Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Young-onset type 2 diabetes and younger current age: increased susceptibility to retinopathy in contrast to other complications

BACKGROUND

Type 2 diabetes diagnosed during youth and early adulthood is aggressive and associated with a high burden of vascular complications. The increase in complications is often attributed to long disease duration and poor metabolic control. Whether people with young-onset type 2 diabetes are inherently more susceptible to long-term complications than those diagnosed in later adulthood is unclear.

METHODS

Prospective data from 3322 individuals, diagnosed between the age of 15 and 70 years and collected 10-25 years after diabetes diagnosis, were analysed. The cross-sectional associations between age at diagnosis and microvascular and macrovascular complications were analysed using logistic regression models, adjusted for duration of diabetes exposure and metabolic risk factors including blood pressure, cholesterol and updated mean HbA_1c .

RESULTS

The prevalence of retinopathy was highest in those with young-onset type 2 diabetes (diagnosed at age 15 to <40 years). After 10-15 years' diabetes duration, the adjusted odds ratio for retinopathy in this population was 2.8 (95% CI 1.9-4.1; reference group those diagnosed at 60 to <70 years of age). The odds of retinopathy remained higher in people with young-onset type 2 diabetes after longer durations of diabetes exposure; the odds decreased with increasing age at diagnosis. This pattern was not observed in models of other complications: after 10-15 years' diabetes exposure, the adjusted odds ratios for albuminuria, peripheral neuropathy and macrovascular disease in people with young-onset type 2 diabetes were 0.5 (95% CI 0.4-0.8), 0.7 (95% CI 0.5-1.1) and 0.2 (95% CI 0.1-0.3), respectively.

CONCLUSION

After accounting for disease duration and other important confounders, people with type 2 diabetes diagnosed in youth and early adulthood (or with a younger current age) appeared to be inherently more susceptible to retinopathy. For other complications, adjusted risk appears highest in the oldest age of diagnosis group. These data have screening and treatment target implications.

1138 OSA In A Patient With PFO, Is It The “Perfect Storm” For A Stroke? A Case Series Of 3 Patients With Stroke At Young Age, Due To PFO And Comorbid OSA

Introduction

Approximately 25% of all strokes are cryptogenic in nature, and about 50% of all young patients with cryptogenic stroke are found to have patent foramen ovale (PFO), which is known to be the most common cause of right-to-left shunting (RTLS). Studies have shown a 2.2-fold increase in right-to-left shunt in patients with OSA and PFO, compared to patients with PFO alone. Hence, increasing the risk of cardio-embolic stroke in such patients. We present a case series of 3 patients with PFO that had embolic stroke at a young age and were found to have comorbid OSA, the likely exacerbating factor of a RTLS.

Methods

A 38-year old female, a 59-year old male, and a 27-year old female presented with stroke-like symptoms without clear vascular pathology. Upon further work-up, all were found to have PFO with RTLS. Subsequently, these patients were referred for sleep evaluation, and each one was found to severe REM-related OSA with prominent oxygen desaturations. All three patients were started on PAP therapy for control of their OSA. Two out of the 3 patients opted for PFO closure, and the 3rd patient opted for anti-platelet therapy alone. He has had no recurrence of TIA/stroke after 12 years so far.

Results

These cases illustrate a correlation between right-to-left shunting and severe REM-related OSA, through possible elevation of right-sided pressure due to nocturnal desaturations/hypoxemia. Hence, it is worth consideration that the increased right-sided pressure induced by apneic events in sleep may be a potential exacerbating factor in producing stroke-like symptoms sooner in patients with PFO than in patients with PFO who are without OSA.

Conclusion

It may be beneficial to assess young patients with stroke due to PFO, for comorbid OSA as a cause of the RTLS. This would help to prevent recurrent stroke in such patients and improve quality of life.

Support

No financial support.

1270 Wobbly Knees: Cataplexy Or Seizure? A Case Report

Introduction

Cataplexy (associated with narcolepsy) is difficult to differentiate from conditions such as seizure, syncope or TIA, but using validated clinical tools can help. We report a case that was mistakenly diagnosed as cataplexy, delaying diagnosis and treatment of his underlying seizures.

