MILITARY MEDICINE, 176, 4:451, 2011

Acute Water Intoxication During Military Urine Drug Screening

Maj Molly A. Tilley, USAF MC ; Maj Casey L. Cotant, USAF MC

ABSTRACT Random mandatory urine drug screening is a routine practice in the military. The pressure to produce a urine specimen creates a temptation to consume large volumes of water, putting those individuals at risk of acute water intoxication. This occurs when the amount of water consumed exceeds the kidney’s ability to excrete it, resulting in hyponatremia owing to excess amount of water compared to serum solutes. The acute drop in serum osmolality leads to cerebral edema, causing headaches, confusion, seizures, and death. There has been increasing awareness of the danger

of overhydration among performance athletes, but dangers in other groups can be underappreciated. We present the case Downloaded from https://academic.oup.com/milmed/article/176/4/451/4345329 by guest on 23 September 2021 of a 37-year-old male Air Force offi cer who developed acute water intoxication during urine drug screening. Our case demonstrates the need for a clear Air Force policy for mandatory drug testing to minimize the risk of developing this potentially fatal condition.

INTRODUCTION lying on his back in the rest room, restless, and inarticulate. Acute and chronic hyponatremia are common disorders that Intravenous normal saline was started and the patient was are associated with adverse clinical outcomes.1 Typically, acute monitored by telemetry. He had a normal sinus rhythm, with hyponatremia is encountered in the hospitalized patient with blood pressure of 140/62 and heart rate of 97. Over the next several co-morbidities or in post-surgical patients with con- few minutes, the patient was described as having “dry heaves” comitant pain and nausea. Less well-recognized is the devel- and “seizure-like activity” before curling up in the fetal posi- opment of acute hyponatremia in the setting of acute water tion. The patient was treated with lorazepam and transported intoxication. We present a case of hyponatremia in an oth- to the hospital. He remained anuric before arriving at the drug erwise healthy male precipitated by a combination of stress, testing facility. excessive fl uid consumption, and urinary retention. This case In the emergency room, a Foley catheter was placed and more highlights the need for policies to limit water intake and con- than 2 L of urine was drained. Lab results revealed hypona- stant vigilance for this serious condition in all institutions that tremia, Na 122 mEq/L (122 mmol/L), and hypokalemia, K use mandatory urine drug screening. 2.9 mEq/L (2.9 mmol/L). No urine studies were taken at that time. His exam was notable for lethargy, and the patient had CASE trouble with short-term memory. The neurologic exam was Our patient is a 37-year-old active duty Air Force male who otherwise normal. was in excellent health with a past medical history notable Ninety minutes after arrival to the hospital, the patient had only for obstructive sleep apnea treated with modafi nil and already produced 4.5 L of urine via foley catheter. By that time, continuous positive airway pressure. At approximately 7:00 his serum sodium had increased to 132 mEq/L (132 mmol/L) a.m., the patient was instructed to report for a routine military and urine osmolality was 53 mOsm/kg (53 mmol/kg). Over urine drug screen test. This test requires that the patient be the next several hours, serial lab tests ( Table I ) showed that the able to produce urine under direct visual observation, which patient continued to produce dilute urine and his serum sodium had historically been diffi cult for the patient. In an unsuccess- level was getting normal. Neither IV fl uid nor dietary restric- ful attempt to produce urine, the patient drank sixteen 30-oz tion were prescribed. Once the patient’s sodium had normal- containers (over 14 L) of water between the 9:00 a.m. and ized to 139 mEq/L (139 mmol/L), the patient’s urine output 12:00 p.m. decreased and essentially matched his intake. His neurologi- Approximately 3 hours after commencing his water intake, cal status completely normalized, the patient was discharged the staff noticed that the patient was complaining of abdomi- the next afternoon, and his drug test returned negative. No nal pain and acting confused. At 2:20 p.m., the patient’s odd efforts were made to slow his rate of correction because his behavior and abdominal pain prompted the transfer of the hyponatremia was thought to be acute and the risk of osmotic patient to the Family Practice Clinic. Eighty minutes later, demyelination was thus low. a code blue was called by a passerby who found the patient DISCUSSION Hyponatremia, defi ned as a serum sodium concentration of Wilford Hall Medical Center, 2200 Bergquist Drive, Suite 1, Lackland less than 136 mEq/L (136 mmol/L), is commonly encoun- AFB, TX 78236. 1 The views expressed in this article are those of the authors and do not nec- tered in clinical practice. Hypotonic hyponatremia, refl ecting essarily refl ect the offi cial policy or position of the United States Air Force, an excess of water relative to solute, is most commonly caused Department of Defense, or the U.S. Government. by an impaired ability of the kidney to excrete free water, as is

