Common Caveats in Emergency Medicine Diagnoses:
1. Appendicitis misdiagnosed as Acute Gastroenteritis: AGE
Professor Manning mentioned a study in a hospital in the USA which revealed that high percentages (can't remember exact figures) of appendicitis cases were misdiagnosed as AGE. Prof Manning jokingly explained that it was probably because AGE is an easier and more convenient diagnosis (no need for observation or further hospital stays!) compared to acute appendicitis!
Anyway, i've been taught that the classical presentation of appendicitis is that of poorly localized periumbilical pain migrating towards the RIF to become a well localized area of sharp stabbing pain and tenderness. This classical teaching raises 3 issues:
(i) What is classical isn't the commonest: this only applies if the appendix lies anterior to the cecum. The appendix, however, is most often located retrocecally
(ii) A well localized pain: if a person has a well localized area of pain and tenderness,
(iii) Risk of perforation: atypical presentations commonly confuse the physician and results in misdiagnoses. As often mentioned, the very young have difficulties in expressing themselves resultign in diagnostic difficulties. The elderly suffer from the same problems, and are also guilty of atypical presentations (E.g. a large majority of them do not have fever or raised WCC during an infective process). Other atypical presentations include the pregnant women, where the area of pain may not be at the RIF but instead, pushed by the gravid uterus, be located at the Right hypochondrium and as such, is often misdiagnosed as cholecystitis.
To help a physician with diagnosing acute appendicitis: The Alvarado Score
Alvarado = MANTRELS
Migratory pain: 1 point
Anorexia: 1 point
Nausea/Vomiting: 1 point
Tenderness at RIF: 2 points: this shows the emphasis of a localized area of pain (which if present, is very unlikely AGE)
Rebound tenderness 1 point
Elevated Temp: 1 point
Leukocytosis: 2 points (do note that in a large number of elderly patients, WCC isn't raised)
Shift to the Left: 1 point
There are opponents to the usage of Alvarado score in the diagnosis of appendicitis. Well these people are aka the surgeons. Well when stuck in the emergency department and not having a CT scan readily available (unlike the surgical dudes), alvarado score is immensely precious.
7-10: high risk, surgical referral STAT (Surgical Reg pls)
4-6: moderate risk: EDTU for serial observation and wait for Surgical Reg to R/V
1-3: low risk of appendicitis: discharge, explain that it is unlikely appendicitis, that the risk of appendicitis developing over the next 24 hours is equivalent to my own. Tell the patient to return the following morning (12-24 hours later) or when the pain gets worse.
2. Ectopic pregnancy:
Risk factors: basically anything that disrupts the anatomy and function of the hoohoos
(i) PID (increasingly common in Singapore, especially Chlamydia infections)
(ii) Previous surgery/Ashermann's syndrome
(iii) Infertility (duh)
(iv) previous ectopic pregs
(v) endometriosis
95% of ectopic pregnancies are tubal pregnancies
Contrary to common misconception, the more distal the tubal pregnancy is actually safer than those involving mroe proximal sections of the oviduct. Why?
- Ampulla: commonest site of tubal pregnancy. The isthmus is the least common i think. The reason why tubal pregnancy at the isthmus is so dangerous is because the ovarian artery and its big branches are in close proximity to the oviductal isthmus. Subsequent invasion and perforation of these arteries may result in massive haemorrhage, much more so than that of tubal pregnancies involving the ampulla.
Classical presentation: Like appendicitis, classical is not neccessarily the commonest. In fact in ectopic pregnancy, the classical triad below only happens in 25% of the cases
(i) Lower abdominal pain
(ii) Vaginal spotting (NOT FRANK BLEED! just vaginal spotting! the bleed is internal!)
(iii) adnexal mass
On examination: DVE (vaginal examination)
- adnexal mass
- cervical motion tenderness (peritoneal sign)
- uterine enlargement (for those not known to be pregnant) or uterus small for age (for those who are pregnant)
What to do?:
(i) Estabilish if the bleed is part of her normal menstrual cycle: Time, duration, volume
(ii) do a UPT! Nurses in NUH A and E are empowered by Prof Manning to do UPTs. They are very cheap, easy to carry out, sensitive, specific and can detect raised hCG as early as 7-10 days after fertilization! (older models detect 2 weeks later). uhCG 15-50mIU/ml = 95-100% sensitive and specific.
