractory hypoxemia but with little effect on mortality.

Inhaled Prostacyclins for Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

Studies evaluating inhaled prostacyclins for the management of acute respiratory distress syndrome (ARDS) have produced inconsistent results regarding their effect on oxygenation. The purpose of this systematic review and meta-analysis was to evaluate the change in the Pao₂/Fio₂ ratio after administration of an inhaled prostacyclin in patients with ARDS.

DATA SOURCES

We searched Ovid Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane, Scopus, and Web of Science.

STUDY SELECTION

We included abstracts and trials evaluating administration of inhaled prostacyclins in patients with ARDS.

DATA EXTRACTION

Change in the Pao₂/Fio₂ ratio, Pao₂, and mean pulmonary artery pressure (mPAP) were extracted from included studies. Evidence certainty and risk of bias were evaluated using Grading of Recommendations Assessment, Development, and Evaluation and the Cochrane Risk of Bias tool.

DATA SYNTHESIS

We included 23 studies (1,658 patients) from 6,339 abstracts identified by our search strategy. The use of inhaled prostacyclins improved oxygenation by increasing the Pao₂/Fio₂ ratio from baseline (mean difference [MD], 40.35; 95% CI, 26.14-54.56; p < 0.00001; I² = 95%; very low quality evidence). Of the eight studies to evaluate change in Pao₂, inhaled prostacyclins also increased Pao₂ from baseline (MD, 12.68; 95% CI, 2.89-22.48 mm Hg; p = 0.01; I² = 96%; very low quality evidence). Only three studies evaluated change in mPAP, but inhaled prostacyclins were found to improve mPAP from baseline (MD, -3.67; 95% CI, -5.04 to -2.31 mm Hg; p < 0.00001; I² = 68%; very low quality evidence).

CONCLUSIONS

In patients with ARDS, use of inhaled prostacyclins improves oxygenation and reduces pulmonary artery pressures. Overall data are limited and there was high risk of bias and heterogeneity among included studies. Future studies evaluating inhaled prostacyclins for ARDS should evaluate their role in ARDS subphenotypes, including cardiopulmonary ARDS.

A retrospective review of implementation of an inhaled epoprostenol protocol in the emergency department

INTRODUCTION

Inhaled epoprostenol is a selective pulmonary vasodilator that has shown a potentially broad number of applications in the management of critically ill patients. To date, the vast majority of the literature with regard to efficacy, indications for use, and adverse effects of inhaled epoprostenol is focused on use of this agent in critical care settings, with relatively little literature describing use of inhaled epoprostenol in the Emergency Department. This retrospective review sought to examine instances in which inhaled epoprostenol was administered in the Emergency Department of a tertiary-care, Level I trauma center following implementation of a clinical pathway for administration of this medication for cases of refractory hypoxemia, RV dysfunction, and refractory hypoxemia. Primary outcomes were monitoring for adverse effects (i.e. hypotension), trend in FiO2 requirement over time, and clinical indication for initiation of inhaled epoprostenol.

METHODS

An automated review was performed to query cases in which inhaled epoprostenol had been initiated in the Emergency Department following adoption of the inhaled epoprostenol clinical pathway. Cases were excluded if the medication was initiated in the prehospital setting, ordered but not administered, or administered for a period of <1 h. Vital signs and co-administration of vasopressors were followed before and following epoprostenol administration to assess for change over time. Clinical indication of epoprostenol administration was assessed via manual chart review.

RESULTS

Inhaled epoprostenol was administered in 20 instances, with 15 cases ultimately meeting inclusion criteria. There were no cases of clinically significant hypotension (MAP <65) in any of the cases in which inhaled epoprostenol was administered in the Emergency Department, and mean vasopressor requirement did not increase over time. A majority of patients saw a reduction in FiO2 requirement following administration of inhaled epoprostenol. The most common indication for initiation of inhaled epoprostenol based on manual chart review was pulmonary embolism.

DISCUSSION

In this review of cases in which inhaled epoprostenol was administered following adoption of a clinical pathway for medication administration, there were no cases of hypotension or other adverse effects that appear to be attributable to medication administration. Pulmonary embolism and refractory hypoxemia were the most common noted indications for administration of inhaled epoprostenol. Further research is warranted regarding development of clinical protocols for administration of inhaled pulmonary vasodilators in the Emergency Department setting.

Predicting Impact of Prone Position on Oxygenation in Mechanically Ventilated Patients with COVID-19

OBJECTIVES

Prone positioning is widely used in mechanically ventilated patients with COVID-19; however, the specific clinical scenario in which the individual is most poised to benefit is not fully established. In patients with COVID-19 respiratory failure requiring mechanical ventilation, how effective is prone positioning in improving oxygenation and can that response be predicted?

