Peripheral Administration of Norepinephrine: A Prospective Observational Study.

BACKGROUND: Historically, norepinephrine has been administered through a central venous catheter (CVC) because of concerns about the risk of ischemic tissue injury if extravasation from a peripheral IV catheter (PIVC) occurs. Recently, several reports have suggested that peripheral administration of norepinephrine may be safe. RESEARCH QUESTION: Can a protocol for peripheral norepinephrine administration safely reduce the number of days a CVC is in use and frequency of CVC placement? STUDY DESIGN AND METHODS: This was a prospective observational cohort study conducted in the medical ICU at a quaternary care academic medical center. A protocol for peripheral norepinephrine administration was developed and implemented in the medical ICU at the study site. The protocol was recommended for use in patients who met prespecified criteria, but was used at the treating clinician's discretion. All adult patients admitted to the medical ICU receiving norepinephrine through a PIVC from February 2019 through June 2021 were included. RESULTS: The primary outcome was the number of days of CVC use that were avoided per patient, and the secondary safety outcomes included the incidence of extravasation events. Six hundred thirty-five patients received peripherally administered norepinephrine. The median number of CVC days avoided per patient was 1 (interquartile range, 0-2 days per patient). Of the 603 patients who received norepinephrine peripherally as the first norepinephrine exposure, 311 patients (51.6%) never required CVC insertion. Extravasation of norepinephrine occurred in 35 patients (75.8 events/1,000 d of PIVC infusion [95% CI, 52.8-105.4 events/1,000 d of PIVC infusion]). Most extravasations caused no or minimal tissue injury. No patient required surgical intervention. INTERPRETATION: This study suggests that implementing a protocol for peripheral administration of norepinephrine safely can avoid 1 CVC day in the average patient, with 51.6% of patients not requiring CVC insertion. No patient experienced significant ischemic tissue injury with the protocol used. These data support performance of a randomized, prospective, multicenter study to characterize the net benefits of peripheral norepinephrine administration compared with norepinephrine administration through a CVC.

Lung ultrasonography derived B-line scores as predictors of left ventricular end-diastolic pressure and pulmonary artery wedge pressure.

BACKGROUND: Non-invasive assessment of elevated left ventricular end-diastolic pressure (LVEDP) and pulmonary artery wedge pressure (PAWP) in patients with heart diseases is challenging. Lung ultrasonography (LUS) is a promising modality for predicting LVEDP and PAWP. METHODS: Fifty-seven stable ambulatory patients who underwent right and left heart catheterization were included. Following the procedures, LUS was performed in twenty-eight ultrasonographic zones, and the correlation between five different LUS derived B-line scores with LVEDP and PAWP was examined. RESULTS: The B-line index correlated with LVEDP and PAWP, with coefficients of 0.45 (p = 0.006) and 0.30 (p = 0.03), respectively. B-line index showed an AUC of 0.76 for identifying LVEDP > 15 mmHg (p = 0.01) and an AUC of 0.73 for identifying PAWP > 15 mmHg (p = 0.008). Overall, scores performances were similar in predicting LVEDP or PAWP > 15 mmHg. A B-line index ≥ 28 was significantly associated with LVEDP > 15 mmHg (OR: 9.97) and PAWP > 15 mmHg (OR: 6.61), adjusted for age and indication for heart catheterization. CONCLUSIONS: LUS derived B-line scores are moderately correlated with PAWP and LVEDP in patients with heart diseases. A B-line index ≥ 28 can be used to predict elevated LVEDP and PAWP with high specificity.

Echocardiographic profiles and hemodynamic response after vasopressin initiation in septic shock: A cross-sectional study.