(iii) 14/16 G 2x large bore IV cannulae
(iv) GXM (for E blood)
Simple Rules of Thumb:
Young women + syncope + abdominal pain: Ectopic pregnancy
Young persons + syncope + headache: SAH
Old + syncope + abdominal pain = AAA
Old + syncope + chest pain + diaphoresis = AMI
Musings: When asked how much blood is lost in a patient with ectopic pregnancy, say 1.5L! Why? nobody knows. its like an O and G rule. 1.5 L. As though these specialists have fingers made of measuring tubes.
Other killers with abdominal pain:
1. AAA:
- classical Pxn: Pentad: old + pulsatile abdominal mass + collapse + back pain radiating to abdomen (or vice versa) + hypotension
- Mx: U/S
2. Mesenteric Ischaemia
- post prandial pain + pain out of proportion (rolls around) + co morbidities (anything that results in low CO: CCF, dehydration, elderly) + blood in rectum (late sign: prepare the undertakers)
Mx: bedside lactate = raised due to metabolic acidosis
3. Perforated Viscus
- Gastric aetiologies
- Perforated malignancy
Pxn: Abdo pain + patient keeps still (peritoneal irritation) + guarding
Mx: erect/decubitus CXR/AXR
4. Pancreatitis: A triad
Pxn:
(i) patient sits up, hunched forward, or lying on his side: Why? ==> Pancreas is a retroperitoneal organ. this is to allow relieve of pressure of the lumbar spine against which the pancreas is pressed against
(ii) Epigastric pain radiating to the back
(iii) Vomiting: this is especially important. in fact, Prof Manning mentioned that without vomiting, pancreatitis is less likely the cause of abdominal pain, thus no need to order amylase or lactase
5. Intestinal Obstriuction
6. Extraabdominal causes:
- inferior MI
- basilar pneumonia: diaphragm has multiple innervations, referred pain to epigastrium
- DKA
- ureteric colic, testicular torsion
- Methanol poisoning: Russian sailors, drunk + abdopain + blindness
Quiz of the Day:
Now i have a quiz for everyone here. The answers at the bottom so try not to look at it.
An elderly gentlemen came into the A and E presenting with:
(i) colicky loin to groin pain
(ii) blood in urine
(iii) abdominal pain
On further questioning:
(i) no previous history of stones
(ii) first episode of the presentation described above
SO whats your DIAGNOSIS?
ANSWER:
aaa lanerarpus
aaa lla fo %2
1. Appendicitis misdiagnosed as Acute Gastroenteritis: AGE
Professor Manning mentioned a study in a hospital in the USA which revealed that high percentages (can't remember exact figures) of appendicitis cases were misdiagnosed as AGE. Prof Manning jokingly explained that it was probably because AGE is an easier and more convenient diagnosis (no need for observation or further hospital stays!) compared to acute appendicitis!
Anyway, i've been taught that the classical presentation of appendicitis is that of poorly localized periumbilical pain migrating towards the RIF to become a well localized area of sharp stabbing pain and tenderness. This classical teaching raises 3 issues:
(i) What is classical isn't the commonest: this only applies if the appendix lies anterior to the cecum. The appendix, however, is most often located retrocecally
(ii) A well localized pain: if a person has a well localized area of pain and tenderness,
(iii) Risk of perforation: atypical presentations commonly confuse the physician and results in misdiagnoses. As often mentioned, the very young have difficulties in expressing themselves resultign in diagnostic difficulties. The elderly suffer from the same problems, and are also guilty of atypical presentations (E.g. a large majority of them do not have fever or raised WCC during an infective process). Other atypical presentations include the pregnant women, where the area of pain may not be at the RIF but instead, pushed by the gravid uterus, be located at the Right hypochondrium and as such, is often misdiagnosed as cholecystitis.
To help a physician with diagnosing acute appendicitis: The Alvarado Score
Alvarado = MANTRELS
Migratory pain: 1 point
Anorexia: 1 point
Nausea/Vomiting: 1 point
Tenderness at RIF: 2 points: this shows the emphasis of a localized area of pain (which if present, is very unlikely AGE)
Rebound tenderness 1 point
Elevated Temp: 1 point
Leukocytosis: 2 points (do note that in a large number of elderly patients, WCC isn't raised)
Shift to the Left: 1 point
There are opponents to the usage of Alvarado score in the diagnosis of appendicitis. Well these people are aka the surgeons. Well when stuck in the emergency department and not having a CT scan readily available (unlike the surgical dudes), alvarado score is immensely precious.
