Category Archives: Concise Critical Appraisal

Airway Driving Pressure and Lung Stress in ARDS Patients

Since the first description of acute respiratory distress syndrome (ARDS) in the 1960s, numerous studies have sought the optimal tidal volume, positive end-expiratory pressure, plateau pressure, and inspired fraction of oxygen to reduce ventilator-induced lung injury. Chiumello et al set out to evaluate if airway driving pressure could accurately predict lung stress in ARDS patients.

They found that airway driving pressure can detect lung overstress with an acceptable accuracy.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

EIP Prolongation in ARDS Patients

End-inspiratory pause (EIP) prolongation decreases dead space-to-tidal volume ratio and partial pressure of carbon dioxide in arterial blood (PaCO2). We do not know the physiological benefits of this approach to improve respiratory system mechanics in acute respiratory distress syndrome (ARDS) patients when mild hypercapnia is of no concern. Aguirre-Bermeo et al, therefore, set out to address this unknown.

They found that prolonging EIP allowed a significant decrease in tidal volume without changes in PaCO2 in passively ventilated ARDS patients. This produced a significant decrease in plateau pressure and driving pressure and significantly increased respiratory system compliance, which suggests less overdistension and less dynamic strain.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Examining Pantoprazole or Placebo for Stress Ulcer Prophylaxis

Pantoprazole is frequently administered to critically ill patients for prophylaxis against gastrointestinal bleeding. However, comparison to placebo has been inadequately evaluated, and pantoprazole has the potential to cause harm. Therefore, Selvanderan and colleagues set out to evaluate benefit or harm associated with pantoprazole administration.

They found no evidence of benefit or harm with the prophylactic administration of pantoprazole to mechanically ventilated critically ill patients anticipated to receive enteral nutrition.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Assessing Impact of Conservative vs. Conventional Oxygen Therapy

Among critically ill patients, is a conservative oxygenation strategy aimed to maintain arterial saturation within physiologic limits more beneficial than a conventional strategy? Girardis et al set out to answer this question.

They found that among critically ill intensive care unit patients with a length of stay of 72 hours or longer, a conservative protocol for oxygen therapy may be beneficial; however, because the trial they initiated was terminated early, these findings must be considered preliminary.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Assessing Tissue Oxygenation and Microvascular Reactivity in ICU Patients

Impaired microcirculatory perfusion and tissue oxygenation during critical illness are associated with adverse outcome. The aim of a study by Donati et al was to detect alterations in tissue oxygenation or microvascular reactivity and their ability to predict outcome in critically ill patients using thenar near-infrared spectroscopy (NIRS) with a vascular occlusion test (VOT).

They found that in critically ill patients, NIRS with a VOT enables identification of alterations in tissue oxygen extraction capacity and microvascular reactivity that can predict mortality.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Cellular Mechanisms of Prevention of Ischemia-Reperfusion Injury

Ischemic preconditioning is the phenomenon whereby brief periods of sublethal ischemia protect against a subsequent, more prolonged, ischemic insult. In remote ischemic preconditioning, ischemia to one organ protects other organs at a distance. Olenchock et al created mouse models to ask if inhibition of the alpha-ketoglutarate-dependent dioxygenase Egln1, which senses oxygen and regulates the hypoxia-inducible factor transcription factor, could suffice to mediate local and remote ischemic preconditioning.

Using somatic gene deletion and a pharmacological inhibitor, they found that inhibiting Egln1 systemically or in skeletal muscles protects mice against myocardial ischemia-reperfusion injury.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Dysbiosis Across Multiple Body Sites in Critically Ill Adult Surgical Patients

Current evidence suggests that symbiosis of commensal microflora play a significant role in health and illness. The effect that commensal microflora play in critical care is less well known. Yeh et al set out to assess the dynamics of colonization of critically ill surgical and trauma patients. The authors examined 32 critically ill surgical and trauma patients in a major tertiary care intensive care unit (ICU) and collected information on bacterial colonization at gastrointestinal, tracheal, urinary, oral, and skin sites.