PURPOSE: Vasopressin, used as a catecholamine adjunct, is a vasoconstrictor that may be detrimental in some hemodynamic profiles, particularly left ventricular (LV) systolic dysfunction. This study tested the hypothesis that echocardiographic parameters differ between patients with a hemodynamic response after vasopressin initiation and those without a response. METHODS: This retrospective, single-center, cross-sectional study included adults with septic shock receiving catecholamines and vasopressin with an echocardiogram performed after shock onset but before vasopressin initiation. Patients were grouped by hemodynamic response, defined as decreased catecholamine dosage with mean arterial pressure ≥ 65 mmHg six hours after vasopressin initiation, with echocardiographic parameters compared. LV systolic dysfunction was defined as LV ejection fraction (LVEF) <45%. RESULTS: Of 129 included patients, 72 (56%) were hemodynamic responders. Hemodynamic responders, versus non-responders, had higher LVEF (61% [55%,68%] vs. 55% [40%,65%]; p = 0.02) and less-frequent LV systolic dysfunction (absolute difference  -16%; 95% CI -30%,-2%). Higher LVEF was associated with higher odds of hemodynamic response (for each LVEF 10%, response OR 1.32; 95% CI 1.04-1.68). Patients with LV systolic dysfunction, versus without LV systolic dysfunction, had higher mortality risk (HR(t) = e[0.81-0.1*t]; at t = 0, HR 2.24; 95% CI 1.08-4.64). CONCLUSIONS: Pre-drug echocardiographic profiles differed in hemodynamic responders after vasopressin initiation versus non-responders.

Lung Ultrasonographic Signs in Pulmonary Disease - A Video Review.

Lung ultrasound (US) is a well-established imaging tool in the inpatient and critical care setting. It has proven its worth in the rapid bedside diagnosis of a variety of conditions pertaining to the lungs and the thorax. Lung US was initially introduced as a bedside imaging tool to evaluate the size and characteristics of pleural effusion. Over the years, the field of lung ultrasonography has rapidly expanded introducing nuances in image interpretation. Numerous primary and secondary signs have been described in the literature to identify both normal and abnormal findings. The primary signs can help narrow the list of differential diagnoses, whereas the addition of secondary signs help create an imaging pattern facilitating the confirmation of diagnosis or recognition of the underlying disease process. These wide variety of signs and patterns can present a challenge to the learning of lung ultrasonography, particularly to a novice user. We sought to compile a comprehensive list of these findings to serve as a useful resource to aid effortless adoption of lung ultrasonography in clinical practice. In this review, we narrate the evolution of lung US, describe common protocols applied in performance of the lung US, and illustrate a comprehensive list of common lung US signs and patterns along with their differential diagnosis and clinical utility.

Characteristics of Cumulative Annual Radiation Exposure in Young Intensive Care Unit Survivors.

OBJECTIVES: Patients admitted to the intensive care unit (ICU) are at high risk for hazardous medical radiation exposure. However, the cumulative annual radiation exposure in ICU survivors remains unknown. METHODS: This was a single-center retrospective study of all critically ill adult patients admitted to the 64-bed adult medical ICU at a quaternary medical center. The study included patients aged 18 to 39 years admitted through the year 2013 (January 1, 2013-December 31, 2013) who survived their respective ICU admission. RESULTS: A total of 353 patients were included in the study. The median cumulative effective dose (CED) for the calendar year was 9.14 mSv (interquartile range, 1.74-27 mSv). In 11.6% of the patients (n = 41), CED was more than 50 mSv, while 5.1% of the patients (n = 18) exceeded annual CED of 100 mSv. Overall, radiation exposure from ICU-related imaging studies was lower than those from other medical settings (mean difference, -9.2 ± 83.6; P < 0.05). However, there was no statistically significant difference in exposure (ICU versus non-ICU) when restricting the analysis to patients with a CED of greater than 50 and greater than 100 mSv. Eighty-seven percent of the original cohort was alive at the end of the year. CONCLUSIONS: Young ICU survivors are at risk for high annual radiation exposure from both ICU and non-ICU sources. A subset is exposed to hazardous annual radiation exposure in excess of 100 mSv.

Adherence to blood product transfusion guidelines-An observational study of the current transfusion practice in a medical intensive care unit.

