This month’s case is by David R Bell PhD, co-author of Medical Physiology: Principles for Clinical Medicine, 3e (ISBN: 9781451110395) For more information, or to purchase your copy, visit: http://tiny.cc/Rhoades4e, with 15% off using the discount code: MEDUCATION.
The case below is followed by a quiz question, allowing you a choice of diagnoses. Select the one letter section that best describes the patient’s condition.
A 28-year old woman has an unremarkable pregnancy through her first 28 weeks of gestation, with normal weight gain and no serious complications. She has no previous history of diabetes, hypertension of other systemic disease before or during her current pregnancy. During her 30-week checkup, her blood pressure measures 128/85, and she complains about feeling slightly more “bloated” than usual with swelling in her legs that seems to get more uncomfortable as the day goes on. Her obsterician recommends that she get more bed rest, stay off her feet as much as possible and return for evaluation in one week.
At the one-week follow-up, the patient presents with noticable”puffiness” in her face, and a blood pressure of 145/95. She complains she has been developing headaches, sporadic blurred vision, right-sided discomfort and some shortness of breath. She has gained more than 10 lb (4.5kg) in the past week. A urinalysis on the patient revelas no glucose but a 3+ reading for protein. Her obstetrician decides to admit her immediately to a local tertiary care hospital for further evaluation. Over the next 24 hours, the patient’s urine output is recorded as 500mL and contains 6.8 grams of protein.
Her plasma albumin level is 3.1 g/dl, hemacrit 48%, indirect bilirubin 1.5mg/dl and blood platelets=77000/uL, respectively. Her blood pressure is now 190/100.
It is decided to try to deliver the foetus. The expelled placenta is small and shows signs of widespread ischmic damage. Within a week of delivery, the mother’s blood pressure returns to normal, and her oedema subsides. One month later, the mother shows no ill effects of thos later-term syndrome.
What is the clinical diagnosis of this patient’s condition and its underlying pathophysiology?
A. Gestational Hypertension
C. Gestational Diabetes
D. Compression of the Inferior Vena Cava
The correct answer is "B. Preeclampsia".
The patient’s symptoms and laboratory findings are consistent with a diagnosis of Preeclampsia, which is a condition occurring in some pregnancies that causes life-threatening organ and whole body regulatory malfunctions. The patient’s negative urine glucose is inconsistent with gestational diabetes. Gestational hypertension or vena caval compression cannot explain all of the patient findings. The patient has three major abnormal findings- generalised oedema, hypertension and proteinuria which are all common in preeclampsia. Although sequalae of a normal pregnancy can include water and salt retention, bloating, modest hypertension and leg swelling (secondary to capillary fluid loss from increased lower limb capillary hydrostatic pressure due to compression of the inferior vena cava by the growing foetus/uterus), oedema in the head and upper extremities, a rapid 10 pound weight gain and shortness of breath suggests a generalized and serious oedematous state. The patient did not have hypertension before or within 20 weeks gestation (primary hypertension) and did not develop hypertension after the 20th week of pregnancy with no other abnormal findings (gestational hypertension). Hypertension with proteinuria occurring beyond the 20th week of pregnancy however is a hallmark of preeclampsia. In addition, the patient has hemolysis (elevated bilirubin and LDH levels), elevated liver enzyme levels and thrombocytopenia. This is called the HELLP syndrome (HELLP = Hemolysis, Elevated Liver enzymes and Low Platelets.), and is considered evidence of serious patient deterioration in preeclampsia.
A urine output of 500 ml in 24 hours is 1/2 to 1/4 of normal output in a hydrated female and indicates renal insufficiency. Protein should never be found in the urine and indicates loss of capillaries integrity in glomeruli which normally are not permeable to proteins. The patient has substantial 24 urine protein loss and hypoalbuminemia. However, generally plasma albumin levels must drop below 2.5 gm/dl to decrease plasma oncotic pressure enough to cause general oedema. The patient’s total urinary protein loss was insufficient in this regard. Capillary hyperpermeability occurs with preeclampsia and, along with hypertension, could facilitate capillary water efflux and generalized oedema. However myogenic constriction of pre-capillary arterioles could reduce the effect of high blood pressure on capillary water efflux. An early increase in hematocrit in this patient suggests hemoconcentration which could be caused by capillary fluid loss but the patient’s value of 48 is unremarkable and of little diagnostic value because increased hematocrit occurs in both preeclampsia and normal pregnancy.
