COVID-19: using chest CT of major trauma patients to monitor and evaluate the effect of lockdown and the importance of household size.

AIM: To use theory and practice to show how disease progression and regression can be described pre- and post-lockdown using an attack-sustain-decline-respite (ASDR) model and investigate how pre-lockdown disease prevalence and household size impacts on the effectiveness of lockdown. MATERIALS AND METHODS: Computed tomography (CT) scans from major trauma patients (considered as a random population sample) from the radiology department of St George's University Hospitals NHS Trust, London, have been used to explore COVID-19 disease at the population level. RESULTS: At lockdown on 23 March 2020 in the catchment area of St George's University Hospitals NHS Trust, an earlier paper showed that there was a high prevalence of disease of >20%. With further follow-up and at the end of lockdown, it have been now estimated that around 57% of the population had been affected, which was similar to that predicted from a simple model based on average household size and prevalence at lockdown. With an average household size of around three persons, there was a 2-week sustain period and a 5-week decline period before the prevalence of the disease returned to background levels. CONCLUSIONS: The present results suggest that the effect of lockdown is dependent on the disease prevalence at the start of lockdown and the average household size. It may therefore be important to lockdown early in an area with a high average household size. This paper is the second in a series of papers to show how radiology measurements of major trauma patients can be used to help monitor the spread of the COVID-19 pandemic.

COVID-19: could CT provide the best population level biomarker? Incidental COVID-19 in major trauma patients suggests higher than predicted rates of infection in London.

AIM: To evaluate incidental findings in major trauma patients, and to explore whether computed tomography (CT) could be used to assess prevalence and estimate disease spread in the general population. MATERIALS AND METHODS: The study population included all patients admitted following major trauma between 1 January 2020 and 30 April 2020 with CT including the lungs (n=523). Major trauma patients admitted pre-COVID-19 from 1-31 January and 1-31 March 2019 comprised a control group (n=252). The assessing radiologists, blinded to the time period, used double reading with consensus to determine if the patient had CT signs of COVID-19. Lung appearances were classified as no evidence of COVID-19; minor signs; or major signs. The proportion of patients with incidental COVID-19 changes was recorded over the study period, and the percentage of the population who had been affected by COVID-19 by the end of April 2020 estimated. RESULTS: CT appearances consistent with COVID-19 began to exceed a background pre-COVID rate in the second week of February and did not decline until 2 weeks after lockdown. By the end of April 2020, approximately 45% of the population had been infected. CONCLUSIONS: CT of major trauma patients can be used to monitor the spread of COVID-19. This novel technique could be used retrospectively or prospectively anywhere where trauma scans are available, to monitor the disease in the local population.

Frequency and severity of general surgical emergencies during the COVID-19 pandemic: single-centre experience from a large metropolitan teaching hospital.

INTRODUCTION: The COVID-19 pandemic has put significant stress on healthcare systems globally. This study focuses on emergency general surgery services at a major trauma centre and teaching hospital. We aimed to identify whether the number of patients and the severity of their presentation has significantly changed since the implementation of a national lockdown. MATERIALS AND METHODS: This study is a retrospective review of acute referrals (from general practice and accident and emergency) to the emergency general surgery team over a 14-day period before (group 1) and during (group 2) lockdown. RESULTS: A total of 151 patients were reviewed by the general surgical team in group 1 and 75 in group 2 (a 50.3% reduction). The number of days with symptoms prior to presentation was significantly shorter in group 1 compared with group 2 (3 vs 4, p = 0.04). There was no significant difference in the National Early Warning Score, white blood cell count, lymphocytes and C-reactive protein on admission between the two groups of patients. There were significantly fewer patients admitted after lockdown compared with pre-lockdown (66% vs 48%, p = 0.01). Length of hospital stay was significantly shorter during lockdown compared with pre-lockdown (5 days vs 4 days, p = 0.04). CONCLUSION: Fewer patients were referred and admitted during lockdown compared with pre-lockdown, and the length of stay was also significantly reduced. There was also a delay in presentation to hospital, although these patients were not more unwell based on the scoring criteria used within this study.

In-depth analysis of delays to patient discharge: a metropolitan teaching hospital experience.

