Successful and Rapid Reduction in Neurosedative and Analgesic Medications in Complex Infants with Severe Bronchopulmonary Dysplasia After Tracheostomy Placement: Experience with 24-hour Propofol Infusions.

Infants with severe bronchopulmonary dysplasia may require high doses of neurosedative medications to ensure pain control and stability following tracheostomy placement. Subsequent weaning of these medications safely and rapidly is a challenge. We describe a 24-hour propofol infusion to reduce neurosedative medications in 3 high-risk infants following tracheostomy placement.

Stability and Compatibility of an Intramuscular Fetal Anesthetic Cocktail for Fetal Intervention.

INTRODUCTION: The aim of the study was to evaluate chemical stability and physical compatibility when combining fentanyl, rocuronium, and atropine in a fixed ratio to support intramuscular drug delivery during fetal intervention and surgery. METHODS: A highly concentrated combination of fentanyl, rocuronium, and atropine was created based on common prescribing practices at a maternal-fetal care center. Chemical stability testing was completed using liquid chromatograph mass spectrometry-mass spectrometry (LC/MS-MS) to detect and quantitate atropine, rocuronium, and fentanyl, with fentanyl-d5 being an internal standard at 6, 12, 24, and 36 h following sample preparation. Physical compatibility testing was completed using United States Pharmacopeia (USP) <788> recommended analytical technique of light obscuration in addition to novel backgrounded membrane imaging at 6 and 24 h following sample preparation. Physical compatibility was determined using USP <788> particle count limits for both techniques. RESULTS: Based on LC/MS-MS results, the samples retained expected medication concentrations at all time points tested. For physical compatibility testing, the particle counts met criteria to be considered compatible per USP <788> large-volume particle count thresholds at 6 h by both methods but exceeded tolerable thresholds at 24 h. DISCUSSION/CONCLUSION: The combination of rocuronium, fentanyl, and atropine for intramuscular fetal administration is physically compatible and chemically stable for 6 h.

Mortality risk following self-harm in young people: a population cohort study using the Northern Ireland Registry of Self-Harm.

BACKGROUND: Self-harm is a recognised predictor of suicide and is most common in those aged under 25 years. The aims of this study were to describe the characteristics of young people who present with self-harm; quantify the risk of suicide and other causes of death during follow up, and to identify factors associated with mortality risk. METHODS: The Northern Ireland Registry of Self-Harm (NIRSH) is a national registry capturing complete data on all presentations made to the 12 Emergency Departments (EDs) in Northern Ireland (NI). Data relating to self-harm presentations registered in the NIRSH between 2012 and 2015 were linked to primary care registrations and death records up until 31st December 2018. Logistic regression was employed to examine the factors associated with self-harm. Cox regression was used to estimate mortality risk following self-harm and explore the associated risk factors. RESULTS: The cohort consisted of 390,740 individuals aged 10-24 years registered with a General Practitioner (GP) in NI. During follow-up, 4,450 individuals presented with self-harm. Rates of self-harm were highest in females, those aged 20-24 years (ORadj  = 3.53, 95% CI 3.28-3.80, p < .001), and in the most deprived areas (ORadj  = 2.71, 95% CI 2.45-2.99, p < .001). Thirty five individuals who presented with self-harm died by suicide, accounting for 23% of all suicide deaths in the cohort. Suicide risk was increased 19-fold in those who presented with self-harm after adjustment for age, sex and area-level factors (HRadj  = 19.00, 95% CI 12.80-28.21, p < .001). Increased suicide risk was observed in males (HRadj  = 2.04, 95% CI 0.99-4.23, p = .05) and those using more violent methods of self-injury (HRadj  = 3.89, 95% CI 1.65-9.13, p < .001). CONCLUSIONS: Young people who self-harm are at a significantly greater risk of suicide. Almost a quarter of young people who died by suicide in NI had presented to EDs with self-harm, highlighting that the ED may provide a nodal point of intervention among a typically hard to identify and reach population.

Suicide risk following ED presentation with self-harm varies by hospital.

