CASE REPORT: Metabolic Alkalosis After Using Enhanced Water to Dilute Powdered Formula

Abstract In this case study report of an infant with metabolic alkalosis, the healthcare team worked to discover the cause of the illness. They found that well-meaning parents had diluted their newborn’s powdered formula with electrolyte-enhanced water. Electrolyte balance in the newborn is reviewed in this article, along with information about en- hanced waters. It is essential that nurses working with new families be aware that heavily advertised enhanced waters could be used unknowingly by parents for their new- borns, and that the consequences could be dire. his is the story of parents who wanted to do the right Key Words: Bottle feeding; Infant formula; thing for their infant, but unknowingly were influ- enced by advertising, and wound up with a sick baby. Infant nutrition disorders; Parent education. T The World Health Organization recommends exclusive breastfeeding for the first 6 months of life, a recommenda- tion generally supported by other health advisory groups (Venter & Dean, 2008). Breast milk is composed of over 300 components, while commercially prepared formula contains approximately 75 components (Venter & Dean, 2008). Human milk is specific to the infant, and is unlike any marketed feeding preparation (Gartner & Eidelman, 2005). Breast milk evolves as the infant grows, changing to provide the most appropriate nutrition for the child at their stage of development (Wagner, Graham, & Hope, 2006). Breast milk also conveys significant benefits to the infant, including a decrease in the incidence or severity of a wide range of infectious diseases such as respiratory tract infec- tion, necrotizing enterocolitis, and otitis media, a decreased risk for sudden infant death syndrome, type 1 and type 2 diabetes, and some forms of cancer (Gartner & Eidelman, 2005). Additionally, research suggests that breastfeeding is associated with enhanced cognitive development (Gartner & Eidelman, 2005).

290 VOLUME 34 | NUMBER 5 September/October 2009 Anne Kathryn Eby, BSN, RN

Spatz (2006) identifies several important steps in encour- aging the new mother to breastfeed, including a focus on provision of milk, rather than breastfeeding, as some mothers Recently, electrolyte-enhanced waters may choose to bottle-feed breast milk. Nurses must also fo- cus on providing information to the mother and family on have been aggressively marketed in the the benefits of human milk, and establishing and maintain- United States. ing an adequate milk supply. We know as nurses, however, that some mothers may not desire to breastfeed, or may be unable to breastfeed, and may instead use formula. This case tress. After being evaluated by the physician, she was ad- study concerns a woman who chose to feed her infant with mitted to the pediatric unit of the local hospital for hypox- prepared formula, had the baby’s best interests at heart, but emia, poor oral intake, respiratory distress, and respiratory unknowingly chose an unconventional, and eventually a syncytial virus bronchiolitis. Prior to this episode, Mary detrimental way to dilute the formula. The components of had an uncomplicated prenatal and neonatal course. formula are meant to closely mimic breast milk. In both During the course of her hospitalization the parents breast milk and infant formula, over half of the calories mentioned that they had been diluting Mary’s brand name come from fat. Carbohydrates may be in the form of lactose powdered formula with an electrolyte-enhanced water. (as in cow’s milk formulas) or sucrose or cornstarch in soy- Electrolyte waters are being marketed aggressively in the based formulas. Vitamins and minerals, usually in amounts United States, and the manufacturer of this particular prod- specified by the FDA, are also added to infant formula. uct advertises it as “vapor distilled” and as (water in) “its purest original state.” The packaging does state that the Case Presentation water contains calcium chloride, magnesium chloride, and A twenty-day-old female “Mary” was brought to the pedi- potassium bicarbonate, but it became clear to us in the atrician’s office for a worsening cough and respiratory dis- course of working with this family that merely labeling the

