Acute appendicitis

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Key Recommendations

The usual standard of care for the management of uncomplicated appendicitis in adults continues to be operative.

There is emerging evidence to suggest that a nonoperative, antibiotic-only approach may be feasible in select patient populations, who wish to avoid surgery, and who accept the risk of up to 39% recurrence.[86] In such cases, it is recommended that the diagnosis of uncomplicated appendicitis be confirmed by imaging, and that patient expectations be managed via a shared decision-making process.[7][87][88][89] The evidence supporting nonoperative management of appendicitis continues to be conflicting, and further research is warranted.[90][91][92][93] There is more evidence to support a nonoperative approach in children than in adults.[7][87][88][94][95][96][97][98][99] Pregnant patients with acute appendicitis should be managed with obstetric support.[100]

Uncomplicated presentation

Once the diagnosis of acute appendicitis is made, patients should be given nothing by mouth.

Intravenous fluids should be started.[101] Give patients adequate analgesia.[12][45]

Adults

Prompt appendectomy remains the treatment of choice in international guidelines and should be recommended in most cases.[7] A single preoperative dose of a broad-spectrum antibiotic such as ceftriaxone or cefotaxime plus metronidazole should be given to patients with uncomplicated appendicitis undergoing appendectomy.[7][89][102] An alternative is cefotetan plus metronidazole.[7] In patients with a beta-lactam allergy or contraindication to these regimens, ciprofloxacin or levofloxacin plus metronidazole can be used.[7][89][102] Postoperative antibiotics are not indicated.[7][89] Cefotetan is a less desirable option because of the increasing resistance of anaerobic bacteria to this agent and possible decreased efficacy.[7][89][102]

An antibiotic-only approach may be reasonable for select groups with uncomplicated appendicitis (suspected or confirmed on computed tomographic scan), where patients understand the risk of recurrent appendicitis.[7][86][87][88][91] In this scenario, initial antibiotic therapy should be with a broad-spectrum antibiotic regimen such as ceftriaxone, cefotaxime, cefepime, or ceftazidime plus metronidazole.[7][89][102] Piperacillin/tazobactam is also an option.[89][102] Ciprofloxacin or levofloxacin plus metronidazole may be used if beta-lactams are contraindicated.[7][89][102] In patients at risk of infection by antimicrobial resistant organisms, antibiotic options include ertapenem, imipenem/cilastatin, meropenem, or aztreonam plus vancomycin and metronidazole.[7][89][102] After clinical improvement in 1 to 2 days, antibiotics can be swapped to an oral regimen to complete a total duration of 7 to 10 days. Oral options include ciprofloxacin or levofloxacin plus metronidazole, or amoxicillin/clavulanate (if local rates of Escherichia coli resistance are <10%).[7][89][102] An antibiotic-only approach is not recommended if an appendicolith is present since nonoperative management carries a significant failure rate.[2][7][103] A conservative antibiotic-only approach should be avoided in pregnant patients.[7]

Systemic fluoroquinolone antibiotics (e.g., ciprofloxacin, levofloxacin) may cause serious, disabling, and potentially long-lasting or irreversible adverse events. This includes, but is not limited to: tendinopathy/tendon rupture; peripheral neuropathy; arthropathy/arthralgia; aortic aneurysm and dissection; heart valve regurgitation; dysglycemia; and central nervous system effects including seizures, depression, psychosis, and suicidal thoughts and behavior.[104]

Prescribing restrictions apply to the use of fluoroquinolones, and these restrictions may vary between countries. In general, fluoroquinolones should be restricted for use in serious, life-threatening bacterial infections only. Some regulatory agencies may also recommend that they must only be used in situations where other antibiotics, that are commonly recommended for the infection, are inappropriate (e.g., resistance, contraindications, treatment failure, and unavailability).
Consult your local guidelines and drug formulary for more information on suitability, contraindications, and precautions.

