Use of sedatives, opioids, and neuromuscular blocking agents in patients with acute lung injury and acute respiratory distress syndrome

Current Practice Review in the Management of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) presents as an acute inflammatory lung injury characterized by refractory hypoxemia and non-cardiac pulmonary edema. An estimated 10% of patients in the intensive care unit and 25% of those who are mechanically ventilated are diagnosed with ARDS. Increased awareness is warranted as mortality rates remain high and delays in diagnosing ARDS are common. The COVID-19 pandemic highlights the importance of understanding ARDS management. Treatment of ARDS can be challenging due to the complexity of the disease state and conflicting existing evidence. Therefore, it is imperative that pharmacists understand both pharmacologic and non-pharmacologic treatment strategies to optimize patient care. This narrative review provides a critical evaluation of current literature describing management practices for ARDS. A review of treatment modalities and supportive care strategies will be presented.

Agitation is a Common Barrier to Recovery of ICU Patients

Importance: Agitation is common in mechanically ventilated ICU patients, but little is known about physician attitudes regarding agitation in this setting. Objectives: To characterize physician attitudes regarding agitation in mechanically ventilated ICU patients. Design, Setting, and Participants: We surveyed critical care physicians within a multicenter health system in Western Pennsylvania, assessing attitudes regarding agitation during mechanical ventilation and use of and confidence in agitation management options. We used quantitative clinical vignettes to determine whether agitation influences confidence regarding readiness for extubation. We sent our survey to 332 critical care physicians, of whom 80 (24%) responded and 69 were eligible (had cared for a mechanically ventilated patient in the preceding three months). Main Outcomes and Measures: Respondent confidence in patient readiness for extubation (0-100%, continuous) and frequency of use and confidence in management options (1-5, Likert). Results: Of 69 eligible responders, 61 (88%) agreed agitation is common and 49 (71%) agreed agitation is a barrier to extubation, but only 27 (39%) agreed their approach to agitation is evidence-based. Attitudes regarding agitation did not differ much by practice setting or physician demographics, though respondents working in medical ICUs were more likely (P = .04) and respondents trained in surgery or emergency medicine were less likely (P = .03) than others to indicate that agitation is an extubation barrier. Fifty-three (77%) respondents reported they frequently use non-pharmacologic measures to treat agitation, and 42 (70%) of those who reported they used non-pharmacologic measures during the prior 3 months indicated confidence in their effectiveness. In responses to clinical vignettes, confidence in patient's readiness for extubation was significantly lower if the patient was agitated (P < .001) or tachypneic (P < .001), but the presence of both agitation and tachypnea did not reduce confidence compared with tachypnea alone (P = .24). Conclusions and Relevance: Most critical care physicians consider agitation during mechanical ventilation a common problem and agreed that agitation is a barrier to extubation. Treatment practice varies widely.

Neuromuscular blockade in mechanically ventilated pneumonia patients with moderate to severe hypoxemia: A multicenter retrospective study

BACKGROUND/PURPOSE

The benefit of neuromuscular blockades (NMBs) in critically ill patients receiving mechanical ventilation remains uncertain. Therefore, we aimed to investigate whether NMB use is associated with improved survival of mechanically ventilated pneumonia patients with moderate to severe hypoxemia.

METHODS

This retrospective multicenter study was conducted at five university-affiliated hospitals. Data of pneumonia patients aged 18 years and older who received mechanical ventilation between January 1, 2011, and December 31, 2020, were analyzed.

RESULTS

In a total of 1,130 patients, the mean patient age was 73.1 years (SD±12.6), and the overall mortality rate at 30 d was 29.5% (n = 333). NMB users had a higher 30 d mortality rate than NMB nonusers (33.9% vs. 26.8%, P = 0.014). After PS matching, the 30 d mortality rate was not significantly different between NMB users and nonusers (33.4% vs. 27.8%, p = 0.089). However, 90 d mortality rate was significantly increased in NMB users (39.7% vs. 31.9%, p = 0.021). Univariable Cox proportional hazard regression analyses showed that NMB use ≥ 3 d was significant risk factor for the 90 d mortality than those with < 3 d use (90 d mortality HR 1.39 [95% CI: 1.01-1.91], P = 0.045).

CONCLUSIONS

NMB use was not associated with lower 30 d mortality among mechanically ventilated pneumonia patients with moderate to severe hypoxemia. Rather, NMB users had higher 90 d mortality, furthermore, and NMB use ≥ 3 d was associated with a higher risk of long-term mortality compared to NMB use < 3 d. Therefore, care should be taken to avoid extended use of NMB in critically ill pneumonia patients during mechanical ventilation.

Immediate Effect of Mechanical Ventilation Mode and Sedative Infusion on Measured Diaphragm Thickness

Rationale: In patients who are mechanically ventilated, diaphragm thinning on ultrasound is thought to correlate with diaphragm atrophy and has been associated with prolonged intubation. Factors other than atrophy, however, may cause changes in diaphragm thickness, which may confound studies examining changes in diaphragm thickness over time. Objectives: To determine if changes in the mode of mechanical ventilation or an interruption of sedatives have immediate effects on diaphragm thickness measurements in adult patients in the intensive care unit who are mechanically ventilated. Methods: Adult patients receiving invasive mechanical ventilation for less than 48 hours were included. Diaphragm thickness was measured at end-expiration and peak inspiration using ultrasound while patients were receiving both volume assist-control and pressure-support modes in a randomized crossover fashion. In patients receiving sedatives, additional measurements were taken after an interruption of sedatives. Measurements were compared between modes and on assist-control before and after an interruption of sedatives. Results: Of 85 patients enrolled, 66 had measurements on assist-control and spontaneous modes, and 40 had measurements before and after an interruption of sedatives. End-expiratory diaphragm thickness increased by a median of 0.08 mm after an interruption of sedatives (95% confidence interval [CI], 0.002 mm to 0.164 mm; P = 0.017), corresponding to a median increase of 6.5%. No difference was seen when comparing measurements taken on volume assist-control and pressure support (median difference, 0 mm; 95% CI, -0.07 mm to 0.08 mm; P = 0.98). Conclusions: End-expiratory diaphragm thickness increased by 6.5% after an interruption of sedatives. The effect of sedatives on measured diaphragm thickness should be considered in future studies examining changes in diaphragm thickness over time. Clinical trial registered with Clinicaltrials.gov (NCT04319939).

Opioid-Use, COVID-19 Infection, and Their Neurological Implications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an imminent threat to human health and public safety. ACE2 and transmembrane serine protease 2 proteins on host cells provide the viral entry point to SARS-CoV-2. Although SARS-CoV-2 mainly infects the respiratory system, there have been reports of viral neurotropism and central nervous system injury as indicated by plasma biomarkers, including neurofilament light chain protein and glial fibrillary acidic protein. Even with a small proportion of infections leading to neurological manifestation, the overall number remains high. Common neurological manifestations of SARS-CoV-2 infection include anosmia, ageusia, encephalopathy, and stroke, which are not restricted to only the most severe infection cases. Opioids and opioid antagonists bind to the ACE2 receptor and thereby have been hypothesized to have therapeutic potential in treating COVID-19. However, in the case of other neurotropic viral infections such as human immunodeficiency virus (HIV), opioid use has been established to exacerbate HIV-mediated central nervous system pathogenesis. An analysis of electronic health record data from more than 73 million patients shows that people with Substance Use Disorders are at higher risk of contracting COVID-19 and suffer worse consequences then non-users. Our in-vivo and in-vitro unpublished studies show that morphine treatment causes increased expression of ACE2 in murine lung and brain tissue as early as 24 h post treatment. At the same time, we also observed morphine and lipopolysaccharides treatment lead to a synergistic increase in ACE2 expression in the microglial cell line, SIM-A9. This data suggests that opioid treatment may potentially increase neurotropism of SARS-CoV-2 infection. We have previously shown that opioids induce gut microbial dysbiosis. Similarly, gut microbiome alterations have been reported with SARS-CoV-2 infection and may play a role in predicting COVID-19 disease severity. However, there are no studies thus far linking opioid-mediated dysbiosis with the severity of neuron-specific COVID-19 infection.