DESIGN

This is a retrospective observational study from two tertiary care centers including consecutive patients mechanically ventilated for COVID-19 from 3/1/2020 - 7/1/2021. The primary outcome is improvement in oxygenation as measured by PaO₂/FiO₂. We describe oxygenation before, during and after prone episodes with a focus on identifying patient, respiratory or ventilator variables that predict prone positioning success.

SETTING

2 Tertiary Care Academic Hospitals.

PATIENTS

125 patients mechanically ventilated for COVID-19 respiratory failure.

INTERVENTIONS

Prone positioning.

MAIN RESULTS

One hundred twenty-five patients underwent prone positioning a total of 309 times for a median duration of 23 hours IQR (14 - 49). On average, PaO₂/FiO₂ improved 19%: from 115 mm Hg (80 - 148) immediately before proning to 137 mm Hg (95 - 197) immediately after returning to the supine position. Prone episodes were more successful if the pre-prone PaO₂/FiO₂ was lower and if the patient was on inhaled epoprostenol (iEpo). For individuals with severe acute respiratory distress syndrome (ARDS) (PaO₂/FiO₂ < 100 prior to prone positioning) and on iEpo, the median improvement in PaO₂/FiO₂ was 27% in both instances.

CONCLUSIONS

Prone positioning in mechanically ventilated patients with COVID-19 is generally associated with sustained improvements in oxygenation, which is made more likely by the concomitant use of iEpo and is more impactful in those who are more severely hypoxemic prior to prone positioning.

Evaluation of Continuous Inhaled Epoprostenol in the Treatment of Acute Respiratory Distress Syndrome, Including Patients With SARS-CoV-2 Infection

Background

Acute respiratory distress syndrome (ARDS) management is primarily supportive. Pulmonary vasodilators, such as inhaled epoprostenol (iEPO), have been shown to improve PaO2:FiO2 (PF) and are used as adjunctive therapy.

Objective

To identify the positive response rate and variables associated with response to iEPO in adults with ARDS. A positive response to iEPO was defined as a 10% improvement in PF within 6 hours.

Methods

This retrospective study included adults with ARDS treated with iEPO. The primary endpoint was the variables associated with a positive response to iEPO. Secondary endpoints were positive response rate and the change in PF and SpO2:FiO2 within 6 hours. Statistical analysis included multivariable regression.

Results

Three hundred thirty-one patients were included. As baseline PF increased, the odds of responding to iEPO decreased (odds ratio [OR], 0.752, 95% CI, 0.69-0.819, p < 0.001). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related ARDS (OR 0.478, 95% CI, 0.281-0.814, p = 0.007) was associated with decreased odds of a positive response to iEPO. The total population had a 68.3% positive response rate to iEPO. SARS-CoV-2-related ARDS and non-SARS-CoV-2-related ARDS had a 59.5% and 72.7% positive response rate, respectively. iEPO significantly improved PF (71 vs 95, P < 0.001) in the whole population.

Conclusion and Relevance

iEPO was associated with a positive effect in a majority of moderate-to-severe ARDS patients, including patients with SARS-CoV-2-related ARDS. Lower baseline PF and non-SARS-CoV-2-related ARDS were significantly associated with a positive response to iEPO. The ability to predict which patients will respond to iEPO can facilitate better utilization.

Inhaled prostacyclin analogues in COVID-19 associated acute respiratory distress syndrome: scientific rationale

BACKGROUND

COVID-19 associated acute respiratory distress syndrome (CARDS) is a severe form of SARS CoV-2 infection and affects about 15-30% of hospitalized patients with a high mortality rate. Growing research and data suggest several available drugs with appropriate pharmacological effects to treat COVID-19.

MAIN BODY

Prostacyclin analogues are regiments for pulmonary artery hypertension. Prostacyclin analogues are expected to be beneficial in treating CARDS based on at least four rationales: (1) inhaled prostacyclin analogues improve oxygenation, V/Q mismatch, and act as an ARDS therapy alternative; (2) it alleviates direct SARS-CoV-2-related coagulopathy; (3) increases nitric oxide production; and (4) possible anti-inflammatory effect. Prostacyclin analogues are available in oral, intravenous, and inhaled forms. The inhaled form has the advantage over other forms, such as parenteral administration risks. Previously, a meta-analysis demonstrated the beneficial effects of inhaled prostaglandins for ARDS treatment, such as improved PaO2/FiO2 and PaO2 along with reduced pulmonary artery pressure. Currently, two ongoing randomized controlled trials are evaluating inhaled epoprostenol (VPCOVID [NCT04452669]) and iloprost (ILOCOVID [NCT04445246]) for severe COVID-19 patients.