MILITARY MEDICINE, Vol. 176, April 2011 451 Case Report

TABLE I. Review of Laboratory Results she recovered uneventfully after the administration of 1.4 L of IV normal saline and supplemental potassium chloride. Serum Na Serum K Serum Osm Urine Osm Both cases were felt to be secondary to excessive water mEq/L mEq/L mOsm/kg mOsm/kg (mmol/L) (mmol/L) (mmol/L) (mmol/L) intake in a short amount of time, but SIADH may have played Day 1, 4:30 p.m. 122 2.9 n/r n/r a role as well. Situational stress, nausea, and vomiting may 23–25 Day 1, 6:00 p.m. 122 3.0 n/r n/r induce a transient SIADH. Additionally, a recent review Day 1, 9:00 p.m. 132 4.1 265 53 of 6 elderly patients with hyponatremia and urinary retention Day 2, 12:40 a.m. 136 3.4 281 180 revealed that 5 out of the 6 patients had lab criteria consistent Day 2, 4:00 a.m. 139 4.0 289 27 with SIADH. In all 6 cases, the hyponatremia resolved after Day 7, 9:00 a.m. 138 4.6 288 496 urinary catheterization and fl uid restriction, suggesting that n/r, not recorded. bladder distension and pain might have led to SIADH.26 Our Downloaded from https://academic.oup.com/milmed/article/176/4/451/4345329 by guest on 23 September 2021 patient had many risk factors for SIADH, including functional seen in the syndrome of inappropriate anti-diuretic hormone bladder failure, pain, and anxiety. (SIADH). Less frequently seen is an excessive water intake, Given the potential for acute water intoxication, various overwhelming the kidney’s ability to excrete the free water recommendations have been made regarding limits of water load, leading to subsequent hyponatremia.1–3 Often, these con- consumption in persons undergoing urinary drug screening. ditions overlap, such that hyponatremia develops in the setting Klonoff and Jurow recommend no more than 1 L of water be of excessive water intake in addition to a concomitant defect consumed per hour.8 In 2002, Gardner and Gutman, in agree- in renal-free water excretion. ment with contemporarily published Army guidelines, recom- The deleterious effects of acute hyponatremia relate to mended that fl uid intake should not exceed 40 ounces during abrupt changes in the extracellular osmolality and the subse- the drug-testing session.22 quent translocation of water down its concentration gradient Army Regulation 600-85 ( http://acsap.army.mil ) re-iterated into the cell, leading to cerebral edema, headache, confusion, that “the Soldier will be allowed to drink 8 ounces of water seizure, brain-stem herniation, and death.1,4,5 The rapid devel- every 30 minutes but not to exceed a total volume of 40 ounces opment of hyponatremia is catastrophic because the brain in 3 hours.” 27 The Department of Transportation and the has not had time to equilibrate and decrease the intracellu- Department of Justice also have similar standards.22 However, lar osmolality by the extrusion of intracellular solutes such as the U.S. Air Force Instruction (AFI) 44-120 does not place potassium and organic osmolytes. 1,6,7 limits on fl uid consumption. For those with paruresis, the AFI Our patient presented with presumed acute symptomatic provides a thorough section regarding “shy bladder or situ- hyponatremia in the setting of a urine drug screen and parure- ational anxiety,” but fails to specify a suffi cient time or an sis. Paruresis, a phobia that makes it diffi cult or impossible for adequate amount of fl uid that should be consumed before a a patient to urinate in public, is present in approximately 30% patient is evaluated for this disorder.28 Even more challenging, of men and 25% of women.8,9 The lack of micturation leads to the airman is expected to have a medical waiver for paruresis more water intake in an effort to initiate voiding, potentially before the date of his/her random drug testing. It is clear that making the patient at risk for the development of hypona- the consequences of not providing a sample under such vague tremia if >1 L/hour of water is consumed.8 instruction could lead to increased pressure on the airman to Excessive water consumption leading to hyponatremia in drink excess water. Furthermore, the onus is placed upon the the non-psychiatric setting has been described in various set- individual to monitor his or her consumption. This leaves him tings.10–21 To our knowledge, this is only the third reported or her vulnerable to acute water intoxication because of lack case of water intoxication in the setting of work place or mili- of knowledge regarding the perils of overhydration. tary urine drug testing, though other milder cases may have Treatment for paruresis can be challenging. Attempts at gone unrecognized. limiting anxiety can be helpful, though pharmacotherapy with Gardner and Gutman described a case of 20-year-old female atenolol, phenelzine, propranolol, and gabapentin have been who drank 10 to 12 L of water over 2 to 3 hours while exer- attempted with limited success.29–31 Encouragingly, cognitive cising.22 She subsequently developed seizure-like activities. behavioral therapy has been found to signifi cantly improve the Her sodium had decreased from presumably normal levels to symptoms of paruresis.32 If a person is diagnosed with paru- 123 mEq/L (123 mmol/L). A CT scan of her brain obtained resis or is having diffi culty in urinating after intake of 1 L 3 hours after the commencement of symptoms revealed cere- of water, then the person should not be forced to drink more bral edema. The patient died 2 days later as a result of acute water as water intoxication may ensue. water intoxication. We recommend that institutions with mandatory urine drug In 1991, Klonoff and Jurow reported the case of a 40-year- screening institute a policy that limits fl uid consumption to old woman who ingested 3 L of water over 3 hours second- 8 ounces every 30 minutes, with a maximum of 40 ounces ary to paruresis.8 Eight hours later, she was hospitalized with during the testing session. Compliance can be increased with confusion, slurred speech, and an unsteady gait. Her sodium verbal and visual instructions regarding the intake limita- level during admission was 121 mEq/L (121 mmol/L), and tions. The testing staff should receive training on the signs