The effect of age on ventilation management and clinical outcomes in critically ill COVID-19 patients--insights from the PRoVENT-COVID study

Introduction: We analyzed the association of age with ventilation practice and outcomes in critically ill COVID–19 patients requiring invasive ventilation.

Methods: Posthoc analysis of the PRoVENT–COVID study, an observational study performed in 22 ICUs in the first 3 months of the national outbreak in the Netherlands. The coprimary endpoint was a set of ventilator parameters, including tidal volume normalized for predicted bodyweight, positive end–expiratory pressure, driving pressure, and respiratory system compliance in the first 4 days of invasive ventilation. Secondary endpoints were other ventilation parameters, the use of rescue therapies, pulmonary and extrapulmonary complications in the first 28 days in the ICU, hospital– and ICU stay, and mortality.

Results: 1122 patients were divided into four groups based on age quartiles. No meaningful differences were found in ventilation parameters and in the use of rescue therapies for refractory hypoxemia in the first 4 days of invasive ventilation. Older patients received more often a tracheostomy, developed more frequently acute kidney injury and myocardial infarction, stayed longer in hospital and ICU, and had a higher mortality.

Conclusions: In this cohort of invasively ventilated critically ill COVID–19 patients, age had no effect on ventilator management. Higher age was associated with more complications, longer length of stay in ICU and hospital and a higher mortality.

A Clinician's Guide to Dosing Analgesics, Anticonvulsants, and Psychotropic Medications in Continuous Renal Replacement Therapy

Acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) is a common complication in critical illness and has a significant impact on pharmacokinetic factors determining drug exposure, including absorption, distribution, transport, metabolism, and clearance. In this review, we provide a practical guide to drug dosing considerations in critically ill patients undergoing CRRT, focusing on the most commonly used analgesic, anticonvulsant, and psychotropic medications in the clinical care of critically ill patients. A literature search was conducted to identify articles in which drug dosing was evaluated in adult patients receiving CRRT between the years 1980 and 2020. We included articles with pharmacokinetic/pharmacodynamic analyses and those that described medication clearance via CRRT. A summary of the data focused on practical pharmacokinetic and pharmacodynamic principles is presented, with recommendations for drug dosing of analgesics, anticonvulsants, and psychotropic medications. Pharmacokinetic and pharmacodynamic studies to guide drug dosing of analgesics, anticonvulsants, and psychotropic medications in critically ill patients receiving CRRT are sparse. Considering the widespread use of these medications, narrow therapeutic index of these drug classes, and risks of over- and underdosing, additional studies in patients receiving CRRT are needed to inform drug dosing.

Use of music to enhance sleep and psychological outcomes in critically ill patients: a protocol for a systematic review and meta-analysis

INTRODUCTION

Music listening is used as a non-pharmacological intervention in various populations with positive results; however, evidence for its effect on sleep and psychological outcomes in critically ill patients remains unclear. It is essential to understand the impact of music listening for critically ill patients to optimise care and minimise the risk for harm. We will assess whether music listening improves sleep and psychological outcomes in critically ill patients.

METHODS AND ANALYSIS

We will systematically search scientific databases for relevant studies, including PubMed, Embase, CINAHL, PsycINFO, Web of Science, Scopus, ProQuest, the Cochrane Central Register of Controlled Trials, China Biological Medicine Database, China National Knowledge Infrastructure Library, Wan fang databases, VIP Database for Chinese Technical Periodicals and the Chinese Clinical Trial Registry. Databases will be searched for articles published from inception to 10 June 2020. Music therapy journals and reference lists in some articles will be hand-searched. Grey literature will also be searched. We will include randomised and quasi-randomised controlled trials that used music listening to improve sleep and psychological outcomes in critically ill patients. The primary outcomes will be sleep-related outcomes, and secondary outcomes will be anxiety and depression scores and physiological outcomes. Two reviewers will independently verify study eligibility and methodological quality; disagreements will be resolved by a third reviewer or through discussion. The risk of bias will be independently determined using the Cochrane Risk of Bias Tool. The Consolidated Standards of Reporting Trials checklist will be used to examine the quality of included papers. Data will be extracted from eligible studies by two researchers. RevMan V.5.3 will be used for meta-analysis.

ETHICS AND DISSEMINATION

This work will review existing trial data and will not introduce new patient data or interventions; therefore, ethics committee approval is not required. We will disseminate this protocol in a related peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019147202.

The Implementation of Protocol-Based Utilization of Neuromuscular Blocking Agent Using Clinical Variables in Acute Respiratory Distress Syndrome Patients

Supplemental Digital Content is available in the text.

Objectives:

The recent conflicting data on the mortality benefit of neuromuscular blocking agents in acute respiratory distress syndrome and the potential adverse effects of continuous neuromuscular blocking agent necessitates that these medications should be used judiciously with dose reduction in mind. The aims of the study were to improve the process of care by provider education of neuromuscular blocking agent titration and monitoring and to determine the impact of clinical endpoint based neuromuscular blocking agent titration protocol.

Design:

We conducted a proof-of-concept historically controlled study of protocol-based intervention standardizing paralytic monitoring and titration using clinical variables. Education of the protocol was provided to ICU staff via bedside teaching and workshops. The primary outcomes were the time to reach goal paralysis and cumulative neuromuscular blocking agent dose. Secondary outcomes included maintenance of deeper sedation (Richmond Agitation and Sedation Scale –5) prior to neuromuscular blocking agent initiation, total time on mechanical ventilation, length of stay, and mortality.

Setting:

Medical ICU at a quaternary academic hospital between March 2019 and June 2020.

Patients:

Adult severe acute respiratory distress syndrome (Pao₂/Fio₂ <150) patients requiring neuromuscular blocking agent for greater than or equal to 12 hours. Eighty-two patients fulfilled inclusion criteria, 46 in the control group and 36 in the intervention group.

Interventions:

Education and implementation of standardized protocol.

Measurements and Main Results:

Compared with the control group, the time to reach goal paralysis in the intervention group was shorter (8.55 ± 9.4 vs 2.63 ± 5.9 hr; p < 0.0001) on significantly lower dose of cisatracurium (total dose 1,897.96 ± 1,241.0 vs 562.72 ± 546.7 mg; p < 0.0001 and the rate 5.84 ± 2.66 vs 1.99 ± 0.95 µg/kg/min; p < 0.0001). Deeper sedation was achieved at the time of initiation of neuromuscular blocking agent in the intervention arm (mean Richmond Agitation and Sedation Scale –3.3 ± 1.9 vs –4.3 ± 1.7; p = 0.015). There was no significant difference in total time on mechanical ventilation, length of ICU stay, length of hospital stay, and mortality between the two groups.

Conclusions:

Implementation of comprehensive education, standardization of sedation prior to neuromuscular blocking agent initiation, integration of clinical variables in determining paralysis achievement, and proper use of peripheral nerve stimulation served as optimal strategies for the titration and monitoring of neuromuscular blocking agent in acute respiratory distress syndrome. This reduced drug utilization while continuing to achieve benefit without causing adverse effects.