CONCLUSIONS

Inhaled prostacyclin could be considered in patients with refractory, life-threatening hypoxia despite standard management.

Harm Prevalence Due to Medication Errors Involving High-Alert Medications: A Systematic Review

OBJECTIVE

The aim of the study was to determine the prevalence and main types of harm caused by high-alert medication after medication errors (MEs) in hospitals.

METHOD

A literature systematic review was conducted on PubMed, Scopus, Web of Science, and Lilacs. Eligible studies published until June 2017 were included.

RESULT

Of 6244 studies identified through searching four electronic databases, five studies meeting the selection criteria of this study were analyzed. There was wide variation in the overall prevalence of harm due to MEs involving HAM, from 3.8% to 100%, whereas the pooled prevalence was 16.3%. Overall, 0.01% of harm caused by MEs involving HAM resulted in death. The severity of errors ranged from 0.1% to 19.2% for moderate errors, 0.2% to 15.4% for serious errors, and 1.9% lethal to the patients. The highest prevalences of harm occurred after errors involving potassium chloride 15%, insulin, and epoprostenol. The lowest prevalence of harm was related to errors of anticoagulants administration. The methodological heterogeneity limited direct comparisons among the studies.

CONCLUSIONS

Of the 15 drugs on the list of Institute for Safe Medication Practices HAMs in the United States and Brazil, nine did not present scientific evidence of the potential for harm. In general, few studies, characterized by methodological and conceptual heterogeneity, were performed to determine the harm prevalence resulting from errors involving these drugs.

Responsiveness of Inhaled Epoprostenol in Respiratory Failure due to COVID-19

BACKGROUND

Inhaled pulmonary vasodilators are used as adjunctive therapies for the treatment of refractory hypoxemia. Available evidence suggest they improve oxygenation in a subset of patients without changing long-term trajectory. Given the differences in respiratory failure due to COVID-19 and "traditional" ARDS, we sought to identify their physiologic impact.

METHODS

This is a retrospective observational study of patients mechanically ventilated for COVID-19, from the ICUs of 2 tertiary care centers, who received inhaled epoprostenol (iEpo) for the management of hypoxemia. The primary outcome is change in PaO₂/FiO₂. Additionally, we measured several patient level features to predict iEpo responsiveness (or lack thereof).

RESULTS

Eighty patients with laboratory confirmed SARS-CoV2 received iEpo while mechanically ventilated and had PaO₂/FiO₂ measured before and after. The median PaO₂/FiO₂ prior to receiving iEpo was 92 mmHg and interquartile range (74 - 122). The median change in PaO₂/FiO₂ was 9 mmHg (-9 - 37) corresponding to a 10% improvement (-8 - 41). Fifty-percent (40 / 80) met our a priori definition of a clinically significant improvement in PaO₂/FiO₂ (increase in 10% from the baseline value). Prone position and lower PaO₂/FiO₂ when iEpo was started predicted a more robust response, which held after multivariate adjustment. For proned individuals, improvement in PaO₂/FiO₂ was 14 mmHg (-6 to 45) vs. 3 mmHg (-11 - 20), p = 0.04 for supine individuals; for those with severe ARDS (PaO₂/FiO₂ < 100, n = 49) the median improvement was 16 mmHg (-2 - 46).

CONCLUSION

Fifty percent of patients have a clinically significant improvement in PaO₂/FiO₂ after the initiation of iEpo. This suggests it is worth trying as a rescue therapy; although generally the benefit was modest with a wide variability. Those who were prone and had lower PaO₂/FiO₂ were more likely to respond.

Evaluation of the Efficacy and Safety of Inhaled Epoprostenol and Inhaled Nitric Oxide for Refractory Hypoxemia in Patients With Coronavirus Disease 2019

OBJECTIVES

The objectives of this study were to evaluate the efficacy and safety of inhaled epoprostenol and inhaled nitric oxide in patients with refractory hypoxemia secondary to coronavirus disease 2019.

DESIGN

Retrospective single-center study.

SETTING

ICUs at a large academic medical center in the United States.

PATIENTS

Thirty-eight adult critically ill patients with coronavirus disease 2019 and refractory hypoxemia treated with either inhaled epoprostenol or inhaled nitric oxide for at least 1 hour between March 1, 2020, and June 30, 2020.