Delayed patient discharge will likely exacerbate bed shortages. This study prospectively determined the frequency, causes and potential cost implications of delays for 83 consecutive patients, who were inpatients for a total of 888 days. 65% of patients experienced delay whilst awaiting a service. 48% of patients experienced delays that extended their discharge date. Discharge delays accounted for 21% of the cohort's inpatient stay, at an estimated cost of 565 sterling pounds per patient; 77% of these hold-ups resulted from delays in the provision of social and therapy requirements. Discharge delays are costly for hospitals and depressing for patients. Investment is required to enable health and social-care professionals to work more closely to improve the patient journey.

Hepatitis C and hepatic steatosis.

Hepatic steatosis is commonly seen in patients with chronic hepatitis C infection, and the two together have a greater association than by chance alone. Hepatitis C virus is closely associated with lipid metabolism throughout its lifecycle. Hepatic steatosis is more common in genotype 3 infection, due to direct viral effects including through microsomal triglyceride transfer protein, peroxisome proliferator activating receptor, and sterol regulatory element binding protein. In non-genotype 3 infection, hepatic steatosis is considered largely to be due to alterations in host metabolism, particularly through insulin resistance. The clinical relevance of this association has yet to be fully explored. Hepatic steatosis is associated with increased hepatic fibrosis and a reduced level of sustained virological response to pegylated interferon and ribavirin. Small studies trialing adjuvant anti-diabetic therapies or HMG-CoA reductase inhibitors with pegylated-interferon and ribavirin have shown an improved sustained virological response and reduced viral titer. Furthermore, simple lifestyle alterations showed positive effects on parameters of disease activity. These insights raise the possibility of novel treatment options.

Predictors of change in walking distance in patients with peripheral arterial disease undergoing endovascular intervention.

BACKGROUND: Endovascular treatment of peripheral artery disease is becoming frequent, yet the clinical factors which predict ambulatory outcomes are not known. HYPOTHESIS: To identify predictors of change in walking distance in patients who underwent endovascular intervention for their lower extremity peripheral arterial disease (PAD). METHODS: A total of 134 patients underwent lower extremity peripheral arterial intervention, 52 patients were contacted via phone between 1 and 36 months (a mean of 22 mo) after their initial procedure. The remaining 82 patients were excluded due to the following reasons: death (n = 13), contact information was not available (n = 50), and refusal to participate in the follow-up (n = 19). RESULTS: The patients were 63 +/- 12 years old (mean +/- standard deviation [SD]), 46% were male, 47% were diabetics, 49% had coronary artery disease, of whom 29% had prior revascularization, and 22% had coronary artery bypass grafts (CABG). The disease severity described by Fontaine classification were as follows: 44.2% were in stage II, 15.4% were in stage III, and 40.4% were in stage IV. Walking distance was improved in 21% of patients, worsened in 73% of patients, and unchanged in 6% of patients. Stepwise multiple regression demonstrated that patients who started to walk or exercise (R = 0.372, P < 0.012) and who had a prior history of CABG (R = 0.467, P < 0.006) were the only independent predictors of the change in walking distance at follow-up. Those who started to walk reported worse walking distance at follow-up, while those with a history of CABG reported better walking distance at follow-up. CONCLUSION: CABG prior to endovascular intervention is predictive of favorable change in walking distance in patients with PAD at follow-up. Therefore, post-CABG patients are good candidates for exercise rehabilitation and risk factor modification.

Ertapenem clearance during modeled continuous renal replacement therapy.

PURPOSE: To determine ertapenem transmembrane clearance (CLtm) during continuous renal replacement therapy (CRRT) using a validated in vitro model. METHODS: Ertapenem clearance during continuous hemofiltration and hemodialysis was assessed with AN69 and polysulfone hemodiafilters at 4 dialysate (Qd) and ultrafiltration rates (Quf): 1, 2, 3, and 6 l/hour. Blood and dialysate samples were collected at each flow rate and assayed for urea (control solute) and ertapenem concentrations. The experiment was repeated 5 times for each hemodiafilter type. Ertapenem and urea sieving coefficient (SC) and saturation coefficient (SA) were assessed, and CLtm calculated. RESULTS: In continuous hemofiltration mode, urea and ertapenem SC ranged from 1.00 to 1.19 at all Quf and did not differ between hemodiafilter types. Consequently, convective CLtm also did not differ between hemodiafilters. In continuous dialysis mode, urea Cltm did not differ between hemodiafilter types at any Qd. However, ertapenem SA and CLtm were significantly different between hemodiafilter types at Qd 6l/hour (p<0.001). As Qd increased, mean +/- SD AN69 SA declined significantly from 0.87 +/- 0.12 at Qd 1 l/hour to 0.45 +/- 0.02 at Qd 6 l/hour (p<0.001). Ertapenem SA did not differ at any Qd with the polysulfone hemodiafilter (range 0.71-0.80). CONCLUSION: Ertapenem was cleared substantially in these in vitro CRRT models. However, our findings illustrate discordance between our observed SC and SA and the published unbound fraction of ertapenem. This finding has been reported with many other drugs, including carbapenem antibiotics. If in vivo studies corroborate our SA and SC findings, dosage adjustment for patients receiving CRRT will be required.

