Grissom, Colin K., and Barbara E. Jones. Respiratory health benefits and risks of living at moderate altitude. High Alt Med Biol 19:109-115, 2018.-The respiratory system plays a critical role in the ...series of physiologic responses that occur at high altitude and allows individuals to adapt to and tolerate hypobaric hypoxia. Persons with underlying lung disease may have complications, but sometimes derive benefits, related to residence at high altitude. This review will focus on health benefits and risks of patients with underlying asthma, chronic obstructive pulmonary disease, pulmonary hypertension, or obstructive sleep apnea, who live at altitudes of 1500 to 4500 m. We will also discuss maladaptive responses of the respiratory system at high altitude in previously healthy persons, including development of pulmonary hypertension and sleep-disordered breathing.
Septic cardiomyopathy develops frequently in patients with sepsis and likely increases short-term mortality. However, whether septic cardiomyopathy is associated with long-term outcomes after sepsis ...is unknown. We investigated whether septic patients with septic cardiomyopathy have worse long-term outcomes than septic patients without septic cardiomyopathy.
Retrospective cohort study.
Adult ICU.
Adult ICU patients with sepsis.
None.
Left ventricular global longitudinal systolic strain was our primary measure of septic cardiomyopathy. We employed a suite of multivariable survival analyses to explore linear and nonlinear associations between left ventricular global longitudinal systolic strain and major adverse cardiovascular events, which included death, stroke, and myocardial infarction. Our primary outcome was major adverse cardiovascular event through 24 months after ICU discharge. Among 290 study patients, median left ventricular global longitudinal systolic strain was -16.8% (interquartile range, -20.4% to -12.6%), and 38.3% of patients (n = 111) experienced a major adverse cardiovascular event within 24 months after discharge. On our primary, linear analysis, there was a trend (p = 0.08) toward association between left ventricular global longitudinal systolic strain and major adverse cardiovascular event (odds ratio, 1.03; CI, < 1 to 1.07). On our nonlinear analysis, the association was highly significant (p < 0.001) with both high and low left ventricular global longitudinal systolic strain associated with major adverse cardiovascular event among patients with pre-existing cardiac disease. This association was pronounced among patients who were younger (age < 65 yr) and had Charlson Comorbidity Index greater than 5.
Among patients with sepsis and pre-existing cardiac disease who survived to ICU discharge, left ventricular global longitudinal systolic strain demonstrated a U-shaped association with cardiovascular outcomes through 24 months. The relationship was especially strong among younger patients with more comorbidities. These observations are likely of use to design of future trials.
Routine spontaneous awakening and breathing trial coordination (SAT/SBT) improves outcomes for mechanically ventilated patients, but adherence varies. Understanding barriers to and facilitators of ...consistent daily use of SAT/SBT (implementation determinants) can guide the development of implementation strategies to increase adherence to these evidence-based interventions.
We conducted an explanatory, sequential mixed-methods study to measure variation in the routine daily use of SAT/SBT and to identify implementation determinants that might explain variation in SAT/SBT use across 15 intensive care units (ICUs) in urban and rural locations within an integrated, community-based health system.
We described the patient population and measured adherence to daily use of coordinated SAT/SBT from January to June 2021, selecting four sites with varied adherence levels for semistructured field interviews. We conducted key informant interviews with critical care nurses, respiratory therapists, and physicians/advanced practice clinicians (
= 55) from these four sites between October and December 2021 and performed content analysis to identify implementation determinants of SAT/SBT use.
The 15 sites had 1,901 ICU admissions receiving invasive mechanical ventilation (IMV) for ⩾24 hours during the measurement period. The mean IMV patient age was 58 years, and the median IMV duration was 5.3 days (interquartile range, 2.5-11.9). Coordinated SAT/SBT adherence (within 2 h) was estimated at 21% systemwide (site range, 9-68%). ICU clinicians were generally familiar with SAT/SBT but varied in their knowledge and beliefs about what constituted an evidence-based SAT/SBT. Clinicians reported that SAT/SBT coordination was difficult in the context of existing ICU workflows, and existing protocols did not explicitly define how coordination should be performed. The lack of an agreed-upon system-level measure for tracking daily use of SAT/SBT led to uncertainty regarding what constituted adherence. The effects of the COVID-19 pandemic increased clinician workloads, impacting performance.
Coordinated SAT/SBT adherence varied substantially across 15 ICUs within an integrated, community-based health system. Implementation strategies that address barriers identified by this study, including knowledge deficits, challenges regarding workflow coordination, and the lack of performance measurement, should be tested in future hybrid implementation-effectiveness trials to increase adherence to daily use of coordinated SAT/SBT and minimize harm related to the prolonged use of mechanical ventilation and sedation.
Novel 2009 influenza A(H1N1) infection has significantly affected ICUs. We sought to characterize our region's clinical findings and demographic associations with ICU admission due to novel A(H1N1).
...We conducted an observational study from May 19, 2009, to June 30, 2009, of descriptive clinical course, inpatient mortality, financial data, and demographic characteristics of an ICU cohort. A case-control study was used to compare the ICU cohort to Salt Lake County residents.
The ICU cohort of 47 influenza patients had a median age of 34 years, Acute Physiology and Chronic Health Evaluation II score of 21, and BMI of 35 kg/m2. Mortality was 17% (8/47). All eight deaths occurred among the 64% of patients (n = 30) with ARDS, 26 (87%) of whom also developed multiorgan failure. Compared with the Salt Lake County population, patients with novel A(H1N1) were more likely to be obese (22% vs 74%; P < .001), medically uninsured (14% vs 45%; P < .001), and Hispanic (13% vs 23%; P < .01) or Pacific Islander (1% vs 26%; P < .001). Observed ICU admissions were 15-fold greater than expected for those with BMI > or = 40 kg/m2 (standardized morbidity ratio 15.8, 95% CI, 8.3-23.4) and 1.5-fold greater than expected among those with BMI of 30 to 39 kg/m(2) for age-adjusted and sex-adjusted rates for Salt Lake County.