INTERVENTIONS

Electronic chart review.

MEASUREMENTS AND MAIN RESULTS

Of 93 patients screened, 38 were included in the analysis, with mild (4, 10.5%), moderate (24, 63.2%), or severe (10, 26.3%), with acute respiratory distress syndrome. All patients were initiated on inhaled epoprostenol as the initial pulmonary vasodilator and the median time from intubation to initiation was 137 hours (68-228 h). The median change in Pao₂/Fio₂ was 0 (-12.8 to 31.6) immediately following administration of inhaled epoprostenol. Sixteen patients were classified as responders (increase Pao₂/Fio₂ > 10%) to inhaled epoprostenol, with a median increase in Pao₂/Fio₂ of 34.1 (24.3-53.9). The mean change in Pao₂ and Spo₂ was -0.55 ± 41.8 and -0.6 ± 4.7, respectively. Eleven patients transitioned to inhaled nitric oxide with a median change of 11 (3.6-24.8) in Pao₂/Fio₂. A logistic regression analysis did not identify any differences in outcomes or characteristics between the responders and the nonresponders. Minimal adverse events were seen in patients who received either inhaled epoprostenol or inhaled nitric oxide.

CONCLUSIONS

We found that the initiation of inhaled epoprostenol and inhaled nitric oxide in patients with refractory hypoxemia secondary to coronavirus disease 2019, on average, did not produce significant increases in oxygenation metrics. However, a group of patients had significant improvement with inhaled epoprostenol and inhaled nitric oxide. Administration of inhaled epoprostenol or inhaled nitric oxide may be considered in patients with severe respiratory failure secondary to coronavirus disease 2019.

The Role of Phosphodiesterase-5 Inhibitors in COVID-19: An Exploration of Literature From Similar Pathologies

Coronavirus Disease 2019 (COVID-19) has had a devastating impact on the ability of highly trained healthcare providers to render sufficient care, due to both the significant demand on resources and the unique nature of this disease that make it resistant to traditional therapies. This review sought to determine the potential role of phosphodiesterase-5 inhibitors (PDE-5) in the management of COVID-19 by extrapolating relevant data and clinical studies from other related disease states, including acute respiratory distress syndrome, acute lung injury, and high altitude pulmonary edema. Following a literature search, 4 reports were analyzed and included in this review. While the heterogenicity of data and the small number of trials included limit the interpretation and applicability, it was consistently demonstrated that PDE-5 inhibitors lowered pulmonary arterial pressures. The overall benefit of these agents is seemingly dependent upon the etiology of the respiratory failure, which warrants expanded clinical investigation for COVID-19.

Comparison of Fixed-Dose Inhaled Epoprostenol and Inhaled Nitric Oxide for Acute Respiratory Distress Syndrome in Critically Ill Adults

PURPOSE

Several reports have demonstrated similar effects on oxygenation between inhaled epoprostenol (iEPO) compared to inhaled nitric oxide (iNO) for acute respiratory distress syndrome (ARDS). Previous studies directly comparing oxygenation and clinical outcomes between iEPO and iNO exclusively in an adult ARDS patient population utilized a weight-based dosing strategy. The purpose of this study was to compare the clinical and economic impact between iNO and fixed-dosed iEPO for ARDS in adult intensive care unit (ICU) patients.

METHODS

This retrospective cohort study was conducted at a major academic medical center between January 1, 2014, and October 31, 2018. Patients ≥18 years of age with moderate-to-severe ARDS were included. The primary end point was to compare the mean change in partial arterial oxygen pressure to fraction of inspired oxygen (Pao ₂: Fio ₂) at 4 hours from baseline between iEPO and iNO. Other secondary aims were total acquisition drug costs, in-hospital mortality, ICU and hospital length of stay, and duration of mechanical ventilation.

RESULTS

A total of 239 patients were included with 139 (58.2%) and 100 (41.8%) in the iEPO and iNO groups, respectively. The mean change in Pao ₂: Fio ₂ at 4 hours from baseline in the iEPO and iNO groups were 31.4 ± 54.6 and 32.4 ± 42.7 mm Hg, respectively (P = .88). The responder rate at 4 hours was similar between iEPO and iNO groups (64.7% and 66.0%, respectively, P = .84). Clinical outcomes including mortality, overall hospital and ICU length of stay, and mechanical ventilation duration were similar between iEPO and iNO groups. Estimated annual cost-savings realized with iEPO was USD1 074 433.

