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Tag: Internal Medicine

  • Ionised hypocalcaemia, pt 4: controversies and prognostic indications

    Ionised hypocalcaemia, pt 4: controversies and prognostic indications

    Ionised hypocalcaemia (iHCa) is a well-known electrolyte abnormality in critical human patients, which is also beginning to be recognised in our critical feline and canine patients.

    The exact mechanism for the development of iHCa is still unknown – making prevention difficult, if at all possible. Controversy also exists as to whether treating iHCa is of any benefit, especially in non-clinical cases.

    Despite these issues, serum concentration is proving to be an accurate prognostic indicator for the morbidity and mortality rates of some of the more critical patients.

    Research

    Over the past 30 years, significant resources have been put into trying to demystify the pathophysiological causes of iHCa in critically ill people; however, the exact mechanisms are still to be determined.

    Some proposed mechanisms include:

    • abnormal parathyroid hormone secretion or function
    • abnormal vitamin D synthesis or function
    • hypomagnesaemia
    • calcium chelation
    • alkalaemia
    • calcium sequestration in tissue or cells
    • an increase in calcitonin precursors (procalcitonin)

    In a canine study where endotoxaemia was induced, it was found hypovitaminosis D was associated with iHCa (Holowaychuk et al, 2012).

    Veterinary studies

    The true incidence of iHCa in critically ill canine and feline patients is yet to come to a consensus, due to the limited veterinary studies.

    In one retrospective study, 90% of 55 cats with septic peritonitis was reported to have iHCa (Kellett-Gregory et al, 2010), while only 24% of septic dogs (n=58) was reported to have iHCa (Luschini et al, 2010).

    Regardless of the true incidence, the commonness of this change questions whether a need exists to treat iHCa, especially cases in the mild or non-clinical categories.

    No consensus

    At this stage, no consensus exists to either support or prohibit the treatment of hypocalcaemia in critically ill patients.

    Well-designed prospective studies are scarce in human literature and non-existent in the veterinary field; no evidence-based guidelines are available for treatment.

    Based on logic, arguments for the administration of calcium to critically ill patients include:

    • iHCa during hospitalisation is a negative predictor for morbidity and mortality of patients.
    • Hypocalcaemia can cause decreased myocardial contractility.
    • In hypotensive patients dependent on vasopressors or inotropic agents, the supplementation of calcium may be beneficial.

    Arguments against calcium supplementation include:

    • Calcium accumulation within cells predisposes to hypoxia and ischaemia-reperfusion injury.
    • Increased mortality in experimental models of sepsis when calcium is supplemented, on top of the lack of evidence to support this act.

    Prognostic use

    Serum calcium concentrations – or, rather, the trend of it in hospital – appears to be of valuable prognostic indicators.

    Kellett-Gregory et al (2010) found although no direct associations existed between the presence or severity of iHCa at the time of patient admission, a positive correlation existed between the lowest iCa post-hospitalisation, and the length of hospitalisation and duration of intensive care stay.

    Of the cats that had iHCa, those that failed to return to a normal ionised calcium (iCa) during hospitalisation had a significantly lower rate of survival to discharge. Interestingly, iHCa was not associated with the status of hypotension, coagulopathy or arrhythmias, so cannot be used to predict the occurrence of these.

    These findings were echoed by Luschini et al (2010), where low mean ionised calcium and lowest documented ionised calcium concentrations were found to be associated with a poor outcome. The severity and duration of iHCa appears to be important in determining prognosis in these patients.

    Conclusion

    Controversy exists regarding whether treatment of mild iHCa in critically ill patients is recommended; however, one thing we now know is serum iCa concentration is a reliable predictor of mortality and morbidity in canine and feline patients.

    References

  • The beginning of the end of vet school

    The beginning of the end of vet school

    Hospital
    Exams passed, Jordan can walk the halls of Glasgow’s small animal hospital without feeling like an imposter.

    As regular readers of this blog may have noticed, I was a little apprehensive about starting my final year at veterinary school…

    Having already been in the small animal hospital for two days, we finally received our results – confirming I and many of my fellow classmates had passed our exams and could now wear our final year jackets without guilt and walk around the hospital without feeling like imposters.

    However, despite now knowing we had qualified to be in the hospital, it still felt like we had been thrown in the deep end.

    In at the deep end

    My first rotation was emergency and critical care, with the first part being internal medicine. The first couple of days were spent frantically researching the background of patients coming in for appointments, bumbling through clinical exams and brushing up on my rusty practical skills.

    It was my first time taking consults alone and, after missing out key questions the first few times, I eventually got into the swing of things and made fewer mistakes.

    cat scratch quote
    Image: seregraff / Fotolia.

