The correct answer is: 1mg

## Explanation

The concentration of a solution is typically expressed as the amount of solute (in this case, adrenaline) per volume of solvent (in this case, saline solution). In a 1 in 100,000 solution, there is 1 gram of solute in 100,000 milliliters of solvent. This can also be expressed as 1,000 milligrams (mg) in 100,000 milliliters, or 1 mg in 100 milliliters.

Given that the registrar is preparing a 100ml solution, the amount of adrenaline needed to achieve a 1 in 100,000 concentration would be 1mg.

Let's address each individual answer option:

- 1mg: This is the correct answer. As explained above, a 1 in 100,000 solution translates to 1mg of adrenaline in 100ml of saline solution.
- 10mg: This would result in a 1 in 10,000 solution, which is ten times more concentrated than the desired 1 in 100,000 solution.
- 100mg: This would result in a 1 in 1,000 solution, which is a hundred times more concentrated than the desired 1 in 100,000 solution.
- 1000mg: This would result in a 1 in 100 solution, which is a thousand times more concentrated than the desired 1 in 100,000 solution.
- 0.1mg: This would result in a 1 in 1,000,000 solution, which is ten times less concentrated than the desired 1 in 100,000 solution.

## Mnemonic

A useful mnemonic to remember this is "1 in 100,000 equals 1mg in 100ml". This can help you quickly recall the correct concentration when preparing adrenaline solutions in a clinical setting.

Citations:
https://airwayjedi.com/2021/03/08/clinical-calculations-epinephrine-local-anesthetics/
https://pubmed.ncbi.nlm.nih.gov/27150155/
https://www.medicines.org.uk/emc/product/3673/smpc
https://www.e-safe-anaesthesia.org/sessions/09_07/d/ELFH_Session/1308/tab_1496.html
https://youtube.com/watch?v=FNlq5iL4EQc
https://www.southwestoralsurgery.com/local-anesthetic-dosages-a-new-look-at-an-old-drug-2/
https://www.tuolumnecounty.ca.gov/DocumentCenter/View/19605/2021-APPENDIX
https://medicine.uiowa.edu/iowaprotocols/maximum-recommended-doses-and-duration-local-anesthetics
https://pubmed.ncbi.nlm.nih.gov/22569014/
https://www.medicines.org.uk/emc/product/2024/smpc
https://www.medicines.org.uk/emc/product/3675/smpc
https://healthprofessions.udmercy.edu/academics/na/agm/mathweb09.pdf
https://emergencypedia.com/2014/01/07/the-solution-to-dilution/
https://www.jstage.jst.go.jp/article/bpb/39/5/39_b15-00916/_html/-char/en
http://www.ozemedicine.com/wiki/doku.php?id=adrenaline
https://youtube.com/watch?v=j9TYcKOsU8k
https://e-safe-anaesthesia.org/e_library/03/Pharmacology_and_drug_doses_an_introduction_Update_2008.pdf
https://www.timeofcare.com/epinephrine-dosing-clearly-explained/
https://www.nature.com/articles/s41415-023-6010-7
https://www.uptodate.com/contents/anaphylaxis-emergency-treatment/print
https://medicalguidelines.msf.org/en/viewport/EssDr/english/epinephrine-epn-adrenaline-injectable-16682691.html
https://www.fda.gov/drugs/information-drug-class/single-entity-injectable-drug-products
http://www.columbia.edu/itc/hs/dental/d6401/2007/cartridge.pdf
https://www.bjanaesthesia.org.uk/article/S0007-0912(17)51474-9/pdf
https://acls-algorithms.com/acls-drugs/acls-and-epinephrine/comment-page-7/

Correct Answer: Conduct a thorough investigation to identify potential causes and implement corrective measures

Explanation:

The most appropriate plan of action in this scenario would be to conduct a thorough investigation to identify potential causes and implement corrective measures. This approach aligns with the principles of clinical governance and quality improvement, which are fundamental to healthcare practice in the UK and elsewhere[4][8].

Let's discuss each option in detail:

1. **Do nothing and continue to monitor the situation**: This approach is not advisable because it does not address the issue at hand. Even if the coroner is not concerned, an increase in hospital deaths warrants investigation to ensure patient safety and quality of care[1][7].

