Clinical Practice Guidelines From the AABB: Red Blood Cell Transfusion Thresholds and Storage

IMPORTANCE

More than 100 million units of blood are collected worldwide each year, yet the indication for red blood cell (RBC) transfusion and the optimal length of RBC storage prior to transfusion are uncertain.

OBJECTIVE

To provide recommendations for the target hemoglobin level for RBC transfusion among hospitalized adult patients who are hemodynamically stable and the length of time RBCs should be stored prior to transfusion.

EVIDENCE REVIEW

Reference librarians conducted a literature search for randomized clinical trials (RCTs) evaluating hemoglobin thresholds for RBC transfusion (1950-May 2016) and RBC storage duration (1948-May 2016) without language restrictions. The results were summarized using the Grading of Recommendations Assessment, Development and Evaluation method. For RBC transfusion thresholds, 31 RCTs included 12 587 participants and compared restrictive thresholds (transfusion not indicated until the hemoglobin level is 7-8 g/dL) with liberal thresholds (transfusion not indicated until the hemoglobin level is 9-10 g/dL). The summary estimates across trials demonstrated that restrictive RBC transfusion thresholds were not associated with higher rates of adverse clinical outcomes, including 30-day mortality, myocardial infarction, cerebrovascular accident, rebleeding, pneumonia, or thromboembolism. For RBC storage duration, 13 RCTs included 5515 participants randomly allocated to receive fresher blood or standard-issue blood. These RCTs demonstrated that fresher blood did not improve clinical outcomes.

FINDINGS

It is good practice to consider the hemoglobin level, the overall clinical context, patient preferences, and alternative therapies when making transfusion decisions regarding an individual patient. Recommendation 1: a restrictive RBC transfusion threshold in which the transfusion is not indicated until the hemoglobin level is 7 g/dL is recommended for hospitalized adult patients who are hemodynamically stable, including critically ill patients, rather than when the hemoglobin level is 10 g/dL (strong recommendation, moderate quality evidence). A restrictive RBC transfusion threshold of 8 g/dL is recommended for patients undergoing orthopedic surgery, cardiac surgery, and those with preexisting cardiovascular disease (strong recommendation, moderate quality evidence). The restrictive transfusion threshold of 7 g/dL is likely comparable with 8 g/dL, but RCT evidence is not available for all patient categories. These recommendations do not apply to patients with acute coronary syndrome, severe thrombocytopenia (patients treated for hematological or oncological reasons who are at risk of bleeding), and chronic transfusion-dependent anemia (not recommended due to insufficient evidence). Recommendation 2: patients, including neonates, should receive RBC units selected at any point within their licensed dating period (standard issue) rather than limiting patients to transfusion of only fresh (storage length: <10 days) RBC units (strong recommendation, moderate quality evidence).

CONCLUSIONS AND RELEVANCE

Research in RBC transfusion medicine has significantly advanced the science in recent years and provides high-quality evidence to inform guidelines. A restrictive transfusion threshold is safe in most clinical settings and the current blood banking practices of using standard-issue blood should be continued.

Red blood cell transfusion: a clinical practice guideline from the AABB*

DESCRIPTION

Although approximately 85 million units of red blood cells (RBCs) are transfused annually worldwide, transfusion practices vary widely. The AABB (formerly, the American Association of Blood Banks) developed this guideline to provide clinical recommendations about hemoglobin concentration thresholds and other clinical variables that trigger RBC transfusions in hemodynamically stable adults and children.

METHODS

These guidelines are based on a systematic review of randomized clinical trials evaluating transfusion thresholds. We performed a literature search from 1950 to February 2011 with no language restrictions. We examined the proportion of patients who received any RBC transfusion and the number of RBC units transfused to describe the effect of restrictive transfusion strategies on RBC use. To determine the clinical consequences of restrictive transfusion strategies, we examined overall mortality, nonfatal myocardial infarction, cardiac events, pulmonary edema, stroke, thromboembolism, renal failure, infection, hemorrhage, mental confusion, functional recovery, and length of hospital stay. RECOMMENDATION 1: The AABB recommends adhering to a restrictive transfusion strategy (7 to 8 g/dL) in hospitalized, stable patients (Grade: strong recommendation; high-quality evidence). RECOMMENDATION 2: The AABB suggests adhering to a restrictive strategy in hospitalized patients with preexisting cardiovascular disease and considering transfusion for patients with symptoms or a hemoglobin level of 8 g/dL or less (Grade: weak recommendation; moderate-quality evidence). RECOMMENDATION 3: The AABB cannot recommend for or against a liberal or restrictive transfusion threshold for hospitalized, hemodynamically stable patients with the acute coronary syndrome (Grade: uncertain recommendation; very low-quality evidence). RECOMMENDATION 4: The AABB suggests that transfusion decisions be influenced by symptoms as well as hemoglobin concentration (Grade: weak recommendation; low-quality evidence).