Children

Guidance from the World Society of Emergency Surgery supports nonoperative management as feasible, safe, and effective as initial treatment unless an appendicolith is present.[2][7] However, in the US the usual standard of care for the management of uncomplicated appendicitis in children continues to be operative.[50]

Parenteral antimicrobials that are active against aerobic Gram-negative and anaerobic bacteria should be initiated as soon as the diagnosis of probable appendicitis has been established. Options include ceftriaxone plus metronidazole, piperacillin/tazobactam, or ciprofloxacin plus metronidazole, all as a single dose at the time of surgery.[7][89][102] Postoperative antibiotics are not indicated in children with uncomplicated acute appendicitis since there is no evidence they decrease the rate of surgical infection.[7][89][102]

Appendicectomy should not be delayed for children with uncomplicated acute appendicitis needing surgery beyond 24 hours from admission.[7] Surgery performed within this time is not associated with increased risk of adverse outcomes such as perforation, complications, or operating time in children who receive timely administration of antibiotics and undergo appendectomy less than 24 hours after diagnosis.[7]

As for adults, surgery is recommended in children with appendicoliths since the failure rate of nonoperative management increases in these cases.[2][7] However, in children without an appendicolith and with low risk of perforation, an antibiotic-only approach can be considered. In this scenario, initial antibiotic therapy should be with a broad-spectrum antibiotic regimen such as ceftriaxone or cefotaxime plus metronidazole.[7][89][102] Piperacillin/tazobactam is also an option.[89][102] Ciprofloxacin plus metronidazole may be used if beta-lactams are contraindicated.[89][102] In patients at risk of infection by antimicrobial resistant organisms, antibiotic options include ertapenem, imipenem/cilastatin, or meropenem.[7][89][102] After clinical improvement in 1 to 2 days, antibiotics can be swapped to an oral regimen to complete a total duration of 7 to 10 days. Oral options include amoxicillin/clavulanate, or ciprofloxacin plus metronidazole.[7][89][102]

Complicated presentation

Adults

Complications of acute appendicitis occur in 4% to 6% of adults and include gangrene with subsequent perforation or intra-abdominal abscess.[21]

Initial management includes keeping the patient nothing by mouth and starting intravenous fluids.[101] Give patients adequate analgesia.[12][45] Patients who are in shock should be given a bolus of intravenous fluid to help maintain a stable pulse rate and BP.[105] See Shock. Pregnant patients with acute appendicitis should be managed with obstetric support.[100]

Intravenous antibiotics (e.g., ceftriaxone, cefotaxime, cefepime, ceftazidime, ciprofloxacin, or levofloxacin plus metronidazole; or piperacillin/tazobactam) should be started immediately and continued until the patient becomes afebrile and the leukocytosis is corrected.[7][89][102]

For more severe infections, patients who are at risk of infection with antimicrobial resistant organisms, or who have healthcare associated infections, antibiotic options include ertapenem, imipenem/cilastatin, meropenem, or aztreonam plus vancomycin and metronidazole.[7][89][102] Combination antibiotic regimens may also be used based on local sensitivities and protocols.[21] See your local drug information source for guidance on antibiotic selection for pregnant patients.

In patients with acute peritonitis, appendectomy should be performed without delay.[7] Patients presenting with right lower quadrant abscess should be managed with intravenous antibiotics and drainage either by interventional radiology (computed tomography-guided drainage) or by operative drainage. If there is clinical improvement and the signs and symptoms are completely resolved, interval appendectomy may be unnecessary.[7][106][107][108][109]

Interval appendectomy is performed if the symptoms do not completely resolve and/or if symptoms recur.[7][13] Interval appendicectomy is also recommended in all patients over 30 years old with complicated appendicitis initially treated nonoperatively; in addition, any patient ages ≥40 years with uncomplicated appendicitis who has conservative management without interval appendicectomy should undergo screening with colonoscopy and interval full-dose contrast-enhanced computed tomography (CT) scan.[7][110] Interval appendectomy can also be used to identify patients who have underlying appendiceal neoplasm; interval appendectomy may reduce the future risk of appendiceal neoplasm, particularly in the context of complicated appendicitis.[111][112] The risk of appendiceal neoplasm in patients treated with nonoperative management of complicated appendicitis is 11%, increasing to 16% in patients ages 50 years and older and 43% in patients ages over 80 years.[110][113][114]

Short-term postoperative broad-spectrum antibiotics should be considered for patients who have undergone appendectomy for complicated appendicitis, especially if complete source control has not been achieved.[7][50] Options for oral regimens include amoxicillin/clavulanate, or metronidazole plus levofloxacin or ciprofloxacin.[102][115]

The optimal management for appendicitis with phlegmon or abscess remains subject to debate.[7] Latest evidence suggests that laparoscopic appendectomy is associated with fewer readmissions and fewer additional interventions than conservative management, provided advanced laparoscopic expertize is available.[7][116] Nonoperative management with antibiotics and, if available, percutaneous image-guided drainage is a reasonable alternative if the patient is stable and laparoscopic appendectomy is unavailable, although there is a lack of evidence for its use on a routine basis.[7][50]