BACKGROUND: Patients presenting to Emergency Department (ED) with self-harm are recognized to be at high risk of suicide and other causes of death in the immediate period following ED presentation. It is also recognized that there is a large variation in the management and care pathways that these patients experience at EDs. AIMS: This study asks if there is a significant variation in mortality risk according to hospital attended and if this is explained by differences in care management. METHODS: Population-wide data from the Northern Ireland Registry of Self-Harm from April 2012 were linked with centrally held mortality records to December 2019, providing data on self-harm type and ED care. Cox proportional hazards models analyzed mortality risk, coded as suicide, all-external causes and all-cause mortality. RESULTS: Analysis of the 64,350 ED presentations for self-harm by 30,011 individuals confirmed a marked variation across EDs in proportion of patients receiving mental health assessment and likelihood of admission to general and psychiatric wards. There was a significant variation in suicide risk following attendance according to ED attended with the three-fold range between the lowest (HRadj 0.32 95% CIs 0.16, 0.67) and highest. These differences persisted even after adjustment for patient characteristics, variation in types of self-harm, and care management at the ED. CONCLUSIONS: This study suggests that while the management of self-harm cases in the ED is important, it is the availability and access to, and level of engagement with, the subsequent management and care in the community rather than the immediate care at EDs that is most critical for patients presenting to ED with self-harm. However, the initial care in ED is an important gateway in initiating referrals to these services.

Does poor mental health explain socio-demographic gradients in breast cancer screening uptake? A population-based study.

BACKGROUND: Research from the USA indicates disparities in breast cancer screening uptake for women with poor mental health. However, no attempt has been made to examine the contribution of poor mental health to socio-demographic variations in breast screening uptake. The current study aims to examine the impact of self-reported chronic poor mental health on attendance at breast screening in the UK, and to what extent this explains socio-demographic inequalities in screening uptake. METHODS: Breast screening records were linked to 2011 Census records within the Northern Ireland Longitudinal Study. This identified a cohort of 57 328 women who were followed through one 3-year screening cycle of the National Health Service Breast Screening Programme. Information on mental health status, in addition to other individual and household-level attributes, was derived from the 2011 Census. Logistic regression was employed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of attendance at screening. RESULTS: 10.7% of women in the cohort reported poor mental health, and in fully adjusted analyses, these individuals were 23% less likely to attend breast screening (OR 0.77; 95% CI 0.73-0.82). Although poor mental health was a strong predictor of screening uptake, it did not explain the observed inequalities in uptake by socio-economic status, marital status, or area of residence. CONCLUSIONS: This study provides novel evidence of inequalities in breast screening uptake for women with chronic poor mental health in the UK. Targeted interventions are necessary to ensure equitable screening access and to enhance overall mortality benefit.

Perceiving and expressing feelings through actions in relation to individual differences in empathic traits: the Action and Feelings Questionnaire (AFQ).

Empathy is usually conceived of as independent of the non-verbal behaviors which mediate its experience, though embodied cognition theory predicts that individual differences in action representation will affect empathic traits. The "Actions and Feelings Questionnaire" (AFQ) was designed to capture individual differences in self-awareness of own and others' actions, particularly those associated with feelings, which we predicted would correlate with levels of empathic traits. A pilot 30-item questionnaire included items on perceptual sensitivity to action, imitation, action imagery, and gestural and facial expression. It was completed by a sample of 278 adults (mean age 21.2 years; 189 females, 89 males) along with the 15-item Empathic Quotient (EQ) Questionnaire. Total scores on the final 18-item questionnaire showed strong internal coherence (Cronbach's alpha of 0.81) and test-retest reliability (ICC=0.88), marked effect of sex and highly significant correlation with EQ. The questionnaire was administered to participants in an fMRI study investigating the neural correlates of facial imitation. Total AFQ score correlated with activity in somatosensory cortex, insula, anterior cingulate, and visual cortex. The AFQ shows promise as a brief and simple self-report measure sensitive to variability in the self-awareness of actions associated with feelings. It suggests that much of the variability of empathic traits in typical populations is accounted for by variance in this capacity. We suggest that being more empathic really is about being "touchy-feely," and this questionnaire provides a novel measure of action-based empathy.

The effect of transcranial direct current stimulation on task processing and prioritisation during dual-task gait.