September/October 2009 MCN 291 water meant nothing to the new parents. They had no un- of respiratory acidosis, for example, the kidneys will at- - derstanding at all that it could be dangerous to their child tempt to compensate by reabsorbing HCO3 and excreting to use this enhanced water to dilute formula. For many hydrogen ions, while with respiratory alkalosis, the kidneys - new parents, the idea of water in “its purest original state” will secrete HCO3 and reabsorb hydrogen ions (Roman, may be appealing, and may lead them to believe that this is Thimothee, & Vidal, 2008). a “healthier” alternative to tap or bottled water for their The body’s acid-base balance is controlled by the renal and infant. In this case, the parents told us that they thought respiratory systems. The kidneys maintain the composition of this was merely another form of distilled water, which was the extracellular and intracellular fluid and regulate acid-base appropriate to use to dilute the child’s formula. balance by secreting hydrogen ions, reabsorbing sodium and Mary’s electrolytes upon admission showed a hyperkalemic bicarbonate ions, acidifying phosphate salts, and producing metabolic alkalosis with an elevated calcium. Her sodium was ammonia (Pathophysiology Made Incredibly Easy, 1998). 138, potassium was 5.8, chloride was 100, and carbon diox- The respiratory system helps to modify the acid-base balance ide (CO2) was 33. Her blood urea nitrogen was 6, creatinine of the body by increasing respiration in acidosis (to excrete was 0.3, glucose was 83, her calcium was elevated to 10.4, excess CO2) or decreasing respirations in alkalosis. and her magnesium was 2.2. Table 1 shows arterial blood gas To evaluate an arterial blood gas reading, it is necessary to values and variances in newborns. discover whether the pH is normal (7.35-7.45), elevated, or decreased. If the pH is >7.45, the patient is alkalotic, and if it Acid-base balance is <7.35, the patient is acidotic. The second step is to evaluate Body fluids contain acids made of positively charged hy- the PaCO2 to determine if the imbalance is respiratory or + drogen ions (H ) and anions, or negatively charged ions metabolic. If the pH and the PaCO2 move in opposite direc- (Clancy & McVicar, 2007). The measure of a solution’s tions (i.e., the pH is decreased and the PaCO2 is elevated), acidity or alkalinity is the pH. Clancy and McVicar state then the problem is respiratory (Roman et al., 2008). The that “the neutral point (pH of pure water) relates to a situ- third step is to assess the HCO3; if the problem is metabol- + ation in which acid ions (hydrogen [H ]) and alkali ions ic the pH and HCO3 will move in the same direction (i.e., (hydroxyl [OH-]) are equal” (p. 1017). A solution with a pH both will be elevated or decreased) (Roman et al.). The body of less than 7 is considered acid, while a solution with a pH strives to maintain homeostasis by normalizing the pH. In of greater than 7 is considered alkaline, often called “base” cases of compensated acid-base abnormalities, the patient (Clancy & McVicar). The arterial blood pH shows the will have a normal pH but an increased or decreased CO2 or balance between CO2, an acid, and bicarbonate (HCO3), a HCO3 (Roman et al.). In Mary’s case, her arterial blood base. The buffer system of the body acts to regulate the gas demonstrated a metabolic alkalosis (evidenced by an acid-base balance; if there are excess hydrogen ions in the elevated bicarbonate) with respiratory compensation (evi- body fluid, the body will release acid buffers, while if the denced by her elevated PCO2). body fluid is deficient in hydrogen ions, the buffer system will cause the release of alkaline buffers, chemicals which Metabolic Alkalosis release hydrogen ions (Clancy & McVicar). Further com- This acid-base disturbance is caused by an elevation in plas- pensation may be either metabolic or respiratory. In a case ma bicarbonate concentration (Huang & Priestley, 2008). It

TABLE 1. Arterial Blood Gas Va lues and Va riances in the Te rm Newborn

pH HCO3 PCO2 Disorder (7.35-7.45) (22-26) (35-45)

Metabolic alkalosis If i with normal pH, indicates i i respiratory compensation

Respiratory alkalosis If m, indicates i renal compensation m

Metabolic acidosis If m with normal pH, indicates m m respiratory compensation

Respiratory acidosis If i, indicates m renal compensation i Note: Adapted from Brouillette & Waxman, 1997.

292 VOLUME 34 | NUMBER 5 September/October 2009 is often classified as chloride-responsive (indicated by a urine chloride level of less than 10 mEq/L) or chloride- resistant (indicated by a urine chloride level of more than 20 mEq/L) (Huang & Priestley). Metabolic alkalosis is most often caused by a loss of hydrochloric acid through the GI tract, as from vomiting (Huang & Priestley). Poten- tial sequelae associated with metabolic alkalosis in the in- fant include hypoxemia, respiratory arrest, life-threatening cardiac arrhythmias, and seizures (Huang & Priestley).