Evolving targets for sedation during mechanical ventilation

PURPOSES OF REVIEW

Critically ill patients frequently require mechanical ventilation as part of their care. Administration of analgesia and sedation to ensure patient comfort and facilitate mechanical ventilation must be balanced against the known negative consequences of excessive sedation. The present review focuses on the current evidence for sedation management during mechanical ventilation, including choice of sedatives, sedation strategies, and special considerations for acute respiratory distress syndrome (ARDS).

RECENT FINDINGS

The Society of Critical Care Medicine recently published their updated clinical practice guidelines for analgesia, agitation, sedation, delirium, immobility, and sleep in adult patients in the ICU. Deep sedation, especially early in the course of mechanical ventilation, is associated with prolonged time to liberation from mechanical ventilation, longer ICU stays, longer hospital stays, and increased mortality. Dexmedetomidine may prevent ICU delirium when administered nocturnally at low doses; however, it was not shown to improve mortality when used as the primary sedative early in the course of mechanical ventilation, though the majority of patients in the informing study failed to achieve the prescribed light level of sedation. In a follow up to the ACURASYS trial, deep sedation with neuromuscular blockade did not result in improved mortality compared to light sedation in patients with severe ARDS.

SUMMARY

Light sedation should be targeted early in the course of mechanical ventilation utilizing daily interruptions of sedation and/or nursing protocol-based algorithms, even in severe ARDS.

Early neuromuscular blocking agents for adults with acute respiratory distress syndrome: a systematic review, meta-analysis and meta-regression

OBJECTIVE

To determine whether neuromuscular blocking agents (NMBAs) can decrease the mortality of patients with acute respiratory distress syndrome (ARDS) and improve their clinical outcomes.

DESIGN

Systematic review, meta-analysis and meta-regression.

DATA SOURCES

PubMed, Embase, Cochrane Library, Web of Science and ClinicalTrials.gov.

METHODS

Randomised controlled trials (RCTs) comparing the treatment effect of NMBAs with that of placebo (or traditional treatment) in patients with ARDS were carefully selected. The primary outcome was 90-day mortality. The secondary outcomes were 21-28 days mortality, NMBA-related complications (barotrauma, pneumothorax and intensive care unit (ICU)-acquired muscle weakness), days free of ventilation and days not in the ICU by day 28, Medical Research Council score, Acute Physiology and Chronic Health Evaluation II score and arterial oxygen tension (PaO₂)/fractional inspired oxygen (FiO₂) (at 48 hours and 72 hours). Random-effects meta-regression was used to explore models involving potential moderators. Trial sequential analysis was performed to estimate the cumulative effect on mortality across RCTs.

RESULTS

NMBAs were not associated with reduced 90-day mortality (risk ratio (RR) 0.85; 95% CI 0.66 to 1.09; p=0.20). However, they decreased the 21-28 days mortality (RR 0.71; 95% CI 0.53 to 0.96; p=0.02) and the rates of pneumothorax (RR 0.46; 95% CI 0.28 to 0.77; p=0.003) and barotrauma (RR 0.56; 95% CI 0.37 to 0.86; p=0.008). In addition, NMBAs increased PaO₂/FiO₂ at 48 hours (mean difference (MD) 18.91; 95% CI 4.29 to 33.53; p=0.01) and 72 hours (MD 12.27; 95% CI 4.65 to 19.89; p=0.002). Meta-regression revealed an association between sample size (p=0.042) and short-term mortality. Publication year (p=0.050), sedation strategy (p=0.047) and sample size (p=0.046) were independently associated with PaO₂/FiO₂ at 48 hours.

CONCLUSIONS

In summary, the results suggested that use of NMBAs might reduce 21-28 days mortality, NMBA-related complications and oxygenation. However, NMBAs did not reduce the 90-day mortality of patients with ARDS, which contradicts a previous meta-analysis.

PROSPERO REGISTRATION NUMBER

CRD42019139440.

Oxycodone attenuates vascular leak and lung inflammation in a clinically relevant two-hit rat model of acute lung injury

BACKGROUND

Oxycodone is a synthetic opioid receptor agonist that exerts antinociceptive activity via κ-, μ- and δ-opioid receptors (KOR, MOR and DOR, respectively). Activation of MOR has been reported to provide protection against acute lung injury (ALI). We hypothesized that pretreatment with oxycodone would attenuate lung injury at the level of alveolar tight junctions (TJs) and aquaporins (AQPs) and investigated this possibility in a two-hit model of ALI induced by lipopolysaccharide (LPS) and mechanical ventilation (MV).

METHOD

Male Sprague Dawley rats and A59 cells were divided into 6 groups: the control group, ALI group, oxycodone-pretreated group, and oxycodone/κ-, μ-, or δ-opioid receptor antagonist-pretreated groups. The rats were pretreated with oxycodone 30 min before intravenous injection of LPS and then allowed to recover for 24 h prior to MV, establishing a two-hit model of ALI. The cells were similarly treated with oxycodone (with or without antagonists) 30 min after exposure to lipopolysaccharide. The cells were cyclically stretched 24 h later to mirror the in vivo MV protocol.

RESULTS

Oxycodone alleviated the histological lung changes in the rats with ALI and decreased pulmonary microvascular permeability both in vivo and in vitro. Oxycodone upregulated the expression of claudin-5, ZO-1, AQP1, and AQP5 but downregulated the expression of TNF-α, IL-1β, TLR4, NF-κB, MMP9, and caspase-3 and suppressed endothelial apoptosis in vivo and in vitro. These protective effects of oxycodone were partly eliminated by KOR and MOR antagonists but not by DOR antagonists.

CONCLUSION

Oxycodone pretreatment appears to act via κ- and μ-opioid receptors to ameliorate LPS- and MV-induced lung injury by suppressing inflammation and apoptosis, and this protective effect might be mediated through the inhibition of the TLR4/NF-κB pathways.

Myorelaxants in ARDS patients

Neuromuscular blocking agents (NMBAs) inhibit patient-initiated active breath and the risk of high tidal volumes and consequent high transpulmonary pressure swings, and minimize patient/ ventilator asynchrony in acute respiratory distress syndrome (ARDS). Minimization of volutrauma and ventilator-induced lung injury (VILI) results in a lower incidence of barotrauma, improved oxygenation and a decrease in circulating proinflammatory markers. Recent randomized clinical trials did not reveal harmful muscular effects during a short course of NMBAs. The use of NMBAs should be considered during the early phase of severe ARDS for patients to facilitate lung protective ventilation or prone positioning only after optimising mechanical ventilation and sedation. The use of NMBAs should be integrated in a global strategy including the reduction of tidal volume, the rational use of PEEP, prone positioning and the use of a ventilatory mode allowing spontaneous ventilation as soon as possible. Partial neuromuscular blockade should be evaluated in future trials.

Neuromuscular Blockade Applicability in Early Acute Respiratory Distress Syndrome

Neuromuscular blockade with deep sedation appears to offer no advantage to patients with acute respiratory distress syndrome who can be managed with lighter sedation. In those patients requiring deep sedation, the addition of neuromuscular blockade may be beneficial.

Neuromuscular blockade in acute respiratory distress syndrome: a systematic review and meta-analysis of randomized controlled trials

Background

Neuromuscular blocking agent (NMBA) has been proposed by medical guidelines for early severe acute respiratory distress syndrome (ARDS) because of its survival benefits. However, new studies have provided evidence contradicting these results.

Method

A search was performed of the Pubmed, Scopus, Clinicaltrials.gov, and Virtual Health Library databases for randomized controlled trials (RCT) evaluating 28-day mortality in ARDS patients treated with NMBA within 48 h. An English language restriction was applied. Relevant data were extracted and pooled into risk ratios (RR), mean differences (MD), and corresponding 95% confidence intervals (CI) using random-effect model. Sensitivity and meta-regression analysis were performed.

