By Jerome Semakula
Last
month I was one of a group of fourth year medical students who attended a short
training on use of ultrasound in emergency medicine at Makerere University
College of Health Sciences. This was organized by emergency medicine
enthusiasts at the College together with visiting Emergency medicine residents
from Yale University, USA. This training was meant to introduce clinical
year-students to the use of ultrasound in diagnosing emergency conditions.
There were two sessions, the first of which was a short lecture on the basics
of using ultrasound, its indications and interpretation of ultrasound images.
This was then followed up with a bedside practical demonstration which was done
at Mulago Hospital and involved a real patient with real signs and symptoms.
This particular patient to be examined presented with fever and general body
weakness. He had been sick for a while and for almost a fortnight he was being
treated for Malaria at a clinic but his relatives had chosen to bring him to
Mulago hospital because of his continuing deteriorating condition. It was not clear what the exact cause was but
quick history and examination revealed a high possibility of septicemia. He had
a high fever, tachycardia (fast heart rate) and tachypnea (fast respiratory
rate) but no identified focus of infection. His chest X-Ray was unremarkable
and the attending intern doctor had already requested for a blood culture and
started the young man on antibiotics and intravenous fluids.
Ultrasound
was required to study his abdominal organs and peritoneum and rule out any
abdominal focus of infection. For each major organ, the ultrasound viewing was
done by medical students present including me.
We used a portable ultrasound
gadget about the size of a mobile phone. We were tasked with applying the
general principles learnt in the previous week to study the different organs
and give a description of each as seen on the screen of the gadget. Different
planes were applied such as sagittal, coronal and transverse to appreciate the
different anatomical structures of the abdomen. Ultrasound scanning was done
for the spleen, kidneys, liver and peritoneum. All organs appeared normal with
no signs of pathology and no free fluid in his peritoneum. In addition to the
abdominal organs, viewing of the abdominal aorta and inferior vena cava as well
as examination of the heart and its chambers was done. The patient awaited for
blood culture results as he was started on broad spectrum antibiotics to manage
any possible infection.
"This teaching session not only allowed me to appreciate radiological aspects of human anatomy but also more importantly taught me how to identify quickly danger signs in a severely ill patient using ultrasound."
Ultrasound
is an oscillating sound pressure wave with a frequency greater than the upper
limit of the human hearing range (greater than 20kHz). An ultrasound device and
probe produces such sounds that are generated from the probe and travel through
the tissues of the patient and then return to the probe as they encounter
tissues of different densities. The intensity of the returning echo determines
brightness of the image on the screen. Strong signals produce white or
hyperechoic images as seen with bone. Weak echo signals returning to the probe
translate into dark black, or hypoechoic images on the ultrasound screen as
seen with fluid.
The use of ultrasound in medicine started more than 50 years
ago when it was mainly used in cardiology and obstetrics to investigate
patients without the unwanted exposure to dangerous radiation that was
encountered with the use of X-ray. Whereas there have been advancements in
radiological devices such as the CT scan and MRI, ultrasound remains one of the
most commonly ordered radiological investigations in most hospitals in Uganda
because its effective, quick and cheap.
In many high income countries,
there has been a shift in medical training toward supraspecialization, where
diagnostic imaging and intervention procedures are increasingly performed by
physicians with no formal radiology training as a result of which the concept
of “point-of-care ultrasonography” (PCUS) where limited, problem-directed
bedside ultrasound is performed by hospital specialists has arisen[1].
Currently, this has become an established practice in vascular access,
abdominal aortic aneurysm screening, rheumatology, critical care, and emergency
cardiac function assessment. The more liberal use of ultrasound by
non-radiology specialists has been facilitated by the introduction of portable
hand-held ultrasound devices, as well as the development of more affordable and
user-friendly ultrasound equipment. Surgeons and emergency physicians have
adopted focused assessment with sonography in trauma (FAST) scanning to
determine the presence or absence of free fluid in the abdomen, pelvis, or
pericardium to guide further assessment with computed tomography or to expedite
surgical exploration.
The current growing
interest in Emergency medicine in the country, Uganda, (see milestones) and future establishment of
emergency medicine as an expanding specialty in Makerere University and
possibly other medical schools in Uganda will depend on training of medical
school graduates (doctors) but also equipping medical students early in their
training with skills such as Ultrasound use in emergency settings. A recent study
comparing the diagnostic accuracy for various forms of cardiac disease between
first-year medical students with 18 hours of ultrasound training and
board-certified cardiologists armed with their stethoscopes demonstrated a
large advantage for the students. [2]
The
potential use of portable ultrasound bedside examination is vast in the Uganda
setting not only for the emergency (casualty) units but also for the many
obstetric facilities especially in upcountry health centers where running of
heavy equipment can be a problem due to shortage of skilled staff and power
shortages.
Ultrasound technology has
progressed greatly over time. It is predicted that ultrasound equipment will
become more compact and will be the new stethoscope of the future [3,4]. It can
therefore be argued that it is important to introduce ultrasound and its
significance in undergraduate teaching in the early years of their education.
As emergency medicine enthusiasts continue to work on establishing the roots of
emergency medicine in Uganda’s health care system, it is of utmost importance
that medical students as well as those in the field are trained in such areas
as diagnostics in emergency medicine to increase effectiveness and efficiency
of emergency care in health care centers in the country.
References
1. Beaulieu Y, Marik PE. Bedside
ultrasonography in the ICU. part 1. Chest. 2005;128:881-895.
2. Kobal SL, Trento L, Baharami S, et al. Comparison of
effectiveness of hand-carried ultrasound to bedside cardiovascular physical
examination. Am J Cardiol.2005; 96:1002–6.
3. Heilo A, Hansen AB, Holck P,
Laerum F: Ultrasound ‘electronic vivisection’ in the teaching of human anatomy for
medical students. Eur J Ultrasound 1997, 5:203–207.
4. Hoppmann R, Michell WE, Carter
JB, McMahon C, Lill PH, Brownlee NA, Carnevale KA: Ultrasound in second year
pathology medical education. Journal of the South Carolina Academy of Science
2008, 7(1):11–12
Jerome is fourth year medical student at Makerere University College of Health Sciences and is very passionate about all things Emergency
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