Key facts:
Authors: Alex Tan, Richard Lin, Anil Ghosh, Asif Haq
Top Tip: Acute appendicitis is the commonest general surgical emergency. 'Active' observation is important
Key Differential Diagnoses
Females only
- Ectopic pregnancy
- Other gynae (PID, Ovarian torsion, Mittelschmerz’s)
Males only
- Right-sided testicular torsion
Both sexes
- Bowel (Obstruction/Intussusception, Perforation, Carcinoma caecum, CD (terminal ileitis), Strangulated hernia, Gastroenteritis)
- Urinary (UTI/pyelonephritis, renal colic)
- Other (Mesenteric adenitis, Meckel’s diverticulitis)
Key Investigations
- FBC, CRP
- Urinalysis (& urinary B-HCG levels in all females of child-bearing age)
Key Treatment
- NBM
- Concurrent examination and investigation
- Re-examine abdomen, re-check vital signs ('active observation')
- IV FLUIDS
- IV MORPHINE 10mg & IV CYCLIZINE 10mg
- Open appendicectomy or laparoscopic surgery
- Note: in females, laparoscopic approach may be favourable to exclude differential diagnoses for females
Key Management Decision
- Surgery
Background
The classical history occurs in only 50% of patients; diagnosis is based on clinical evaluation not investigations
Introduction
- Appendicitis is the commonest cause of acute abdominal pain warranting surgery; 10% of the population experience appendicitis at some point; because of it is common, the diagnosis should be considered in any patient with an acute abdomen. Acute and chronic appendicitis were first described by Reginald Fitz in 1886
- Diagnosis is clinical, sometimes supplemented by CT or ultrasound
- Treatment is surgical removal
- The symptoms of appendicitis can vary. It can be hard to diagnose appendicitis in young children, the elderly, and women of childbearing age
- No single sign, symptom, or diagnostic test accurately confirms the diagnosis of appendiceal inflammation in all cases
- The classic history of anorexia and periumbilical pain followed by nausea, right lower quadrant (RLQ) pain, and vomiting occurs in only 50% of cases. For all these reasons, the diagnosis can be challenging despite being a 'simple' disease
- A normal appendix is removed in 10-20% of cases, and 33% of nonpregnant women of childbearing age
- When the diagnosis is made, an appendicectomy should be performed without delay
- Perforation rate is 15-20%, higher in children and the elderly
- Mortality = 1%; small but do not forget; significant in older patients (20% >70y)
Note: investigate elderly patients managed conservatively - to exclude a carcinoma of caecum
Definition
- Inflammation of the vermiform appendix
Etymology
- From Latin appendere, to hang upon
Epidemiology
- Affects approximately 10% of the population in the UK
- Most common age is 10-20 years; some familial predisposition occurs
- No age groups are exempted from this surgical emergency
- Incidence is approximately 1.4 times higher in males than females
Causes
- Obstructed appendicular lumen can be due to:
- Faecaliths (most common) - when calcium and faecal debris are layered around inspissated faeces in the appendix
- Lymphoid follicle hyperplasia (most common) - due to inflammatory/infectious disorders including Crohn’s disease and gastroenteritis
- Obstruction of the lumen of the appendix - due to micro-organisms (e.g. Schistosomes species), foreign body, strictures, TB or tumours
Types (variations in position of appendix)
- Retrocaecal/retrocolic (>60%)
- Subcaecal and pelvic (30%)
- Pre-ileal and post-ilial
- Variations in the position of the appendix
Risk factors
- Diet lacking in fibre, thereby decreasing the faecal viscosity and decreasing bowel transit time
Symptoms
- Acute abdominal pain, 1-3 days duration
- Classically, initially poorly localised central abdominal/periumbilical pain that migrates to the right iliac fossa region; and becomes more sharper, constant and well-localised pain
- Pain can be worse with moving and coughing
- Anorexia
- Nausea or vomiting (in appendicitis, vomiting often occurs after the onset of pain. If vomiting precedes pain, it is suggestive of intestinal obstruction)
- Urinary frequency may occur (due to the inflamed appendix irritating the bladder or ureter)
- Constipation or even diarrhoea may occur (due to the inflamed pelvic appendix irritating the rectum)
- May be a history of similar less severe episodes
Note: duration of symptoms is less than 48 hours in approximately 80% of adults but tends to be longer in elderly persons and in those with perforation. Approximately 2% of patients report duration of pain in excess of 2 weeks
Key questions
- “Where is the tummy pain? Did it begin from the navel and travel to the groin on the right side?”
- “Have you lost your appetite?”
- “Do you feel sick? Have you vomited? Did the tummy pain happen before the vomiting?”
- “Does your tummy hurt when you cough/move around/stand? Are you most comfortable lying still?”
