Where is the lower abdomen
An Approach to Acute Abdominal Pain
hello everyone its erik from strong
medicine today i'm discussing an
approach to acute abdominal pain
diagnostic frameworks for acute
abdominal pain are either based on
anatomic region or by organ system with
a former more common if using the region
to organize the list of possible
diagnoses the abdomen can be divided
into four quadrants with the humble
Lycus at the center however it's
probably even better to divide it into
nine regions right upper quadrant
epigastric left upper quadrant left
flank left lower quadrant suprapubic
rarely called hypogastric right lower
quadrant right flank and parry umbilical
in the center because this nine region
framework is the most common let's take
a closer look at it
when trying to consider what diseases
might cause pain located in a certain
region the simplest principle is to
consider what structures are within that
region so pain in the right upper
quadrant suggests liver or biliary
pathology while pain in the left upper
quadrant it could be from the spleen now
I'm going to go through specific
ideologies while traveling around the
abdomen
starting in the epigastric region pain
located here can be from gastro
esophageal reflux disease gastritis
peptic ulcer disease gastroparesis most
commonly a complication of diabetes
pancreatitis and occasionally referred
pain from acute coronary syndrome pain
in the left upper quadrant can be from a
splenic infarct splenic abscess or
splenic rupture a sub diaphragmatic
abscess or referred pain from a left
lower lobe pneumonia pain in either
flank can be from Nefera with isis
pyelonephritis which is infection of the
kidney or a perinephric abscess which is
an abscess adjacent to the kidney Perry
umbilical pain is most commonly from
simple viral gastroenteritis but could
also be from a small bowel obstruction
mesenteric ischemia which is like angina
of the guts any ruptured abdominal
aortic aneurysm suprapubic pain can be
from cystitis or a simple urinary tract
infection pelvic inflammatory disease
which is a severe complication of
sexually transmitted infections seen in
women or an ectopic pregnancy which
occurs when an embryo is implanted
somewhere other than the uterus a
condition which results in a non viable
pregnancy and is life-threatening to the
mother
pain in the right and left lower
quadrants have similar pathologies
including ovarian and testicular tortion
a ruptured ovarian cyst a tubo-ovarian
abscess and ectopic pregnancy two
differences between the left and right
lower quadrants appendicitis pain is
located in the right lower quadrant only
unless the patient has an unusual
anatomic variation in the position of
the intra-abdominal organs and
diverticulitis is more common on the
left than on the right last is the right
upper quadrants which i think of as a
more distinctive entity than the others
on account of particularly complex and
numerous potential liver and biliary
pathologies there so let's take a look
at that region a little more closely we
can divide ideologies of right upper
quadrant pain into those from the liver
those from the biliary system and other
ideologies of hepatic pain can be
divided into infectious and
non-infectious under infectious is acute
viral hepatitis and deliver abscess
non-infectious causes include alcohol
and medication induced hepatitis hepatic
congestion from heart failure and bud
Kyary syndrome caused by obstruction of
the hepatic vein biliary pathologies can
also be divided into infectious and
non-infectious under infectious are
acute cholecystitis which is
inflammation and infection of the
gallbladder an acute cholangitis which
is inflammation and infection of the
common bile duct relevant non-infectious
pathologies of the gallbladder include
simple gallstones which lead to a
condition known as biliary colic and
choledocholithiasis a mouthful that
means a gallstone trapped within or
actively passing through the common bile
duct lastly in the other causes of right
upper quadrant pain are referred pain
from a right lower lobe pneumonia and a
right-sided sub diaphragmatic abscess
there are some ideologies of acute
abdominal pain that can be either
generalized or poorly localized
including inflammatory bowel disease
infectious colitis such as C difficile
spontaneous bacterial peritonitis
occurring in patients with chronic
ascites secondary peritonitis typically
occurring from bowel perforation and
diabetic ketoacidosis some relatively
rare but nevertheless important causes
of acute abdominal pain adrenal
insufficiency acute intermittent
porphyria and abdominal migraine
angioedema which sometimes surprises
people since we are more familiar with
angioedema causing swelling of the
mucous membranes of the face and throats
but the same process can occur in the
guts colonic pseudo obstruction herpes
zoster in which the pain can
occasionally precede the onset of the
unilateral vesicular rash by a few days
and a rectus sheath
EEMA Toma
let's bring back the abdomen picture to
make a few more points about location
some ideologies of abdominal pain have
common patterns of radiation for example
pyelonephritis typically radiates around
the flank to the lateral back while
nefra lathis
radiates to the groin hepatic and
biliary pathology often radiates to the
right shoulder and pain from
pancreatitis and a Triple A can radiate
straight backwards
when it comes specifically to
appendicitis there is a classic
migratory pattern to the pain early