Report of Case

A 42 years old male presented with “freezing spells” described as spontaneous episodes of weakness in his knees. He may stagger and drop objects but had never fallen. He denies loss of consciousness. Post-ictally, he takes a moment to readjust his body and returns to baseline. There was no warning or aura before the episodes. These spells initially occurred 1-2 times/year in 2002, then progressed to 1/month by 2006 and then increased to 15 times/day in Jan 2019, lasting 5-10 seconds at a time. He became hesitant to drive. He was evaluated by a pulmonologist/sleep specialist. PSG showed Mild OSA but MSLT wasn’t suggestive of Narcolepsy. He was prescribed CPAP but stopped after 6 months since it didn’t improve his symptoms. He was prescribed Venlafaxine to treat presumptive Cataplexy, without any benefit. Eventually, he was referred to neurology/sleep clinic. Cataplexy questionnaire was administered and was negative: specifically, there were no emotional triggers of his episodes, such as hearing a joke, laughing or crying. Due to the stereotyped nature of his spells, he was referred to epilepsy specialist. He underwent 72 hours video EEG monitoring which showed that his clinical episodes were associated with EEG abnormality, suggestive of frontal lobe epilepsy. He was placed on Keppra and Oxcarbazepine. On follow up visit, he reported improvement in seizure frequency from 10-20/day to 1-2/day.

Conclusion

A validated1 clinical Tool such as Stanford Cataplexy questionnaire helps in differentiation of Cataplexy from other forms of transient muscle weakness. It can prevent 15 years delay in diagnosis and treatment of patients, or use of unnecessary medication.

0809 A Randomized Double-blind, Placebo Controlled Trial With Cross-over, To Assess The Efficacy Of Correcting Vitamin D Deficiency In Improving The Symptoms Of Restless Legs Syndrome (RLS)

Introduction

Recent studies have shown an association of low Vitamin D levels and severity of RLS symptoms. However, effect of treatment of Vit D deficiency on RLS symptoms was not reported, nor were other exacerbating factors for RLS such as iron deficiency or OSA addressed in prior studies, but have been addressed in our study.

Methods

This is an ongoing study at the JFKMC Sleep Clinic. Eligible Patients with RLS include those with vitamin D 25,hydroxy deficiency (&lt;20 ng/ml), or insufficiency (&lt;30 ng/ml). Such patients will be enrolled in the study after comorbid conditions like iron deficiency and OSA have been adequately corrected. Randomization of the patients will be done by the JFK pharmacy so the patient and provider are blinded to the substance. Substance A or B could be either Vitamin D3 Capsule 50,000 IU, or placebo. Each patient takes A for 6 weeks and then crosses over to B for 6 weeks. Weekly iRLS questionnaires will be collected. Actiwatch Device, to assess activity count per minute, will be worn on the ankle at night for one week time periods: at baseline, at end of 6 weeks of taking A and then at the end of 6 weeks of taking B. Vitamin D levels will also be assessed after each course of supplementation and correlated with subjective and objective findings.

Results

Between July 7, 2019 to current, 50 consecutive patients seen in sleep clinic with RLS were assessed for vitamin D levels. Ages ranged from 23-86 years. 27 patients were female (54%). Two patients met inclusion criteria and have started their 13-week study.

Conclusion

This study will help to establish the role of Vitamin D deficiency as a risk factor for RLS, independent of ferritin levels, and comorbid OSA, in affected individuals. This may help to discover a potentially treatable form of RLS.

Support

No financial support.

Intranasal octenidine and universal chlorhexidine bathing can reduce meticillin-resistant Staphylococcus aureus acquisition in an extended care facility in Singapore

Meticillin-resistant Staphylococcus aureus (MRSA) is prevalent in extended care facilities. We conducted a quasi-experimental before-after study in a 100-bed rehabilitation hospital, from January 2013 to June 2019. Universal chlorhexidine bathing was implemented throughout the period, with intranasal octenidine for MRSA colonizers added from September 2017. Interrupted time-series with segmented regression analysis revealed that after adjusting for at-admission MRSA colonization and hand hygiene compliance, a constant trend was observed pre implementation of intranasal octenidine (adjusted mean coefficient: 0.012; 95% confidence interval: -0.037 to 0.06), with an immediate decrease with implementation (-2.145; -0.248 to -0.002; P = 0.033), followed by a significant reduction in MRSA acquisition post implementation (-0.125; -0.248 to -0.002; P = 0.047).