CONCLUSION

Fixed-dose iEPO was comparable to iNO in patients with moderate-to-severe ARDS for oxygenation and ventilation parameters as well as clinical outcomes. Significant cost-savings were realized with iEPO use.

Use and costs of inhaled nitric oxide and inhaled epoprostenol in adult critically ill patients: A quality improvement project

PURPOSE

Inhaled epoprostenol and inhaled nitric oxide are pulmonary vasodilators commonly used in the management of acute respiratory distress syndrome and right ventricular failure; however, they have vastly different cost profiles. The purpose of the project was to transition from nitric oxide to epoprostenol as the inhaled pulmonary vasodilator (IPV) of choice in adult critically ill patients and evaluate the effect of the transition on associated usage and costs.

METHODS

A single-center, prospective, before and after quality improvement project including adult patients receiving inhaled nitric oxide, inhaled epoprostenol, or both was conducted in 7 adult intensive care units, operating rooms, and postanesthesia care units of a tertiary care academic medical center. The total number of patients, hours of therapy, and costs for each agent were compared between stages of protocol implementation and annually.

RESULTS

Seven hundred twenty-nine patients received inhaled nitric oxide, inhaled epoprostenol, or both during the study period. The monthly inhaled nitric oxide use in number of patients, hours, and cost decreased during all stages of the project (p < 0.01). The monthly inhaled epoprostenol use in number of patients, hours, and cost increased during all stages (p < 0.01). Overall, total IPV use increased during the study. However, despite this increase in usage, there was a 47% reduction in total IPV cost.

CONCLUSION

Implementation of a staged protocol to introduce and expand inhaled epoprostenol use in adult critically ill patients resulted in decreased use and cost of inhaled nitric oxide. The total cost of all IPV was decreased by 47% despite increased IPV use.

Acute Respiratory Distress Syndrome: Etiology, Pathogenesis, and Summary on Management

The acute respiratory distress syndrome (ARDS) has multiple causes and is characterized by acute lung inflammation and increased pulmonary vascular permeability, leading to hypoxemic respiratory failure and bilateral pulmonary radiographic opacities. The acute respiratory distress syndrome is associated with substantial morbidity and mortality, and effective treatment strategies are limited. This review presents the current state of the literature regarding the etiology, pathogenesis, and management strategies for ARDS.

Moderate to Severe Acute Respiratory Distress Syndrome Management Strategies: A Narrative Review

Acute respiratory distress syndrome (ARDS) remains a common complication associated with significant negative outcomes in critically ill patients. Lung-protective mechanical ventilation strategies remain the cornerstone in the management of ARDS. Several therapeutic options are currently available including fluid management, neuromuscular blocking agents, prone positioning, extracorporeal membrane oxygenation, corticosteroids, and inhaled pulmonary vasodilating agents (prostacyclins and nitric oxide). Unfortunately, an evidence-based, standard-of-care approach in managing ARDS beyond lung-protective ventilation remains elusive, contributing to significant variability in clinical practice. Although the optimal therapeutic strategy for managing moderate to severe ARDS remains extremely controversial, therapies supported with more robust clinical evidence should be considered first. The purpose of this narrative review is to discuss the published clinical evidence for both pharmacologic and nonpharmacologic management strategies in adult patients with moderate to severe ARDS as well as to discuss practical considerations for implementation.

Inhaled Epoprostenol Through Noninvasive Routes of Ventilator Support Systems

BACKGROUND

The administration of inhaled epoprostenol (iEPO) through noninvasive routes of ventilator support systems has never been previously evaluated.

OBJECTIVE

Describe the use of iEPO when administered through noninvasive routes of ventilator support systems.

METHODS

Critically ill patients admitted to the intensive care unit who received iEPO through noninvasive routes were analyzed. Improvements in respiratory status and hemodynamic parameters were evaluated. Safety end points assessed included hypotension, rebound hypoxemia, significant bleeding, and thrombocytopenia.

RESULTS

A total of 36 patients received iEPO through noninvasive routes: high-flow oxygen therapy through nasal cannula, n = 29 (81%) and noninvasive positive-pressure ventilation, n = 7 (19%). Sixteen patients had improvement in their respiratory status: mean decrease in fraction of inspired oxygen (FiO₂), 20% ± 13%; mean increase in partial pressure of arterial oxygen to FiO₂ (PaO₂/FiO₂) ratio, 60 ± 50 mm Hg; and mean decrease in HFNC oxygen flow rate, 6 ± 3 liters per minute (LPM). Eight patients had declines in their respiratory status (mean increase in FiO₂, 30% ± 20%; mean decrease in PaO₂/FiO₂ ratio, 38 ± 20 mm Hg; and mean increase in HFNC oxygen flow rate, 15 ± 10 LPM), and 12 patients had no change in their respiratory status. Conclusion and Relevance: This represents the first evaluation of the administration of iEPO through noninvasive routes of ventilator support systems and demonstrates that in critically ill patients, iEPO could be administered through a noninvasive route. Further evaluation is needed to determine the extent of benefit with this route of administration.

