Accuracy of Noninvasive Blood Pressure Monitoring in Critically Ill Adults.

Background: Blood pressure (BP) is routinely invasively monitored by an arterial catheter in the intensive care unit (ICU). However, the available data comparing the accuracy of noninvasive methods to arterial catheters for measuring BP in the ICU are limited by small numbers and diverse methodologies. Purpose: To determine agreement between invasive arterial blood pressure monitoring (IABP) and noninvasive blood pressure (NIBP) in critically ill patients. Methods: This was a single center, observational study of critical ill adults in a tertiary care facility evaluating agreement (≤10% difference) between simultaneously measured IABP and NIBP. We measured clinical features at time of BP measurement inclusive of patient demographics, laboratory data, severity of illness, specific interventions (mechanical ventilation and dialysis), and vasopressor dose to identify particular clinical scenarios in which measurement agreement is more or less likely. Results: Of the 1852 critically ill adults with simultaneous IABP and NIBP readings, there was a median difference of 6 mm Hg in mean arterial pressure (MAP), interquartile range (1-12), P < .01. A logistic regression analysis identified 5 independent predictors of measurement discrepancy: increasing doses of norepinephrine (adjusted odds ratio [aOR] 1.10 [95% confidence interval, CI 1.08-1.12] P = .03 for every change in 5 µg/min), lower MAP value (aOR 0.98 [0.98-0.99] P < .01 for every change in 1 mm Hg), higher body mass index (aOR 1.04 [1.01-1.09] P = .01 for an increase in 1), increased patient age (aOR 1.31 [1.30-1.37] P < .01 for every 10 years), and radial arterial line location (aOR 1.74 [1.16-2.47] P = .04). Conclusions: There was broad agreement between IABP and NIBP in critically ill patients over a range of BPs and severity of illness. Several variables are associated with measurement discrepancy; however, their predictive capacity is modest. This may guide future study into which patients may specifically benefit from an arterial catheter.

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

OBJECTIVES: Prone positioning is widely used in mechanically ventilated patients with COVID-19; however, the specific clinical scenario in which the individual is most poised to benefit is not fully established. In patients with COVID-19 respiratory failure requiring mechanical ventilation, how effective is prone positioning in improving oxygenation and can that response be predicted? DESIGN: This is a retrospective observational study from two tertiary care centers including consecutive patients mechanically ventilated for COVID-19 from 3/1/2020 - 7/1/2021. The primary outcome is improvement in oxygenation as measured by PaO2/FiO2. We describe oxygenation before, during and after prone episodes with a focus on identifying patient, respiratory or ventilator variables that predict prone positioning success. SETTING: 2 Tertiary Care Academic Hospitals. PATIENTS: 125 patients mechanically ventilated for COVID-19 respiratory failure. INTERVENTIONS: Prone positioning. MAIN RESULTS: One hundred twenty-five patients underwent prone positioning a total of 309 times for a median duration of 23 hours IQR (14 - 49). On average, PaO2/FiO2 improved 19%: from 115 mm Hg (80 - 148) immediately before proning to 137 mm Hg (95 - 197) immediately after returning to the supine position. Prone episodes were more successful if the pre-prone PaO2/FiO2 was lower and if the patient was on inhaled epoprostenol (iEpo). For individuals with severe acute respiratory distress syndrome (ARDS) (PaO2/FiO2 < 100 prior to prone positioning) and on iEpo, the median improvement in PaO2/FiO2 was 27% in both instances. CONCLUSIONS: Prone positioning in mechanically ventilated patients with COVID-19 is generally associated with sustained improvements in oxygenation, which is made more likely by the concomitant use of iEpo and is more impactful in those who are more severely hypoxemic prior to prone positioning.