Large somal size is associated with the expression of galanin but not with neuronal birthdate in the sexually dimorphic male nucleus of ferret's preoptic area/anterior hypothalamus.

Using Nissl and Golgi stains, a sexually dimorphic male nucleus (MN) comprised of a cluster of large cells with large dendritic arbors has been identified in the dorsal preoptic area/anterior hypothalamus (POA/AH) of male ferrets. The MN-POA/AH is formed only in males by the action of estradiol derived from the neural aromatization of testosterone during the last quarter of a 41-day gestation. The ferret's dorsal POA/AH is also characterized by a sex difference in the expression of the neuropeptide galanin which first arises in males around embryonic day (e) 34. We asked whether the male-typical phenotype of large somal size is related to birthdate and/or the capacity of dorsal POA/AH neurons to express galanin. In experiment 1 we labeled cohorts of cells born on E20, E24, or E28 by injecting the amniotic sacs of individual fetuses with the thymidine analogue bromodeoxyuridine (BrdU). On postnatal day 20, BrdU-immunoreactive cells were visualized immunohistochemically, counterstained with cresyl violet, and their somal sizes were measured. BrdU-immunoreactive cells were significantly larger in the males' MN-POA/AH than in a comparable region of females, regardless of when they were born between E20 and E28. In experiment 2 galanin-immunoreactive cells in the dorsal POA/AH of adult ferrets were visualized immunohistochemically, and their somal sizes were measured. Somal areas of galanin-immunoreactive cells were significantly larger in the MN-POA/AH of intact, breeding, or castrated and testosterone-treated males than in the corresponding area of females. Our results suggest that cells in the males' MN-POA/AH are more likely to be larger than cells in females' corresponding region, regardless of birthdate. Finally, in adulthood the male-typical phenotype of large Nissl-stained somal areas of MN-POA/AH cells may, in part, reflect their increased galanin expression.

Evaluation of the ability of altrenogest to control the equine estrous cycle.

In our experience, altrenogest has not always been able to exert predictable control over the estrous cycle of the mare. Therefore, we examined 12 mares that were treated with altrenogest to identify reasons for its failure to control the estrous cycle. The mares were fed altrenogest for 15 to 20 days and were examined for follicle development, ovulation, and corpus luteum formation during treatment. Through the use of real-time ultrasonography and radioimmunoassay for progesterone, we concluded that altrenogest was unable to suppress the growth of follicles to preovulatory size in some mares, leading to ovulation during treatment or earlier than expected after the end of treatment. In addition, altrenogest did not appear to shorten the life-spans of the corpora lutea that were formed during treatment; in 4 mares, this resulted in the persistence of corpora lutea after the end of the suggested 15-day periods of treatment. The latter findings led us to suggest that if a luteolytic dose of prostaglandin had been given at the end of altrenogest treatment, there would have been improved control over the estrous cycle. The results of our study confirmed our clinical impressions that altrenogest may be satisfactory to control the equine estrous cycle under some circumstances, but it should not be used when precise control over ovulation is required.

Massive obstructive urolithiasis in a bull used for artificial insemination.

A seven-year-old Jersey bull used for artificial insemination showed clinical signs of obstructive urolithiasis. This was confirmed by catheterisation and subsequent urethrotomy over the site of obstruction distal to the sigmoid flexure. Although urine flow was elicited after removal of the calculi, this was only temporary and the animal had to be killed 24 hours later. On post mortem examination about 2 kg of round, smooth, pearl-like calculi were found in the urinary bladder and the urethra of the sigmoid flexure was studded with similar calculi. It was concluded that urethrotomy at the sigmoid flexure or penectomy post scrotally would not have alleviated this condition.