The relationship between cognition and gait is often explored using a dual-task gait paradigm, which represents the ability to divide cognitive resources during walking. Recent evidence has suggested that the prefrontal cortex is involved in the allocation of cognitive resources during dual-task gait, though its precise role is unclear. Here, we used anodal and cathodal transcranial direct current stimulation (tDCS) to probe the role of the prefrontal cortex in the control of stride time variability (STV), trunk RoM and cognitive task performance during dual-task gait. As task difficulty has been shown to mediate the dual-task cost, we also manipulated walking speed to see whether the effects of tDCS on dual-task gait were influenced by walking difficulty. Ten adults performed a serial subtraction task when walking at either preferred walking speed or 25 % of preferred walking speed, before and after receiving tDCS of the left prefrontal cortex. Anodal tDCS reduced STV and the dual-task cost on STV and improved cognitive task performance. Cathodal tDCS increased STV and appeared to increase the dual-task cost on STV, but did not affect cognitive task performance. There was no effect of tDCS on trunk RoM, and the effects of tDCS were not mediated by walking speed. The effect of dual-task gait on stride time variability and cognitive task performance was altered by the application of tDCS, and these effects were polarity dependent. These results highlight the role of the prefrontal cortex in biasing task performance during dual-task gait and indicate that tDCS may be a useful tool for examining the role of the cortex in the control of dual-task gait.

Effect of Practical Precooling on Neuromuscular Function and 5-km Time-Trial Performance in Hot, Humid Conditions Among Well-Trained Male Runners.

This study investigated whether torso and thigh precooling during a warm-up effects neuromuscular function and 5-km time-trial performance in hot, humid conditions. Eight well-trained male runners completed 3 randomized time-trials in 32.2 ± 0.8° C and 48.6 ± 6.7% relative humidity. A 30-minute warm-up was completed with no cooling (Control), precooling by an ice vest (Vest), or ice packs covering the thighs (Packs). Before the warm-up and after the time-trial, supramaximal femoral nerve stimulation was delivered during and following maximal isometric contractions. Core and skin temperature, heart rate, and perceptual ratings were recorded before and during the warm-up and time-trial. Overall performance time was improved in Packs compared with Control (1,407 ± 80 seconds vs. 1,492 ± 88 seconds; p ≤ 0.05) but not in Vest (1,444 ± 71 seconds; p > 0.05). In Packs, a higher exercise intensity (p ≤ 0.05) and less cumulative time (p < 0.01) were evident during the last kilometer compared with Control. Maximum voluntary force, voluntary activation, muscle contractility, and membrane excitability were not different after exercise or between conditions. Ten minutes after the warm-up, skin temperature was lower in Vest and Packs compared with Control (p < 0.01). Thermal strain and body heat content change was lower in Vest and Packs, respectively (p ≤ 0.05). Findings indicate that torso and thigh precooling during a warm-up reduces thermoregulatory strain. However, thigh opposed to torso precooling provides greater performance improvements. Neuromuscular function did not aid performance, indicating that transient changes in afferent feedback and muscle recruitment may enhance endurance trial performance.

Peak power output provides the most reliable measure of performance in prolonged intermittent-sprint cycling.

The aims of this study were to determine the reliability of an intermittent-sprint cycling protocol and to determine the efficacy of one practice session on main trials. Eleven men, moderately trained team-sport athletes, completed three visits to the laboratory involving a graded-exercise test and practice session and two trials of a cycling intermittent-sprint Protocol separated by three days. Data for practice and main trials were analysed using typical error of measurement, intra-class correlation and least-products regression to determine reliability. Typical error of measurement (expressed as a coefficient of variation) and intra-class correlation for peak power output from all 20 sprints for trial 1 and trial 2 were 2.9 ± 12.8% (95% confidence interval: 2.0-5.0%) and 0.96 (95% confidence interval: 0.85-0.99), respectively. Typical errors of measurement and intra-class correlation for mean power output for all 20 sprints for trials 1 and 2 were 4.2 ± 11.9% (95% confidence interval: 2.9-7.4%) and 0.90 (95% confidence interval: 0.66-0.97), respectively. The results suggest that peak power output provides a more reliable measure than mean power output. The Cycling Intermittent-Sprint Protocol provides reliable measures of intermittent-sprint performance.

Physical compatibility of medications with concentrated neonatal and pediatric parenteral nutrition: A simulated Y-site drug compatibility study.