7-10: high risk, surgical referral STAT (Surgical Reg pls)
4-6: moderate risk: EDTU for serial observation and wait for Surgical Reg to R/V
1-3: low risk of appendicitis: discharge, explain that it is unlikely appendicitis, that the risk of appendicitis developing over the next 24 hours is equivalent to my own. Tell the patient to return the following morning (12-24 hours later) or when the pain gets worse.
2. Ectopic pregnancy:
Risk factors: basically anything that disrupts the anatomy and function of the hoohoos
(i) PID (increasingly common in Singapore, especially Chlamydia infections)
(ii) Previous surgery/Ashermann's syndrome
(iii) Infertility (duh)
(iv) previous ectopic pregs
(v) endometriosis
95% of ectopic pregnancies are tubal pregnancies
Contrary to common misconception, the more distal the tubal pregnancy is actually safer than those involving mroe proximal sections of the oviduct. Why?
- Ampulla: commonest site of tubal pregnancy. The isthmus is the least common i think. The reason why tubal pregnancy at the isthmus is so dangerous is because the ovarian artery and its big branches are in close proximity to the oviductal isthmus. Subsequent invasion and perforation of these arteries may result in massive haemorrhage, much more so than that of tubal pregnancies involving the ampulla.
Classical presentation: Like appendicitis, classical is not neccessarily the commonest. In fact in ectopic pregnancy, the classical triad below only happens in 25% of the cases
(i) Lower abdominal pain
(ii) Vaginal spotting (NOT FRANK BLEED! just vaginal spotting! the bleed is internal!)
(iii) adnexal mass
On examination: DVE (vaginal examination)
- adnexal mass
- cervical motion tenderness (peritoneal sign)
- uterine enlargement (for those not known to be pregnant) or uterus small for age (for those who are pregnant)
What to do?:
(i) Estabilish if the bleed is part of her normal menstrual cycle: Time, duration, volume
(ii) do a UPT! Nurses in NUH A and E are empowered by Prof Manning to do UPTs. They are very cheap, easy to carry out, sensitive, specific and can detect raised hCG as early as 7-10 days after fertilization! (older models detect 2 weeks later). uhCG 15-50mIU/ml = 95-100% sensitive and specific.
(iii) 14/16 G 2x large bore IV cannulae
(iv) GXM (for E blood)
Simple Rules of Thumb:
Young women + syncope + abdominal pain: Ectopic pregnancy
Young persons + syncope + headache: SAH
Old + syncope + abdominal pain = AAA
Old + syncope + chest pain + diaphoresis = AMI
Musings: When asked how much blood is lost in a patient with ectopic pregnancy, say 1.5L! Why? nobody knows. its like an O and G rule. 1.5 L. As though these specialists have fingers made of measuring tubes.
Other killers with abdominal pain:
1. AAA:
- classical Pxn: Pentad: old + pulsatile abdominal mass + collapse + back pain radiating to abdomen (or vice versa) + hypotension
- Mx: U/S
2. Mesenteric Ischaemia
- post prandial pain + pain out of proportion (rolls around) + co morbidities (anything that results in low CO: CCF, dehydration, elderly) + blood in rectum (late sign: prepare the undertakers)
Mx: bedside lactate = raised due to metabolic acidosis
3. Perforated Viscus
- Gastric aetiologies
- Perforated malignancy
Pxn: Abdo pain + patient keeps still (peritoneal irritation) + guarding
Mx: erect/decubitus CXR/AXR
4. Pancreatitis: A triad
Pxn:
(i) patient sits up, hunched forward, or lying on his side: Why? ==> Pancreas is a retroperitoneal organ. this is to allow relieve of pressure of the lumbar spine against which the pancreas is pressed against
(ii) Epigastric pain radiating to the back
(iii) Vomiting: this is especially important. in fact, Prof Manning mentioned that without vomiting, pancreatitis is less likely the cause of abdominal pain, thus no need to order amylase or lactase
5. Intestinal Obstriuction
6. Extraabdominal causes:
- inferior MI
- basilar pneumonia: diaphragm has multiple innervations, referred pain to epigastrium
- DKA
- ureteric colic, testicular torsion
- Methanol poisoning: Russian sailors, drunk + abdopain + blindness
Quiz of the Day:
Now i have a quiz for everyone here. The answers at the bottom so try not to look at it.
An elderly gentlemen came into the A and E presenting with:
(i) colicky loin to groin pain
(ii) blood in urine
(iii) abdominal pain
On further questioning:
(i) no previous history of stones
(ii) first episode of the presentation described above
SO whats your DIAGNOSIS?
ANSWER:
aaa lanerarpus
aaa lla fo %2
posted by scientia at
5:42 AM
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