appendicitis triggering just visceral
pain fibers is first felt not in the
right lower quadrant but rather in the
perio umbilical area where it's actual
location is kind of vague and not yet
associated with tenderness in the next
phase as the perineum overlying the
appendix becomes inflamed the pain is
now felt more in the right lower
quadrants and is associated with
significant tenderness and the lead
phase if the appendicitis is not
identified and treated in a timely
fashion perforation occurs leading to
generalized pain along with peritoneal
signs from secondary peritonitis
visceral pain fibers poorly localized
compared to somatic fibers to innervate
the peritoneum as a consequence
despite the specific anatomic framework
are reviewed earlier pain does not
always map neatly to specific abdominal
quadrants or regions for example
visceral pain from foregut structures is
most common in the epigastric region but
can be found in either the right or left
upper quadrants or near the umbilicus
painful mid gut structures can extend
into the epigastrium and super pubic
regions hindgut structures can lead to
pain throughout half the abdomen pain
from the GU system and reproductive
systems can be widespread and even pain
from the liver and biliary system can
extend outside the right upper quadrants
now I'll shift to discussing the
step-by-step evaluation of abdominal
pain starting from the history one of
the most important questions is the
chronology of the pain for example its
acuity of onset and extremely abrupt
onset suggest a bowel perforation or
vascular catastrophe including
intra-abdominal thromboembolism ruptured
triple-a and ovarian or testicular
tortion how long is the pain been
present for and whether it is episodic
or continuous as a general rule episodic
pain suggests a less imminently
dangerous pathology such as biliary
colic peptic ulcer disease GERD chronic
mesenteric ischemia and gastroparesis
but that rule isn't perfect since
intermittent epigastric pain could be an
atypical presentation of acute coronary
syndrome as I just reviewed the location
and radiation of pain is helpful at
narrowing down diagnostic possibilities
determine what the exacerbating factors
are for example pain related in any way
to food intake suggests either upper GI
pancreatic or biliary pathology ask
about the presence of associated
symptoms including nausea and vomiting
diarrhea or constipation
evidence of GI bleed lack of flatus or
passing gas fever jaundice dysuria or
hematuria obviously take a past medical
and surgical history and a gynecological
history to medication history sexual
history for STI risk factors substance
use history particularly alcohol travel
history and a general exposure history
after vitals a focused physical exam
should of course include a thorough
abdominal exam and if any type of
reproductive pathology is on the
differential for a female patient a
pelvic exam
since cardiac and pulmonary disease can
refer to the upper abdomen those exams
should be performed as well
you may notice here that I have not
listed a rectal exam that's because it's
generally not indicated unless anal
rectal or prostatic disease is
specifically suspected
key Labs in the workup of acute
abdominal pain include cbc lfts
metabolic panel and a light pace the
last of which is specifically to help
identify pancreatitis historically
another test called amylase was also
frequently ordered in this presentation
but it's nonspecific and does not
contribute useful information other
frequently considered tests if the
patient is a woman of childbearing age
get a urine HCG to screen for pregnancy
even if she reports no sexual activity
patients are sometimes not forthcoming
and an ectopic pregnancy is not a
diagnosis you or your patient can afford
to miss if a cute bow ischemia is
suspected an elevated lactate would be
consistent with infarction unless the
patient is young healthy and without
cardiovascular risk factors order a
troponin and an ECG
to rule out acute coronary syndrome if
the pain is upper abdominal or where the
patient has concurrent pulmonary
symptoms order a chest x-ray if the
patient reports either dysuria or
hematuria check a UA plus or minus urine
culture depending on suspicion for a
urinary infection and there are numerous
indications for either a CT ultrasound
or rarely other imaging modality while
as a general rule at least in the United
States clinicians over rely on imaging
in most circumstances in my experience
acute abdominal pain is not one of them
point in my approach to symptom videos I
usually present a diagnostic algorithm
that one could follow to arrive at the
single most likely diagnosis but with
acute abdominal pain there are just too
many ideologies to reasonably include in
one algorithm so instead I'm going to
review a handful of illness scripts for
some of the most common diagnoses which
will compare and contrast typical
historical features risk factors common
exam findings and the relevant
diagnostic tests I'll divide these
scripts in half
starting with causes of general and or
more midline pain and will then
separately compare and contrast the four
most common causes of right upper
quadrant pain
first let's compare and contrast public
ulcer disease gastroenteritis small
bowel obstruction appendicitis and
pancreatitis in PUD the pain is
epigastric occasionally radiating to the
back it may be triggered by eating there
is occasionally associated nausea and
vomiting and/or overt signs of GI
bleeding like mallanna but these are