COVID-19 in Singapore and Malaysia: Rising to the Challenges of Orthopaedic Practice in an Evolving Pandemic

With the increasing number of COVID-19 cases and related deaths worldwide, we decided to share the development of this condition in Singapore and Malaysia. First few cases were diagnosed in the two countries at the end of January 2020, and the numbers have surged to thousands by end of March 2020. We will focus on strategies adopted by the government and also the Orthopaedic community of the two countries up till the beginning of April 2020. We hope that by sharing of relevant information and knowledge on how we are managing the COVID-19 condition, we can help other communities, and health care workers to more effectively overcome this pandemic.

P319 Evidence for abnormal deformational reserve in hypertrophic cardiomyopathy on exercise: is it a game-changer?

Funding Acknowledgements

None

Hypertrophic obstructive cardiomyopathy (HOCM) is characterized by muscle hypertrophy and fibrosis, interfering with force generation and relaxation. Abnormal ventricular (LV) myocardial deformation have been demonstrated in patients with HOCM at rest, but there is lack of data regarding the deformational mechanics in exercise. AIMS: We wanted to assess the adaptability of LV deformational behaviour to physical exercise in HCM patients as compared to healthy control subjects.

METHODS

24 obstructive HOCM (age 51.2 ± 14.2yrs; 16 men, LVOT-obstruction 56 ± 19mmHg at rest or on Valsalva maneuver) and 32 control subjects (50.9 ± 6.8 yrs, 19 men from the MAGYAR-PATH Registry) underwent supine bicycle stress echocardiography (ESE) with measurements of 2D- and Doppler, 2D-Speckle Tracking Tracking Imaging and 3D-Full Volume Analysis. Beyond conventional LV/RV functional measurements; peak longitudinal (LS), circumferential (CS) Strain values; peak Twist and Torsion angles; post-systolic shortening index (PSS) and diastolic phase indices (Untwisting time - UTT and rate - UTR) calculated; the UTR/Twist ratio was given as "coupling index". The LV/RV-EF calculated by 3D-Full Volume Analysis off-line by TomTec Arena™ software both at rest and on submaximal ESE.

RESULTS

The HOCM group had lower resting LS (-14.6 ± 4.5 vs 18.4 ± 2.6%, p &lt; 001) but higher CS (-32.9 ± 5.1 vs 28.8 ± 2.3%, p &lt; 0.001) and Twist angles (9.9 ± 2.6 vs 6.1 ± 2.2º, p &lt; 0.01) than control subjects. Exercise induced an increase in all strains in control subjects, but much less in HOCM (LS: -21.4 ± 3.5 vs 15.1 ± 3.0% and CS: -33.9 ± 3.6 vs 34.1 ± 4.2% in HOCM, p &lt; 0.02 in controls, NS in HOCM); the increase of Twist angle was minimal in HOCM (Δ1.2 ± 1.2 vs Δ3.6 ± 2.3º in controls, p &lt; 0.01). The PSS was more pronounced on ESE in HOCM than in controls (46.6 ± 12 vs 21.2 ± 9.6% in controls, p &lt; 0.001). Peak UTR was slower (118 ± 2.1 vs 133.1 ± 14.1 º/s) during ESE and occured later (141 ± 19 vs 121 ± 9.1% of systolic time, p &lt; 0.02) in HOCM than in controls. There was significant relationship between the Twist and UTR in control subjects (β=-0.0807, p &lt; 0.001), but not in HOCM (β=-0.0046, p = 0.05). The UTR/Twist ratio diminished only in HOCM but not in controls (-8.0 ± 0.6 vs -13.1 ± 2.5 1/s, p &lt; 0.02).