Aerosolized prostacyclins for acute respiratory distress syndrome (ARDS)

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a critical condition that is associated with high mortality and morbidity. Aerosolized prostacyclin has been used to improve oxygenation despite the limited evidence available so far.This review was originally published in 2010 and updated in 2017.

OBJECTIVES

To assess the benefits and harms of aerosolized prostacyclin in adults and children with ARDS.

SEARCH METHODS

In this update, we searched CENTRAL (2017, Issue 4); MEDLINE (OvidSP), Embase (OvidSP), ISI BIOSIS Previews, ISI Web of Science, LILACS, CINAHL (EBSCOhost), and three trials registers. We handsearched the reference lists of the latest reviews, randomized and non-randomized trials, and editorials, and cross-checked them with our search of MEDLINE. We contacted the main authors of included studies to request any missed, unreported or ongoing studies. The search was run from inception to 5 May 2017.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs), irrespective of publication status, date of publication, blinding status, outcomes published or language. We contacted trial investigators and study authors to retrieve relevant and missing data.

DATA COLLECTION AND ANALYSIS

Three authors independently abstracted data and resolved any disagreements by discussion. Our primary outcome measure was all-cause mortality. We planned to perform subgroup and sensitivity analyses to assess the effect of aerosolized prostacyclin in adults and children, and on various clinical and physiological outcomes. We assessed the risk of bias through assessment of methodological trial components and the risk of random error through trial sequential analysis.

MAIN RESULTS

We included two RCTs with 81 participants.One RCT involved 14 critically ill children with ARDS (very low quality of evidence), and one RCT involved 67 critically ill adults (very low quality evidence).Only one RCT (paediatric trial) provided data on mortality and found no difference between intervention and control. However, this trial was eligible for meta-analysis due to a cross-over design.We assessed the benefits and harms of aerosolized prostacyclin. One RCT found no difference in improvement of partial pressure of oxygen in arterial blood/fraction of inspired oxygen (PaO₂/FiO₂) ratio (mean difference (MD) -25.35, 95% confidence interval (CI) -60.48 to 9.78; P = 0.16; 67 participants, very low quality evidence).There were no adverse events such as bleeding or organ dysfunction in any of the included trials. Due to the limited number of RCTs, we were unable to perform the prespecified subgroup and sensitivity analyses or trial sequential analysis.

AUTHORS' CONCLUSIONS

We are unable to tell from our results whether the intervention has an important effect on mortality because the results were too imprecise to rule out a small or no effect. Therefore, no current evidence supports or refutes the routine use of aerosolized prostacyclin for people with ARDS. There is an urgent need for more RCTs.

Zinc Chloride Smoke Inhalation Induced Severe Acute Respiratory Distress Syndrome: First Survival in the United States with Extended Duration (Five Weeks) Therapy with High Dose Corticosteroids in Combination with Lung Protective Ventilation

Zinc chloride smoke bomb exposure is frequently seen in military drills, combat exercises, metal industry works, and disaster simulations. Smoke exposure presents with variety of pulmonary damage based on the intensity of the exposure. Smoke induced severe acute respiratory distress syndrome (ARDS) is often fatal and there are no standard treatment guidelines. We report the first survival of smoke induced severe ARDS in the United States (US) with prolonged use of high dose steroids (five weeks) and lung protective ventilation alone. Previously reported surviving patients in China and Taiwan required extracorporeal membrane oxygenation (ECMO) and other invasive modalities. We suggest that an extended course of high dose corticosteroids should be considered for the treatment of smoke inhalation related ARDS and should be introduced as early as possible to minimize the morbidity and mortality. We further suggest that patients with smoke inhalation should be observed in the hospital for at least 48 to 72 hours before discharge, as ARDS can have a delayed onset. Being vigilant for infectious complications is important due to prolonged steroid treatment regimen. Patients must also be monitored for critical illness polyneuromyopathy. Additionally, upper airway injury should be suspected and early evaluation by otorhinolaryngology may be beneficial.