BACKGROUND: Blood transfusions though life-saving are not entirely benign. They are the most overused procedure in the hospital and have been under scrutiny by the 'Choosing Wisely campaign'. The strict adoption of restrictive transfusion guidelines could improve patient outcomes while reducing cost. OBJECTIVES: In this study, we evaluate adherence to restrictive transfusion guidelines, along with hospital mortality and length of stay (LOS) in transfusion events with a pre-transfusion haemoglobin (Hb) ≥7 g/dl. Additionally, we evaluated associated costs accrued due to unnecessary transfusions. METHODS: We conducted a retrospective observational study in a 64-bed medical intensive care unit (MICU) of an academic medical centre involving all adult patients (N = 957) requiring packed red blood cell transfusion between January 2015 and December 2015. RESULTS: In total, 3140 units were transfused with a mean pre-transfusion Hb of 6.75 ± 0.86 g/dl. Nine hundred forty-four (30%) transfusion events occurred with a pre-transfusion Hb ≥7 g/dl, and 385 (12.3%) of these occurred in patients without hypotension, tachycardia, use of vasopressors, or coronary artery disease. Forgoing them could have led to a savings of approximately 0.3 million dollars. Transfusion events with pre-transfusion Hb ≥7 g/dl were associated with an increased mortality in patients with acute blood loss (odds ratio [OR] 2.08, 95% confidence interval [CI] 1.11-3.88; p = 0.02) and LOS in patients with chronic blood loss (ß1 .8.26, 95% CI 4.09-12.43; p < 0.01). CONCLUSION: A subset of anaemic patients in the MICU still receive red blood cell transfusions against restrictive guidelines offering hospitals the potential for effective intervention that has both economic and clinical implications.

A CLUE for better assessment of donor lungs: Novel technique in clinical ex vivo lung perfusion.

BACKGROUND: The direCt Lung Ultrasound Evaluation (CLUE) technique was proven to be an accurate method for monitoring extravascular lung water in donor lungs during ex vivo lung perfusion (EVLP) in an experimental model. The aim of this study was to examine the application of CLUE in the clinical setting. METHODS: Lungs were evaluated using acellular EVLP protocol. Ultrasound images were obtained directly from the lung surface. Images were graded according to the percentage of B-lines seen on ultrasound. CLUE scores were calculated at the beginning and end of EVLP for the whole lung, each side, and lobe based on the number (No.) of images in each grade and the total No. of images taken and evaluated retrospectively. RESULTS: A total of 23 EVLP cases were performed resulting in 13 lung transplants (LTxs) with no hospital mortality. Primary graft dysfunction (PGD) occurred in only 1 recipient (PGD3, no PGD2). Significant differences were found between suitable and non-suitable lungs in CLUE scores (1.03 vs 1.85, p < 0.001), unlike the partial pressure of oxygen/fraction of inspired oxygen ratio. CLUE had the highest area under the receiver operating characteristic curve (0.98) compared with other evaluation parameters. The initial CLUE score of standard donor lungs was significantly better than marginal lungs. The final CLUE score in proned lungs showed improvement when compared with initial CLUE score, especially in the upper lobes. CONCLUSIONS: The CLUE technique shows the highest accuracy in evaluating donor lungs for LTx suitability compared with other parameters used in EVLP. CLUE can optimize the outcomes of LTx by guiding the decision making through the whole process of clinical EVLP.

DireCt Lung Ultrasound Evaluation (CLUE): A novel technique for monitoring extravascular lung water in donor lungs.