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

BACKGROUND: Inhaled pulmonary vasodilators are used as adjunctive therapies for the treatment of refractory hypoxemia. Available evidence suggest they improve oxygenation in a subset of patients without changing long-term trajectory. Given the differences in respiratory failure due to COVID-19 and "traditional" ARDS, we sought to identify their physiologic impact. METHODS: This is a retrospective observational study of patients mechanically ventilated for COVID-19, from the ICUs of 2 tertiary care centers, who received inhaled epoprostenol (iEpo) for the management of hypoxemia. The primary outcome is change in PaO2/FiO2. Additionally, we measured several patient level features to predict iEpo responsiveness (or lack thereof). RESULTS: Eighty patients with laboratory confirmed SARS-CoV2 received iEpo while mechanically ventilated and had PaO2/FiO2 measured before and after. The median PaO2/FiO2 prior to receiving iEpo was 92 mmHg and interquartile range (74 - 122). The median change in PaO2/FiO2 was 9 mmHg (-9 - 37) corresponding to a 10% improvement (-8 - 41). Fifty-percent (40 / 80) met our a priori definition of a clinically significant improvement in PaO2/FiO2 (increase in 10% from the baseline value). Prone position and lower PaO2/FiO2 when iEpo was started predicted a more robust response, which held after multivariate adjustment. For proned individuals, improvement in PaO2/FiO2 was 14 mmHg (-6 to 45) vs. 3 mmHg (-11 - 20), p = 0.04 for supine individuals; for those with severe ARDS (PaO2/FiO2 < 100, n = 49) the median improvement was 16 mmHg (-2 - 46). CONCLUSION: Fifty percent of patients have a clinically significant improvement in PaO2/FiO2 after the initiation of iEpo. This suggests it is worth trying as a rescue therapy; although generally the benefit was modest with a wide variability. Those who were prone and had lower PaO2/FiO2 were more likely to respond.

Cholesterol, lipoproteins and subclinical interstitial lung disease: the MESA study.

We investigated associations of plasma lipoproteins with subclinical interstitial lung disease (ILD) by measuring high attenuation areas (HAA: lung voxels between -600 and -250 Hounsfield units) in 6700 adults and serum MMP-7 and SP-A in 1216 adults age 45-84 without clinical cardiovascular disease in Multi-Ethnic Study of Atherosclerosis. In cross-sectional analyses, each SD decrement in high density lipoprotein cholesterol (HDL-C) was associated with a 2.12% HAA increment (95% CI 1.44% to 2.79%), a 3.53% MMP-7 increment (95% CI 0.93% to 6.07%) and a 6.37% SP-A increment (95% CI 1.35% to 11.13%), independent of demographics, smoking and inflammatory biomarkers. These findings support a novel hypothesis that HDL-C might influence subclinical lung injury and extracellular matrix remodelling.

Comparison of the GenCut Core Biopsy System to Transbronchial Biopsy Forceps for Flexible Bronchoscopic Lung Biopsy.

BACKGROUND: Pulmonary nodules are increasingly detected on screening and routine chest imaging, leading to an increase in diagnostic procedures. Bronchoscopy with transbronchial biopsy (TBBx) is the most common diagnostic modality, with diagnostic yield between 43% and 86%, largely dependent on the use of navigational modalities. In 2015 a new biopsy tool by Medtronic, the GenCut core biopsy system [GenCut transbronchial needle aspiration (TBNA)], was developed with the intention of improving yield in lung nodule biopsies. Our goal was to determine the efficacy of this new device when used in addition to TBBx. PATIENTS AND METHODS: This is a prospective observational study of 324 consecutive bronchoscopic lung biopsies in which both TBBx and GenCut TBNA were performed on the same lesion. We recorded patient and nodule characteristics, along with the bronchoscopic modalities used. The primary outcome was the diagnostic yield with the addition of the GenCut TBNA, and the key secondary outcome was the complication rate. RESULTS: Of the 324 nodule biopsies analyzed, 164 (50.6%) were diagnostic via TBBx or GenCut TBNA.In all, 97 (59%) were positive in both TBBx and GenCut TBNA, 43 (26.2%) were positive only in TBBx, and 24 (14.6%) were positive only in GenCut TBNA. Overall, the addition of the GenCut TBNA increased the diagnostic yield by 7.4% (P<0.01). There were 7 complications: 5 pneumothoraxes and 2 episodes of bleeding. CONCLUSION: The diagnostic yield is improved by using the GenCut core biopsy system in addition to traditional TBBx forceps when performing bronchoscopy for pulmonary nodules, without an increase in complications. These biopsy methods should be used in tandem for the greatest yield.