Children

Complications of acute appendicitis occur in less than 19% of children and include gangrene with subsequent perforation or intra-abdominal abscess.[7][116] As with adults, initial management includes keeping the patient nothing by mouth and starting intravenous fluids and intravenous antibiotics. Early appendectomy within 8 hours should be performed in case of complicated appendicitis.[7] Laparoscopic appendectomy is preferred over open appendectomy in children where laparoscopic equipment and expertize are available.[7][117][118]

Antibiotic options include ceftriaxone or cefotaxime plus metronidazole, or piperacillin/tazobactam. In patients with beta-lactam allergy or other contraindications to the preceding regimens, ciprofloxacin plus metronidazole can be used.[7][89][102] Postoperative antibiotics for less than 7 days seems to be safe and is not associated with an increased risk of complications.[89] These can be switched from intravenous to oral form after 48 hours in children with complicated appendicitis, if there is clinical improvement and white cell count (WCC) has normalized, with an overall length of therapy shorter than 7 days.[7][89][102] Options for oral regimens include amoxicillin/clavulanate, or ciprofloxacin plus metronidazole.[7][89][102]

As per management of adults with phlegmon or abscess, nonoperative management (antibiotics and, if available, percutaneous image-guided drainage) is a reasonable alternative if the patient is stable and laparoscopic appendectomy is unavailable.[7] Nonoperative management has been associated with better results in terms of complication rate and readmission rate in children but evidence does not support its routine use.[119][120]

Surgical options

There are two operative options for appendectomy: open and laparoscopic. Most procedures are now undertaken laparoscopically.

In adults, the choice of appendectomy generally depends upon the experience of the surgeon. Studies have shown laparoscopic appendectomy to have better cosmetic results, shorter length of hospital stay, reduced postoperative pain, and reduced risk of wound infection compared with open appendectomy.[121][122] [ ] [Evidence B] Laparoscopic appendectomy is recommended for uncomplicated appendicitis, as well as complicated and perforated appendicitis.[123][124] It is also considered the safest approach in obese patients.[7][125]

In children, laparoscopic appendectomy decreases the incidence of overall postoperative complications, including wound infection and duration of total hospital stay.[118][121][126][127][128][129]

In pregnant patients, laparoscopic appendectomy should be preferred to open appendectomy when surgery is indicated and where expertize of laparoscopy is available.[130][131] It is safe in terms of risk of fetal loss and preterm delivery.[130][131] Compared with open surgery during pregnancy, laparoscopic appendectomy is associated with shorter length of hospital stay and lower incidence of surgical site infection. Laparoscopy is technically safe and feasible during pregnancy.[7][130][131][132]

Peripheral intravascular catheter: animated demonstration

How to insert a peripheral intravascular catheter into the dorsum of the hand.

Practical suturing techniques: animated demonstrations

Demonstrates interrupted sutures, vertical mattress sutures, horizontal mattress sutures, continuous subcuticular sutures, and continuous sutures.

[Figure caption and citation for the preceding image starts]: Acute appendicitis - intraoperative specimen.Nasim Ahmed, MBBS, FACS; used with permission [Citation ends].

Antibiotic-only therapy

Antibiotics alone for the treatment of uncomplicated appendicitis can be successful in selected patients who wish to avoid surgery, and who accept the risk of up to 39% recurrence.[86][91] In such cases, it is recommended that the diagnosis of uncomplicated appendicitis is confirmed by imaging, and that patient expectations are managed via a shared decision-making process.[7][87][88][89]

In this scenario, broad-spectrum antibiotics are recommended. The recommended regimens are the same as for uncomplicated presentation (see above).

An antibiotic-only approach is not recommended in pregnant patients or if an appendicolith is present.[2][7][103]

Outpatient laparoscopic appendectomy

Some patients may be discharged safely after laparoscopic appendectomy without hospitalization.[134] This outpatient approach is suitable for patients with uncomplicated appendicitis, provided that an ambulatory pathway with well-defined ERAS (Enhanced Recovery After Surgery) protocols and patient information/consent are locally established.[7] ERAS implementation after laparoscopic appendectomy carries similar rates of morbidity and readmissions compared with conventional care.[135] Its potential benefits include earlier recovery after surgery and lower hospital and social costs.[7]

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