452 MILITARY MEDICINE, Vol. 176, April 2011 Case Report and symptoms of hyponatremia and remain alert for individ- 10. Pickering LK , Hogan GR : Voluntary water intoxication in a normal child . uals displaying characteristic behavior. Also, if paruresis is J Pediatr 1971 ; 78: 316 – 8 . diagnosed, either pharmacologic or cognitive behavioral ther- 11. Friedman E , Hanany J , Halkin H : Unsuspected urethral stricture present- ing as acute water intoxication . J Urol 1983 ; 130: 566 . apy should be considered. By adhering to these guidelines, we 12. Anastassiades E , Wilson R , Stewart JSW , Perkin GD : Fatal brain oedema feel that the risk of developing symptomatic or lethal hypona- due to accidental water intoxication . BMJ 1983 ; 287: 1181 – 2 . tremia can be signifi cantly reduced. 13. Christenson LL , Scott D : Acute water intoxication following pelvic ultra- sound examination . Postgrad Med 1985 ; 77: 161 – 2 . 14. Kott E , Marcus Y : Acute brain edema due to water loading in a young CONCLUSION woman . Eur Neurol 1985 ; 24: 221 – 4 . Hyponatremia is a potentially life-threatening condition that 15. Lipsky MS , Zabak DL : Hyponatremia resulting from pelvic ultrasound preparation . J Fam Pract 1987 ; 25: 216 – 7 . can occur even in individuals who are otherwise quite healthy. 16. Shapira I , Isakov A , Almog C : Hyponatremia as the result of preparation Our patient had a complete and uncomplicated recovery, but for abdominal ultrasound examination . JCU 1988 ; 16: 61 – 2 . Downloaded from https://academic.oup.com/milmed/article/176/4/451/4345329 by guest on 23 September 2021 as the literature review shows, others have been less fortunate. 17. Garigan T , Ristedt DE : Death from hyponatremia as a result of acute Mandatory drug testing puts individuals at risk for excessive water intoxication in an army basic trainee . Mil Med 1999 ; 164: 234 – 8 . hydration as a result of the incentive to quickly consume fl uids 18. Frizzell RT , Lang GH , Lowance DC , Lathan SR : Hyponatremia and ultramarathon running . JAMA 1986 ; 255: 772 – 4 . combined with potential stress, paruresis, bladder distention, 19. Hiller WD : Dehydration and hyponatremia during triathlons . Med Sci and pain. Increasing awareness of acute water intoxication and Sports Exerc 1989 ; 21: S219 – S21 . formalizing the recommendations outlined previously will 20. Almond CS , Shin AY , Fortescue EB , et al : Hyponatremia among runners signifi cantly improve the safety of urine drug screening and in the Boston Marathon . N Engl J Med 2005 ; 352: 1550 – 6 . hopefully prevent future tragedies related to hyponatremia. 21. Gardner JW : Death by water intoxication . Mil Med 2002 ; 167: 432 – 4 . 22. Gardner JW , Gutman FD: Fatal water intoxication of an army trainee dur- ing urine drug testing . Mil Med 2002 ; 167: 435 – 7 . 