Initial pH, base deficit, lactate, anion gap, strong ion difference, and strong ion gap predict outcome from major vascular injury

OBJECTIVE

This study determines whether acid-base data obtained in the emergency department correlate with outcome from major vascular injury.

DESIGN

Observational, retrospective record review of trauma patients requiring vascular repair (torso or extremity, January 1988 to December 1997). Data included age, Injury Severity Score, injury mechanism, survival, laboratory profiling, calculated anion gap, strong ion difference, and strong ion gap. Patients were divided into survivors and nonsurvivors with comparison by Student's t-test; significance was assumed for p < or = .05. Multivariate logistic regression was used for further analysis of univariate predictors of mortality, and receiver operator characteristic curves were generated for mortality from each variable.

SETTING

Urban level I trauma facility.

PATIENTS

Trauma patients requiring vascular repair of torso or extremity injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Both nonsurvivors (n = 64) and survivors (n = 218) were similar with respect to age (31 +/- 9 vs. 31.5 +/- 10.5, p = 0.15) and injury mechanics (81% penetrating in survivors vs. 83% penetrating in nonsurvivors, p = .71). Non-survivor Injury Severity Score exceeded that of survivors (27.5 +/- 7.8 vs. 12.4 +/- 9.4, p < .001). Nonsurvivor pH (7.06 +/- 0.15 vs. 7.34 +/- 0.08, p < .001) and apparent strong ion difference (31.38 +/- 4.39 vs. 37.53 +/- 3.86, p < .001) were significantly lower, whereas nonsurvivor standard base excess (-17.9 +/- 5.1 vs. -2.9 +/- 4.4 mEq/L, p < .001), lactate (11.1 +/- 3.6 vs. 3.6 +/- 1.5 mmol/L, p < .001), anion gap (28.2 +/- 4.1 vs. 15.6 +/- 3.1, p < .001), and strong ion gap (10.8 +/- 3.2 vs. 2.4 +/- 1.8, p < .001) were higher. All but one nonsurvivor had initial emergency department pH < or = 7.26, standard base excess < or = -7.3 mEq/L, lactate > or = 5 mmol/L, and strong ion gap > or = 5 mEq/L. All of the acid-base descriptors were strongly associated with outcome, but the strong ion gap discriminated most strongly with an area under the receiver operator characteristic of 0.991 (95% confidence interval, 0.972-0.998).

CONCLUSIONS

The initial emergency department acid-base variables of pH, base deficit, lactate, anion gap, apparent strong ion difference, and strong ion gap discriminate survivors from non-survivors of major vascular injury. The strong ion gap is most strongly predictive of mortality following major vascular trauma.

The pharmacology of bimatoprost (Lumigan)

Bimatoprost (Lumigan) is a pharmacologically unique and highly efficacious ocular hypotensive agent. It appears to mimic the activity of a newly discovered family of fatty acid amides, termed prostamides. One biosynthetic route to the prostamides involves anandamide as the precursor. Bimatoprost pharmacology has been extensively characterized by binding and functional studies at more than 100 drug targets, which comprise a diverse variety of receptors, ion channels, and transporters. Bimatoprost exhibited no meaningful activity at receptors known to include antiglaucoma drug targets as follows: adenosine (A(1-3)), adrenergic (alpha(1), alpha(2), beta(1), beta(2)), cannabinoid (CB(1), CB(2)), dopamine (D(1-5)), muscarinic (M(1-5)), prostanoid (DP, EP(1-4), FP, IP, TP), and serotonin (5HT(1-7)). Bimatoprost does, however, exhibit potent inherent pharmacological activity in the feline iris sphincter preparation, which is prostamide-sensitive. Bimatoprost also resembles the prostamides in that it is a potent and highly efficacious ocular hypotensive agent. A single dose of bimatoprost markedly reduces intraocular pressure in dogs and laser-induced ocular hypertensive monkeys. Decreases in intraocular pressure are well maintained for at least 24 hr post-dose. Human studies have demonstrated that systemic exposure to bimatoprost is low and that accumulation does not occur. The sclera is the preferred route of accession to the eye. The high scleral permeability coefficient Papp is a likely contributing factor to the rapid onset and long-acting ocular hypotensive profile of bimatoprost.