2. **Discuss with the pathologist to determine why deaths are increasing**: While discussing with the pathologist could provide valuable insights, it is not sufficient on its own. The issue likely involves multiple factors beyond the scope of pathology, including clinical care processes, patient demographics, and hospital policies[1][5].

3. **Review the patient notes to identify the nurse on duty during the increased deaths**: This approach could be part of a broader investigation, but focusing solely on the nurse on duty could be misleading. It assumes that the increase in deaths is due to nursing care, which may not be the case. The issue could be related to broader systemic factors, such as hospital policies, clinical guidelines, or patient characteristics[1][5].

4. **Conduct a thorough investigation to identify potential causes and implement corrective measures**: This is the most appropriate action. A comprehensive investigation would involve reviewing clinical records, speaking with staff, analyzing hospital policies, and possibly conducting a clinical audit. The goal would be to identify any systemic issues or processes that could be contributing to the increased deaths. Once these issues are identified, corrective measures can be implemented to improve patient safety and care quality[1][4][5].

5. **Report the findings to the hospital board and request additional resources**: While reporting findings to the hospital board is an important part of addressing the issue, it should be done after an investigation has identified the potential causes. Requesting additional resources may be necessary, but it should be based on the findings of the investigation[1][4].

Citations:
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1472716/
[2] https://www.usatoday.com/in-depth/news/nation/2021/12/22/covid-deaths-obscured-inaccurate-death-certificates/8899157002/
[3] https://www.ncbi.nlm.nih.gov/books/NBK541113/
[4] https://www.england.nhs.uk/clinaudit/
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4587502/
[6] https://missouriindependent.com/2021/12/22/uncounted-inaccurate-death-certificates-across-the-country-hide-the-true-toll-of-covid-19/
[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6297330/
[8] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6465800/
[9] https://www.wric.com/news/local-news/henrico-county/hca-henrico-doctors-hospital-issues-action-plans-following-death-of-patient-irvo-otieno/
[10] https://www.cbsnews.com/colorado/news/coronvirus-colorado-coroners-worry-test-shortages-uncounted-deaths/
[11] https://www.ama-assn.org/practice-management/ama-steps-forward/after-physician-suicide-responding-organization-toolkit
[12] https://repository.rcsi.com/articles/report/National_Audit_of_Hospital_Mortality_summary_report_2021/24211476
[13] https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2783986
[14] https://www.usfa.fema.gov/downloads/pdf/publications/handbook_for_ems_medical_directors.pdf
[15] https://oig.hhs.gov/oei/reports/oei-09-04-00350.pdf
[16] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7604184/
[17] https://www.samhsa.gov/sites/default/files/national-guidelines-for-behavioral-health-crisis-care-02242020.pdf
[18] https://www.rcplondon.ac.uk/file/3334/download
[19] https://www.nidirect.gov.uk/articles/coroners-post-mortems-and-inquests
[20] https://www.cnbc.com/2018/02/22/medical-errors-third-leading-cause-of-death-in-america.html
[21] https://www.safetyandquality.gov.au/sites/default/files/migrated/Analysis-Plan.pdf
[22] https://www.sunderlandcoroner.co.uk/useful-information/when-a-death-is-reported-to-the-coroner/cause-of-death-is-not-established/
[23] https://www.who.int/news-room/fact-sheets/detail/patient-safety
[24] https://bmchealthservres.biomedcentral.com/articles/10.1186/s12913-022-08568-0
[25] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8927891/

Squamous cell carcinoma

In the given scenario, the most likely diagnosis is squamous cell carcinoma. The patient presents with a progressive, painful swelling in the right face, with a tender, hard, irregular mass in the parotid region fixed to the skin and with ulceration. These features are consistent with squamous cell carcinoma, which is a type of cancer that starts as a growth of cells on the skin and can affect the parotid gland. The other options are less likely due to the following reasons:

1. Mucoepidermoid carcinoma: Although it is the most common type of salivary gland cancer, it usually presents as a slow-growing, asymptomatic parotid gland swelling without facial nerve involvement. The painful and ulcerated nature of the mass in this case makes mucoepidermoid carcinoma less likely.
2. Adenoid cystic carcinoma: This type of cancer is usually slow-growing and often appears to be low grade when examined in the lab. The rapid progression and painful nature of the mass in this case make adenoid cystic carcinoma less likely.
3. Sialadenitis: This is an inflammation of the salivary glands, which can cause facial swelling and tenderness. However, the hard, irregular mass and ulceration in this case are not typical features of sialadenitis.
4. Pleomorphic adenoma: This is a benign salivary gland tumor that usually presents as a slow-growing, asymptomatic, mobile mass without causing ulceration of the overlying mucosa. The painful, fixed, and ulcerated nature of the mass in this case makes pleomorphic adenoma less likely.