Severe ARDS with multiorgan dysfunction in the absence of bacterial infection was a common clinical presentation. In this cohort, young nonwhites without medical insurance were disproportionately likely to require ICU care. Obese patients were particularly susceptible to critical illness due to novel A(H1N1) infection.
Aging-related changes in platelet and monocyte interactions may contribute to adverse outcomes in sepsis but remain relatively unexamined. We hypothesized that differential platelet-monocyte ...aggregate (PMA) formation in older septic patients alters inflammatory responses and mortality.
We prospectively studied 113 septic adults admitted to the intensive care unit with severe sepsis or septic shock. Patients were dichotomized a priori into one of two groups: older (age ≥ 65 years, n = 28) and younger (age < 65 years, n = 85). PMA levels were measured in whole blood via flow cytometry within 24 hours of admission. Plasma levels of IL-6 and IL-8, proinflammatory cytokines produced by monocytes upon PMA formation, were determined by commercial assays. Patients were followed for the primary outcome of 28-day, all-cause mortality.
Elevated PMA levels were associated with an increased risk of mortality in older septic patients (hazard ratio for mortality 5.64, 95% confidence interval 0.64-49.61). This association remained after adjusting for potential confounding variables in multivariate regression. Receiver operating curve analyses demonstrated that PMA levels greater than or equal to 8.43% best predicted 28-day mortality in older septic patients (area under the receiver operating curve 0.82). Plasma IL-6 and IL-8 levels were also significantly higher in older nonsurvivors. In younger patients, neither PMA levels nor plasma monokines were significantly associated with mortality.
Increased PMA formation, and associated proinflammatory monokine synthesis, predicts mortality in older septic patients. Although larger studies are needed, our findings suggest that heightened PMA formation in older septic patients may contribute to injurious inflammatory responses and an increased risk of mortality.
To provide guidance to clinicians, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of ...accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and a balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is the 2019 update of the Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the prevention and treatment of acute ...mountain sickness (AMS), high altitude cerebral edema (HACE), and high altitude pulmonary edema (HAPE). These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations for their roles in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to the prevention and management of each disorder that incorporate these recommendations.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In septic shock, assessment of cardiac function often relies on invasive central venous oxygen saturation (ScvO2). Ventricular strain is a non-invasive method of assessing ventricular wall ...deformation and may be a sensitive marker of heart function. We hypothesized that it may have a relationship with ScvO2 and lactate.
We prospectively performed transthoracic echocardiography in patients with severe sepsis or septic shock and measured (1) left ventricular longitudinal strain from a four-chamber view and (2) ScvO2. We excluded patients for whom image quality was inadequate or for whom ScvO2 values were unobtainable. We determined the association between strain and ScvO2 with logistic and linear regression, using covariates of mean arterial pressure, central venous pressure, and vasopressor dose. We determined the association between strain and lactate. We considered strain greater than -17% as abnormal and strain greater than -10% as severely abnormal.
We studied 89 patients, 68 of whom had interpretable images. Of these patients, 42 had measurable ScvO2. Sixty percent of patients had abnormal strain, and 16% had severely abnormal strain. Strain is associated with low ScvO2 (linear coefficient -1.05, p =0.006; odds ratio 1.23 for ScvO2 <60%, p =0.016). Patients with severely abnormal strain had significantly lower ScvO2 (56.1% vs. 67.5%, p <0.01) and higher lactate (2.7 vs. 1.9 mmol/dl, p =0.04) than those who did not. Strain was significantly different between patients, based on a threshold ScvO2 of 60% (-13.7% vs. -17.2%, p =0.01) but not at 70% (-15.0% vs. -18.2%, p =0.08).
Left ventricular strain is associated with low ScvO2 and hyperlactatemia. It may be a non-invasive surrogate for adequacy of oxygen delivery during early severe sepsis or septic shock.
OBJECTIVES:Tachycardia is common in septic shock, but many patients with septic shock are relatively bradycardic. The prevalence, determinants, and implications of relative bradycardia (heart rate, < ...80 beats/min) in septic shock are unknown. To determine mortality associated with patients who are relatively bradycardic while in septic shock.
DESIGN:Retrospective study of patients admitted for septic shock to study ICUs during 2005–2013.
SETTING:One large academic referral hospital and two community hospitals.
PATIENTS:Adult patients with septic shock requiring vasopressors.
INTERVENTION:None.
MEASUREMENTS:Primary outcome was 28-day mortality. We used multivariate logistic regression to evaluate the association between relative bradycardia and mortality, controlling for confounding with inverse probability treatment weighting using a propensity score.
RESULTS:We identified 1,554 patients with septic shock, of whom 686 (44%) met criteria for relative bradycardia at some time. Twenty-eight-day mortality in this group was 21% compared to 34% in the never-bradycardic group (p < 0.001). Relatively bradycardic patients were older (65 vs 60 yr; p < 0.001) and had slightly lower illness severity (Sequential Organ Failure Assessment, 10 vs 11; p = 0.004; and Acute Physiology and Chronic Health Evaluation II, 27 vs 28; p = 0.008). After inverse probability treatment weighting, covariates were balanced, and the association between relative bradycardia and survival persisted (p < 0.001).
CONCLUSIONS:Relative bradycardia in patients with septic shock is associated with lower mortality, even after adjustment for confounding. Our data support expanded investigation into whether inducing relative bradycardia will benefit patients with septic shock.
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