BACKGROUND: Extravascular lung water (EVLW) could change in donor lungs in a time-dependent fashion during procurement or ex-vivo lung perfusion (EVLP) and may vary across different zones. Current techniques for EVLW assessment are either subjective, general estimation, or not feasible in the clinical setting. An accurate and non-invasive diagnostic tool for EVLW would be desirable for donor lung assessment and management. Therefore, we studied the feasibility and accuracy of direCt Lung Ultrasound Evaluation (CLUE) technique. METHODS: Eleven lungs were utilized for the human model and 6 lungs for the porcine model. Lungs underwent EVLP for 2 hours. In CLUE, ultrasound images were taken directly from the lungs. A scoring system was created for each point based on the percentage of B-lines. Images were graded according to the degree of edema. An equation was used to calculate total lung and lobe scores based on number of images of each grade. RESULTS: CLUE point score correlated with wet/dry ratio in human and porcine models (n = 99, r = 0.863, p < 0.001; and n = 31, r = 0.916, p < 0.001, respectively). CLUE total lung score correlated with lung weight (n = 19, r = 0.812, p < 0.001; and n = 12, r = 0.895, p < 0.001, respectively). CLUE lobe score correlated negatively with partial pressure of oxygen/fraction of inspired oxygen ratio in the human model (n = 20, r = -0.775, p < 0.001). CONCLUSIONS: EVLW monitoring in donor lungs with CLUE after procurement is feasible and CLUE scores were found to be significantly correlated with lung weight, wet/dry, and PaO2/FIO2 ratio.

Utilization of Thoracic Ultrasound for Confirmation of Central Venous Catheter Placement and Exclusion of Pneumothorax: A Novel Technique in Real-Time Application.

AIM: To evaluate the safety and utility of ultrasonography as a tool to confirm central venous catheter (CVC) position and to exclude insertion-related pneumothorax in place of chest radiography (CXR) in a tertiary medical intensive care unit (ICU). METHODS: We randomized 60 consecutive medical ICU patients to conventional or ultrasound groups for CVC placement. Both groups had CVCs inserted under ultrasound guidance. The intervention group underwent real-time transthoracic echocardiography to assist in catheter positioning and chest ultrasonography for exclusion of pneumothorax. Our primary end point was reduction in CXR use. The secondary end point was time elapsed from the end of procedure to the availability of CVC for use. χ2 test was used to compare the 2 groups for the primary end point. T test was used to compare the 2 groups for the secondary end point. RESULTS: Thirty patients were randomized to the conventional group and 30 were randomized to the ultrasound group. One patient was excluded in the control group since the procedure needed to be aborted. Patient characteristics were well matched for age, body mass index, and acute physiologic assessment and chronic health evaluation (APACHE III) scores. There was a 56.7% ( P < .0001) reduction in CXR use in the ultrasound arm. Mean time to use was 53.6 minutes in the control group and 25 minutes in the ultrasound arm ( P = .0015). Mean time required to complete the procedure was 27.7 minutes in the control group and 24.1 minutes in the ultrasound group ( P = .2053). No pneumothorax was detected in either arm. CONCLUSION: Ultrasound-guided CVC placement and positioning with a minor modification in technique reduced the use of bedside CXR and reduced the time to use of the CVC.

Radiation Exposure in the Medical ICU: Predictors and Characteristics.

BACKGROUND: Patients admitted to the medical ICU (MICU) are often subjected to multiple radiologic studies. We hypothesized that some endure radiation dose exposure (cumulative effective dose [CED]) in excess of annual US federal occupational health standard limits (CED ≥ 50 mSv) and 5-year cumulative limit (CED ≥ 100 mSv). We also evaluated the correlation of CED with Acute Physiology and Chronic Health Evaluation (APACHE) III score and other clinical variables. METHODS: Retrospective observational study conducted in an academic medical center involving all adult admissions (N = 4,155) to the MICU between January 2013 and December 2013. Radiation doses from ionizing radiologic studies were calculated from reference values to determine the CED. RESULTS: Three percent of admissions (n = 131) accrued CED ≥ 50 mSv (1% [n = 47] accrued CED ≥ 100 mSv). The median CED was 0.72 mSv (interquartile range, 0.02-5.23 mSv), with a range of 0.00 to 323 mSv. Higher APACHE III scores (P = .003), longer length of MICU stay (P < .0001), sepsis (P = .03), and gastrointestinal disorders and bleeding (P < .0001) predicted higher CED in a multivariable linear regression model. Patients with gastrointestinal bleeding and disorders had an odds ratio of 21.05 (95% CI, 13.54-32.72; P < .0001) and 6.94 (95% CI, 3.88-12.38; P < .0001), respectively, of accruing CED ≥ 50 mSv in a multivariable logistic regression model. CT scan and interventional radiology accounted for 49% and 38% of the total CED, respectively. CONCLUSIONS: Patients in the MICU are exposed to radiation doses that can be substantial, exceeding federal annual occupational limits, and in a select subset, are > 100 mSv. Efforts to justify, restrict, and optimize the use of radiologic resources when feasible are warranted.