Healthcare Worker With Large Vessel Acute Ischemic Stroke Likely Related to Mild SARS-CoV-2 Infection.

We report the case of a healthcare worker who presented with a large vessel acute ischemic stroke in setting of a mild SARS-CoV-2 infection and provide a review of the emerging literature on COVID-related stroke. A 43-year-old female presented with right-sided hemiparesis, aphasia and dysarthria. She had a nonproductive of cough for 1 week without fever, fatigue or dyspnea. A CT Head, CT angiography and CT perfusion imaging revealed a M1 segment occlusion of the left middle cerebral artery requiring transfer from a primary to a comprehensive stroke center. A nasopharyngeal swab confirmed SARS-CoV-2 infection prior to arrival at the accepting center. During the thrombectomy a 3 cm thrombus was removed. Thrombus was also evident in the 8 French short sheath during closure device placement so a hypercoagulable state was suspected. Stroke work-up revealed a glycosylated hemoglobin of 8.7%, elevation of inflammatory markers and an indeterminate level of lupus anticoagulant IgM. On discharge home, she had near complete neurological recovery. This case highlights suspected mechanisms of hypercoagulability in SARS-CoV-2 infection and the importance of optimizing stroke care systems during the COVID-19 pandemic.

Fluid Balance Predicts Need for Intubation in Subjects With Respiratory Failure Initiated on High-Flow Nasal Cannula.

BACKGROUND: High-flow nasal cannula (HFNC) has gained widespread use for acute hypoxemic respiratory failure on the basis of recent publications that demonstrated fewer intubations and perhaps lower mortality in certain situations. However, a subset of patients initiated on HFNC for respiratory failure ultimately do require intubation. Our goal was to identify patient-level features predictive of this outcome. METHODS: This was a retrospective cohort study of subjects with hypoxemic respiratory failure treated with HFNC. Individuals were described as having succeeded (if weaned from HFNC) or failed (if they required intubation). A variety of easily measurable variables were evaluated for their ability to predict intubation risk, analyzed via a multivariate logistic regression model. RESULTS: Of a total of 74 subjects, 42 succeeded and 32 failed. The mean ± SD net fluid balance in the first 24 h after HFNC initiation was significantly lower in the success group versus the failure group (-33 ± 80 mL/h vs 72 ± 117 mL/h; P < .01). An adjusted model found only fluid balance and the previously described respiratory rate (breathing frequency [f]) to oxygenation (ROX) index ([[Formula: see text]/[Formula: see text]]/f) at 12 h as significant predictors of successful weaning (negative fluid balance adjusted odds ratio 0.77 [95% CI 0.62-0.96] for -10 mL/h increments [P = .02]; ROX adjusted OR 1.72 [1.15-2.57], P < .01). CONCLUSIONS: A negative fluid balance while on HFNC discriminated well between those who required intubation versus those who were successfully weaned.

Using a Laryngeal Mask Airway During Percutaneous Dilatational Tracheostomy is Safe and Obviates the Need for Paralytics.