Respiratory Alkalosis This is an acid-base disturbance typically caused by an underlying hypoxia, metabolic acidosis, or stimulation of respiration by the central nervous system (Mancini & Deshpande, 2006). Sequelae from respiratory alkalosis may Parents unaware of the dangers may include altered mentation, seizures, and very rarely, dys- rhythmias in patients with underlying cardiac disease mistakenly believe that they are (Mancini & Deshpande). helping their child’s nutritional status Metabolic Acidosis by diluting formula with vitamin/ This acid-base disturbance is characterized by a decreased serum pH resulting from a decrease in plasma bicarbonate electrolyte-enhanced water. concentration or an increase in hydrogen ion concentration (Priestley, 2006). Causes may include undiagnosed diabetes mellitus and diabetic ketoacidosis, toxin ingestion (includ- During her hospitalization, Mary’s cardiopulmonary status ing salicylates or ethanol), or sepsis. Clinical findings may and oxygen saturations were closely monitored. She received include lethargy, coma, seizures, hyperventilation or Kuss- oxygen initially to maintain a saturation of 92%, although maul’s respirations, and signs of dehydration or low cardiac later in the course of the hospitalization this goal was changed output (Priestley). to 88%. She was fed breast milk and Pedialyte ad lib, and her intake, output, and daily weights were closely monitored. Respiratory Acidosis Saline wash and suctioning were ordered as needed, and acet- This acid-base disturbance is characterized by an increased aminophen was given every 4 hours as needed for fever or ir- PCO2 resulting from an imbalance between carbon dioxide ritability. A chest X-ray was obtained which demonstrated a production by the body and excretion from the lungs mild degree of atelectasis or infiltrate. A pediatric cardiology (Priestley & Litman, 2009). Clinical manifestations may consult was obtained for a grade 2/6 heart murmur and an include depressed consciousness and a hyperdynamic isolated elevated blood pressure. The murmur was identified cardiovascular state characterized by tachycardia, high car- as a pulmonary outflow murmur with no treatment required, diac output, and decreased systemic vascular resistance and the elevated blood pressure was most likely an erroneous (Priestley & Litman). reading. An echocardiogram revealed a structurally normal heart with normal function. She did not receive intravenous Mary’s Hospital Course fluids or medications, and her acid-base imbalance was moni- In order to better understand what was going on with Mary, tored closely and resolved on its own. we contacted the company which manufactured the particu- Mary was hospitalized for 4 days. At the time of dis- lar electrolyte water the parents had used to dilute the pow- charge, Mary’s electrolytes had normalized and her elevated dered formula, and they told us that there are 10mg per liter bicarbonate had resolved. The last electrolyte panel showed of calcium chloride, 10mg per liter of magnesium, and a sodium of 137, a potassium of 6.9 (but with a hemolyzed 15mg per liter of potassium bicarbonate. Mary’s electrolytes specimen), a chloride of 99, a CO2 of 27.7, a BUN of 8, a revealed an underlying metabolic alkalosis with respiratory creatinine of 0.2, a glucose of 91, and a normal AST and compensation, as her pH was 7.43, PCO2 49.6, and her bi- ALT. Her albumin was 3.8, protein was 6.5, calcium was carbonate was 32.2 with a base excess of 6.5. Bicarbonate 10.6, bilirubin was 0.3, and alkaline phosphatase was nor- levels were monitored throughout the course of her admis- mal at 234. The oxygen was weaned to one-thirty-second sion, and this value actually increased to 34.8 approximately liter per minute via nasal cannula; however, she did at times 24 hours into her hospitalization, although her potassium require O2 of up to one-quarter of a liter and so was dis- decreased to 5.4 and her calcium decreased to 10.1. charged home with home O2 and pulse oximetry.