    Despite feeling like I didn’t know anything to begin with, I at least managed to scrape together a few sensible ideas when clinicians tried to worm differentials out of us. It has been a steep learning curve, changing the way of thinking entirely to apply things to a real patient in front of you, which usually has not read the textbook.

    OOH my goodness

    Just as I was beginning to feel comfortable with medicine, we swapped to out of hours – which, against my presumptions, turned out to be a really enjoyable week.

    I adjusted to nights far easier than I expected and was powering through until one particularly long night when a bulldog came in with a suspected gastric dilatation volvulus (GDV).

    This was the first genuine emergency we’d been involved in and stress levels were running high. Having rapidly set up fluid boluses, taken radiographs to confirm our suspicions, checked lactate levels and run in-house bloods, we went through to theatre. After a very long night of surgery and having warned the owner of an extremely grave prognosis, we were delighted to see said bulldog looking bright and happy the following evening, eating and pulling us down the corridors to the runs outside.

    Not all GDVs end with such a happy ending, as we had learned earlier in the week – a dog that underwent the surgery at its own vets came to us for overnight care in ICU and, after a rocky night of a supraventricular tachycardia that we struggled to keep under control, crashed the following morning, was resuscitated successfully once, but could not be saved when it crashed again minutes later.

    Hearts, not brains

    Coming from nights straight back into days, however, was much harder and I felt like a zombie for the first day of my cardiology week.

    On the subsequent days, when my brain was working again, I was able to make a bit more sense of echocardiography and gain a better understanding of some conditions and the tray menu options available.

    I also learned a bit more about the genetics of Bengal cats and found trying to heart scan a cat that’s only two generations away from a leopard cat can be quite challenging (and may involve chasing said cat around the ultrasound room for some time, following an artful escape act).

    This year isn’t going to be a picnic, but, although I already feel exhausted, if last month is anything to go by, it will be an enjoyable one.

  • RCVS council election manifesto: Lucie Goodwin

    RCVS council election manifesto: Lucie Goodwin

    LUCIE GOODWIN

    Lucie Goodwin.

    BVetMed, DipACVIM, MRCVS

    Axiom Veterinary Laboratories, The Manor House, Brunel Road, Newton Abbot, Devon TQ12 4PB.

    T 01626 355655

    M 07834 784385

    E lucie.mrcvs@gmail.com

    PROPOSERS: Katherine Hall, Hayley Mitchell

    I graduated from the RVC in 2004 and spent the following two years working in a busy small animal hospital in Bristol. Having been firmly bitten by the medicine bug, I returned to the RVC in 2006 to undertake an internship and, subsequently, a residency in small animal medicine.

    Following completion of my residency, I returned to the west country to work for the University of Bristol and Langford Veterinary Services as a teaching fellow and internal medicine clinician. I worked at Langford for a very enjoyable two-and-a-half years, before taking a short career break to help to establish the charity Brighter Bristol.

    Since qualifying, I have also had experience of working in the veterinary charity sector and private referral hospitals, both in the UK and US. In my current position as an internal medicine consultant for Axiom Veterinary Laboratories, I am able to combine my enjoyment of veterinary internal medicine with a role that allows me to offer support to practitioners with their cases.

    Outside of work, I love to travel and enjoy being creative. I also continue to volunteer for a number of charities in the Bristol area.

    Manifesto

    Like all vets, I have worked hard to become a member of the RCVS and am incredibly proud to be so. With ongoing challenges facing us, these really are exciting times for our profession and, as members, we should be engaged with our college to help create and shape our preferred future.

    Having worked in a variety of clinical and academic settings, it is of no doubt to me a happy, healthy vet makes a good vet. As a role that has significant emotional and physical demands, it is no wonder a recent survey of BVA members reported reducing stress was the single highest priority for many. I believe there needs to be a culture change within the profession to support mental health and well-being, and the launch of the RCVS Mind Matters Initiative must be applauded as there is much work to be done to provide support to our members.

    Veterinary education needs to meet the demands of the modern profession and it is essential the college reflects and promotes all aspects of veterinary work. It is alarming half of the vets surveyed who graduated within the last eight years reported their careers had not matched their expectations (reference: Vet Futures). Action must be taken to ensure we meet their aspirations and do not lose the skills of these highly qualified individuals.

    I am passionate about the advancement of knowledge within veterinary science, particularly making use of evidence-based medicine and clinical governance. With a number of groups promoting these in practice, there is great potential for input from all areas of the profession.

    If elected, I promise to contribute an enthusiastic and progressive voice to council and I would consider it a privilege to serve the veterinary community in this way.