Volume , Issue

In the clinical setting, appendicitis is for the most a part a routine diagnosis with a well-established treatment plan. Complications are uncommon, and the mortality rate from early surgical intervention is less than 1%. ­However, with 250,000 cases of appendicitis in the U.S. annually, being prepared to identify and possibly treat appendicitis when on a wilderness expedition could be lifesaving.

Historically and in remote locations, appendicitis has a greater than 50% mortality rate without surgery or antibiotics. In austere environments, one must usually rely on physical exam and history. Classic physical exam findings that may assist with diagnosis include McBurney’s point, the obturator sign, and the psoas sign. McBurney is the most reliable of the three but still only has a sensitivity of 83% and specificity of 43%. Because of this, if any of the above signs are found or if the patient is having significant umbilical to right lower quadrant pain, a high suspicion for appendicitis should be present. Other important symptoms that may aid in diagnosis include sudden onset of abdominal pain, increased pain with coughing or movement, nausea and vomiting, gas, bloating, diarrhea or constipation, poor appetite, and fever.

One diagnostic modality that is becoming increasingly available is the portable ultrasound (US). Ultrasound can show direct visualization of the appendix, allowing the provider to monitor change over time. However, diagnostic capability depends heavily on the experience of the user and patient’s body habitus, and consistent practice is necessary to develop this skill. The use of ultrasound in austere environments, including for diagnosing appendicitis, has been discussed in prior issues of Wilderness Medicine Magazine, for example in the Wilderness EMS column here and here, and in the Wilderness Technology column here.

Diagnosis of appendicitis via ultrasound requires the presence of a blind ending, aperistaltic, and non-compressible tube with a diameter of greater than six millimeters evaluated via graded compression (Figures 3&4). Lumen diameter of six to eight millimeters provides a sensitivity of 65% while increasing the cut-off to eight millimeters improves sensitivity to 96%, making ultrasound a valuable aid in diagnosis.


Fig 3. Normal Appendix on ultrasound

Fig 4. Appendicitis with inflamed appendix on ultrasound

If appendicitis is suspected, and the ideal scenario of a swift exit and trip to the emergency department is not available, there are the three viable options: watchful waiting for resolution, treatment with antibiotics, or an open appendectomy.

Watchful Waiting

Watchful waiting in a resource deficient setting will rely on the clinician performing serial abdominal exams and monitoring the patient’s vital signs. Although spontaneous resolution of acute appendicitis is possible, the risk of perforation increases by 16-36% at 36 hours. If this course is chosen, concurrent planning and effort toward evacuation is still necessary. This is why preparation when backpacking or entering other austere environments is so important. Even if traveling with a group of people, let someone know when you plan to return. While expensive, many also hike with GPS satellite messengers in case of such emergencies. Finally, it is important to remember that in the event the patient worsens, management and evacuation may become much more difficult and dangerous for both the patient and rescue team.

Antibiotic Therapy

Due to recurrence rates of 13% to 44.5%, using antibiotics to treat uncomplicated appendicitis is not noninferior to the currently accepted treatment standard of surgical management. However, antibiotics can lead to resolution of illness acutely, as the mean time to recurrence of symptoms is around 4-8 months. This makes antibiotics an ideal treatment plan in austere environments while arranging evacuation to more definitive care. One limitation of this strategy is the efficacy of oral antibiotics compared to intravenous (IV). Of the five major clinical trials that used antibiotics to treat acute appendicitis, only one had a treatment regimen that did not require IV, which would be more challenging to obtain and administer in an austere setting. The study used amoxicillin/clavulonic acid to successfully treat patients; however, the writers pointed out that this option may not be optimal due to increasing E. coli resistance.


Appendectomy in an austere environment certainly sounds extreme, and that’s without even considering the skill of the practitioner or whether the multitude of necessary supplies are available. However, it has been done. In 1961, Dr. Leonid Ivanovich Rogozov performed his own appendectomy under local anesthesia on a ship headed for Antarctica after experiencing worsening appendicitis despite antibiotics. As a trained surgeon, he did have the skill and very likely had the necessary supplies as well. An open appendectomy with limited resources would have very high risk with many considerations, some of which include maximizing the patient’s status pre-operatively, available anesthesia, maintaining sterile conditions, and post-operative management.

Under austere conditions, regional anesthesia should ideally be considered given its relative safety in comparison to other choices. Regional anesthesia options for an appendectomy in these environments include spinal anesthesia (SA), epidural anesthesia (EA), combined spinal epidural anesthesia (CSEA) or a transversus abdominis plane block (TAP block), all of which have been used successfully in patients undergoing abdominal surgeries (Figure 5). Any method could be combined with conscious sedation. However, local anesthesia is not without risk, and can include bradycardia, hypotension, and, although rare, cardiac arrest. Another serious complication to be aware of is total spinal anesthesia (which can occur after EA, SA or CSEA), a complication that could prove fatal in the wilderness. A few less severe complications specific to EA, SA, or CSEA include urinary retention and postdural puncture headache. Post-operatively, concerns related to the procedure include surgical site or intra-abdominal infection, bleeding, pain, deep vein thrombosis, and ileus, to name a few. Overall, a successful appendectomy in the wilderness would require a perfect alignment of fortuitous conditions, and even if possible, complications that can be well managed in the hospital could prove to have devastating consequences when encountered in an austere environment.

What it Boils Down to

Appendicitis in austere environments can be diagnosed with history, physical exam and possibly ultrasound. Significant limitations to confirm a suspected diagnosis in these conditions means wilderness providers should err on the side of caution and assume appendicitis until proven otherwise. Ultrasound has limitations such as body habitus in addition to skill and interpretation of the practitioner. Antibiotics can result in resolution and should be the first line treatment while preparing for evacuation. Anesthesia and surgery require resources and surgical experience that may be unavailable in austere settings. Beyond that, the risks of the procedure will likely outweigh the benefits. Antibiotics and watchful waiting while planning for evacuation are the treatment options with the lowest risk and in most cases should be the plan employed.