Results

From 2675 studies, we included five RCTs in the analysis, for a total of 1461 patients with a mean PaO₂/FIO₂ of 104 ± 35 mmHg. The cisatracurium group had the same risk of death at 28 days (RR, 0.90; 95% CI, 0.78–1.03; I² = 50%, p = 0.12) and 90 days (RR, 0.81; 95% CI, 0.62–1.06; I² = 56%, p = 0.06) as the control group (no cisatracurium). The secondary outcomes of mechanical ventilation duration and ventilator-free days were not different between the two groups. Cisatracurium had a significantly lower risk of barotrauma than the control group with no difference in intensive care unit (ICU)–induced weakness. The PaO₂/FIO₂ ratio was higher in the cisatracurium group but not until 48 h. Meta-regression analysis of the baseline PaO₂/FIO₂ ratio, positive end-expiratory pressure (PEEP) revealed no heterogeneity. Subgroup analysis excluding the trial using high PEEP and light sedation strategy yielded an improvement in all mortality outcomes.

Conclusion

NMBA improves oxygenation only after 48 h in moderate, severe ARDS patients and has a lower barotrauma risk without affecting ICU weakness. However, NMBA does not reduce ventilator-free days, duration of mechanical ventilation or, most importantly, the mortality risk regardless of the severity of ARDS.

Paralytics, Sedation, and Steroids in Acute Respiratory Distress Syndrome

In this article, we discuss the literature behind the use of paralytics, sedation, and steroids in acute respiratory distress syndrome. We explore the controversies and discuss the recommendations for the use of these agents.

Current Use of Neuromuscular Blocking Agents in Intensive Care Units

Neuromuscular blocking agents can be used for purposes such as eliminating ventilator-patient dyssynchrony, facilitating gas exchange by reducing intra-abdominal pressure and improving chest wall compliance, reducing risk of lung barotrauma, decreasing contribution of muscles to oxygen consumption by preventing shivering and limiting elevations in intracranial pressure caused by airway stimulation in patients supported with mechanical ventilation in intensive care units. Adult Respiratory Distress Syndrome (ARDS), status asthmaticus, increased intracranial pressure and therapeutic hypothermia following ventricular fibrillation-associated cardiac arrest are some of clinical conditions that can be sustained by neuromuscular blockade. Appropriate indication and clinical practice have gained importance considering side effects such as ICU-acquired weakness, masking seizure activity and longer durations of hospital and ICU stays. We mainly aimed to review the current literature regarding neuromuscular blockade in up-to-date clinical conditions such as improving oxygenation in early ARDS and preventing shivering in the therapeutic hypothermia along with summarising the clinical practice in adult ICU in this report.

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.

The Use of Volatile Anesthetics as Sedatives for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) remains to pose a high morbidity and mortality without any targeted therapies. Sedation, usually given intravenously, is an important part of clinical practice in intensive care unit (ICU), and the effect of sedatives on patients’ outcomes has been studied intensively. Although volatile anesthetics are not routine sedatives in ICU, preclinical and clinical studies suggested their potential benefit in pulmonary pathophysiology. This review will summarize the current knowledge of ARDS and the role of volatile anesthetic sedation in this setting from both clinical and mechanistic standpoints. In addition, we will review the infrastructure to use volatile anesthetics.

Neuromuscular blocking agents for acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is an acute inflammatory process that impairs the ability of the lungs to oxygenate thereby resulting in respiratory failure. Treatment of ARDS is often a multimodal approach using both nonpharmacologic and pharmacologic treatment strategies in addition to trying to reverse the underlying cause of ARDS. Neuromuscular blocking agents (NMBAs) have been prescribed to patients with ARDS as they are thought to decrease inflammation, oxygen consumption, and cardiac output and help facilitate ventilator synchrony. NMBAs have only been evaluated in patients with early, severe ARDS in three multicenter, randomized, controlled trials (n = 432), but have resulted in decreased inflammation and improved oxygenation, ventilator-free days, and mortality. Despite reports of NMBAs being associated with adverse effects like postparalytic quadriparesis, myopathy, and prolonged recovery, these effects have not been seen in patients receiving short courses of NMBAs for ARDS. A large multicenter, prospective, randomized, placebo-controlled trial is ongoing to confirm benefit of NMBAs in early, severe ARDS when adjusting for limitations of the previous studies. The current available literature suggests that 48 h of NMBA therapy in patients with early, severe ARDS improves mortality, without resulting in additional patient harm.

Limiting sedation for patients with acute respiratory distress syndrome - time to wake up

PURPOSE OF REVIEW

Critically ill patients with acute respiratory distress syndrome (ARDS) may require sedation in their clinical care. The goals of sedation in ARDS patients are to improve patient comfort and tolerance of supportive and therapeutic measures without contributing to adverse outcomes. This review discusses the current evidence for sedation management in patients with ARDS.

RECENT FINDINGS

Deep sedation strategies should be avoided in the care of patients with ARDS because deep sedation has been associated with increased time on mechanical ventilation, longer ICU and hospital length of stay, and higher mortality in critically ill patients. Adoption of protocol-based, light-sedation strategies is preferred and improves patient outcomes. Although the optimal sedative agent for ARDS patients is unclear, benzodiazepines should be avoided because of associations with oversedation, delirium, prolonged ICU and hospital length of stay, and increased mortality. Minimizing sedation in patients with ARDS facilitates early mobilization and early discharge from the ICU, potentially aiding in recovery from critical illness. Strategies to optimize ventilation in ARDS patients, such as low tidal volume ventilation and high positive end-expiratory pressure can be employed without deep sedation; however, deep sedation is required if patients receive neuromuscular blockade, which may benefit some ARDS patients. Knowledge gaps persist as to whether or not prone positioning and extracorporeal membrane oxygenation can be tolerated with light sedation.

SUMMARY

Current evidence supports the use of protocol-based, light-sedation strategies in critically ill patients with ARDS. Further research into sedation management specifically in ARDS populations is needed.

Sedation and neuromuscular blocking agents in acute respiratory distress syndrome

Mechanical ventilation (MV) is the cornerstone of acute respiratory distress syndrome (ARDS) management. The use of protective ventilation is a priority in this acute phase of lung inflammation. Neuromuscular blocking agents (NMBAs) induce reversible muscle paralysis. Their use in patients with ARDS remains controversial but occurs frequently. NMBAs are used in 25-45% of ARDS patients for a mean period of 1±2 days. The main indications of NMBAs are hypoxemia and facilitation of MV. For ethical reasons, NMBA use is inseparable from sedation in the management of early ARDS. During paralysis, sedation monitoring seems to be necessary to avoid awareness with recall. Three randomized controlled trials (RCTs) have demonstrated that the systematic use of NMBAs in the early management of ARDS patients improves oxygenation. Furthermore, the most recent trial reported a reduction of mortality at 90 days when NMBAs were infused over 48 hours. Spontaneous ventilation (SV) during MV at the acute phase of ARDS could improve oxygenation and alveolar recruitment, but it may not allow protective ventilation. The major risk is an increase in ventilator-induced lung injury. However, the adverse effects of NMBAs are widely discussed, particularly the occurrence of intensive care unit (ICU)-acquired weakness. This review analyses the recent findings in the literature concerning sedation and paralysis in managing ARDS.

Experienced Use of Dexmedetomidine in the Intensive Care Unit: A Report of a Structured Consensus

Objective

Management of pain, agitation and delirium (PAD) remains to be a true challenge in critically ill patients. The pharmacological proprieties of dexmedetomidine (DEX) make it an ideal candidate drug for light and cooperative sedation, but many practical questions remain unanswered. This structured consensus from 17 intensivists well experienced on PAD management and DEX use provides indications for the appropriate use of DEX in clinical practice.