CONCLUSIONS

The HOCM patients had significantly impaired strain-adaptability; developed post-systolic shortening and no LV Torsional reserve was found on exercise. Also, I detected decreased and delayed UTR indices in the HOCM group. These findings support evidence for reduced systolic-diastolic coupling efficiency, assessed by Twist-Untwist mechanics in HOCM patients, which can contribute to the development of exercise-related symptoms and the dynamic LVOT-obstruction. This unique pattern of deformational behaviour to exercise can help in the differential diagnostic workup in patients with LV hypertrophy of unknown aetiology and also would hold additional value in the risk stratification process for patients with HCM-phenotypes.

Let-7 regulates cell cycle dynamics in the developing cerebral cortex and retina

In the neural progenitors of the developing central nervous system (CNS), cell proliferation is tightly controlled and coordinated with cell fate decisions. Progenitors divide rapidly during early development and their cell cycle lengthens progressively as development advances to eventually give rise to a tissue of the correct size and cellular composition. However, our understanding of the molecules linking cell cycle progression to developmental time is incomplete. Here, we show that the microRNA (miRNA) let-7 accumulates in neural progenitors over time throughout the developing CNS. Intriguingly, we find that the level and activity of let-7 oscillate as neural progenitors progress through the cell cycle by in situ hybridization and fluorescent miRNA sensor analyses. We also show that let-7 mediates cell cycle dynamics: increasing the level of let-7 promotes cell cycle exit and lengthens the S/G2 phase of the cell cycle, while let-7 knock down shortens the cell cycle in neural progenitors. Together, our findings suggest that let-7 may link cell proliferation to developmental time and regulate the progressive cell cycle lengthening that occurs during development.

Multiple Shape Coexistence in ^{110,112}Cd

From detailed spectroscopy of ^{110}Cd and ^{112}Cd following the β^{+}/electron-capture decay of ^{110,112}In and the β^{-} decay of ^{112}Ag, very weak decay branches from nonyrast states are observed. The transition rates determined from the measured branching ratios and level lifetimes obtained with the Doppler-shift attenuation method following inelastic neutron scattering reveal collective enhancements that are suggestive of a series of rotational bands. In ^{110}Cd, a γ band built on the shape-coexisting intruder configuration is suggested. For ^{112}Cd, the 2^{+} and 3^{+} intruder γ-band members are suggested, the 0_{3}^{+} band is extended to spin 4^{+}, and the 0_{4}^{+} band is identified. The results are interpreted using beyond-mean-field calculations employing the symmetry conserving configuration mixing method with the Gogny D1S energy density functional and with the suggestion that the Cd isotopes exhibit multiple shape coexistence.

Increased tuberculosis risk among immigrants arriving in California with abnormal domestic chest radiographs

SETTING

Tuberculosis (TB) cases in California, USA, occur predominantly among foreign-born persons, many of whom have abnormal chest radiographs (CXRs) on overseas medical examination. These persons are recommended for follow-up TB evaluation upon arrival in the United States.

OBJECTIVE

To estimate the increased TB risk associated with abnormal vs. normal domestic CXRs among individuals arriving with abnormal overseas CXRs.

DESIGN

Cox regression analyses of 35 633 foreign-born persons aged 15 years who arrived in California during 1999-2012 with abnormal overseas CXRs and were free of imported active TB. Domestic CXRs were conducted during post-arrival evaluation. Subsequent cases through 2014 were identified from California's TB registry.

RESULTS

A total of 121 (0.3%) arrivers developed TB disease. Progression rates were respectively 63.6 (95%CI 50.8-76.4) and 25.4 (95% CI 15.7-35.2) cases/100 000 person-years among persons with abnormal and normal domestic CXRs. Relative to arrivers with normal domestic CXRs, those with abnormal domestic CXRs had an elevated disease risk during the first 4 years after immigration; this increased risk was greatest during the first year (hazard ratio 2.9, 95%CI 1.8-4.8).

CONCLUSION

Among arrivers with abnormal overseas CXRs, those with abnormal CXRs upon domestic evaluation have an elevated disease risk and represent an important target group for preventive treatment.