Simulation training in central venous catheter insertion: improved performance in clinical practice

PURPOSE

To determine whether simulation training of ultrasound (US)-guided central venous catheter (CVC) insertion skills on a partial task trainer improves cannulation and insertion success rates in clinical practice.

METHOD

This prospective, randomized, controlled, single-blind study of first- and second-year residents occurred at a tertiary care teaching hospital from January 2007 to September 2008. The intervention group (n = 90) received a didactic and hands-on, competency-based simulation training course in US-guided CVC insertion, whereas the control group (n = 95) received training through a traditional, bedside apprenticeship model. Success at first cannulation and successful CVC insertion served as the primary outcomes. Secondary outcomes included reduction in technical errors and decreased mechanical complications.

RESULTS

Blinded independent raters observed 495 CVC insertions by 115 residents over a 21-month period. Successful first cannulation occurred in 51% of the intervention group versus 37% of the control group (P = .03). CVC insertion success occurred for 78% of the intervention group versus 67% of the control group (P = .02). Simulation training was independently and significantly associated with success at first cannulation (odds ratio: 1.7; 95% confidence interval: 1.1-2.8) and with successful CVC insertion (odds ratio: 1.7; 95% confidence interval: 1.1-2.8)--both independent of US use, patient comorbidities, or resident specialty. No significant differences related to technical errors or mechanical complications existed between the two groups.

CONCLUSIONS

Simulation training was associated with improved in-hospital performance of CVC insertion. Procedural simulation was associated with improved residents' skills and was more effective than traditional training.

Red Blood Cell Transfusion: 2023 AABB International Guidelines

Importance

Red blood cell transfusion is a common medical intervention with benefits and harms.

Objective

To provide recommendations for use of red blood cell transfusion in adults and children.

Evidence Review

Standards for trustworthy guidelines were followed, including using Grading of Recommendations Assessment, Development and Evaluation methods, managing conflicts of interest, and making values and preferences explicit. Evidence from systematic reviews of randomized controlled trials was reviewed.

Findings

For adults, 45 randomized controlled trials with 20 599 participants compared restrictive hemoglobin-based transfusion thresholds, typically 7 to 8 g/dL, with liberal transfusion thresholds of 9 to 10 g/dL. For pediatric patients, 7 randomized controlled trials with 2730 participants compared a variety of restrictive and liberal transfusion thresholds. For most patient populations, results provided moderate quality evidence that restrictive transfusion thresholds did not adversely affect patient-important outcomes. Recommendation 1: for hospitalized adult patients who are hemodynamically stable, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). In accordance with the restrictive strategy threshold used in most trials, clinicians may choose a threshold of 7.5 g/dL for patients undergoing cardiac surgery and 8 g/dL for those undergoing orthopedic surgery or those with preexisting cardiovascular disease. Recommendation 2: for hospitalized adult patients with hematologic and oncologic disorders, the panel suggests a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (conditional recommendations, low certainty evidence). Recommendation 3: for critically ill children and those at risk of critical illness who are hemodynamically stable and without a hemoglobinopathy, cyanotic cardiac condition, or severe hypoxemia, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). Recommendation 4: for hemodynamically stable children with congenital heart disease, the international panel suggests a transfusion threshold that is based on the cardiac abnormality and stage of surgical repair: 7 g/dL (biventricular repair), 9 g/dL (single-ventricle palliation), or 7 to 9 g/dL (uncorrected congenital heart disease) (conditional recommendation, low certainty evidence).

Conclusions and Relevance

It is good practice to consider overall clinical context and alternative therapies to transfusion when making transfusion decisions about an individual patient.