PGI2, PGE2 and NO, produced during normal pregnancy, cause vasorelaxation and luminal expansion of uterine arteries, which supports placental blood flow and development. Current theory suggests that over production of endothelin, thromboxane and oxygen radicals in preeclampsia antagonize vasorelaxation while stimulating platelet aggregation, microthrombi formation and endothelial destruction. These could cause oedema, hypertension, renal/hepatic deterioration and placental ischemia with release of vasotoxic factors. The patient’s right-sided pain is consistent with liver pathology (secondary to hepatic DIC or oedematous distention).
Severe hypertension in preeclampsia can lead to maternal end organ damage, stroke, and death. Oedematous distension of the liver can cause hepatic rupture and internal hemorrhagic shock. Having this patient carry the baby to term markedly risks the life of the mother and is not considered current acceptable clinical practice. Delivery of the foetus and termination of the pregnancy is the only certain way to end preeclampsia.
This case is by David R Bell PhD, co-author of Medical Physiology: Principles for Clinical Medicine, 3e (ISBN: 9781451110395)
For more information, or to purchase your copy, visit: http://tiny.cc/Rhoades4e.
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What is Problem Based Learning?
During my time at medical school, I enjoyed (at times) a curriculum delivered through the traditional model. As the name suggests, this is an approach experienced by the majority of doctors to date. The traditional model was first implemented by the American Medical College Association and American Academy of Medicine in 1894 (Barr, 2010) and has been used by the majority of medical schools. It traditionally consists of didactic lectures in the initial years covering the basic sciences followed by clinical years, where students learn clinical medicine while attending hospital placements.
Is It Better?
A few years after my graduation I found myself teaching at a university which had fully adopted the use of problem based learning (PBL) in the delivery of their curriculum. PBL is a philosophy of teaching that has increasingly been used in medical education over the past 40 years. It has rapidly been replaced or supplemented in medical education as opposed to the traditional model. PBL seeks to promote a more integrated and active approach to learning right from the first year with less reliance on didactic lectures.
Having been involved in these two different approaches to medical education, I was interested to explore what the evidence was for and against each. For the purposes of this blog, I have looked at four specific areas. These include student attitudes, academic achievement, the academic process of learning and clinical functioning and skills.
Student attitudes to PBL have been highly featured in studies and many show that there is a clear favourability towards this philosophy of teaching. Blumberg and Eckenfel (1988) found that students in a problem based preclinical curriculum rated this three times higher than those in the a traditional group in terms of what they expect to experience, what they would like, and what they actually experienced. Heale et al (1988) found physicians in the problem-solving sessions rated a Continuing Medical Education short course higher compared to others who attended traditional lectures and large-group sessions. Vernon and Black (1993) performed a Meta analysis on 12 studies that looked at attitudes and towards PBL and found PBL was favored in some way by all studies. PBL appears to be preferred by the majority of students at a range of academic levels. However, Trappler (2006) found that converting a conventional curriculum to a problem based learning model for part of a psychopathology course did not show complete favourability. Students preferred the conventional lectures given by experts, rather than PBL groups run by mentors and not experts. They did however show preference towards PBL small group sessions run by experts
Academic achievement is an important factor to assess. Vernon and Blake (1993) compared a number of studies and found that those, which could be compared, showed a significant trend favouring traditional teaching methods. However, it was felt this might not be reliable. When looking at the heterogeneity of the studies there was significant variation that could not be accounted for by chance alone. Interestingly, they found that there was significant geographical variation across the United States such that New Mexico showed consistently negative effects and Michigan State showed consistently positive. Other studies have shown that the traditional method may show a slightly better outcome when assessing academic achievement. Schmidt et al (1987) looked at the same progress test taken among students in six different Universities in the Netherlands and found that those taught by a traditional approach showed slightly better outcomes. Baca et al (1990) compared performances of medical students in two separate tracks, one PBL the other a traditional model. Baca et al found that PBL students scored slightly lower in the National Board of Medical Examiners (NBME) examinations. Dochy et al (2003) conducted a meta analysis comparing 43 studies and found that when considering the effect of PBL on the knowledge of students the combined effect size is slightly negative.
The academic process of learning
It is important in medical education to enable people to continue life long learning, to overcome problems and fill in knowledge gaps. Coles (1990) and Entwistle (1983) found that PBL students would place more emphasis on understanding and meaning compared to just rote learning, seen more in those taught by a traditional approach. Students on a PBL course also place more focus on using resources such as the library and online sources rather than those taught in a traditional approach (Rankin, 1992). Students taught by a traditional model place more emphasis on the resources supplied by the faculty itself. It has also been shown that students who learn through a process of problem solving, are more likely to use this spontaneously to solve new problems in the future compared with those taught in a traditional way (Bransford et al, 1989).
