How Sterile is Your Insulin?

Hello, Summarians!

Hard to believe it is the middle of November. A couple of very practical studies that bring some useful conclusions. I hope that you enjoy…

Please give me feedback on ways I can make it more useful to you.

If it is valuable to you please consider sending it on to a friend 😄 

Multi-dose Vial Sterility of Insulin

The study aimed to assess the sterility of refrigerated multi-dose insulin vials over a period of six months during which they were routinely used. The research included two types of insulin: insulin glargine U100 with metacresol and protamine zinc insulin U40 with phenol as preservatives. Each day, twice a day, the vials were aspirated using new syringes. To evaluate sterility, half of the vials were wiped with an alcohol swab before insulin was drawn. 

Throughout the study, 454 samples were taken and cultured. Only one sample showed growth of Staphylococcus epidermidis, which was not repeated in subsequent tests. This particular vial was later removed from the study due to accidental breakage. No other vials showed signs of microbial contamination. 

The findings suggest that using refrigerated multi-dose insulin vials for up to six months does not pose a significant risk of infection to patients, even when an alcohol swab is not used before each aspiration. This implies that the preservatives in the insulin are effective in maintaining sterility over an extended period of regular use. 

Berg AS, Jacob ME, Mamo LB, Pluta DH, Lunn KF. Refrigerated multi-dose insulin vials remain sterile through 6 months of use. J Small Anim Pract. 2023 Aug 9. doi: 10.1111/jsap.13664.  PMID: 37559404. 

Bottom line — The preservatives seem to be working during the 6 month time frame.

Stats for Emergency Care in Horses

This study in equine medicine focused on emergency admissions in equine hospitals, examining trends and factors influencing these emergencies. The study had three main objectives: to determine factors affecting the frequency of equine emergencies, identify risk factors for nonsurvival in primary emergencies, and determine risk factors for nonsurvival in all emergencies (both primary and referral). 

Key findings include: 

• Emergency Trends: Saturdays and Sundays saw the highest number of small animal emergency admissions, while weather-related factors such as atmospheric pressure changes also influenced equine emergencies. High barometric pressure was linked to increased sudden infant death syndrome and other conditions in humans, while in veterinary medicine, these changes were associated with diseases like ischemic stroke and gastrointestinal volvulus. 

• Survival Rates: Equids presenting to referral centers had a survival rate of about 75%. The study showed a higher survival rate for primary emergencies (92%) than for referral cases (68%). The higher survival rate in primary emergencies could be due to the less critical nature of these cases compared to referral cases. 

• Factors Affecting Survival: Various factors were associated with the survival of equine emergencies. These included the month of the year, gastrointestinal sounds, and packed cell volume (PCV). For instance, an absence of gastrointestinal sounds significantly increased the odds of mortality, and a higher PCV was linked to higher mortality rates across all emergency types. 

• Impact of Weather and Season: The study observed a seasonal pattern in equine emergencies, with higher average and dropping barometric pressures associated with increased emergency admissions. Higher temperatures were also linked to an increased rate of emergencies. 

• Veterinarian Experience Level: Interestingly, veterinarians with 1-4 years of experience had higher survival rates in emergencies than more senior clinicians, possibly reflecting the nature of cases handled by different experience levels. 

• Limitations: The study's retrospective nature led to some data limitations. Weather data obtained from one central location might not accurately represent the entire practice area, and there was potential bias in clinicians' prognostic assessments. 

In conclusion, the study found that day of the week, barometric pressure, temperature, age, heart rate, gastrointestinal sounds, PCV, and veterinarian experience level significantly impacted the rate and survival outcomes of equine emergencies. 

Bouton J, Fielding L, Major D, Deane E, Mayer J, Rhodes D. Retrospective evaluation of factors associated with emergency frequency and survival in equids presenting for emergency care (2019-2020): 3071 cases. J Vet Emerg Crit Care (San Antonio). 2023 Sep-Oct;33(5):598-605. doi: 10.1111/vec.13332. Epub 2023 Aug 10. PMID: 37561021. 

Bottom line — Good info to help during a difficult time.

Detecting Urinary Calculi in Small Animals

 The study on the radiographic identification of urinary calculi significantly revises the traditional understanding of the radiopacity of different types of uroliths. Historically, calcium oxalate and struvite uroliths were known for their ease of identification due to mineral opacity, while urate and cystine calculi were considered difficult to detect on radiographs. Recent research, however, challenges this notion. It has been found that urate and cystine calculi, previously thought to be nonmineral opaque, are often visible on digital radiographs. This revelation emerged from studies using various diagnostic methods, including conventional film radiography, double contrast cystography, and ultrasonography. Clinical cases have also corroborated these findings, showing the clear identification of pure cystine and urate cystoliths in radiographs. The research aimed to evaluate the sensitivity, specificity, and accuracy of digital radiography in detecting and measuring uroliths of different compositions, particularly focusing on those greater than 2 mm in size. The findings confirmed that both urate and cystine cystoliths are detectable on digital radiographs with high accuracy, contradicting earlier beliefs about their nonmineral opaque nature. The ability to measure uroliths was also found to be unaffected significantly by bladder size. Overall, these findings represent a significant advance in the diagnostic approach to urinary calculi, highlighting the increased capabilities of digital radiography and revising long-held views on the visibility of various types of urinary calculi. 

 DeBow, P, Auger, M, Fazio, C, et al. The most common types of uroliths larger than 1 mm are readily visible and accurately measured in an in vitro setting mimicking the canine abdomen using digital radiography. Vet Radiol Ultrasound. 2023; 64: 806–812. https://doi.org/10.1111/vru.13268 

Bottom line — Rads can be used to screen for all types of calculi...

Just putting things in perspective …