Airway pressure release ventilation increases cardiac performance in patients with acute lung injury/adult respiratory distress syndrome

BACKGROUND

The purpose of the present study is to determine whether airway pressure release ventilation (APRV) can safely enhance hemodynamics in patients with acute lung injury (ALI) and/or adult respiratory distress syndrome (ARDS), relative to pressure control ventilation (PCV).

METHODS

Patients with severe acute lung injury or ARDS who were managed with inverse-ratio pressure control ventilation, neuromuscular blockade and a pulmonary artery catheter were switched to APRV. Hemodynamic performance, as well as pressor and sedative needs, was assessed after discontinuing neuromuscular blockade

RESULTS

Mean age was 58 +/- 9 years (n = 12) and mean Lung Injury Score was 7.6 +/- 2.1. Temperature and arterial oxygen tension/fractional inspired oxygen (FiO2) were similar among the patients. Peak airway pressures fell from 38 +/- 3 for PCV to 25 +/- 3 cmH2O for APRV, and mean pressures fell from 18 +/- 3 for PCV to 12 +/- 2 cmH2O for APRV. Paralytic use and sedative use were significantly lower with APRV than with PCV. Pressor use decreased substantially with ARPV. Lactate levels remained normal, but decreased on APRV. Cardiac index rose from 3.2 +/- 0.4 for PCV to 4.6 +/- 0.3 l/min per m2 body surface area (BSA) for APRV, whereas oxygen delivery increased from 997 +/- 108 for PCV to 1409 +/- 146 ml/min for APRV, and central venous pressure declined from 18 +/- 4 for PCV to 12 +/- 4 cmH2O for APRV. Urine output increased from 0.83 +/- 0.1 for PCV to 0.96 +/- 0.12 ml/kg per hour for APRV.

CONCLUSION

APRV may be used safely in patients with ALI/ARDS, and decreases the need for paralysis and sedation as compared with PCV-inverse ratio ventilation (IRV). APRV increases cardiac performance, with decreased pressor use and decreased airway pressure, in patients with ALI/ARDS.

Differential effects of lesions in medial and dorsal raphe of the rat: latent inhibition and septohippocampal serotonin levels

Rats received either 0 or 30 preexposures to a tone which was later used as a conditioned stimulus (CS) in a two-way avoidance task. Tone preexposure resulted in retarded conditioning in normal animals and animals with dorsal raphe lesions. This latent inhibition effect, however, was not present in animals with medial raphe lesions. The failure of CS preexposure to retard conditioning in animals with medial raphe lesions was not due to differences in auditory sensitivity or shock reactivity. Biochemical analysis indicated that whereas medial raphe lesions significantly reduced serotonin in the septohippocampal complex, dorsal raphe lesions had no such effect. The results are discussed in terms of the differing roles of the mesolimbic and mesostriatal serotonergic systems in learning to ignore irrelevant stimuli.

Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)

Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associated with poor prognosis, particularly in high-risk patients. The cornerstones in the management of complicated IAIs are timely effective source control with appropriate antimicrobial therapy. Empiric antimicrobial therapy is important in the management of intra-abdominal infections and must be broad enough to cover all likely organisms because inappropriate initial antimicrobial therapy is associated with poor patient outcomes and the development of bacterial resistance. The overuse of antimicrobials is widely accepted as a major driver of some emerging infections (such as C. difficile), the selection of resistant pathogens in individual patients, and for the continued development of antimicrobial resistance globally. The growing emergence of multi-drug resistant organisms and the limited development of new agents available to counteract them have caused an impending crisis with alarming implications, especially with regards to Gram-negative bacteria. An international task force from 79 different countries has joined this project by sharing a document on the rational use of antimicrobials for patients with IAIs. The project has been termed AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections). The authors hope that AGORA, involving many of the world's leading experts, can actively raise awareness in health workers and can improve prescribing behavior in treating IAIs.

Increased Firearm Injury During the COVID-19 Pandemic: A Hidden Urban Burden

Background

Public health measures were instituted to reduce COVID-19 spread. A decrease in total emergency department volume followed, but the impact on injury is unknown. With lockdown and social distancing potentially increasing domicile discord, we hypothesized that intentional injury increased during COVID-19, driven primarily by an increase in penetrating trauma.