Administration of Inhaled Pulmonary Vasodilators to the Mechanically Ventilated Neonatal Patient

Pulmonary hypertension is a life-threatening condition that affects people of all ages that can occur as an idiopathic disorder at birth or as part of a variety of cardiovascular and infectious disorders. It is commonly treated with inhaled pulmonary vasodilators such as nitric oxide and less frequently using formulations and analogs of prostacyclin. To minimize systemic effects and preserve pulmonary vasodilation, vasodilators are often administered directly into the airway. Nitric oxide is the only USA Food and Drug Administration-approved inhaled pulmonary vasodilator that can be used during mechanical ventilation. Over the past two decades, interest has grown in the use of aerosolized prostacyclin and prostacyclin analogs for the treatment of pulmonary hypertension during mechanical ventilation. Clinicians who administer inhaled prostacyclin may not have a clear understanding of its risks because of the lack of data from large clinical trials examining safety and efficacy; moreover, its safe use remains poorly documented. The off-label use of drugs is legitimate, but prescribers must recognize the potential complications and liability in doing so. This manuscript aims to address potential problems related to the aerosol administration of pulmonary vasodilators in the mechanically ventilated neonatal patient.

Treatment of Persistent Pulmonary Hypertension of the Newborn: Use of Pulmonary Vasodilators in Term Neonates

Persistent pulmonary hypertension of the newborn (PPHN) represents a challenging condition associated with significant morbidity. A successful transition from intrauterine to extrauterine life is contingent on adequate pulmonary vasodilation. Several pathophysiologies contribute to the failure of this cascade and may result in life-threatening hypoxia and acidosis in the newborn. Management includes optimal respiratory support, adequate sedation and analgesia, and support of vascular tone and cardiac function. Pulmonary vasodilation has the potential to overcome the cycle of hypoxia and acidosis, improving outcome in these infants. Oxygen and inhaled nitric oxide represent the foundation of therapy. Tertiary pulmonary vasodilators represent a greater challenge, selecting between therapies that include prostanoids, sildenafil, and milrinone. Variable levels of evidence exist for each agent. Thorough review of available data informing efficacy and adverse effects contributes to the development of an informed approach to neonates with refractory PPHN.

The role of inhaled prostacyclin in treating acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a syndrome of acute lung injury that is characterized by noncardiogenic pulmonary edema and severe hypoxemia second to a pathogenic impairment of gas exchange. Despite significant advances in the area, mortality remains high among ARDS patients. High mortality and a limited spectrum of therapeutic options have left clinicians searching for alternatives, spiking interest in selective pulmonary vasodilators (SPVs). Despite the lack of robust evidence, SPVs are commonly employed for their therapeutic role in improving oxygenation in patients who have developed refractory hypoxemia in ARDS. While inhaled epoprostenol (iEPO) also impacts arterial oxygenation by decreasing ventilation-perfusion (V/Q) mismatching and pulmonary shunt flow, this effect is not different from inhaled nitric oxide (iNO). The most effective and safest dose for yielding a clinically significant increase in PaO2 and reduction in pulmonary artery pressure (PAP) appears to be 20-30 ng/kg/min in adults and 30 ng/kg/min in pediatric patients. iEPO appears to have a ceiling effect above these doses in which no additional benefit may be derived. iNO and iEPO have shown similar efficacy profiles; however, they differ with respect to cost and ease of therapeutic administration. The most beneficial effects of iEPO have been seen in adult patients with secondary ARDS as compared with primary ARDS, most likely due to the difference in etiology of the two disease states, and in patients suffering from baseline right ventricular heart failure. Although iEPO has demonstrated improvements in hemodynamic parameters and oxygenation in ARDS patients, due to the limited number of randomized clinical trials and the lack of studies investigating mortality, the use of iEPO cannot be recommended as standard of care in ARDS. iEPO should be reserved for those refractory to traditional therapies.

The use of inhaled prostaglandins in patients with ARDS: a systematic review and meta-analysis

OBJECTIVE

This study aimed to determine whether inhaled prostaglandins are associated with improvement in pulmonary physiology or mortality in patients with ARDS and assess adverse effects.

METHODS

The following data sources were used: PubMed, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, reference lists, conference proceedings, and ClinicalTrials.gov. Studies selected included randomized controlled trials and nonrandomized studies. For data extraction, two reviewers independently screened titles and abstracts for eligibility. With regard to data synthesis, 25 studies (two RCTs) published over 21 years (1993-2014) were included. The PROSPERO registration number was CRD42014013180.