BACKGROUND: The physical intravenous Y-site compatibility of 15 different medications with highly concentrated neonatal and pediatric parenteral nutrition (PN) compounds is described, using existing and novel methods. METHODS: PN formulations were developed based on common prescribing practices in a 400+-bed freestanding children's hospital. Medications at commonly used pediatric concentrations were mixed in a 1:1 ratio with both pediatric and neonatal PN formulations and incubated at room temperature for 4 h to simulate Y-site administration. Samples were then analyzed using the light obscuration (LO) technique, as recommended by United States Pharmacopeia (USP) chapter 788, in addition to novel flow imaging (FI) microscopy and backgrounded membrane imaging (BMI). Physical compatibility was determined using USP 788 particle count limits for all techniques. RESULTS: Most combinations were found to be compatible per USP 788 thresholds. Pediatric PN was incompatible by at least two methods with cisatracurium 2 mg/ml, sildenafil 0.8 mg/ml, furosemide 10 mg/ml, and ketamine 10 mg/ml. Neonatal PN was incompatible by at least two methods with cisatracurium 2 mg/ml and furosemide 10 mg/ml. Overall, results for 20 of the 30 combinations (66%) agreed across all three methods. FI and BMI results agreed for 22 of 30 combinations. LO agreed with FI in 25 of 30 combinations, and BMI and LO results agreed in 23 of 30 combinations. CONCLUSION: Most combinations tested were found to be compatible across all methods. Novel methods of FI and BMI seem useful to further evaluate LO findings and improve accuracy of particle counts when assessing PN-medication combinations.

Physical Compatibility of Y-site Pediatric Drug Administration: A Call for Question of US Pharmacopeia Standards.

OBJECTIVE: To evaluate the physical intravenous Y-site compatibility of 29 combinations of medications at commonly used pediatric concentrations using both existing and novel techniques. METHODS: Medication combinations included were selected by a varied group of pediatric inpatient pharmacists, and then assessed by 3 independent reviewers for existing literature. For each combination, 2 different medications were mixed together in a 1:1 ratio and incubated at room temperature for 4 hours to simulate Y-site administration. Each sample was then analyzed using the US Pharmacopeia (USP) <788> recommended analytical technique of light obscuration (LO) in addition to novel flow imaging (FI) microscopy and backgrounded membrane imaging (BMI). Physical compatibility was determined using USP chapter <788> large volume particle count limits for all techniques. RESULTS: A total of 29 different medication combinations were studied. Five combinations met criteria for compatibility by all 3 techniques. The remaining 24 combinations reached the threshold to be considered incompatible by at least 1 of the 3 techniques. Light obscuration, BMI, and FI identified 14%, 59%, and 76% of combinations as incompatible, respectively. All samples deemed incompatible by LO were also incompatible by at least 1 of the other 2 techniques. Flow imaging and BMI results agreed in 69% of samples tested. CONCLUSIONS: Most combinations tested were found to be incompatible by at least 1 of the 3 instruments used. Light obscuration appears to have reduced accuracy for identifying particulate resulting in physical medication incompatibility when compared with the novel techniques of FI and BMI.

Psychosocial and Cultural Processes Underlying the Epidemiological Paradox within U.S. Latino Sexual Risk: A Systematic Review.

According to the epidemiological paradox, less acculturated Latina/o youth display fewer sexual risk behaviors. A systematic review was performed on psychosocial and cultural mechanisms potentially underlying the epidemiological paradox in sexual risk behaviors of U.S. Latina/o youth across acculturation measures (between January 2000 to October 2022). Thirty-five publications (n = 35) with forty-eight analyses of underlying mechanisms met the inclusion criteria. Thirty-one results from twenty-three publications found supporting evidence that one of the five factors was an underlying mechanism in the epidemiological paradox (n = 13 parenting practices, n = 4 peer influences, n = 4 familismo values, n = 4 religiosity, n = 6 traditional gender norms) as, generally protective, mediators or moderators in the link between acculturation and sexual risk behaviors. Studies varied in the sexual risk behavior examined and measurement of acculturation, but primarily employed cross-sectional designs and recruited samples through schools. Mechanisms that enhance close ties and unity of the family, such as those of familismo values and positive parenting, reduce the likelihood of sexual risk behaviors as Latina/o youth become more acculturated. Future directions are discussed which may provide guidance for risk prevention and intervention.

Successful Management of Fetal Torsades de Pointes and Long QT Syndrome by a Cardio-Obstetrical Team.

A 32-week fetus with tachycardia and bradycardia, diagnosed with torsades de pointes, atrioventricular block, and sinus bradycardia due to a de novo KCNH2 mutation was successfully managed by a cardio-obstetrical team. Maternal/fetal pharmacogenomic testing resulted in appropriate drug dosing without toxicity and delivery of a term infant in sinus rhythm.

Supraspinal fatigue after normoxic and hypoxic exercise in humans.