Signs
- Tachycardia & fever (37.5-38oC in uncomplicated cases; may be higher if perforation)
- Lying still (indicative of peritonitis), with shallow breaths
- Dry furred tongue with foetor oris
- Tenderness in RIF; maximal over McBurney’s point (one-third along the line from right anterior superior iliac spine to umbilicus)
- Coughing or movement worsens the pain
- Guarding
- Rebound & percussion tenderness (suggests peritoneal inflammation)
- Additional signs: pain felt in the right lower quadrant with palpation of the left lower quadrant (Rovsing sign); an increase in pain from passive extension of the right hip joint that stretches the iliopsoas muscle (psoas sign); or pain caused by passive internal rotation of the flexed thigh (obturator sign).
- Digital rectal examination may cause pain on right iliac fossa region
Investigation
Regular assessment is more important than investigation; re-examine in 6 hours, especially if the decision to operate has not yet been made
Blood
- FBC (WC ↑; neutrophils >75%) and CRP (↑) in an otherwise fit and well patient
- Other possible tests: U&E, LFTs, Group & Save, Clotting
Other
- Urinalysis (to exclude UTI)
- CXR not normally required; but do erect CXR if perforation suspected and look for free gas
- Supine AXR not normally required, unless obstruction suspected
- ECG, in older patients
- In females, if suspect ectopic pregnancy, check for B-HCG levels in urine
Key investigations
- FBC, CRP
- Urinalysis (& check for B-HCG levels in urine in females)
Specialist investigations
- AXR - no diagnostic criteria for appendicitis
- Abdominal ultrasound - may show aperistaltic and non-compressible structure with diameter >6mm; sensitivity 86% and specificity 81%
- Transvaginal pelvic US - consider in women of child-bearing age, to exclude obstetric and gynaecological disease
- CT abdomen - may show abnormal appendix/calcified appendicolith associated with periappendiceal inflammation (diameter >6mm); sensitivity 94% and specificity 95%
- MRI abdomen - no diagnostic criteria for appendicitis, but may be considered in cases whereby the patient is pregnant
CT abdomen
Differential diagnoses
Females only
- Ectopic pregnancy (this must be excluded in all females of child-bearing age)
- Pelvic inflammatory disease (salpingitis, pyosalpynx & tubovarian abscess)
- Ovarian torsion
- Mittelschmerz’s syndrome (ruptured luteal cyst)
Males only
- Right-sided testicular torsion (always examine the testes)
Both sexes
- Intestinal obstruction
- Intussusception (ileo-ileal, ileo-colic, colo-colic)
- Perforation (peptic ulcer, colon, small bowel; check an erect CXR for free gas)
- Urinary tract infection, ureteric colic or pyelonephritis
- Crohn’s disease or mesenteric adenitis
- Meckel’s diverticulitis
- Carcinoma of the caecum, or ascending colon; patients is almost always >40y, mass may be palpable with microcytic anaemia; may be perforated, with free gas on CXR; caecal diverticulitis
- Strangulation of hernia (femoral, inguinal)
Note: other diagnoses include: gastroenteritis; cholecystitis: usually RUQ, but can be difficult to distinguish from retrocaecal appendicitis
Treatment
A later (>6h) appendicectomy, performed by seniors, may be better in uncomplicated cases
Treatment (definitive, surgical)
- For confirmation of the diagnosis and haemodynamically unstable patients (shock, septicaemia, perforation, peritonitis):
- Open appendicectomy - traditionally used to treat deteriorating patients. This approach usually involves making a muscle splitting gridiron incision over McBurney’s point made perpendicular to a line connecting the umbilicus and anterior superior iliac spine or a Lanz’s incision. This approach depends on the operating surgeon
- Laparoscopic appendicectomy - increasingly common approach in hospital. A systematic review showed reduction in wound infections, postoperative pain, length of hospital stay and time to return to work
- The additional advantages of this approach are the ability to perform a diagnostic laparoscopy initially to reveal any other intra-abdominal pathology, any gynaecology pathology in a female patient and to assess the extent of appendicitis, including any perforation. The drawback involves the level of expertise of the surgeon and the facilities available
Debate: early vs later appendicectomy
- There is debate whether emergency appendicectomy (<6h of admission) reduces the risk of perforation or complication versus urgent appendicectomy (>6h)
- According to a retrospective case review study, no significant differences in perforation rate among the two groups were noted (P=0.397). Various complications (abscess formation, re-admission) showed no significant differences (P=0.667, 0.999). Other studies have found similar results
- It was concluded that beginning antibiotic therapy and delaying appendicectomy from the middle of the night to the next day does not significantly increase the risk of perforation or other complications
Supportive measures
Drugs
- Analgesic control (e.g. IV MORPHINE 10 mg). Anti-emetic (IV CYCLIZINE 10 mg, avoid metoclopramide if you suspect any intestinal obstruction)
- IV access, fluid resuscitation (e.g. colloids)
- IV ANTIBIOTICS (according to local protocol). Appendicectomy should be preceded by IV antibiotics. For nonperforated uncomplicated appendicitis, no further antibiotics are required. If the appendix is perforated, antibiotics should be continued until the patient's temperature and WC count have normalised or continued for a fixed course. If appendicitis unlikely, do not give AB
- Oxygen, if hypoxic
Nursing observations
- NBM. Monitor TPR, BP and saturation of oxygen
Emergency management
- Resuscitation
- Maintenance of airway, breathing and circulation in a surgical emergency
Key Management Decision
Surgery
Treatment (alternative, conservative)
For patients who are haemodynamically stable, have mild abdominal signs and symptoms and appendicitis has been suspected, but not confirmed as the main diagnosis
- It is imperative to discuss this decision with the lead consultant
- Continue to re-examine the patient and re-assess the vital signs every hour to confirm/exclude the diagnosis
- Establish IV access and prescribe IV fluid (e.g. 0.9% normal saline, colloids) if patient is dehydrated
- Prescribe adequate analgesia and anti-emetic (as above)
- If suspect causes other than appendicitis - including appendix mass or abscess - proceed to perform investigations (abdominal ultrasound or CT scan) as long as patient is kept comfortable and is haemodynamically stable
- Admit the patient into the general surgical ward if unable to exclude the diagnosis
- Pre/perioperative antibiotic (check the hospital policy) should be administered in all patients to reduce incidence of postoperative wound infection and intra-abdominal abscess formation
Prescribing issues
- Make sure to check for any allergic/drug-related reactions from the patient before administering pre/perioperative antibiotics. The last thing you want is an anaphylactic reaction!