Clinical functioning and skills
Clinical competence is an important aspect in medical education and has been measured in studies comparing PBL and traditional methods. The traditional model focuses acquisition of clinical competence in the final years of a program with hospital placements. In a PBL course it may be more integrated early on. There are however, only a few studies that look at clinical competence gained in undergraduate PBL courses. Vernon and Blake (1993) compared some of these studies and found that students obtained better clinical functioning in a PBL setting compared to a traditional approach. This was statistically significant, however there was still significant heterogeneity amongst studies and for conclusive results to be made 110 studies would have to be compared, rather that the 16 samples they were able to use. They also found that in contrast to the NBME I giving better results in the traditional model, PBL students score slightly higher in NBME II and federation licensing examination which related more on clinical functioning than basic sciences.
On reflection, this evidence has indicated to me that PBL is a very valuable approach and it has a number of benefits. The traditional model in which I was taught has provided a good level of academic education. However, it may not have supported me as well as a PBL course in other areas of medical education such as academic process, clinical functioning and satisfaction. On reflection and current recommendations are for a hybridisation of the PBL and traditional approach to be used (Albanese, 2010) and I would support this view in light of the evidence.
Baca, E., Mennin, S. P., Kaufman, A., and Moore-West, M. A Comparison between a Problem-Based, Community Orientated track and Traditional track Within One Medical school. In Innovation in Medical Education; An Evaluation of Its Present Status. New York: Springer publishing
Barr D. (2010) Revolution or evolution? Putting the Flexner Report in context. Medical Education; 45: 17–22
Blumberg P, Eckenfels E. (1988) A comparison of student satisfaction with their preclinical environment in a traditional and a problem based curriculum. Research in Medical Education: Proceedings of the Twenty-Seventh Annual Conference, pp. 60- 65
Bransford, J. D., Franks, J. J., Vye, N. J., & Sherwood, R. D. (1989). New Approaches to Instruction: Because Wisdom Can't Be Told. In S. Vosiadou & A. Ortony (Eds.), Similarity and Analogical Reasoning (pp. 470 297). New York: Cambridge University Press.
Coles CR. (1990) Evaluating the effects curricula have on student learning: toward a more competent theory for medical education. In: Innovation in medical education: an evaluation of its present status. New York: Springer publishing; 1990;76-93.
Dochy F., Segersb M., Van den Bosscheb P., Gijbelsb D., (2003) Effects of problem-based learning: a meta-analysis. Learning and Instruction. 13:5, 533-568
Entwistle NJ, Ramsden P. Understanding student learning. London: Croom Helm; 1983
Heale J, Davis D, Norman G, Woodward C, Neufeld V, Dodd P. (1988) A randomized controlled trial assessing the impact of problem-based versus didactic teaching methods in CME. Research in Medical Education.;27:72-7.
Trappler B., (2006) Integrated problem-based learning in the neuroscience curriculum - the SUNY Downstate experience. BMC Medical Education 6: 47.
Rankin JA. Problem-based medical education: effect on library use. Bull Med Libr Assoc 1992;80:36-43.
Schmidt, H G; Dauphinee, W D; Patel, V L (1987) Comparing the effects of problem-based and conventional curricula in an international sample Journal of Medical Education. 62(4): 305-15
Vernon D. T., Blake R. L., (1993) Does Problem-based learning work? A meta-analysis of evaluated research. Academic Medicine.
Complimentary medicine (CAM) is controversial, especially when it is offered by the NHS! You only have to read the recent health section of the Telegraph to see Max Pemberton and James LeFanu exchanging strong opinions. Most of the ‘therapies’ available on the market have little to no evidence base to support their use and yet, I believe that it has an important role to play in modern medicine.
I believe that CAM is useful not because of any voodoo magic water or because the soul of a tiger lives on in the dust of one of its claws but because modern medicine hasn’t tested EVERYTHING yet and because EVERY DOCTOR should be allowed to use a sugar pill or magic water to ease the anguish of the worried well every now and again. The placebo effect is powerful and could be used to help a lot of patients as well as save the NHS a lot of money.
I visited my grandfather for a cup of coffee today. As old people tend to do we discussed his life, his life lessons and his health . My grandfather is 80-something years old and worked as a collier underground for about 25 years before rising up through the ranks of management. In his entire life he has been to hospital twice: Once to have his tonsils removed and once to have a TKR – total knee replacement. My granddad maintains that the secret of his good health is good food, plenty of exercise, keeping his mind active and 1 dried Ivy berry every month! He takes the dried ivy berries because a gypsie once told his father that doing so would prevent infection of open wounds; common injuries in those working under ground. It is my granddad’s firm belief that the ivy berries have kept him healthy over the past 60 years, despite significant drinking and a 40 year pack history! My grandfather is the only person I know who takes this quite bizarre and potentially dangerous CAM, but he has done so for over half a century now and has suffered no adverse effects (that we can tell anyway)!