Inadequate cerebral O2 availability has been proposed to be an important contributing factor to the development of central fatigue during strenuous exercise. Here we tested the hypothesis that supraspinal processes of fatigue would be increased after locomotor exercise in acute hypoxia compared to normoxia, and that such change would be related to reductions in cerebral O2 delivery and tissue oxygenation. Nine endurance-trained cyclists completed three constant-load cycling exercise trials at ∼80% of maximal work rate: (1) to the limit of tolerance in acute hypoxia; (2) for the same duration but in normoxia (control); and (3) to the limit of tolerance in normoxia. Throughout each trial, prefrontal cortex tissue oxygenation and middle cerebral artery blood velocity (MCAV) were assessed using near-infrared spectroscopy and trans-cranial Doppler sonography, respectively. Cerebral O2 delivery was calculated as the product of arterial O2 content and MCAV. Before and immediately after each trial, twitch responses to supramaximal femoral nerve stimulation and transcranial magnetic stimulation were obtained to assess neuromuscular and cortical function, respectively. Exercise time was reduced by 54%in hypoxia compared to normoxia (3.6 ± 1.3 vs. 8.1 ± 2.9 min; P<0.001). Cerebral O2 delivery,cerebral oxygenation and maximum O2 uptake were reduced whereas muscle electromyographic activity was increased in hypoxia compared to control (P <0.05).Maximum voluntary force and potentiated quadriceps twitch force were decreased below baseline after exercise in each trial;the decreases were greater in hypoxia compared to control (P<0.001), but were not different in the exhaustive trials (P>0.05). Cortical voluntary activation was also decreased after exercise in all trials, but the decline in hypoxia (Δ18%) was greater than in the normoxic trials (Δ5-9%)(P <0.05). The reductions in cortical voluntary activation were paralleled by reductions in cerebral O2 delivery. The results suggest that curtailment of exercise performance in acute severe hypoxia is due, in part, to failure of drive from the motor cortex, possibly as a consequence of diminished O2 availability in the brain.

Effects of Transportation of IV Bags Containing Protein Formulations Via Hospital Pneumatic Tube System: Particle Characterization by Multiple Methods.

In hospitals, often drug products in intravenous (IV) bags are transported via pneumatic tube systems (PTS). The goal of this study was to evaluate the effects of such transportation of protein products on particle formation in polyvinyl chloride (PVC) and polyolefin (PO) IV bags, containing either IV saline or dextrose. We studied intravenous immunoglobulin (IVIG) and a monoclonal antibody (mAb). Particles were quantified with flow imaging, light obscuration and nanoparticle tracking analysis. PTS transportation of IVIG caused large increases in protein particle concentrations, with much greater increases observed in saline than in dextrose. The increases were greater in IV solutions in PO than those in PVC bags. With the mAb, PTS transportation in saline caused increases in protein particle levels in PO bags, but not in PVC bags. Transportation in dextrose did not result in significant increases in mAb particle concentrations in IV bags made of either material. Overall, the results document that the PTS transportation can result in large increases in protein particles and that magnitude of these increases depends the protein itself, the bag material and the IV solution. The main conclusion is that protein products in IV solutions should not be transported in hospital PTS.

Disparities in Breast Cancer Screening Uptake for Women With Mental Illness in the United Kingdom.

INTRODUCTION: Although there is evidence of disparities in breast cancer screening for women with mental illness in the U.S., there is a dearth of studies examining this association in the United Kingdom, where health care is provided free at the point of access. This population-based study examines the influence of mental illness, as assessed by the uptake of psychotropic medications, on breast screening uptake in the United Kingdom. METHODS: A cohort of 57,328 women identified from 2011 Census records within the Northern Ireland Longitudinal Study was followed through a single 3-year screening cycle (2011-2014) of the National Health Service Breast Screening Programme. Mental illness was identified by a receipt of psychotropic medication in the 3 months preceding screening invite. Individual- and household-level attributes were derived from Census records. Data were analyzed in 2019. RESULTS: More than a third of women received ≥1 prescription for psychotropic medication in the 3 months preceding screening invite. The odds of attendance in these individuals were reduced by 15% (OR=0.85, 95% CI=0.81, 0.88). Attendance was particularly low for women prescribed antipsychotics (OR=0.63, 95% CI=0.56, 0.70), anxiolytics (OR=0.61, 95% CI=0.57, 0.66), and hypnotics (OR=0.68, 95% CI=0.63, 0.72). CONCLUSIONS: These findings confirm the existence of significant disparities in breast screening uptake for women with mental illness. Targeted interventions are warranted to prevent avoidable breast cancer deaths in these individuals, especially given the increasing prevalence of mental illness.