Methods

A modified RAND/UCLA appropriateness method was used. In four predefined patient populations, the clinical scenarios do not properly cope by the current recommended pharmacological strategies (except DEX), and the possible advantages of DEX use were identified and voted for agreement, after reviewing literature data.

Results

Three scenarios in medical patients, five scenarios in patients with acute respiratory failure undergoing non-invasive ventilation, three scenarios in patients with cardiac surgery in the early postoperative period and three scenarios in patients with overt delirium were identified as challenging with the current PAD strategies. In these scenarios, the use of DEX was voted as potentially useful by most of the panellists owing to its specific pharmacological characteristics, such as conservation of cognitive function, lack of effects on the respiratory drive, low induction of delirium and analgesia effects.

Conclusion

DEX might be considered as a first-line sedative in different scenarios even though conclusive data on its benefits are still lacking.

Perceived safety and efficacy of neuromuscular blockers for acute respiratory distress syndrome among medical intensive care unit practitioners: A multicenter survey

PURPOSE

Neuromuscular blocking agents (NMBAs) are frequently used in patients with acute respiratory distress syndrome (ARDS). The purpose of this survey is to describe providers' knowledge and perceived efficacy and safety of NMBAs in patients with ARDS.

MATERIALS AND METHODS

We performed a prospective, multicenter survey of medical intensive care unit intensivists, fellows, nurse practitioners (NPs), physician's assistants (PAs), and pharmacists at 5 tertiary care centers between July 2012 and May 2013.

RESULTS

A total of 335 surveys were sent to providers, with a 47% response rate. Ninety-eight percent of providers correctly identified that NMBAs lack anxiolytic and analgesic properties. The effect of end-organ damage on NMBA clearance was less commonly identified by NPs/PAs for both hepatic (P=.0077) and renal (P=.0272) dysfunction compared with physicians. More NP/PAs identified the association of consciousness with the use of NMBAs than physicians (P=.047). Forty-two percent of prescribers reported always or frequently using continuous-infusion NMBAs in patients with severe ARDS, with 89% initiating NMBAs because of ventilator dyssynchrony. Prescribers perceived continuous NMBAs to be more effective than inhaled prostaglandins (74% vs 56%) in severe ARDS but less safe (45% vs 84%). Train of 4 was identified by 54% of prescribers as their primary method for titration.

CONCLUSION

Providers are knowledgeable about NMBAs, but educational opportunities exist. Perceptions about the efficacy and safety of NMBAs varied among prescribers, and inconsistencies existed in the prioritization of management strategies for ARDS.

Effects of Music Intervention on State Anxiety and Physiological Indices in Patients Undergoing Mechanical Ventilation in the Intensive Care Unit

Patients in intensive care units (ICUs) often experience stress and anxiety. Although stress and anxiety can be pharmacologically attenuated, some drugs cause adverse side effects such as bradycardia, immobility, and delirium. There is thus a need for an alternative treatment with no substantial adverse effects. Music intervention is a potential alternative. In the present study, we used cortisol levels, subjective questionnaires, and physiological parameters to explore the anxiety-reducing effects of music intervention in a sample of ICU patients on mechanical ventilation. Patients admitted to the ICU for ≥ 24 hr were randomly assigned to the music intervention ( n = 41) or control group ( n = 44). Music group patients individually listened to music from 4:00 to 4:30 p.m.; control group patients wore headphones but heard no music for the same 30 min. Anxiety was measured using serum cortisol levels, the Chinese Version of the State-Trait Anxiety Inventory, the Visual Analogue Scale for Anxiety, heart rate, and blood pressure. After adjusting for demographics, analysis of covariance showed that the music group had significantly better scores for all posttest measures ( p < .02) and pre–post differences ( p < .03) except for diastolic blood pressure. Because of music intervention’s low cost and easy administration, clinical nurses may want to use music to reduce stress and anxiety for ICU patients. A single 30-min session might work immediately without any adverse effects. However, the duration of the effect is unclear; thus, each patient’s mood should be monitored after the music intervention.

Severe hypoxemia: which strategy to choose

BACKGROUND

Acute respiratory distress syndrome (ARDS) is characterized by a noncardiogenic pulmonary edema with bilateral chest X-ray opacities and reduction in lung compliance, and the hallmark of the syndrome is hypoxemia refractory to oxygen therapy. Severe hypoxemia (PaO2/FiO2 < 100 mmHg), which defines severe ARDS, can be found in 20-30 % of the patients and is associated with the highest mortality rate. Although the standard supportive treatment remains mechanical ventilation (noninvasive and invasive), possible adjuvant therapies can be considered. We performed an up-to-date clinical review of the possible available strategies for ARDS patients with severe hypoxemia.

MAIN RESULTS

In summary, in moderate-to-severe ARDS or in the presence of other organ failure, noninvasive ventilatory support presents a high risk of failure: in those cases the risk/benefit of delayed mechanical ventilation should be evaluated carefully. Tailoring mechanical ventilation to the individual patient is fundamental to reduce the risk of ventilation-induced lung injury (VILI): it is mandatory to apply a low tidal volume, while the optimal level of positive end-expiratory pressure should be selected after a stratification of the severity of the disease, also taking into account lung recruitability; monitoring transpulmonary pressure or airway driving pressure can help to avoid lung overstress. Targeting oxygenation of 88-92 % and tolerating a moderate level of hypercapnia are a safe choice. Neuromuscular blocking agents (NMBAs) are useful to maintain patient-ventilation synchrony in the first hours; prone positioning improves oxygenation in most cases and promotes a more homogeneous distribution of ventilation, reducing the risk of VILI; both treatments, also in combination, are associated with an improvement in outcome if applied in the acute phase in the most severe cases. The use of extracorporeal membrane oxygenation (ECMO) in severe ARDS is increasing worldwide, but because of a lack of randomized trials is still considered a rescue therapy.

CONCLUSION

Severe ARDS patients should receive a holistic framework of respiratory and hemodynamic support aimed to ensure adequate gas exchange while minimizing the risk of VILI, by promoting lung recruitment and setting protective mechanical ventilation. In the most severe cases, NMBAs, prone positioning, and ECMO should be considered.

A ventilator strategy combining low tidal volume ventilation, recruitment maneuvers, and high positive end-expiratory pressure does not increase sedative, opioid, or neuromuscular blocker use in adults with acute respiratory distress syndrome and may improve patient comfort

BACKGROUND

The Lung Open Ventilation Study (LOV Study) compared a low tidal volume strategy with an experimental strategy combining low tidal volume, lung recruitment maneuvers, and higher plateau and positive end-expiratory pressures (PEEP) in adults with acute respiratory distress syndrome (ARDS). Herein, we compared sedative, opioid, and neuromuscular blocker (NMB) use among patients managed with the intervention and control strategies and clinicians' assessment of comfort in both groups.

METHODS

This was an observational substudy of the LOV Study, a randomized trial conducted in 30 intensive care units in Canada, Australia, and Saudi Arabia. In 16 centers, we recorded daily doses of sedatives, opioids, and NMBs and surveyed bedside clinicians about their own comfort with the assigned ventilator strategy and their perceptions of patient comfort. We compared characteristics and outcomes of patients who did and did not receive NMBs.