Study Design

A retrospective review of acute adult patient care in an urban Level I trauma center assessed injury patterns. Presenting patient characteristics and diagnoses from 6 weeks pre to 10 weeks post statewide stay-at-home orders (March 16, 2020) were compared, as well as with 2015-2019. Subsets were defined by intentionality (intentional vs nonintentional) and mechanism of injury (blunt vs penetrating). Fisher exact and Wilcoxon tests were used to compare proportions and means.

Results

There were 357 trauma patients that presented pre stay-at-home order and 480 that presented post stay-at-home order. Pre and post groups demonstrated differences in sex (35.6% vs 27.9% female; p = 0.02), age (47.4 ± 22.1 years vs 42 ± 20.3 years; p = 0.009), and race (1.4% vs 2.3% Asian; 63.3% vs 68.3% Black; 30.5% vs 22.3% White; and 4.8% vs 7.1% other; p = 0.03). Post stay-at-home order mechanism of injury revealed more intentional injury (p = 0.0008). Decreases in nonintentional trauma after adoption of social isolation paralleled declines in daily emergency department visits. Compared with earlier years, 2020 demonstrated a significantly greater proportion of intentional violent injury during the peripandemic months, especially from firearms.

Conclusions

Unprecedented social isolation policies to address COVID-19 were associated with increased intentional injury, especially gun violence. Meanwhile, emergency department and nonintentional trauma visits decreased. Pandemic-related public health measures should embrace intentional injury prevention and management strategies.

Clinical review: Acid-base abnormalities in the intensive care unit -- part II

Acid-base abnormalities are common in the critically ill. The traditional classification of acid-base abnormalities and a modern physico-chemical method of categorizing them will be explored. Specific disorders relating to mortality prediction in the intensive care unit are examined in detail. Lactic acidosis, base excess, and a strong ion gap are highlighted as markers for increased risk of death.

Ptosis and cataract surgery. A multivariant computer analysis of a prospective study

A prospective study investigated the effect of local anesthesia, eyelid edema and superior rectus muscle injury on postoperative ptosis. Patients were randomized into four groups to study these effects. Group A received a Van Lint eyelid block and a superior rectus bridle suture. Group B received a Van Lint block and an episcleral retraction suture. Group C received a Nadbath retroauricular facial nerve block and a superior rectus bridle suture. Group D received a Nadbath block and an episcleral retraction suture. Results of the study indicate that postoperative ptosis can be significantly reduced by varying our operative techniques. Postoperative ptosis was significantly increased in group A and reduced in group D. It appears that trauma to the superior rectus muscle complex is the most critical factor in postoperative ptosis. Fifty five and one-half percent of the population entered the study with preoperative ptosis. Preoperative ptosis had no effect on postoperative ptosis. Lid crease, superior sulcus fullness and lash rotation are poor anatomical landmarks of levator insertion in the elderly population, both preoperatively and postoperatively.

Abnormal Calcium Levels During Trauma Resuscitation Are Associated With Increased Mortality, Increased Blood Product Use, and Greater Hospital Resource Consumption: A Pilot Investigation

BACKGROUND

Admission hypocalcemia predicts both massive transfusion and mortality in severely injured patients. However, the effect of calcium derangements during resuscitation remains unexplored. We hypothesize that any hypocalcemia or hypercalcemia (either primary or from overcorrection) in the first 24 hours after severe injury is associated with increased mortality.

METHODS

All patients at our institution with massive transfusion protocol activation from January 2013 through December 2014 were identified. Patients transferred from another hospital, those not transfused, those with no ionized calcium (Ca) measured, and those who expired in the trauma bay were excluded. Hypocalcemia and hypercalcemia were defined as any level outside the normal range of Ca at our institution (1-1.25 mmol/L). Receiver operator curve analysis was also used to further examine significant thresholds for both hypocalcemia and hypercalcemia. Hospital mortality was compared between groups. Secondary outcomes included advanced cardiovascular life support, damage control surgery, ventilator days, and intensive care unit days.