In summary, the most likely diagnosis in this case is squamous cell carcinoma due to the progressive, painful swelling with a hard, irregular mass fixed to the skin and with ulceration.

Citations:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861979/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4478272/
https://oralcancerfoundation.org/facts/rare/mucoepidermoid-carcinoma/
https://www.mayoclinic.org/diseases-conditions/squamous-cell-carcinoma/symptoms-causes/syc-20352480
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5773992/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8757944/
https://www.cancer.org/cancer/types/salivary-gland-cancer/about/what-is-salivary-gland-cancer.html
https://www.skincancer.org/skin-cancer-information/squamous-cell-carcinoma/
https://www.mountsinai.org/health-library/symptoms/facial-swelling
https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/pilomatrixoma
https://www.ncbi.nlm.nih.gov/books/NBK537277/
https://health.ucdavis.edu/pathology/education/residency_program/caseofthemonth/index.html
https://www.mayoclinic.org/diseases-conditions/parotid-tumor/cdc-20388269
https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/647774
https://insightsimaging.springeropen.com/articles/10.1007/s13244-015-0418-9
https://emedicine.medscape.com/article/1289616-overview
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4443580/
https://pubs.rsna.org/doi/full/10.1148/rg.2021200079
https://www.frontiersin.org/articles/10.3389/fsurg.2021.800563
https://www.sciencedirect.com/topics/medicine-and-dentistry/mucoepidermoid-carcinoma
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/kidneys-age-related-problems
https://www.ccjm.org/content/ccjom/20/4/445.full.pdf
https://en.wikipedia.org/wiki/Mucoepidermoid_carcinoma
https://www.cedars-sinai.org/health-library/diseases-and-conditions/s/salivary-gland-disease-and-tumors.html
https://casereports.bmj.com/content/2014/bcr-2013-202776

The correct answer is A) Usher syndrome type 1.

## Explanation

The child's symptoms of profound sensorineural hearing loss, difficulty with balance and coordination, nystagmus, and bone spicule-shaped pigment deposits in the retina are indicative of Usher syndrome. Usher syndrome is an autosomal recessive condition that results in retinitis pigmentosa with associated congenital hearing loss. There are three main types of Usher syndrome, and the symptoms described align most closely with Usher syndrome type 1.

### A) Usher syndrome type 1

Usher syndrome type 1 is associated with profound congenital sensorineural hearing loss and poor vestibular function, which would explain the child's hearing loss and balance issues. The presence of bone spicule-shaped pigment deposits in the retina is a characteristic feature of retinitis pigmentosa, which is a component of Usher syndrome.

### B) Usher syndrome type 2

Usher syndrome type 2 results in mild congenital hearing loss with normal vestibular function. Given the child's profound hearing loss and balance issues, this is less likely to be the correct diagnosis.

### C) Usher syndrome type 3

Usher syndrome type 3 is rare and can have slowly progressive hearing loss. This does not align with the child's symptoms of profound congenital hearing loss.

### D) Pendred syndrome

Pendred syndrome is a genetic disorder that can cause hearing loss, but it is typically associated with thyroid problems and does not typically present with retinitis pigmentosa or balance issues. Therefore, this is unlikely to be the correct diagnosis.

### E) Waardenburg syndrome

Waardenburg syndrome is a group of genetic conditions that can cause hearing loss and changes in coloring (pigmentation) of the hair, skin, and eyes. However, it does not typically present with retinitis pigmentosa or balance issues, making it an unlikely diagnosis in this case.

## Mnemonic

A helpful mnemonic to remember the features of Usher syndrome type 1 is "USH1: Unsteady (vestibular issues), Silent (profound hearing loss), and Hazy sight (retinitis pigmentosa)".