RESULTS

One randomized controlled trial showed no difference in the change in mean Pao2 to Fio2 ratio when comparing inhaled alprostadil to placebo: 141.2 (95% CI, 120.8-161.5) to 161.5 (95% CI, 134.6-188.3) vs 163.4 (95% CI, 140.8-186.0) to 186.8 (95% CI, 162.9-210.7), P = .21. Meta-analysis of the remaining studies demonstrated that inhaled prostaglandins were associated with improvement in Pao2 to Fio2 ratio (16 studies; 39.0% higher; 95% CI, 26.7%-51.3%), and Pao2 (eight studies; 21.4% higher; 95% CI, 12.2%-30.6%), and a decrease in pulmonary artery pressure (-4.8 mm Hg; 95% CI, -6.8 mm Hg to -2.8 mm Hg). Risk of bias and heterogeneity were high. Meta-regression found no association with publication year (P = .862), baseline oxygenation (P = .106), and ARDS etiology (P = .816) with the treatment effect. Hypotension occurred in 17.4% of patients in observational studies.

CONCLUSIONS

In ARDS, inhaled prostaglandins improve oxygenation and decrease pulmonary artery pressures and may be associated with harm. Data are limited both in terms of methodologic quality and demonstration of clinical benefit. The use of inhaled prostaglandins in ARDS needs further study.

Major publications in the critical care pharmacotherapy literature: January-December 2013

PURPOSE

Ten recently published articles with important implications for critical care pharmacotherapy are summarized.

SUMMARY

The Critical Care Pharmacotherapy Literature Update (CCPLU) group is a national assembly of experienced intensive care unit (ICU) pharmacists across the United States. Group members monitor 25 peer-reviewed journals on an ongoing basis to identify literature relevant to pharmacy practice in the critical care setting. After evaluation by CCPLU group members, selected articles are chosen for summarization and distribution to group members nationwide based on (1) applicability to critical care practice, (2) relevance to pharmacy practitioners, and (3) quality of evidence or research methodology. Hundreds of relevant articles were evaluated by the group during the period January-December 2013, of which 98 were summarized and disseminated nationally to CCPLU group members. Among those 98 publications, 10 deemed to be of particularly high utility to critical care practitioners were included in this review. The 10 articles address topics such as rapid lowering of blood pressure in patients with intracranial hemorrhage, adjunctive therapy to prevent renal injury due to acute heart failure, triple-drug therapy to improve neurologic outcomes after cardiac arrest, and continuous versus intermittent infusion of β-lactam antibiotics in severe sepsis.

CONCLUSION

There were many important additions to the critical care pharmacotherapy literature in 2013, including an updated guideline on the management of myocardial infarction and reports on advances in research focused on improving outcomes in patients with stroke or cardiac arrest and preventing the spread of drug-resistant pathogens in the ICU.

Emerging drugs for acute lung injury

INTRODUCTION

Acute respiratory distress syndromes (ARDS) are devastating disorders of overwhelming pulmonary inflammation and hypoxemia, resulting in high morbidity and mortality.

AREAS COVERED

The main pharmacological treatment strategies have focused on the attempted inhibition of excessive inflammation or the manipulation of the resulting physiological derangement causing respiratory failure. Additionally, such interventions may allow reduced occurence mechanical ventilation injury. Despite promising preclinical and small clinical studies, almost all therapies have been shown to be unsuccessful in large-scale randomized controlled trials. The evidence for pharmacological treatment for ARDS is reviewed. Potential future treatments are also presented.

EXPERT OPINION

We suggest for future clinical trials addressing prevention and early intervention to attenuate lung injury and progression to respiratory failure.

A review of inhaled nitric oxide and aerosolized epoprostenol in acute lung injury or acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are conditions associated with an estimated mortality of 40–50%. The use of inhaled vasodilators can help to improve oxygenation without hemodynamic effects. This article reviews relevant studies addressing the safety and efficacy of inhaled nitric oxide (iNO) and aerosolized epoprostenol (aEPO) in the treatment of life-threatening hypoxemia associated with ARDS and ALI. In addition, the article also provides a practicable guide to the clinical application of these therapies. Nine prospective randomized controlled trials were included for iNO reporting on changes in oxygenation or clinical outcomes. Seven reports of aEPO were examined for changes in oxygenation. Based on currently available data, the use of either iNO or aEPO is safe to use in patients with ALI or ARDS to transiently improve oxygenation. No differences have been observed in survival, ventilator-free days, or attenuation in disease severity. Further studies with consistent end points using standard delivery devices and standard modes of mechanical ventilation are needed to determine the overall benefit with iNO or aEPO.