September/October 2009 MCN 293 Mary’s case was interesting and frightening for us, for with normal infant blood gas values and potential sequelae she had demonstrated a marked metabolic alkalosis, and it associated with acid-base disturbances allows the nurse to was important that everyone understand why this had hap- remain vigilant for potential complications. pened. With the diagnosis of respiratory syncytial virus This case study highlights the need for continuing and bronchiolitis one would expect the child to be acidotic, increased pre- and postnatal education about the nutrition- which may suggest that without the concurrent infection al needs of infants and the proper procedures for diluting this child would have demonstrated a more severe alkalosis. formula. As the product involved in this case and other While it is possible that this child’s tachypnea would lead to enhanced waters become ever more popular among Ameri- an alkalotic state, it was clear to us that Mary had a meta- cans, the need for parental education will grow. Discussion bolic, not a respiratory, alkalosis. of the potential hazards of the use of electrolyte-enhanced An extensive literature review revealed no publications ad- water to dilute formula may prevent infant morbidity such dressing the issue of giving formula mixed with electrolyte- as the marked metabolic alkalosis experienced by the infant in this case study. ✜

Acknowledgment In this case study, the child demon- The author thanks Dr. Michael Garver for his assistance with this project. strated a marked metabolic alkalosis, possibly due to dilution of her formula Anne Kathryn Eby is a Staff Nurse, Orthopedics and Neurosurgery, Benefis Health System, Great Falls, Mont. with electrolyte-enhanced water. Ms. Eby encountered this case while doing a clinical rota- tion as a family nurse practitioner student at Montana State University. She can be reached via e-mail at [email protected] enhanced waters to infants. One Web site “Ask Dr. Sears” The author has disclosed that she has no financial rela- had a few sentences advising parents not to dilute formula tionships related to this article. with these waters (www.askdrsears.com/faq/fo3.asp). References Implications for Nursing Ask Dr. Sears. (2009). Electrolyte Water. Retrieved April 3, 2009, from www.askdrsears.com/faq/fo3.asp This case makes it abundantly clear that parent education Brouillette, R. T., & Waxman, D. H. (1997). Evaluation of the newborns’ needs to include appropriate education about feeding with blood gas status. Clinical Chemistry, 43, 215-227. Clancy, J., & McVicar, A. (2007). Short-term regulation of acid-base home- powdered formula: ostasis of body fluids. British Journal of Nursing, 16(16), 1016-1022. 1. Enhanced vitamin waters should not be used to dilute Gartner, L. M., & Eidelman, A. I. (2005). Breastfeeding and the use of hu- man milk. Pediatrics, 115(2), 496-506. infant formula. Huang, L. H., & Priestley, M. A. (2008). Alkalosis, metabolic. In Emedicine. 2. If using a ready to feed formula, do not dilute further Retrieved March 9, 2009, from http://emedicine.medscape.com/article/ 906819-overview with water or any other liquid. Mancini, M. C., & Deshpande, G. G. (2006). Alkalosis, respiratory. In 3. If using a concentrated infant formula, mix exactly Emedicine. Retrieved March 11, 2009, from http://emedicine.medscape. com/article/906929-overview according to directions on the package. Pathophysiology made incredibly easy! (1998). Springhouse, Pennsylva- 4. Tap water used to reconstitute infant formula should nia: Springhouse Corporation. Priestley, M. A. (2006). Acidosis, metabolic. In Emedicine. Retrieved March be boiled for 1 to 2 minutes to eliminate bacterial con- 9, 2009, from http://emedicine.medscape.com/article/906440-overview. tamination. It must then be allowed to cool fully before Priestley, M. A., & Litman, R. (2009). Acidosis, respiratory. In Emedicine. Retrieved March 12, 2009, from http://emedicine.medscape.com/article/ diluting formula. 906545-overview 5. Unused, diluted formula should be refrigerated imme- Roman, M.A., Thimothee, S., & Vidal, J.E. (2008). Arterial blood gases. MEDSURG Nursing, 17(4), 268-269. diately. Spatz, D. L. (2006). State of the science: Use of human milk and breast- The importance of parent education before and after feeding for vulnerable infants. Journal of Perinatal and Neonatal Nursing, 20(1), 51-55. birth cannot be overstated. It is imperative that nurses con- Venter, C., & Dean, T. (2008). Caring for the newborn: Infant nutrition part tinuously assess parental knowledge and educational needs, 1. British Journal of Midwifery, 16(11), 726-733. Wagner, C. L., Graham, E. M., & Hope, W. W. (2006). Human milk and lac- especially as it relates to proper feeding methods and signs tation. In Emedicine. Retrieved March 9, 2009, from WebMD and symptoms of feeding problems. Additionally, familiarity http://emedicine.medscape.com/article/976504-overview.

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