Detection of Myocardial Dysfunction in Septic Shock: A Speckle-Tracking Echocardiography Study

BACKGROUND

Patients with septic shock are at increased risk of myocardial dysfunction. However, the left ventricular ejection fraction (EF) typically remains preserved in septic shock. Strain measurement using speckle-tracking echocardiography may quantify abnormalities in myocardial function not detected by conventional echocardiography. To investigate whether septic shock results in greater strain changes than sepsis alone, we evaluated strain in patients with sepsis and septic shock.

METHODS

We prospectively identified 35 patients with septic shock and 15 with sepsis. These patients underwent serial transthoracic echocardiograms at enrollment and 24 hours later. Measurements included longitudinal, radial, and circumferential strain in addition to standard echocardiographic assessments of left ventricular function.

RESULTS

Longitudinal strain worsened significantly over 24 hours in patients with septic shock (P < 0.0001) but did not change in patients with sepsis alone (P = 0.43). No significant changes in radial or circumferential strain or EF were observed in either group over the 24-hour measurement period. In patients with septic shock, the significant worsening in longitudinal strain persisted after adjustment for left ventricular end-diastolic volume and vasopressor use (P < 0.0001). In patients with sepsis, adjustment for left ventricular end-diastolic volume and vasopressor use did not alter the finding of no significant differences in longitudinal strain (P = 0.48) or EF (P = 0.96).

CONCLUSIONS

In patients with septic shock, but not sepsis, myocardial strain imaging using speckle-tracking echocardiography identified myocardial dysfunction in the absence of changes in EF. These data suggest that strain imaging may play a role in cardiovascular assessment during septic shock.

The Ventilator Management Team: Repurposing Anesthesia Workstations and Personnel to Combat COVID-19

The coronavirus disease 2019 pandemic resulted in unprecedented numbers of patients with respiratory failure requiring ventilatory support. The number of patients who required critical care quickly outpaced the availability of intensive care unit (ICU) beds. Consequently, health care systems had to creatively expand critical care services into alternative hospital locations with repurposed staff and equipment. Deploying anesthesia workstations to the ICU to serve as mechanical ventilators requires equipment preparation, multidisciplinary planning, and targeted education. We aim to contextualize this process, highlighting major differences between anesthesia workstations and ICU ventilators, and to share the insights gained from our experiences creating an anesthesia provider-based ventilator management team.

Handheld Point-of-Care Ultrasound: Safety Considerations for Creating Guidelines

BACKGROUND

Compared to traditional ultrasound machines, emerging handheld point-of-care-ultrasound (HPOCUS) systems exhibit superior portability and affordability. Thus, they have been increasingly embraced in the intensive care setting. However, there is scarce data on patient safety and current regulatory body guidelines are lacking. Here, we critically appraise the literature with a focus on the merits, concerns, and framework of existing POCUS guidelines. Subsequently, we provide recommendations for future regulatory guidelines.

METHODS

A comprehensive literature review was conducted using the PubMed database employing the key words "point-of-care/handheld/portable ultrasound" and "guidelines" alone, in combination, and using thesaurus terms. Eligible articles were scrutinized for description of potential benefits and concerns of HPOCUS, especially from a patient safety perspective, as well as currently existing POCUS practice guidelines. Data was extracted, reported thematically using a narrative synthesis approach, then subsequently used to guide our proposed guidelines.

RESULTS

The most widely reported benefits of HPOCUS include superior portability, affordability, imaging, facilitation of expedited diagnosis and management, and integration with medical workplace flow. However, major barriers to adoption include device security/patient confidentiality and patient safety. Furthermore, except for a policy published by the American College of Emergency Physicians (ACEP) in 2018, there are few other national regulatory guidelines pertaining to handheld POCUS. In light of this, we propose a framework for HPOCUS guideline development to address these and other concerns. Such guidelines include training and credentialing, bioengineering approval, and strategic integration with electronic medical record systems.

CONCLUSION

HPOCUS can be a powerful tool for expedited diagnosis and management guidance. However, there is limited data regarding patient safety and current regulatory body guidelines are lacking. Our assessment illuminates that there remain many unsolved problems about HPOCUS, and in turn, we propose guidelines to address safe regulation and implementation.

Preoperative Evaluation for Thoracic Surgery

Preoperative evaluation before thoracic surgery aims to separate those patients who will tolerate surgery and those who are not surgical candidates. Predicted postoperative pulmonary function testing helps make this distinction. The preoperative period represents a time for patient engagement and physical optimization to improve postoperative outcomes.

Postintubation Decline in Oxygen Saturation Index Predicts Mortality in COVID-19: A Retrospective Pilot Study

Background

Acute respiratory failure from COVID-19 pneumonia is a major cause of death after SARS-CoV-2 infection. We investigated whether PaO₂/FiO₂, oxygenation index (OI), SpO₂/FiO₂, and oxygen saturation index (OSI), commonly used to assess the severity of acute respiratory distress syndrome (ARDS), can predict mortality in mechanically ventilated COVID-19 patients.

Methods

In this single-centered retrospective pilot study, we enrolled 68 critically ill mechanically ventilated adult patients with confirmed COVID-19. Physiological variables were recorded on the day of intubation (day 0) and postintubation days 3 and 7. The association between physiological parameters, PaO₂/FiO₂, OI, SpO₂/FiO₂, and OSI with mortality was assessed using multiple variable logistic regression analysis. Receiver operating characteristic analysis was conducted to evaluate the performance of the predictive models.

Results

The ARDS severity indices were not statistically different on the day of intubation, suggesting similar baseline conditions in nonsurviving and surviving patients. However, these indices were significantly worse in the nonsurviving as compared to surviving patients on postintubation days 3 and 7. On intubation day 3, PaO₂/FiO₂ was 101.0 (61.4) in nonsurviving patients vs. 140.2 (109.6) in surviving patients, p=0.004, and on day 7 106.3 (94.2) vs. 178.0 (69.3), p < 0.001. OI was 135.0 (129.7) in nonsurviving vs. 84.8 (86.1) in surviving patients (p=0.003) on day 3 and 150.0 (118.4) vs. 61.5 (46.7) (p < 0.001) on day 7. OSI was 12.0 (11.7) vs. 8.0 (10.0) (p=0.006) on day 3 and 14.7 (13.2) vs. 6.5 (5.4) (p < 0.001) on day 7. Similarly, SpO₂/FiO₂ was 130 (90) vs. 210 (90) (p=0.003) on day 3 and 130 (90) vs. 230 (50) (p < 0.001) on day 7, while OSI was 12.0 (11.7) vs. 8.0 (10.0) (p=0.006) on day 3 and 14.7 (13.2) vs. 6.5 (5.4) (p < 0.001) on day 7 in the nonsurviving and surviving patients, respectively. All measures were independently associated with hospital mortality, with significantly greater odds ratios observed on day 7. The area under the receiver operating characteristic curve (AUC) for mortality prediction was greatest on intubation day 7 (AUC = 0.775, 0.808, and 0.828 for PaO₂/FiO₂, OI, SpO₂/FiO₂, and OSI, respectively).

Conclusions

Decline in oxygenation indices after intubation is predictive of mortality in COVID-19 patients. This time window is critical to the outcome of these patients and a possible target for future interventions. Future large-scale studies to confirm the prognostic value of the indices in COVID-19 patients are warranted.