BACKGROUND: Bedside percutaneous tracheostomy (PT) placement in critically ill patients is performed in a variety of ways, largely driven by institutional preference. We have recently transitioned to primarily extubating the patient and placing a laryngeal mask airway (LMA) before tracheostomy insertion in lieu of retracting the endotracheal tube (ETT) in place. This allows for lower sedative use and provides a superior view of the operative field. Here, we seek to describe the safety and efficiency of that approach. METHODS: This is a single-center cross-sectional study from 2014 to 2016 comparing patients who underwent PT with the ETT in place retracted to the proximal larynx versus those who were extubated and had a LMA placed. Procedural length, sedative totals, and safety outcomes were recorded. RESULTS: In total, 125 patients underwent PT during the study period, 75 via a LMA and 50 via existing ETT. There was no difference in procedural duration (LMA: 53.5±21.4 min vs. ETT: 50.4±16.8; P=0.41), total complications (LMA: 29.3% vs. 16%; P=0.09) or major complications (4% in both groups). Cisatracurium use was significantly lower in the LMA arm (LMA: 1.0±3.6 mg vs. ETT: 11.5±5.9 mg; P<0.01). CONCLUSION: Replacing the ETT with an LMA before PT is equally safe, does not increase total procedural duration, and all but eliminates the need for paralytic agents.

Multimodal noninvasive prediction of pulmonary hypertension in IPF.

INTRODUCTION AND OBJECTIVE: Pulmonary hypertension (PH) complicating idiopathic pulmonary fibrosis (IPF) is challenging to diagnose given inaccuracy of transthoracic echocardiogram (TTE) measurements. However, it has significant prognostic implications and is therefore important to accurately identify. METHODS: We conducted a cross-sectional study of patients with IPF who underwent RHC as part of their evaluation. A variety of commonly available noninvasive variables were evaluated for their ability to predict pulmonary arterial pressure in a linear regression model, including the traditionally used right ventricular systolic pressure (RVSP) estimated from TTE. RESULTS: There were 105 eligible patients identified from January 2006 to July 2016. The average age was 62.7 ± 7.7 years, 35 had RHC proven PH and 43% ultimately underwent lung transplantation. A linear model including three terms: RVSP (ANOVA P < .01), the ratio of FVC/DLCO from PFTs (P = .05) and pulmonary artery to aorta diameter ratio from CT (P < .01) was found to predict the mean pulmonary artery pressure more reliably than RVSP alone (R2 .39 vs .29, P < .05), with a lower rate of incorrect classification of PH status in these individuals (27.6 vs 35.2%, P = .05) and high negative predictive value (87.2%). CONCLUSION: If used in conjunction with RVSP from TTE, parameters from PFTs and the CT scan more accurately predict the presence or absence of PH than any of the variables in isolation. Using these in concert may allow greater discrimination in deciding which patients to subject to diagnostic right heart catheterization.

Modeling risk for developing drug resistant bacterial infections in an MDR-naive critically ill population.

PURPOSE: To create a model predictive of an individual's risk of developing a de novo multidrug-resistant (MDR) infection while in the intensive care unit (ICU). METHODS: This is a case-control study in which 189 ICU patients diagnosed with their first infection with an MDR organism were compared on the basis of demographic, past medical and clinical variables to randomly selected ICU patients without such an infection, era-matched in a 2:1 ratio. A prediction tool was derived using multivariate logistic regression. RESULTS: Five features remained predictive of developing an infection with a drug-resistant pathogen: hospitalization within a year [adjusted odds ratio (OR) 2.14], chronic hemodialysis (3.86), underlying oxygen-dependent pulmonary disease (1.86), endotracheal intubation within 24 h (2.46) and reason for ICU admission (respiratory failure 2.89, non-respiratory failure, non-shock presentation 1.85). Using a scoring system (0-7 points) based on the adjusted OR, risk categories were derived (low: 0-2 points, intermediate: 3-4 points and high risk: 5-7 points). The negative predictive value at a score cutoff of 2 is excellent (88.9%). CONCLUSIONS: A clinical prediction rule comprised of five easily measured ICU variables reasonably discriminates between patients who will develop their first MDR infection versus those who will not.