usually absent risk factors include
NSAID use and h pylori infection
physical exam can shield mild to
moderate epigastric tenderness if there
are parents neal science presents the
ulcer has likely perforated and needs a
surgeon routine blood tests are usually
unremarkable unless the patient has
significant bleeding
PUD is diagnosed via EGD which should be
supplemented with testing for HP Laurie
when it comes to gastroenteritis pain is
typically parry umbilical it's often
cramping and associated with nausea
vomiting and diarrhea in most cases
there aren't really significant risk
factors outside of an outbreak the exam
will show mild to moderate Perry on
Biblical or generalized tenderness but
no rigidity or peritoneal science fever
and science of dehydration are common
the only typical abnormal blood test is
an elevated white blood cell count
diagnosis is a clinical one not
requiring any imaging or endoscopy in
just the last several years some US
medical centers have begun employing
stool pcr panels for some patients
presenting with diarrhea in order to
identify the specific pathogen late
gastroenteritis the pain from a small
bowel obstruction is typically
periumbilical and crampy it's associated
with nausea and vomiting abdominal
distension and an absence of flatus risk
factors for an SPO include prior
abdominal or pelvic surgery hernias
foreign body ingestion inflammatory
bowel disease and an intestinal tumor
the exam usually shows abdominal
distension there may be high
pitched rushing bowel sounds there may
be signs of dehydration and a peritoneal
science suggests perforation or
infarction even though in SPO can
usually be diagnosed on history and exam
alone these patients should all get a CT
to identify the location of the
obstruction and to search for potential
causes if for some reason CT is not
available plain films are a reasonable
alternative to definitively confirm the
diagnosis in which case upright and
supine abdominal film should be ordered
plus or minus an upright chest x-ray
which can better identify the presence
of free air
as already discussed pain from the
pendous itis is classically present in
the right lower quadrant but often
begins in the para umbilical region
nausea vomiting in anorexia usually
followed the onset of pain rather than
the other way around if there is severe
generalized pain perforation is likely
there are no major risk factors for
appendicitis on exam the most notable
finding is tenderness and a specific
location called McBurney's points which
is located one third of the distance
along an imaginary line from the
anterior superior iliac spine to the
umbilicus there are some other classic
but less discussed findings such as Rob
Zing's so s and obturator signs patients
are often febrile and once again
peritoneal signs suggest perforation
significant labs in Penta situs include
high white counts and an elevated CRP
while an elevated CRP would be expected
in some other abdominal diseases such as
peritonitis and acute cholecystitis for
some reason it's more discussed as a
feature of appendicitis specifically
there is also a clinical prediction rule
called the Alvarado score which assigns
points to various historical exam and
lab features to give an overall
probability of the diagnosis any patient
with suspected appendicitis should
undergo imaging which can be either CT
or ultrasound the choice of which is
institution clinician and situation
dependent and then there is pancreatitis
in which patients present with
epigastric pain radiating to the back
that's exacerbated by eating and
relieved by sitting up and leaning
forward it's usually associated with
nausea and vomiting this mia is a more
commonly associated symptom in
pancreatitis than with the other
diagnoses in this chart risk factors or
ideologies for pancreatitis include
alcohol and gall stones which together
account for the majority of cases less
common causes include ERCP
hypertriglyceridemia and a variety of
medications on exam severe cases can
present with shock and parry umbilical
or flank
ecchymosis suggests hemorrhage secondary
to pancreatic necrosis
a particularly worrisome sign the most
notable abnormal lab is in very elevated
lipase typically more than three times
the upper limit of normal while a CT
scan is not considered necessary for the
diagnosis it can assess for
complications and help identify gall
stones in the pancreatic duct as a
potential causative factor
now let's run through the illness
scripts of four particularly important
causes of right upper quadrant pain
biliary colic acute cholecystitis acute
cholangitis and acute hepatitis in
biliary colic caused by gall stones
within the gallbladder the pain is
typically episodic lasting 30 minutes to
several hours it's often triggered by
eating there is no associated jaundice
risk factors include female sex
pregnancy obesity rapid weight loss and
diabetes the physical exam is usually
unremarkable as our routine blood tests
a right upper quadrant ultrasound will
show gall stones and help to clinch the
diagnosis but this is a non emergent
study if the clinical presentation is
classic the pain in acute cholecystitis
is progressive over hours nausea and
vomiting are common and since the common
bile duct is not involved there is no
jaundice the most notable risk factor
for acute cholecystitis is the known
presence of pre-existing gall stones on
exam patients are often febrile the
classic finding is an increase in right
upper quadrant tenderness on inspiration