Over the course of the study (and in comparison to healthy controls) colonization in the ICU group showed a decrease in diversity of microflora across multiple sites and a change in colonization from non-pathogenic to pathogenic bacteria.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Long-Term Quality of Life Among Survivors of Severe Sepsis

Severe sepsis currently accounts for 10% of all intensive care unit admissions and is the leading cause of death in U.S. hospitals. Studies have shown that sepsis survivors suffer from many long-term after-effects. Among survivors, mobility and the ability to perform daily activities tend to be limited and are used as markers of quality of life (QoL). However, these prior studies have been small and have not taken into account high burdens of chronic disease prior to sepsis admission. A study conducted by Yende et al is a secondary analysis of two international, randomized clinical trials (A Controlled Comparison of Eritoran and placebo in patients with Severe Sepsis [ACCESS] and PROWESS-SHOCK), with the aim of describing QoL in sepsis survivors. The two cohorts analyzed included only adults with severe sepsis who were fully functional and living at home prior to sepsis hospitalization.

They found that approximately one-third of patients (as described above) who survived hospitalization for severe sepsis had died at six months. A further one-third had not returned to independent living by six months.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Intensive BP Lowering in Patients with Acute Cerebral Hemorrhage

Limited data are available to guide the choice of a target for the systolic blood-pressure level when treating acute hypertensive response in patients with intracerebral hemorrhage. Qureshi et al therefore randomly assigned eligible participants with intracerebral hemorrhage and a Glasgow Coma Scale score of five or more to a systolic blood-pressure target of 110 to 139 mm Hg (intensive treatment) or a target of 140 to 179 mm Hg (standard treatment) in order to test the superiority of intensive reduction of systolic blood pressure to standard reduction.

They found that the treatment of participants with intracerebral hemorrhage to achieve a target systolic blood pressure of 110 to 139 mm Hg did not result in a lower rate of death or disability than standard reduction to a target of 140 to 179 mm Hg.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

The Efficacy of Platelet Transfusion

Platelet transfusion after acute spontaneous primary intracerebral hemorrhage in people taking antiplatelet therapy might reduce death or dependence by reducing the extent of the hemorrhage. Baharoglu et al therefore aimed to investigate whether platelet transfusion with standard care, compared with standard care alone, reduced death or dependence after intracerebral hemorrhage associated with antiplatelet therapy use.

They found that platelet transfusion seems inferior to standard care for people taking antiplatelet therapy before intracerebral hemorrhage.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Sedatives and Their Associations with VAEs and Time to Extubation

Sedative selection is crucial to outcomes in critically ill patients. While benzodiazepines are known to be associated with a longer duration of mechanical ventilation compared to propofol and dexmedetomidine, little data exist comparing these sedatives in association with ventilator-associated events (VAEs). Klompas et al therefore aimed to evaluate the association between these sedatives, VAEs and time to extubation.

They found that sedatives vary in their associations with VAEs and time to extubation but not in their associations with time to hospital discharge or mortality.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.

Peak Lactate and Patient Outcome Following High-Risk Gastrointestinal Surgery

The association between hyperlactatemia and adverse outcome in patients admitted to intensive care units (ICUs) following gastrointestinal surgery has not been reported. Creagh-Brown et al therefore set out to explore the hypothesis that in a large cohort of gastrointestinal surgical patients, the peak serum lactate (in the first 24 hours) observed in patients admitted to the ICU following surgery is associated with unadjusted and severity-adjusted acute hospital mortality and that the strength of association is greater in patients admitted following emergency surgery than in patients admitted following elective surgery.

They found that elevated lactate is independently associated with in-hospital mortality in the postoperative gastrointestinal surgical patient and is no less significant in the context of elective surgery.

Read the full Concise Critical Appraisal by logging into the SCCM eCommunity. Concise Critical Appraisal is a regular feature aimed at highlighting the best and most relevant literature from a variety of academic journals and encouraging discussion around recent studies and research.