Page 108 - Journal of Special Operations Medicine - Fall 2014

effective in facilitating stone passage. Studies have also stone, the patient can develop septic shock. This requires
7
shown that the rate of passage of stone may be improved emergent surgical decompression of the obstruction. If
somewhat by prescribing an α blocker or calcium chan- a patient presents with acute pain and fever, then anti-
nel blocker. Options include tamulosin 0.4mg once a day biotic administration is appropriate. Reasonable initial
or nifedipine for 7 to 14 days ; however, the use of these choices include fluoroquinilones such as ciprofloxacin
6
medications may not be options in the deployed setting. or levofloxacin. If those are unavailable, then ceftriax-
one or ertapenem would be reasonable choices.
How rapidly do I need to evacuate?
What is the risk of recurrence?
This patient does not require immediate evacuation. If
the diagnosis is fairly certain, the patient is hemody- The risk of recurrence is 60% for men and 40% for
namically stable and afebrile, and pain control can be women over 10 years. There is roughly a 10% to 15%
achieved, there is no great urgency to evacuate. If the risk of recurrence in the first year. Some military per-
9
patient is to be “sustained” in the field, then they must sonnel may have avoided disclosing prior stones as it
be adequately hydrated, pain adequately controlled, and may affect their readiness status for deployment.
vital signs observed for deterioration. It would be ap-
propriate to begin charting vital signs, intake, and out- Are there any preventive measures?
put, as is done in a sustained-care setting.
Many experts recommend analysis of the stone to de-
termine its composition. Recommendations on diet and
Patients with a history of existing renal disease, a soli- hydration can be then made based on its composition.
tary kidney, fever, symptoms of infection, or clinical de- However, no preventative measure has been entirely
terioration require emergent evacuation.
successful in completely preventing future stones. Ex-
pert consensus suggests increasing hydration to produce
How likely are they to pass the stone?
2 L/day urine. This aggressive regimen may be tough
10
Research have suggested that patients with a stone of to maintain in operational settings.
5mm or less have a very good chance of passing stones
(Figure 4). This rate is reduced if the stone is between 5
and 10mm, and stones of 10mm or greater are unlikely Case Outcome
to spontaneously pass. Stone passage may take weeks. In In this case, an IV line was started for analgesia. The pa-
8
the field, there is no way of knowing the size of the stone, tient continued with oral hydration. He was given 400mg
so you can observe for fever, deteriorating vital signs, and ibuprofen orally, odansetron 4mg IV, and IV morphine.
intractable pain despite adequate analgesia. If the patient The morphine was titrated in 5mg doses. After four
does pass the stone, it should be collected for analysis.
doses of 20mg, his pain decreased to 3 out of 10. He was
monitored by the clinician and required a couple of doses
Figure 4 An 8mm renal stone.
of morphine over the next 10 hours. His vital signs re-
mained stable, and he continued to urinate appropriately.
Three days after presentation, he urinated out a small
stone measuring about 4mm in width. This was collected
for future analysis. The patient finished his deployment,
and medical follow-up was arranged on returning home.

Acknowledgments
Thanks to Brent, Jamie, Tim, and Vince from Canadian
Special Operations Forces (CANSOF) and Chris from
ADF for working through the case and for their input.

Disclosures

Source: Image courtesy of Wikipedia; The authors have nothing to disclose.
http://en.wikipedia.org/wiki/Kidney_stone.
Disclaimers
What are the complications?
The views and medical opinion herein represent those of
Complications include intractable pain and possible the author. They do not reflect the operational practice
infection. If infection develops behind an obstructing or views of the Canadian Forces or other organization.

100 Journal of Special Operations Medicine Volume 14, Edition 3/Fall 2014