RESULTS

The massive transfusion protocol was activated for 77 patients of whom 36 were excluded leaving 41 for analysis. Hypocalcemia occurred in 35 (85%) patients and hypercalcemia occurred in 9 (22%). Mortality was no different in hypocalcemia versus no hypocalcemia (29% vs 0%; P = .13) but was greater in hypercalcemia versus no hypercalcemia (78% vs 9%; P < .01). Receiver operator curve analysis identified inflection points in mortality outside a Ca range of 0.84 to 1.30 mmol/L. Using these extreme values, 15 (37%) had hypocalcemia with a 60% mortality (vs 4%; P < .01) and 9 (22%) had hypercalcemia with a 78% mortality (vs 9%; P < .01). Patients with extreme hypocalcemia and hypercalcemia also received more red blood cells, plasma, platelets, and calcium repletion.

CONCLUSIONS

Hypocalcemia and hypercalcemia occur commonly during the initial resuscitation of severely injured patients. Mild hypocalcemia may be tolerable, but more extreme hypocalcemia and any hypercalcemia should be avoided. Further assessment to define best practice for calcium management during resuscitation is warranted.

Oxygen debt criteria quantify the effectiveness of early partial resuscitation after hypovolemic hemorrhagic shock

BACKGROUND

The effectiveness of partial resuscitation after hypovolemic hemorrhagic shock with deferment of full resuscitation is critical to successful hypotensive resuscitation.

METHODS

To quantitatively address this issue, 40 canines were bled under anesthesia to a mean oxygen debt (O(2)D) of 104 +/- 7.6 mL/kg over 60 minutes (mortality, 40%). Animals surviving the shock were then immediately resuscitated with 0%, 8.4%, 15%, 30%, or 120% (full resuscitation) of shed volume as 5% albumin and held for 2 hours postshock, when the remaining portion of full resuscitation volume was given. Animals were followed for 7 days postshock with hepatic and renal function studies, and then, under anesthesia, cardiac output and organ biopsy specimens were taken before the animals were killed.

RESULTS

By 2 hours postshock, 0% immediate resuscitation had an O(2)D increase of 80 mL/kg above end of shock, but O(2)D at 8.4% immediate resuscitation decreased -30 mL/kg, 15% immediate resuscitation fell -65 mL/kg, 30% immediate resuscitation decreased -80 mL/kg below end of shock, and O(2)D with 120% full resuscitation fell to preshock levels. All decreases in O(2)D were significantly (p < 0.05) below end of shock, but both 15% and 30% immediate resuscitation exceeded the 8.4% immediate resuscitation rate (p < 0.05) throughout the resuscitation, and 120% full resuscitation exceeded these (p < 0.05). The immediate resuscitation O(2)D response correlated significantly (p < 0.001) with base deficit and lactate, but blood pressure was not a significant discriminator. Seven-day biopsies showed return of bowel mucosa but a pattern of cellular injury in heart, liver, and kidney that improved from 8.4% < 15% < 30 < 120% immediate resuscitation.

CONCLUSION

The data suggest that, compared with 120% postshock immediate resuscitation, 8.4% and 15% immediate resuscitation give poorer results, with 30% immediate resuscitation showing mild, transient, but acceptable changes in organ function allowing for a 2-hour delay until full resuscitation, with complete 7-day recovery. Base deficit and lactate, but not blood pressure, are significant indices of O(2)D.

Start with a subjective assessment of skin temperature to identify hypoperfusion in intensive care unit patients

OBJECTIVE

To determine whether physical examination alone or in combination with biochemical markers can accurately diagnose hypoperfusion.

METHODS

Data from 264 consecutive surgical intensive care unit patients were collected by two intensivists and included extremity temperature, vital signs, arterial lactate, arterial blood gases, hemoglobin, and pulmonary artery catheter values with derived indices. Days of data were divided into data collected from patients with cool extremities (cool skin temperature [CST] group) versus warm extremities (warm skin temperature [WST] group). Values are means +/- SD. Comparisons between groups were made by two-tailed unpaired t test; significance was assumed for p < or = 0.05.