Treatment outcome with a selective RET tyrosine kinase inhibitor selpercatinib in children with multiple endocrine neoplasia type 2 and advanced medullary thyroid carcinoma.

BACKGROUND: Medullary thyroid carcinoma (MTC) in the context of multiple endocrine neoplasia type 2 (MEN2) is caused by mutations in the RET proto-oncogene. Therefore, in children with MEN2 and advanced MTC, the RET tyrosine kinase (TK) pathway is a target for treatment with selpercatinib, a selective RET TK inhibitor. PATIENTS AND METHODS: A retrospective review of the clinical, genetic, biochemical (calcitonin and carcinoembryonic antigen [CEA]) and imaging data of six medically untreated children with MEN2 and recurrent and or progressive MTC. The main parameters were safety and objective treatment response to selpercatinib. RESULTS: Six children (three males and three females, aged 3-12 years), four with MEN2B and two MEN2A, are reported. All had initial total thyroidectomy and extensive neck dissections but subsequently developed recurrent and progressive disease. All experienced an improvement in clinical symptoms with a concomitant biochemical response evidenced by significant fall in serum calcitonin and CEA concentrations. The fall in serum calcitonin was evident within 2 weeks of the start of selpercatinib, and responses were ongoing at a median follow-up of 13 months (range, 11-22 months). Four children with measurable radiological disease had good volume reduction. The most common adverse effects were transient but reversible grade 1 or 2 increase in alanine aminotransferase, serum bilirubin and constipation. No child required a dose modification or had to discontinue selpercatinib because of a drug-related adverse event. CONCLUSION: Selpercatinib has shown excellent therapeutic efficacy with minimal toxicity in children with MEN2 and progressive metastatic RET-mutated MTC.

Disability as a predictor of breast cancer screening uptake: A population-based study of 57,328 women.

OBJECTIVE: Despite a growing body of evidence suggesting inequalities in breast cancer screening uptake in the United States for women with disabilities, few attempts have been made to examine whether this association applies to the United Kingdom. We conducted the first population-wide study investigating the impact of disability on uptake of breast cancer screening in Northern Ireland. METHODS: Breast screening records extracted from the National Breast Screening System were linked to the Northern Ireland Longitudinal Study. This identified a cohort of 57,328 women who were followed through one complete three-year screening cycle of the National Health Service Breast Screening Programme in Northern Ireland. The presence of disability was identified from responses to the 2011 Census. RESULTS: Within this cohort, 35.8% of women reported having at least one chronic disability, and these individuals were 7% less likely to attend compared with those with no disability (odds ratio 0.93; 95% confidence interval 0.89-0.98). Variation in the degree of disparity observed was evident according to the type and number of comorbid disabilities examined. CONCLUSION: This is the first population-wide study in Northern Ireland to identify disparities in breast screening uptake for women with chronic disabilities, in particular, those with multimorbidity. This is of particular concern, given the projected rise in the prevalence of disability associated with the ageing population.

Compatibility of medications with intravenous lipid emulsions: Effects of simulated Y-site mixing.

PURPOSE: To determine the physical intravenous Y-site compatibility of 19 commonly used medications at pediatric concentrations with 3 different types of lipid emulsion. METHODS: Medications at commonly used pediatric concentrations were mixed in a 1:1 ratio with lipid emulsions (Intralipid, Nutrilipid, and Smoflipid) and incubated at room temperature for 4 hours to simulate Y-site administration. Each sample was then diluted with particle-free water and analyzed using the analytical technique of light obscuration recommended in United States Pharmacopeia (USP) general information chapter 729 (USP <729>). Physical compatibility was determined by measuring the percentage of fat residing in globules larger than 5 µm (PFAT5) per USP <729> recommendations. RESULTS: Most combinations tested were physically compatible based on USP <729> regulations. Incompatibilities differed for the different brands of lipid emulsion. The two combinations that met USP <729> criteria for physical incompatibility were cisatracurium 2 mg/mL with Intralipid and gentamicin 2 mg/mL with Smoflipid. CONCLUSION: Three different lipid emulsions were physically compatible at the Y site with the majority of medications tested. Data regarding Y-site compatibility for one lipid emulsion product cannot be safely extrapolated to another without additional testing.