RESULTS

Study groups received similar sedative, opioid, and NMB dosing on days 1, 3, and 7. Patient comfort as assessed by clinicians was not different in the two groups: 93% perceived patients had no/minimal discomfort. In addition, 92% of clinicians were comfortable with the assigned ventilation strategy without significant differences between the two groups. When clinicians expressed discomfort, more expressed discomfort about PEEP levels in the intervention vs control group (2.9% vs 0.7%, P <0.0001), and more perceived patient discomfort among controls (6.0% vs 4.3%, P = 0.049). On multivariable analysis, the strongest associations with NMB use were higher plateau pressure (hazard ratio (HR) 1.15; 95% confidence interval (CI) 1.07 to 1.23; P = 0.0002) and higher daily sedative dose (HR 1.03; 95% CI 1.02 to 1.05; P <0.0001). Patients receiving NMBs had more barotrauma, longer durations of mechanical ventilation and hospital stay, and higher mortality.

CONCLUSIONS

In the LOV Study, high PEEP, low tidal volume ventilation did not increase sedative, opioid, or NMB doses in adults with ARDS, compared with a lower PEEP strategy, and appeared at least as comfortable for patients. NMB use may reflect worse lung injury, as these patients had more barotrauma, longer durations of ventilation, and higher mortality.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT00182195.

Conservative fluid therapy in septic shock: an example of targeted therapeutic minimization

Intravenous fluids (IVFs) represent a basic therapeutic intervention utilized in septic shock. Unfortunately, the optimal method for administering IVFs to maximize patient outcomes is unknown. A meta-analysis of four randomized trials of goal-directed therapy did not demonstrate a significant reduction in mortality (odds ratio 0.609; 95% confidence interval 0.363 to 1.020; P = 0.059), whereas 18 trials with historical controls showed a significant increase in survival (odds ratio 0.580; 95% confidence interval 0.501 to 0.672; P < 0.0001). Based on these data, clinicians should be aware of the potential for harm due to the excessive administration of IVFs to patients with septic shock.

Early sedation and clinical outcomes of mechanically ventilated patients: a prospective multicenter cohort study

Introduction

Sedation overuse is frequent and possibly associated with poor outcomes in the intensive care unit (ICU) patients. However, the association of early oversedation with clinical outcomes has not been thoroughly evaluated. The aim of this study was to assess the association of early sedation strategies with outcomes of critically ill adult patients under mechanical ventilation (MV).

Methods

A secondary analysis of a multicenter prospective cohort conducted in 45 Brazilian ICUs, including adult patients requiring ventilatory support and sedation in the first 48 hours of ICU admissions, was performed. Sedation depth was evaluated after 48 hours of MV. Multivariate analysis was used to identify variables associated with hospital mortality.

Results

A total of 322 patients were evaluated. Overall, ICU and hospital mortality rates were 30.4% and 38.8%, respectively. Deep sedation was observed in 113 patients (35.1%). Longer duration of ventilatory support was observed (7 (4 to 10) versus 5 (3 to 9) days, P = 0.041) and more tracheostomies were performed in the deep sedation group (38.9% versus 22%, P = 0.001) despite similar PaO₂/FiO₂ ratios and acute respiratory distress syndrome (ARDS) severity. In a multivariate analysis, age (Odds Ratio (OR) 1.02; 95% confidence interval (CI) 1.00 to 1.03), Charlson Comorbidity Index >2 (OR 2.06; 95% CI, 1.44 to 2.94), Simplified Acute Physiology Score 3 (SAPS 3) score (OR 1.02; CI 95%, 1.00 to 1.04), severe ARDS (OR 1.44; CI 95%, 1.09 to 1.91) and deep sedation (OR 2.36; CI 95%, 1.31 to 4.25) were independently associated with increased hospital mortality.

Conclusions

Early deep sedation is associated with adverse outcomes and constitutes an independent predictor of hospital mortality in mechanically ventilated patients.

Use of sedation and neuromuscular blockers in critically ill adults receiving high-frequency oscillatory ventilation

BACKGROUND

Nearly all patients receive sedation and neuromuscular blockers (NMBs) during high-frequency oscillatory ventilation (HFOV).

OBJECTIVE

To describe analgo-sedation and NMB use prior to and during HFOV in adults with acute respiratory distress syndrome.

METHODS

Retrospective single-center study of 131 consecutive adults whose care was managed with HFOV from 2002 to 2011.

RESULTS

During the first 4 days of HFOV, 89% and 95% of patients received sedation and opioids, respectively. Upon HFOV initiation, 119 (90.8%) patients received fentanyl doses higher than 200 µg/h; of these, 48 also received more than 20 mg/h of midazolam. Analgo-sedation doses increased significantly over time such that doses were double by day 3. Factors independently associated with fentanyl doses higher than 200 µg/h were NMB ever used (OR 4.43; 95% CI 1.26-15.65, p = 0.02), pH less than 7.15 (OR 2.08; 95% CI 1.22-3.5, p = 0.007), worsening partial pressure of oxygen/fraction of inspired oxygen (OR 1.05; 95% CI 1.00-1.10, p = 0.04), and Acute Physiology and Chronic Health Evaluation (APACHE) II score (OR 0.87; 95% CI 0.79-0.97, p = 0.009). Deep sedation was commonly administered when NMBs were not being used, with 99.2% of sedation-agitation scores of 1 or 2. Eighty-six patients (65.6%) received NMBs and use was greatest on day 1 (59.5%). Train-of-Four was measured every hour for 53.4% of patients; 29.2% of the measurements were 0 of 4. NMB use declined over the 10-year study period.

CONCLUSIONS

High analgo-sedation doses were associated with APACHE II scores, worsening gas exchange, and NMB use. Two thirds of patients received NMBs; use was highest on day 1 and subsequently declined. The percentage of patients who received NMB during HFOV in our study was lower than that previously reported. Future research should evaluate patient outcomes with and without use of NMBs, as well as the potential to manage patients with less sedation.

Post-traumatic stress disorder symptoms after acute lung injury: a 2-year prospective longitudinal study

BACKGROUND

Survivors of critical illnesses often have clinically significant post-traumatic stress disorder (PTSD) symptoms. This study describes the 2-year prevalence and duration of PTSD symptoms after acute lung injury (ALI), and examines patient baseline and critical illness/intensive care-related risk factors.

METHOD

This prospective, longitudinal cohort study recruited patients from 13 intensive care units (ICUs) in four hospitals, with follow-up 3, 6, 12 and 24 months after ALI onset. The outcome of interest was an Impact of Events Scale - Revised (IES-R) mean score ≥1.6 ('PTSD symptoms').

RESULTS

During the 2-year follow-up, 66/186 patients (35%) had PTSD symptoms, with the greatest prevalence by the 3-month follow-up. Fifty-six patients with post-ALI PTSD symptoms survived to the 24-month follow-up, and 35 (62%) of these had PTSD symptoms at the 24-month follow-up; 50% had taken psychiatric medications and 40% had seen a psychiatrist since hospital discharge. Risk/protective factors for PTSD symptoms were pre-ALI depression [hazard odds ratio (OR) 1.96, 95% confidence interval (CI) 1.06-3.64], ICU length of stay (for a doubling of days, OR 1.39, 95% CI 1.06-1.83), proportion of ICU days with sepsis (per decile, OR 1.08, 95% CI 1.00-1.16), high ICU opiate doses (mean morphine equivalent ≥100 mg/day, OR 2.13, 95% CI 1.02-4.42) and proportion of ICU days on opiates (per decile, OR 0.83, 95% CI 0.74-0.94) or corticosteroids (per decile, OR 0.91, 95% CI 0.84-0.99).

CONCLUSIONS

PTSD symptoms are common, long-lasting and associated with psychiatric treatment during the first 2 years after ALI. Risk factors include pre-ALI depression, durations of stay and sepsis in the ICU, and administration of high-dose opiates in the ICU. Protective factors include durations of opiate and corticosteroid administration in the ICU.