This has led me to think about the origin of medicine and the evolution of modern medicine from ancient treatments: Long ago medicine meant ‘take this berry and see what happens’. Today, medicine means ‘take this drug (or several drugs) and see what happens, except we’ll write it down if it all goes wrong’. Just as evidence for modern therapies have been established, is there any known evidence for the ivy berry and what else is it used for?
My grandfather gave me a second piece of practical advice this afternoon, in relation to the treatment of open wounds:
To stop bleeding cover the wound in a bundle of spiders web. You can collect webs by wrapping them up with a stick, then slide the bundle of webs off the stick onto the wound and hold it in place.
If the wound is quite deep then cover the wound in ground white pepper.
I have no idea whether these two tips actually work but they reminded me of ‘QuickClot’ (http://www.z-medica.com/healthcare/About-Us/QuikClot-Product-History.aspx) a powder that the British Army currently issues to all its frontline troops for the treatment of wounds. The powder is poured into the wound and it forms a synthetic clot reducing blood loss. This technology has been a life-saver in Afghanistan but is relatively expensive. Supposing that crushed white pepper has similar properties, wouldn’t that be cheaper? While I appreciate that the two are unlikely to have the same level of efficacy, I am merely suggesting that we do not necessarily dismiss old layman’s practices without a little investigation. I intend to go and do a few searches on pubmed and google but just thought I’d put this in the public domain and see if anyone has any corroborating stories.
If your grandparents have any rather strange but potentially useful health tips I’d be interested in hearing them. You never know they may just be the treatments of the future!
BOXING Day, 1.30am. “Are you the doctor on call?” I wrenched my reluctant brain from its REM state. “Yes.”
“I’m worried about my wife. She’s 16 weeks pregnant and very gassy.”
“Burping and farting. Smells terrible! It’s keeping us both awake. I’m worried it could be serious.”
By the time I ascertained that there were no sinister symptoms and that the likely culprit was the custard served with Christmas pudding (the patient was lactose intolerant), I was wide awake. My brain refused to power down for hours, as if out of spite for being so rudely aroused.
I have a confession to make. When the Australian Federal Government announced that it was planning to abolish after-hours practice incentive payments, I was delighted. I know, I know, I should have been outraged along with the rest of you. After all, the RACGP predicted that after-hours care would be decimated if incentives were removed. Comparisons were made with the revamp of the UK system in 2004, which led to 90% of the profession opting out of after-hours work. Much as I sympathised, I was secretly rubbing my hands together with selfish glee. Surely this would mean that our semi-rural practice would stop doing all of our own on-call and free me from my after-hours responsibilities?
I detest being on call. I loathe it with a passion completely out of proportion to the imposition it actually causes. I’m on call for the practice and our local hospital only once a week and the workload isn’t onerous. Middle-of-the-night calls aren’t all that frequent, but my sleep can be disturbed by their mere possibility, leaving me tired and cranky. If I’m forced suddenly into “brain on, work mode” by a phone call, I can kiss hours of precious slumber goodbye.
I love to sleep, but, as with drawing and tennis, I’m not very good at it. I gaze with envy at those lucky devils who nap on public transport and fight malicious urges to disturb their peaceful repose. If I’m not supine, in a quiet, warm room, with loose-fitting clothing, a firm mattress and a pillow shaped just-so, I can forget any chance of sleep. Let’s just say I can relate to the Princess and the Pea story. I bet she wouldn’t have coped well with being phoned in the middle of the night either.
If these nocturnal calls were all bona fide emergencies, I wouldn’t mind so much. It’s the crap that really riles me. I’ve received middle-of-the-night phone calls from patients who are constipated, patients with impacted cerumen (“Me ear’s blocked, Doc. I can’t sleep”) and patients with insomnia who want to know if it’s safe to take a second sedative.
The call that took the on-call cake for me, though, was from a couple who woke me at 11.30 one night to settle an argument.
“My husband says that bacteria are more dangerous than viruses but I reckon viruses are worse. After all, AIDS is a virus. Can you settle it for us so we can get some sleep? It would really help us out.”
I kid you not.
Genevieve Yates is an Australian GP, medical educator, medico-legal presenter and writer. You can read more of her work at http://genevieveyates.com