23. Allen TD : Psychogenic urinary retention . South Med J 1972 ; 65: 302 – 4 . REFERENCES 24. Rowe JW , Shelton RL , Helderman JH , Vestel RE , Robertson GL : 1. Adrogue HJ , Madias NE : Hyponatremia. N Engl J Med 2000 ; 342: Infl uence of the emetic refl ex on vasopressin release in man . Kidney Int 1581 – 9 . 1979 ; 16: 729 – 35 . 2. Goldman MB , Luchins DJ , Robertson GL : Mechanisms of altered water 25. Schrier RW , Berl T : Nonosmolar factors affecting renal water excretion . metabolism in psychotic patients with polydipsia and hyponatremia. N Engl J Med 1975 ; 292: 81 – 8 . N Engl J Med 1988 ; 318: 397 – 403 . 26. Galperin I , Friedmann R , Feldman H , Sonnenblick M : Urinary retention: 3. Kramer DS , Drake ME Jr : Acute psychosis, polydipsia, and inappropri- a cause of hyponatremia? Gerontology 2007 ; 53: 121 – 4 . ate secretion of antidiuretic hormone . Am J Med 1983 ; 75: 712 – 4 . 27. Army Regulation 600-85. Headquarters , Department of the Army , 4. Arieff AI , Guisado R : Effects on the central nervous system of hyperna- Washington, DC , 2 Feb 2009 . Available at http://acsap.army.mil ; accessed tremic and hyponatremic states . Kidney Int 1976 ; 10: 104 – 16 . Feb 2010 . 5. Arief AI , Llach f, Massry SG : Neurological manifestations and morbidity 28. Air Force Instruction 44-120 . HQ USAF/SGI . 1 Jul 2000 . Available at of hyponatremia: correlation with brain water and electrolytes. Medicine www.e-publishing.af.mil ; accessed Feb 2010 . 1976 ; 55: 121 – 9 . 29. Hatterer JA , Gorman JM , Fyer AJ , et al : Pharmacotherapy of four men 6. Verbalis JG , Gullans SR : Hyponatremia causes large sustained reduc- with paruresis . Am J Psychiatry 1990 ; 147: 109 – 11 . tions in brain content of multiple organic osmolytes in rats. Brain Res 30. Zgourides GD , Warren R : Propranolol treatment of paruresis (psycho- 1991 ; 567: 274 – 82 . genic urinary retention): a brief case report. Percept Mot Skills 1990 ; 71: 7. Gullans SR , Verbalis JG : Control of brain volume during hyperosmolar 885 – 6 . and hypoosmolar conditions . Annu Rev Med 1993 ; 44: 289 – 301 . 31. Kaufman KR : Monotherapy treatment of paruresis with gabapentin . Int 8. Klonoff DC , Jurow AH : Acute water intoxication as a complication of Clin Psychopharmacol 2005 ; 20: 53 – 5 . urine drug testing in the workplace . JAMA 1991 ; 265: 84 – 5 . 32. Soifer S , Himle J , Walsh K : Paruresis (shy bladder syndrome): a 9. Rees B , Leach D : The social inhibition of micturation (paruresis): sex cognitive-behavioral treatment approach . Soc Work Health Care 2010 ; similarities & differences . J Am Coll Health 1975 ; 23: 203 – 5 . 49: 494 – 507 .

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