Page 85 - JSOM Summer 2022

hypoglycemia. 30,41,45,46 Sodium bicarbonate (one 50mEq am- cellular storage, and glucagon, which mobilizes stored energy
pule IV push) may be considered, but is generally reserved for for conversion to glucose (gluconeogenesis). Both hormones
patients with concomitant acidosis (military literature spe- are produced by the pancreas. Normal glucose levels gener-
cifically advises against its use unless blood pH is less than ally range between 70mg/dL and 99mg/dL in a fasted state
7.2). 41,44,46 Especially in cases of suspected rhabdomyolysis, and less than 140mg/dL in a non-fasted state, but random lev-
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IV fluids should be given often and early to replenish fluid els can generally be as high as 200mg/dL without concerns.
34
losses and dilute ECF potassium. The diuretic furosemide Dysregulation of blood glucose primarily results from diabetes
may be considered to aid renal excretion, but this should be mellitus, occurring from an outright lack of insulin (type 1) or
balanced against suspected renal injury, as abnormally high insulin receptor resistance (type 2). As diabetic patients can
doses may be required to attain effect. 30,41 Although unlikely require specialty care and may quickly deteriorate in the set-
to be available in remote settings, medics may consider the use ting of trauma or disease, the diagnosis is considered a bar to
of potassium removing oral agents such as sodium polystyrene deployment status and by regulation results in submission for
56
sulfonate (better known as Kayexalate), although some cau- medical discharge. However, the remote medic should not
tion may be warranted given a few extremely rare case reports therefore assume all military patients do not have these condi-
of bowel necrosis. 41,44,45 tions, as both can present after entering active service, and can
be present in co-located civilian counterparts. 57,58
Potassium reevaluation frequency is scattered but can be
considered at 1- to 4-hour intervals or longer depending on Hypoglycemia (Low Blood Glucose)
severity and evaluation capacity. 30,41,42 Continuous cardiac The most common cause of hypoglycemia is overdose of diabe-
monitoring should be utilized until potassium levels return to tes controlling medications. While recent strenuous activity, di-
normal ranges, with repeat ECGs performed with subsequent etary restrictions, and starvation may suggest the diagnosis, this
laboratory evaluation. 30,41,42 information may be unavailable on initial evaluation. Hypogly-
cemia (blood glucose < 70mg/dL) can manifest with diaphoresis,
Calcium and Hypocalcemia palpitations, and behavioral and neurocognitive changes (given
Calcium (Ca ) helps regulate cellular membrane stability, es- the brain’s high glucose consumption relative to other body sys-
2+
pecially important in cardiac muscle. Prehospital point of care tems). While 70mg/dL is often the cut-off for diagnosis, more
testing generally measures calcium not bound to proteins, severe symptoms generally present with levels below 55mg/
known as ionized calcium (iCa). In military medicine, calcium dL. 55,59,60 Immediate treatment depends largely on patient cogni-
loss is primarily concerning in traumatic hemorrhage given its tion. If able, oral supplementation with 15–20g of simple carbo-
coagulation cascade prominence and the “lethal diamond” hydrates is recommended via an apple juice box or 2 tablespoons
resulting when combined with hypothermia, acidosis, and co- of cake frosting or table honey. 60,61 Resourceful medics can like-
agulopathy that demonstrates increased patient mortality. 47–49 wise use small amounts of candy or other carbohydrate-rich bev-
Definitions of hypocalcemia vary (generally iCa < 4.5mg/dL erages. Patients unable to tolerate oral supplementation (severely
or < 1.2 mmol/L), but severity focuses beyond laboratory cut- altered or impaired) should be treated with IV glucose. While 1
offs to include symptomatic progression, cardiac findings, and ampule of dextrose 50% (D W) is traditionally recommended,
50
hemorrhage implications. 47,50 The transfusion of chelated blood administration should be done only via 18g or larger angiocath-
products risks citrate toxicity and worsening hypocalcemia in eter, with caution for risk of extravasated tissue necrosis with if
hemorrhage. 47,50,51 Acute evaluation in atraumatic patients may extravasation occurs, as well as for rebound hypoglycemia. 62,63
reveal perioral paresthesias, muscle cramping, Chvostek’s sign Lesser complication concerns exist for IV D W, though a greater
10
(facial muscle twitching with facial nerve tapping), and Trous- volume is required to have a significant effect. 62,63
seau’s sign (involuntary wrist flexion when blood pressure cuff
is inflated 20mmHg above systolic blood pressure for 3 min- Hyperglycemia (random blood glucose > 200mg/dL) may man-
utes). 52,53 Hypocalcemia-induced prolonged cardiac cell repo- ifest with excessive thirst, frequent urination or less specific
larization manifests as QT prolongation on ECG, which can symptoms. This can occur secondary to insulin dysregulation
progress to lethal torsades de pointes if untreated. 54 (undiagnosed or improperly treated diabetes mellitus) or stress
release of the hormone cortisol as occurs secondary to infec-
Treatment of hypocalcemia in the hemorrhagic shock patient tion. 64,65 Evaluation includes search for underlying cause, with
should be initiated immediately with blood product resuscita- further evaluation (including venous blood gas and lactate, if
tion. JTS guidelines advise for initial dosing of 1g of calcium available) to exclude diabetic ketoacidosis and hyperosmolar
(as 30mL of 10% calcium gluconate or 10mL of 10% calcium hyperglycemia state. The use of IV fluids may help initially,
66
chloride) with initial transfusion, and an additional gram after but persistent hyperglycemia generally requires short-acting
50
every 4 units of blood products are given. Although calcium insulin (0.1mg/kg given subcutaneously or intravenously). 66,67
monitoring is recommended, no specified frequency is recom- Particular care should be made to evaluate for potassium lev-
mended in military literature. Additional measurements may els prior to insulin administration, as insulin can shift potas-
be considered with each calcium dose, specifically with every sium and cause hypokalemia (described above). Labs should
4 units of blood products given, and after any cardiac changes be repeated every 30–120 minutes, depending on presentation,
on monitoring, in order to maintain an iCa > 1.2 mmol/L. and additionally within 20–30 minutes after completion of in-
terventions. Medics should note that subsequent blood sugar
Glucose levels below 200mg/dL are a relative goal, and further evalu-
Glucose is the body’s primary energy source, generally ob- ation and management should include specialty consultation.
tained from carbohydrate breakdown or hepatic glucone-
ogenesis. It additionally functions as a vital cotransporter Creatinine and Blood Urea Nitrogen
for cellular electrolyte movement. Blood glucose levels are Though not common to all point of care testing, evaluation
primarily regulated through a balance of insulin, facilitating for overall renal dysfunction can help explain electrolyte

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