Citations:
https://webeye.ophth.uiowa.edu/eyeforum/atlas/pages/usher.htm
https://www.ncbi.nlm.nih.gov/medgen/811461
https://rarediseases.org/rare-diseases/retinitis-pigmentosa/
https://www.ncbi.nlm.nih.gov/medgen/65889
https://www.science.gov/topicpages/e/early-onset+retinal+dystrophies
https://www.boystownhospital.org/research/sensory-neuroscience/gene-expression/retinitis-pigmentosa
https://www.science.gov/topicpages/c/cone+rod+dystrophy.html
https://downloads.aap.org/DOSP/JournalClub/GeneticsCombined.pdf

The correct answer is: 4 mm

The choice of surgical excision margins for basal cell carcinoma (BCC) is a balance between ensuring complete removal of the tumor (oncologic safety) and minimizing the size of the surgical defect for the best cosmetic outcome. The size of the margin can depend on several factors, including the size of the tumor, its location, and its histological subtype.

In the case of a well-defined primary BCC on the cheek measuring 1.5 cm in diameter, a 4 mm surgical excision margin is most appropriate. This recommendation is based on several studies and guidelines:

1. A systematic review of literature found that a 4 mm margin is adequate for preventing recurrence in most types of BCC, including nodular BCCs[1]. The study also found that a 3 mm surgical margin could be safely used for BCC lesions 2 cm or smaller, but the rate of complete excision increased with larger margins[1].

2. A retrospective chart study and evaluation of the Dutch guideline found that a margin of 3 mm was sufficient in 99.6% of BCCs categorized as low risk[2]. However, the guideline recommended surgical margins of 3 mm for small (≤ 10 mm) primary BCC and 5 mm for large (> 10 mm), high-risk or recurrent BCC[2].

3. A study in Advances in Skin & Wound Care found that for BCC less than 2 cm in diameter, a 3-mm surgical margin may be as safe and effective as a 5-mm margin[3]. However, none of the 46 lesions excised with 5-mm margins indicated a positive tumor presence, suggesting a wider margin may be more effective in ensuring complete removal of the tumor[3].

4. The American Academy of Dermatology (AAD) recommends surgical excision with 4-mm clinical margins for BCC[5].

5. A study in Arch Dermatol found that for tumors with a diameter less than 2 cm, a minimum margin of 4 mm was necessary to totally eradicate the tumor in more than 95% of cases[7].

6. The Australasian Journal of Plastic Surgery suggests an excision margin of 3–4 mm for low-risk BCCs, especially on visible regions such as the face[8].

In conclusion, a 4 mm surgical excision margin is most appropriate for a well-defined primary BCC on the cheek measuring 1.5 cm in diameter. This margin size provides a balance between oncologic safety and cosmesis, ensuring complete removal of the tumor while minimizing the size of the surgical defect.

Citations:
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430350/
[2] https://www.medicaljournals.se/acta/content/html/10.2340/00015555-3705
[3] https://journals.lww.com/aswcjournal/fulltext/2020/04000/recommended_surgical_margins_for_basal_cell.7.aspx
[4] https://www.verywellhealth.com/surgical-margin-in-skin-cancer-3010780
[5] https://emedicine.medscape.com/article/277783-overview
[6] https://pubmed.ncbi.nlm.nih.gov/32821563/
[7] https://jamanetwork.com/journals/jamadermatology/article-abstract/548052
[8] https://ajops.com/article/37724-margin-of-error-accuracy-of-estimated-excision-margins
[9] https://www.sciencedirect.com/science/article/pii/S0365059620302890
[10] https://www1.racgp.org.au/ajgp/2021/june/marking-a-surgical-margin-for-excision-of-a-kerati
[11] https://e-acfs.org/m/journal/view.php?number=807
[12] https://www.nature.com/articles/s41433-020-0768-5
[13] https://www.liebertpub.com/abs/doi/10.1001/jamafacial.2013.1011
[14] https://www.practiceupdate.com/content/recommended-surgical-margins-for-basal-cell-carcinoma/98037
[15] https://dermnetnz.org/topics/histological-clearance-and-recurrence-of-keratinocyte-cancers
[16] https://scialert.net/fulltext/?doi=pjbs.2009.1408.1414
[17] https://www.sciencedirect.com/science/article/pii/S0365059623000557
[18] https://ijdvl.com/excision-of-basal-cell-carcinomas-smaller-than-1-cm-with-2-mm-safety-margins-lateral-margin-adequacy-evaluated-by-double-bladed-scalpel-method/
[19] https://ejhm.journals.ekb.eg/article_175169_2092362ef34e56d7683e8eef4dbdc5ed.pdf