Admit?
- Absolutely! Do not discharge the patient home until you (and your consultant) have ruled out appendicitis as a possible cause and have arrived at another diagnosis
Bed plan
- General surgical ward ± ITU (if needed for elderly patients who are not fit and well)
Referrals
- General surgical team
The Rest
Appendicitis can present in different ways, regardless of age
Maxim
- "If in doubt, take it out - especially in pregnancy"
Complications
- Gangrenous appendicitis and perforation (15-20%) - urgent surgery is required
- Appendix mass when the inflamed appendix becomes enveloped by the omentum. May be detected by ultrasound or CT scan. Treated by early surgery with antibiotics.
- Appendix abscess if appendix mass fails to resolve. The patient may have increased pain, swinging pyrexia, tachycardia and leucocytosis. Diagnosed with US or CT abdomen. Usually treated by drainage (surgical/ percutaneous) & antibiotics
- Postoperative wound infection - affects up to 20% in gangrenous and perforated appendicitis. Requires broad spectrum antibiotics. The risk of postoperative wound infection can be reduced by administering pre/perioperative antibiotics. Role of post-operative antibiotics is unclear
- (Late) post-operative intestinal obstruction from adhesions - risk can reduced by performing laparoscopic appendicectomy
- Other acute complications include pelvic abscess, subphrenic abscess, paralytic ileus and septicaemia
Risk Stratification: Alvrado Scoring System
- Symptoms: migratory right iliac fossa pain (scores 1), nausea or vomiting (1), anorexia (1)
- Signs: tenderness in the right iliac fossa (2), rebound tenderness in the right iliac fossa (1), elevated temperature (1)
- Laboratory findings: leukocytosis (2), shift to the left of neutrophils (1)
Calculation: from a total possible score of 10, one study recommended further investigation with CT scan for a score of 4-6, and consideration of appendicectomy for scores of 7 or above
Follow-up
- Interval appendicectomy is reserved for patients treated conservatively approximately 6-12 weeks after the initial presentation, provided they develop further symptoms or complications
- In addition to older patients managed conservatively, it is imperative to exclude a carcinoma of the caecum by investigations (CT abdomen and colonoscopy)
Prognosis
- Mortality rate = 1%; attributable to complications of the disease rather than to surgical intervention
- In patients older than 70 years, the rate rises above 20%, primarily because of diagnostic and therapeutic delay
- Mortality can increase to 5-20% if perforation occurs, therapeutic/diagnostic delay and increasing with age
2° Prevention + Health promotion
- Interval appendicectomy is only performed for those managed conservatively if they develop persistent symptoms or complications
- For appendicular inflammatory mass treated with antibiotics, the individual will require a colonoscopy prior to surgery to exclude underlying colonic carcinoma or Crohn’s disease
Don't forget
- To keep monitoring and re-examining the patients managed conservatively
- To be mindful of late-onset postoperative intestinal obstruction from adhesions for patients undergoing open surgery
- A normal WC and/or CRP does not exclude appendicitis
- To rule out carcinoma of caecum in older patient
- To exclude pregnancy (and ectopic) in woman of child-bearing age
- To exclude testicular torsion in young man with RIF pain
Red flags
- Shock (hypotension, tachycardia, tachypnoea)
- Peritonitis (tender, rigid abdomen and rebound tenderness)
Synonyms and keywords: appendix, appendectomy, perforated appendix, ruptured appendix, blocked appendix, uncomplicated appendicitis, uncomplicated appendectomy, appendicitis, laparoscopic appendectomy