when the diaphragm descends pushing the
liver and gallbladder into the examiners
stationary hands this is known as
Murphy's sign there's also something
called the sonographic Murphy sign in
which pain is worse with inspiration
when the pressure is applied to the
right upper quadrant with an ultrasound
probe at the exact location of the
gallbladder since the examiner can
directly see it on the screen this is
thought to be more specific than the
classic Murphy sign routine lab tests
usually reveal and elevated white counts
with normal or near-normal l.f.t.s a
definitive diagnosis can usually be made
with a right upper quadrant ultrasound
in acute cholangitis the pain is similar
to acute cholecystitis and nausea and
vomiting are also common however
jaundice also occurs risk factors for a
cou cholangitis include benign biliary
strictures and malignant obstruction of
the biliary system including pancreatic
tumors as a very general rule patients
appear more ill than in other common
causes of right upper quadrant pain
but this is less often the case in the
elderly and in those on
immunosuppressive medications common
test findings include a high white count
high bilirubin which is predominantly
direct or conjugated bilirubin high
alkaline phosphatase and there may or
may not be mild to moderate elevation of
ast and alt if after the history exam
and blood tests the pretest probability
of cholangitis is high one can proceed
directly to an ERCP otherwise consider a
right upper quadrant ultrasound and the
last diagnosis to discuss is acute
hepatitis which is acute infection and
or inflammation of the liver the
symptoms of acute hepatitis can be
similar to those of acute cholangitis
though in my experience the onset is
slightly more prolonged risk factors
were more appropriately ideologies here
include hepatitis viruses particularly a
alcohol acetaminophen toxicity and
autoimmune hepatitis there are many
other causes of acute hepatitis but
these for cover the overwhelming
majority in the US and other Western
countries on exam fever is sometimes
present and there can be a variety of
findings related to liver dysfunction
depending upon the severity and acuity
of presentation
Labs include high white count extremely
elevated ast and alt often over 1000
high alphas high bilirubin classically
with direct and indirect being roughly
equal and an elevated INR other tests
you should order include hepatitis virus
serologies and acetaminophen level
though a single number is impossible to
interpret in the absence of a known time
of acute drug ingestion also if another
etiology of the hepatitis has not been
clearly established Auto antibodies for
autoimmune hepatitis are reasonable to
order
when discussing acute abdominal pain
it's common to hear the term surgical
abdomen use of this term implies that
the underlying etiology requires an
emergent evaluation by a surgeon
specific exam characteristics that are
consistent with a surgical abdomen
include rigidity also known as
involuntary guarding which is the most
concerning of abdominal physical
findings
unusually severe tenderness to palpation
science of peritonitis known as
peritoneal signs include rebound
tenderness this is the finding that pain
caused by slow abdominal pressure
applied by the examiner's hands is not
as severe as a pain caused by the quick
release of that pressure
it includes a positive cough test in
which pain is worsened by coughing the
bed bump test in which it is worsened by
the examiner pumping the bed hard which
works best on a gurney rather than a
sturdy hospital bed or the heel strike
test in which pain is worsened by the
examiner firmly striking the patient's
heel in ambulatory patients the heel
strike test can be done by asking the
patient to stand and jump in place and
absent bowel sounds
none of these findings in isolation
necessarily indicate a surgical abdomen
but seeing multiple of them in a patient
whose history is consistent with a
possible surgical emergency would
suggest this general situation
also not every surgical emergency
presents with a surgical abdomen
specifically emergencies which are extra
peritoneal such as a ruptured aortic
aneurysm the term surgical abdomen is
sometimes used interchangeably with the
term acute abdomen although some
clinicians use the latter term more
broadly to mean any patient with acute
abdominal pain and any notable physical
exam findings irrespective of likely
pathology
finally I'll end by listing those
conditions to particularly consider in
patients with abdominal pain who are
presenting with shock at the time of
initial presentation these include acute
cholangitis bowel perforation balan
farken ruptured ectopic pregnancy
ruptured triple-a splenic rupture any
condition with concurrent massive GI
bleed and an acute myocardial infarction
the key takeaway points for this video
acute abdominal pain is one of the most
common presenting symptoms to the
emergency room and urgent care
there are many ideologies ranging in
severity from benign and self-limited to
imminently life-threatening idealogy
czar associated with specific locations
of pain but they do not always map as
precisely to anatomic quadrants as
references typically suggest abdominal
pain can be referred from intrathoracic
pathologies and finally the presence of
rigidity unusually severe tenderness to
palpation peritoneal signs and absent
bowel sounds are consistent with a
surgical abdomen which usually requires
emergent surgical consultation
you