Revisiting Ultrasound-Guided Subclavian/Axillary Vein Cannulations: Importance of Pleural Avoidance With Rib Trajectory.

The Centers for Disease Control and Prevention guidelines for the prevention of catheter-related bloodstream infections suggest using "a subclavian site, rather than an internal jugular or a femoral site, in adult patients." This recommendation is based on evidence of lower rates of thrombosis and catheter-related bloodstream infections in patients with subclavian central venous catheters (CVCs) compared to femoral or internal jugular sites. However, preference toward a subclavian approach to CVC insertion is hindered by increased risk of mechanical complications, especially pneumothorax, when compared to other sites. This is largely related to the proximity of the subclavian vein to the pleural space and the traditional "blind" or anatomic landmark approach used in subclavian vein cannulation. We revisit a method that may provide increased safety and avoidance of pneumothorax during ultrasound-guided subclavian/axillary vein cannulation. This is achieved by directing the needle toward the subclavian vein at a point where it traverses over the second rib, providing a protective rib shield between the vessel and pleura as a safety net for operators. The technique also allows for increased compressibility of the subclavian/axillary vein in the event of bleeding complication.

Right ventricular echocardiographic parameters are associated with mortality after acute pulmonary embolism.

BACKGROUND: There is limited information on the utility of certain echocardiographic measurements, such as right ventricular (RV) strain analysis, in predicting mortality in patients with acute pulmonary embolism (PE). METHODS: A total of 211 patients with acute PE admitted to a medical intensive care unit (ICU) were retrospectively identified. Echocardiographic variables were prospectively measured in this cohort. The focus was on ICU, hospital, and long-term mortality. RESULTS: The mean age was 61 ± 15 years. Median Acute Physiology and Chronic Health Evaluation IV and simplified Pulmonary Embolism Severity Index scores were 60 (interquartile range, 40-71) and 2 (interquartile range, 1-2), respectively. Thirty-eight patients (18%) died during the sentinel hospitalization (13% died in the ICU). A total of 61 patients (28.9%) died during a median follow-up period of 15 months (interquartile range, 5-26 months). The echocardiographic variables associated with long-term mortality (from PE diagnosis) were ratio of RV to left ventricular end-diastolic diameter (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.2-4.8), tricuspid annular plane systolic excursion (HR, 0.53; 95% CI, 0.31-0.92), and RV-right atrial gradient (HR, 1.02; 95% CI, 1.01-1.4). ICU mortality was associated with ratio of RV to LV end-diastolic diameter (HR, 4.4; 95% CI, 1.3-15), RV systolic pressure (HR, 1.03; 95% CI, 1.01-1.05), tricuspid annular plane systolic excursion (HR, 0.4; 95% CI, 0.18-0.9), and inferior vena cava collapsibility < 50% (HR, 4.3; 95% CI, 1.7-11). These variables remain significantly associated with mortality after adjusting by Acute Physiology and Chronic Health Evaluation IV score, Pulmonary Embolism Severity Index score, or the use of thrombolytic agents. RV strain parameters were not correlated with hospital or long-term mortality. CONCLUSIONS: Four simple parameters that measure different aspects of the right ventricle (ratio of RV to left ventricular end-diastolic diameter, RV systolic pressure, tricuspid annular plane systolic excursion, and inferior vena cava collapsibility) were independently associated with mortality in patients presenting with acute PE who were admitted to the ICU.