RESULTS

There were 328 days of observations in the CST group versus 439 in the WST group. There were no differences (p > 0.05) between CST and WST data with regard to heart rate (107 +/- 14 vs. 99 +/- 19 beats/min), systolic blood pressure (118 +/- 24 vs. 127 +/- 28 mm Hg), diastolic blood pressure (57 +/- 14 vs. 62 +/- 15 mm Hg), pulmonary artery occlusion pressure (14 +/- 6 vs. 16 +/- 5 mm Hg), Fio2 (0.48 +/- 0.7 vs. 0.45 +/- 0.2), hemoglobin (8.8 +/- 1.6 vs. 9.3 +/- 1.3 g/dL), Pco2 (44.3 +/- 11.8 vs. 40.7 +/- 9.2 mm Hg), or Po2 (96.4 +/- 12.6 vs. 103.8 +/- 22.2 mm Hg). However, cardiac output (5.3 +/- 2.2 vs. 8.2 +/- 2.6 L/min), cardiac index (2.9 +/- 1.2 vs. 4.3 +/- 1.2 L/min/m2), pH (7.32 +/- 0.2 vs. 7.39 +/- 0.07), TCO2 (19.5 +/- 3.1 vs. 25.1 +/- 4.8 mEq/L), and Svo2 (60.2 +/- 4.4% vs. 68.2 +/- 7.8%) were all significantly lower (p < 0.05) in CST patients compared with WST patients. By comparison, lactate (4.7 +/- 1.5 vs. 2.2 +/- 1.6 mmol/L, p < 0.05) was significantly elevated in patients with cool extremities.

CONCLUSION

Combining physical examination with serum bicarbonate and arterial lactate identifies patients with hypoperfusion as defined by low Svo2 and cardiac index. Hypoperfusion may occur despite supranormal cardiac indices. Patients with cool extremities and elevated lactate levels may benefit from a pulmonary artery catheter to guide but not initiate therapy.

Increased mesolimbic dopamine binding following chronic haloperidol treatment

It is well documented that chronic neuroleptic treatment creates a dopamine receptor supersensitivity in the striatum. The present study examined the effect of chronic neuroleptic treatment on mesolimbic dopamine receptor binding. Rats received either 0.5 mg/kg of haloperidol, 50 mg/kg of sodium phenobarbital, or 0.9% saline daily for 21 days. One week following the last injection, the rats were sacrificed and the septi were removed for the 3H-dopamine binding assay. Haloperidol treatment resulted in a 52% increase in 3H-dopamine binding in the septum, whereas phenobarbital treatment caused no significant change.

Amiodarone keratopathy. Correlation to dosage and duration

Amiodarone hydrochloride, a benzofurane derivative used for the treatment of cardiac arrhythmias, is known to cause a verticillate epithelial keratopathy, which has been classified into three stages. Patients receiving low dosages of 100 to 200 mg of amiodarone daily retain clear corneas or show stage 1 changes only, regardless of duration of treatment or total amount of substance ingested. Patients receiving higher dosages of 400 to 1,400 mg/day show stage 2 and 3 changes, depending on duration of treatment. This keratopathy progresses, even with reduced dosage; however, complete regression occurs once administration of medication is discontinued.

Arteriography for Lower Gastrointestinal Hemorrhage: Role of Preceding Abdominal Computed Tomographic Angiogram in Diagnosis and Localization

IMPORTANCE

Optimizing the nature and sequence of diagnostic imaging when managing lower gastrointestinal hemorrhage may reduce subsequent morbidity and mortality.

OBJECTIVES

To determine if preceding visceral arteriography with computed tomographic angiography (CTA) in acute lower gastrointestinal hemorrhage increases hemorrhage identification and localization and to determine if CTA was superior to nuclear scintigraphy when used as a pre-angiogram test.

DESIGN, SETTING, AND PARTICIPANTS

Analysis was conducted of prospectively acquired data from an interventional radiology database and of individual electronic medical records from an academic tertiary medical center. On January 1, 2009, a new, evidence-based, institutional protocol that formally incorporated CTA to manage acute lower gastrointestinal hemorrhage was launched after multidisciplinary consultation. All records of patients who underwent visceral angiography (VA) for acute lower gastrointestinal hemorrhage from January 1, 2005, to December 31, 2012, were evaluated.

EXPOSURES

Imaging, procedural, and operative details were abstracted from the medical records of all patients who underwent VA for lower gastrointestinal hemorrhage.

MAIN OUTCOMES AND MEASURES

Visceral angiography results and efficacy were compared in patients before and after protocol implementation and compared based on which imaging method was used prior to angiography.