Pharmacological interventions in acute respiratory distress syndrome

Pharmacological interventions are commonly considered in acute respiratory distress syndrome (ARDS) patients. Inhaled nitric oxide (iNO) and neuromuscular blockers (NMBs) are used in patients with severe hypoxemia. No outcome benefit has been observed with the systematic use of iNO. However, a sometimes important improvement in oxygenation can occur shortly after starting administration. Therefore, its ease of use and its good tolerance justify iNO optionally combined with almitirne as a rescue therapy on a trial basis. Recent data from the literature support the use of a 48-h infusion of NMBs in patients with a PaO2 to FiO2 ratio <120 mmHg. No strong evidence exists on the increase of ICU-acquired paresis after a short course of NMBs. Fluid management with the goal to obtain zero fluid balance in ARDS patients without shock or renal failure significantly increases the number of days without mechanical ventilation. On the other hand, patients with hemodynamic failure must receive early and adapted fluid resuscitation. Liberal and conservative fluid strategies therefore are complementary and should ideally follow each other in time in the same patient whose hemodynamic state progressively stabilizes. At present, albumin treatment does not appear to be justified for limitation of pulmonary edema and respiratory morbidity. Aerosolized β2-agonists do not improve outcome in patients with ARDS and one study strongly suggests that intravenous salbutamol may worsen outcome in those patients. The early use of high doses of corticosteroids for the prevention of ARDS in septic shock patients or in patients with confirmed ARDS significantly reduced the duration of mechanical ventilation but had no effect or even increased mortality. In patients with persistent ARDS after 7 to 28 days, a randomized trial showed no reduction in mortality with moderate doses of corticosteroids but an increased PaO2 to FiO2 ratio and thoracopulmonary compliance were found, as well as shorter durations of mechanical ventilation and of ICU stay. Conflicting data exist on the interest of low doses of corticosteroids (200 mg/day of hydrocortisone) in ARDS patients. In the context of a persistent ARDS with histological proof of fibroproliferation, a corticosteroid treatment with a progressive decrease of doses can be proposed.

Effects of patient-directed music intervention on anxiety and sedative exposure in critically ill patients receiving mechanical ventilatory support: a randomized clinical trial

IMPORTANCE

Alternatives to sedative medications, such as music, may alleviate the anxiety associated with ventilatory support.

OBJECTIVE

To test whether listening to self-initiated patient-directed music (PDM) can reduce anxiety and sedative exposure during ventilatory support in critically ill patients.

DESIGN, SETTING, AND PATIENTS

Randomized clinical trial that enrolled 373 patients from 12 intensive care units (ICUs) at 5 hospitals in the Minneapolis-St Paul, Minnesota, area receiving acute mechanical ventilatory support for respiratory failure between September 2006 and March 2011. Of the patients included in the study, 86% were white, 52% were female, and the mean (SD) age was 59 (14) years. The patients had a mean (SD) Acute Physiology, Age and Chronic Health Evaluation III score of 63 (21.6) and a mean (SD) of 5.7 (6.4) study days.

INTERVENTIONS

Self-initiated PDM (n = 126) with preferred selections tailored by a music therapist whenever desired while receiving ventilatory support, self-initiated use of noise-canceling headphones (NCH; n = 122), or usual care (n = 125).

MAIN OUTCOMES AND MEASURES

Daily assessments of anxiety (on 100-mm visual analog scale) and 2 aggregate measures of sedative exposure (intensity and frequency).

RESULTS

Patients in the PDM group listened to music for a mean (SD) of 79.8 (126) (median [range], 12 [0-796]) minutes/day. Patients in the NCH group wore the noise-abating headphones for a mean (SD) of 34.0 (89.6) (median [range], 0 [0-916]) minutes/day. The mixed-models analysis showed that at any time point, patients in the PDM group had an anxiety score that was 19.5 points lower (95% CI, -32.2 to -6.8) than patients in the usual care group (P = .003). By the fifth study day, anxiety was reduced by 36.5% in PDM patients. The treatment × time interaction showed that PDM significantly reduced both measures of sedative exposure. Compared with usual care, the PDM group had reduced sedation intensity by -0.18 (95% CI, -0.36 to -0.004) points/day (P = .05) and had reduced frequency by -0.21 (95% CI, -0.37 to -0.05) points/day (P = .01). The PDM group had reduced sedation frequency by -0.18 (95% CI, -0.36 to -0.004) points/day vs the NCH group (P = .04). By the fifth study day, the PDM patients received 2 fewer sedative doses (reduction of 38%) and had a reduction of 36% in sedation intensity.

CONCLUSIONS AND RELEVANCE

Among ICU patients receiving acute ventilatory support for respiratory failure, PDM resulted in greater reduction in anxiety compared with usual care, but not compared with NCH. Concurrently, PDM resulted in greater reduction in sedation frequency compared with usual care or NCH, and greater reduction in sedation intensity compared with usual care, but not compared with NCH.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00440700.

Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit

OBJECTIVE

To revise the "Clinical Practice Guidelines for the Sustained Use of Sedatives and Analgesics in the Critically Ill Adult" published in Critical Care Medicine in 2002.

METHODS

The American College of Critical Care Medicine assembled a 20-person, multidisciplinary, multi-institutional task force with expertise in guideline development, pain, agitation and sedation, delirium management, and associated outcomes in adult critically ill patients. The task force, divided into four subcommittees, collaborated over 6 yr in person, via teleconferences, and via electronic communication. Subcommittees were responsible for developing relevant clinical questions, using the Grading of Recommendations Assessment, Development and Evaluation method (http://www.gradeworkinggroup.org) to review, evaluate, and summarize the literature, and to develop clinical statements (descriptive) and recommendations (actionable). With the help of a professional librarian and Refworks database software, they developed a Web-based electronic database of over 19,000 references extracted from eight clinical search engines, related to pain and analgesia, agitation and sedation, delirium, and related clinical outcomes in adult ICU patients. The group also used psychometric analyses to evaluate and compare pain, agitation/sedation, and delirium assessment tools. All task force members were allowed to review the literature supporting each statement and recommendation and provided feedback to the subcommittees. Group consensus was achieved for all statements and recommendations using the nominal group technique and the modified Delphi method, with anonymous voting by all task force members using E-Survey (http://www.esurvey.com). All voting was completed in December 2010. Relevant studies published after this date and prior to publication of these guidelines were referenced in the text. The quality of evidence for each statement and recommendation was ranked as high (A), moderate (B), or low/very low (C). The strength of recommendations was ranked as strong (1) or weak (2), and either in favor of (+) or against (-) an intervention. A strong recommendation (either for or against) indicated that the intervention's desirable effects either clearly outweighed its undesirable effects (risks, burdens, and costs) or it did not. For all strong recommendations, the phrase "We recommend …" is used throughout. A weak recommendation, either for or against an intervention, indicated that the trade-off between desirable and undesirable effects was less clear. For all weak recommendations, the phrase "We suggest …" is used throughout. In the absence of sufficient evidence, or when group consensus could not be achieved, no recommendation (0) was made. Consensus based on expert opinion was not used as a substitute for a lack of evidence. A consistent method for addressing potential conflict of interest was followed if task force members were coauthors of related research. The development of this guideline was independent of any industry funding.

CONCLUSION

These guidelines provide a roadmap for developing integrated, evidence-based, and patient-centered protocols for preventing and treating pain, agitation, and delirium in critically ill patients.

