Page 109 - JSOM Summer 2023

Critical Hypophosphatemia in a

Special Operations Combat Dive Candidate

A Case Report

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1
Gerrit W. Davis, MD, FS *; Jeremy Czarnik, SO-ATP, DMT ;
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Joshua Evans, APA-C, DMO, FAWM ; Owen McGrane, MD, FAWM 4

ABSTRACT
In contrast to shallow water (hypoxic) blackout and swim- muscle weakness, muscle pain, arrhythmias, and respiratory
ming-induced pulmonary edema (SIPE), acute electrolyte distur- failure. Physiologic complications in addition to the above in-
bance secondary to acute respiratory alkalosis is not considered clude cardiomyopathy, hemolysis, immunosuppression, throm-
a common Combat Swimmer injury but has the potential to be bocytopenia, rhabdomyolysis, hepatic decompensation, and
life-threatening. We present the case of a 28-year-old Special diaphragmatic weakness. 2,4–6
Operations Dive Candidate who presented to the Emergency
Department after a near-drowning incident with altered mental Hypophosphatemia is not commonly thought of as a possi-
status, generalized weakness, respiratory distress, and tetany. bly life-threatening pool-based Combat Diver training in-
He was found to have severe symptomatic hypophosphatemia jury. More commonly, shallow water (hypoxic) blackout,
(1.00mg/dL) and mild hypocalcemia secondary to intentional swimming- induced pulmonary edema (SIPE), and rhabdo-
hyperventilation between subsurface “cross-overs,” causing myolysis occur in the Combat Dive Candidate. We present
subsequent acute respiratory alkalosis. This is a unique presen- the case of a Combat Dive Candidate who developed criti-
tation of a common electrolyte abnormality in a highly spe- cal hypophosphatemia with associated hypocalcemia, mani-
cialized population that is self-limiting when caused by acute fested by altered mental status, tetany, respiratory distress,
respiratory alkalosis but poses a significant danger to Combat and generalized weakness. These findings were likely due to
Swimmers if rescue personnel are not able to respond quickly. hyperventilation-induced acute respiratory alkalosis in be-
tween pool “cross-overs”.
Keywords: hypophosphatemia; combat swimmer; acute res-
piratory alkalosis; hyperventilation
Case Presentation
A 28-year-old male was brought into the Emergency Depart-
ment by unit medics after an episode of near drowning, altered
Introduction
mental status, tetany, and respiratory distress while conduct-
Hypophosphatemia is a common electrolyte abnormality in ing “cross-overs” in the pool. The patient was conducting this
the hospitalized and critically ill patient; however, severe hy- exercise as part of the culmination day of the “Maritime As-
pophosphatemia (≤1.0mg/dL) is less common and is estimated sessment Course,” which is a preparatory course for Special
to have an incidence of 0.24% in the hospitalized population. Operations Personnel prior to attending the Combat Diver
1
Causes of hypophosphatemia can be grouped into four gen- Qualification Course. Between “cross-overs,” the patient be-
eral categories: intracellular redistribution, increased urinary gan to complain of severe cramping and paresthesia of the
excretion, decreased intestinal absorption, and purposeful re- right arm and chest while holding onto the gunwale. He sub-
moval through hemodialysis or other similar therapies. More sequently began to complain of this sensation spreading to his
specifically, hypophosphatemia may be caused by acute respi- lower extremities. The patient was noted to be hyperventilat-
ratory alkalosis, refeeding syndrome, poor oral intake of phos- ing and in respiratory distress when he became unresponsive
phate rich foods, diabetic ketoacidosis, hyperparathyroidism, and sank below the surface level. A Dive Medical Technician
post-parathyroidectomy “hungry bone syndrome,” alcohol use (DMT) recovered him from the pool and rendered aid. He
disorder, antacid use, phosphate binder use, chronic diarrhea, was placed on a face mask at 8L/min of supplemental oxygen
dialysis, vitamin D deficiency, sepsis, salicylate toxicity, dex- but did not fully recover and was brought to the Emergency
trose infusion, diuretics, and chronic steroids, amongst other Department. Upon arrival, he was unable to ambulate on his
less common causes. Symptoms of severe hypophosphate- own, was minimally responsive, and was noted to be in re-
2,3
mia include altered mental status, paresthesia, seizures, coma, spiratory distress. Outside of his tachypnea, vital signs were
*Correspondence to gerritwdavis@gmail.com
1 CPT Gerrit W. Davis is affiliated with the Department of Emergency Medicine, Madigan Army Medical Center, Joint Base Lewis–McChord, WA.
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2 MSG Jeremy Czarnik is affiliated with the 1st Special Forces Group (Airborne), Joint Base Lewis–McChord. CPT Joshua Evans is affiliated
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with the 1st Special Forces Group (Airborne), Joint Base Lewis–McChord. LTC Owen McGrane is affiliated with the Department of Emergency
Medicine, Madigan Army Medical Center, Joint Base Lewis–McChord.
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