RESULTS

A total of 161 angiographic procedures were performed during the study period (78 before and 83 after protocol implementation). Use of CTA increased from 3.8% to 56.6%, and use of nuclear scintigraphy decreased from 83.3% to 50.6% following protocol implementation (P < .001). Preceding angiography with CTA resulted in similar angiography contrast administration (mean [SD] amount for CTA prior to VA, 135 [63] vs 160 [77] mL; P = .18) and fluoroscopy time (mean [SD], 26.3 [16.8] vs 32.2 [34.9] minutes; P = .34). Although nuclear scintigraphy and CTA had similar sensitivity and specificity, localization of hemorrhage site by CTA was more precise and consistent with angiography findings. As a pre-angiography test, compared with nuclear scintigraphy, CTA reduced overall the number of imaging studies required (mean [SD] number per patient admission, 2.1 [0.3] vs 2.5 [0.8]; P = .005) and resulted in administration of more overall contrast (mean [SD], 220 [80] vs 130 [70] mL; P < .001) without worsening renal function.

CONCLUSIONS AND RELEVANCE

Preceding VA with a diagnostic study improves positive localization of the site of lower gastrointestinal hemorrhage compared with VA alone. Increasing the use of CTA for pre-angiography imaging may reduce overall imaging studies while appearing to increase positive yield at VA. Computed tomographic angiography can be used as part of a lower intestinal hemorrhage management algorithm and does not appear to worsen renal function despite the additional contrast load.

Coronavirus Disease 2019 Pandemic Measures: Reports From a National Survey of 9,120 ICU Clinicians

IMPORTANCE

Recent reports identify that among hospitalized coronavirus disease 2019 patients, 30% require ICU care. Understanding ICU resource needs remains an essential component of meeting current and projected needs of critically ill coronavirus disease 2019 patients.

OBJECTIVES

This study queried U.S. ICU clinician perspectives on challenging aspects of care in managing coronavirus disease 2019 patients, current and anticipated resource demands, and personal stress.

DESIGN, SETTING, AND PARTICIPANTS

Using a descriptive survey methodology, an anonymous web-based survey was administered from April 7, 2020, to April 22, 2020 (email and newsletter) to query members of U.S. national critical care organizations.

MEASUREMENTS AND MAIN RESULTS

Through a 16-item descriptive questionnaire, ICU clinician perceptions were assessed regarding current and emerging critical ICU needs in managing the severe acute respiratory syndrome coronavirus 2 infected patients, resource levels, concerns about being exposed to severe acute respiratory syndrome coronavirus 2, and perceived level of personal stress. A total of 9,120 ICU clinicians responded to the survey, representing all 50 U.S. states, with 4,106 (56.9%) working in states with 20,000 or more coronavirus disease 2019 cases. The 7,317 respondents who indicated their profession included ICU nurses (n = 6,731, 91.3%), advanced practice providers (nurse practitioners and physician assistants; n = 334, 4.5%), physicians (n = 212, 2.9%), respiratory therapists (n = 31, 0.4%), and pharmacists (n = 30, 0.4%). A majority (n = 6,510, 88%) reported having cared for a patient with presumed or confirmed coronavirus disease 2019. The most critical ICU needs identified were personal protective equipment, specifically N95 respirator availability, and ICU staffing. Minimizing healthcare worker virus exposure during care was believed to be the most challenging aspect of coronavirus disease 2019 patient care (n = 2,323, 30.9%). Nurses report a high level of concern about exposing family members to severe acute respiratory syndrome coronavirus 2 (median score of 10 on 0-10 scale). Similarly, the level of concern reached the maximum score of 10 in ICU clinicians who had provided care to coronavirus disease 2019 patients.

CONCLUSIONS

This national ICU clinician survey identifies continued concerns regarding personal protective equipment supplies with the chief issue being N95 respirator availability. As the pandemic continues, ICU clinicians anticipate a number of limited resources that may impact ICU care including personnel, capacity, and surge potential, as well as staff and subsequent family members exposure to severe acute respiratory syndrome coronavirus 2. These persistent concerns greatly magnify personal stress, offering a therapeutic target for professional organization and facility intervention efforts.