Pharmacotherapy for acute respiratory distress syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a continuum of a clinical syndrome of respiratory failure due to refractory hypoxia. Acute respiratory distress syndrome is differentiated from ALI by a greater degree of hypoxemia and is associated with higher morbidity and mortality. The mortality for ARDS ranges from 22-41%, with survivors usually requiring long-term rehabilitation to regain normal physiologic function. Numerous pharmacologic therapies have been studied for prevention and treatment of ARDS; however, studies demonstrating clear clinical benefit for ARDS-related mortality and morbidity are limited. In this focused review, controversial pharmacologic therapies that have demonstrated, at minimum, a modest clinical benefit are discussed. Three pharmacologic treatment strategies are reviewed in detail: corticosteroids, fluid management, and neuromuscular blocking agents. Use of corticosteroids to attenuate inflammation remains controversial. Available evidence does not support early administration of corticosteroids. Additionally, administration after 14 days of disease onset is strongly discouraged. A liberal fluid strategy during the early phase of comorbid septic shock, balanced with a conservative fluid strategy in patients with ALI or ARDS during the postresuscitation phase, is the optimum approach for fluid management. Available evidence supports an early, short course of continuous-infusion cisatracurium in patients presenting with severe ARDS. Evidence of safe and effective pharmacologic therapies for ARDS is limited, and clinicians must be knowledgeable about the areas of controversies to determine application to patient care.

The role of neuromuscular blockers in ARDS: benefits and risks

PURPOSE OF REVIEW

Neuromuscular blocking agents (NMBAs) are part of the pharmaceutical arsenal employed to treat acute respiratory distress syndrome (ARDS). However, their use remains controversial because the potential benefits of these agents are counterbalanced by possible adverse effects. This review summarizes advantages and risks of NMBAs based on the most recent literature.

RECENT FINDINGS

NMBAs have been shown to improve oxygenation during severe ARDS in three randomized controlled trials. The most recent results demonstrated that NMBAs decrease 90-day in-hospital mortality, particularly in the most hypoxaemic patients. NMBAs have not been shown to be an independent risk factor of neuromyopathy in most studies.

SUMMARY

NMBAs are commonly used in ARDS (25-55% of patients), but the benefits and the risks of using these agents are controversial. Recent data suggest that a continuous infusion of cisatracurium during the first 48  h of ARDS, particularly for patients with a P(a)O(2)/F(i)O(2) ratio less than 120, can decrease 90-day in-hospital mortality. NMBAs do not appear to be an independent risk factor for ICU-acquired weakness if they are not given with corticosteroids or in patients with hyperglycaemia.

Current knowledge of acute lung injury and acute respiratory distress syndrome

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) continues to be a major cause of mortality in adult and pediatric critical care medicine. This article discusses the pulmonary sequelae associated with ALI and ARDS, the support of ARDS with mechanical ventilation, available adjunctive therapies, and experimental therapies currently being tested. It is hoped that further understanding of the fundamental biology, improved identification of the patient's inflammatory state, and application of therapies directed at multiple sites of action may ultimately prove beneficial for patients suffering from ALI/ARDS.

Does music influence stress in mechanically ventilated patients?

OBJECTIVES

Mechanically ventilated patients experience profound stress. Interventions are needed to ameliorate stress that does not cause adverse effects. The purpose of this study was to explore the influence of music on stress in a sample of patients over the duration of ventilatory support.

RESEARCH METHODOLOGY/DESIGN

Randomised controlled trial; randomised patients (56.8+16.9 years, 61% male, APACHE III 57.2+18.3) receiving ventilatory support to: (1) patient-directed music (PDM) where patients self-initiated music listening whenever desired from a preferred collection, (2) headphones only to block ICU noise, or (3) usual ICU care. Twenty-four hour urinary cortisol samples were collected from a sub-set of subjects with intact renal function and not receiving medications known to influence cortisol levels (n=65).

SETTING

12 ICUs in the Midwestern United States.

MAIN OUTCOME MEASURES

Urinary free cortisol (UFC), an integrative biomarker of stress.

RESULTS

Controlling for illness severity, gender, and baseline UFC (29-45 mg/day), mixed models analysis revealed no significant differences among groups in UFC over the course of ventilatory support.

CONCLUSION

While music did not significantly reduce cortisol, less profound spikes in UFC levels were observed but that, given the limitations of the research, this observation could have occurred merely by chance.

Treatment of four psychiatric emergencies in the intensive care unit

OBJECTIVES

To review the diagnosis and management of four selected psychiatric emergencies in the intensive care unit: agitated delirium, neuroleptic malignant syndrome, serotonin syndrome, and psychiatric medication overdose.

DATA SOURCES

Review of relevant medical literature.

DATA SYNTHESIS

Standardized screening for delirium should be routine. Agitated delirium should be managed with an antipsychotic and, possibly, dexmedetomidine in treatment-refractory cases. Delirium management should also include ensuring a calming environment and adequate pain control, minimizing benzodiazepines and anticholinergics, normalizing the sleep-wake cycle, providing sensory aids as required, and providing early physical and occupational therapy. Neuroleptic malignant syndrome should be treated by discontinuing dopamine blockers, providing supportive therapy, and possibly administering medications (benzodiazepines, dopamine agonists, and/or dantrolene) or electroconvulsive therapy, if indicated. Serotonin syndrome should be treated by discontinuing all serotonergic agents, providing supportive therapy, controlling agitation with benzodiazepines, and possibly administering serotonin2A antagonists. It is often unnecessary to restart psychiatric medications upon which a patient has overdosed in the intensive care unit, though withdrawal syndromes should be prevented, and communication with outpatient prescribers is vital.

CONCLUSIONS

Understanding the diagnosis and appropriate management of these four psychiatric emergencies is important to provide safe and effective care in the intensive care unit.

Diurnal sedative changes during intensive care: impact on liberation from mechanical ventilation and delirium

OBJECTIVE

To determine whether benzodiazepine and propofol doses are increased at night and whether daytime and nighttime sedative doses are associated with delirium, coma, and delayed liberation from mechanical ventilation.

DESIGN

Single-center, prospective cohort study nested within the Awakening and Breathing Controlled randomized trial.

SETTING

Saint Thomas Hospital in Nashville, TN, from 2004 to 2006.

PATIENTS

Adult patients receiving mechanical ventilation for >12 hrs with continuous recording of hourly sedation dosing.

INTERVENTIONS

We measured hourly doses of benzodiazepine and propofol exposure during the daytime (7 AM to 11 PM) and nighttime (11 PM to 7 AM) for 5 days. We quantified nighttime dose increases by subtracting the average hourly daytime dose on the preceding day from subsequent average hourly nighttime dose. We used multivariable logistic regression to determine whether daytime and nighttime dose increases were independently associated with delirium, coma, and delayed liberation from mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

Among 140 patients, the median Acute Physiology and Chronic Health Evaluation II score was 27 (interquartile range 22-33). Among those receiving the sedatives, benzodiazepine and propofol doses were increased at night on 40% and 41% of patient-days, respectively. Of 485 patient-days, delirium was present on 160 (33%) and coma on 206 (42%). In adjusted models, greater daytime benzodiazepine dose was independently associated with failed spontaneous breathing trial and extubation, and subsequent delirium (p<.02 for all). Nighttime increase in benzodiazepine dose was associated with failed spontaneous breathing trial (p<.01) and delirium (p=.05). Daytime propofol dose was marginally associated with subsequent delirium (p=.06).

CONCLUSIONS

Nearly half of mechanically ventilated intensive care unit patients received greater doses of sedation at night, a practice associated with failed spontaneous breathing trials, coma, and delirium. Over the first 5 days in our study, patients spent 75% of their time in coma or delirium, outcomes that may be reduced by efforts to decrease sedative exposure during both daytime and nighttime hours in the intensive care unit.