When Urine pH Really Matters

Andrea Lynne Parker, MSN, RN, CPNP-AC; Sarah A. Martin, MS, RN, CPNP-PC/AC, CCRN; Terea Giannetta, MSN, RN, CPNP


J Pediatr Health Care. 2007;21(2):117-119,139-141. 

In This Article

Case Study

Chief complaint

The mother of a 4-week-old boy reported to the emergency department triage nurse that for the past 2 days her son had been "feeding poorly, vomiting, and sleeping a lot."

History of present illness

J.D., a 4-week-old Hispanic boy, was brought to the emergency department by his parents for the above complaint. Reportedly, J.D. usually ate 2 to 3 ounces of Carnation Good Start every 3 to 4 hours, but per his mother, he had only had about 1 to 1.5 ounces every 4 hours for the past day. His mother was not able to check his temperature at home, but stated that he felt "hot." His parents stated that he had a runny nose 1 week prior, but that his cold symptoms had resolved.

Birth and past medical history

J.D. was born full-term via a normal spontaneous vaginal delivery. At birth, he weighed 2.9 kg. There was minimal prenatal care per mother's report. J.D.'s mother stated that there were no complications during delivery and that she had been discharged home with J.D. within a few days. J.D. received his first hepatitis B immunization prior to discharge from newborn nursery. A neonatal newborn screen was done and was negative. J.D. had had no previous hospitalizations or surgeries. J.D. did not have a primary care provider and had not seen a health care provider since birth. J.D. had no known drug or food allergies.

Family history

J.D.'s family history is non-contributory.

Personal/social/developmental history

J.D. lives with his father and mother within an urban area. His parents do not speak English. There are no other siblings. There are no cigarette smokers or pets in the household. There has been no recent travel for either J.D. or his parents.

Review of systems

The infant's review of systems was significant for fever, vomiting (non-bloody, non-bilious), decreased appetite, and lethargy. Until 1 week prior, J.D. had been awake, alert, and feeding vigorously. There was no jaundice after birth and no history of a cardiac murmur or known structural cardiac defects. He had been having 4 to 5 bowel movements a day, which were soft and brown. Urine output was reported as 6 to 8 wet diapers a day; however, within the past week, his mother stated that she was only changing 2 to 3 wet diapers a day.

Physical examination in the emergency department

On presentation the to emergency department, J.D. had a temperature of 38.5°C (rectal), heart rate of 130 beats/min, respiratory rate of 45 breaths/min, and blood pressure of 95/50 mm Hg. His current weight is 3.2 kg (5th percentile) and his length is 52 cm (25th percentile). The general impression is of an ill-appearing, lethargic, Hispanic male neonate.

Results of a head, ears, eyes, nose, and throat exam revealed a normocephalic and atraumatic head, with anterior fontanel soft and sunken. Both tympanic membranes appeared pearly white. J.D.'s conjunctivas were clear, and his eyes were anicteric with pupils equal and reactive to light. There was no rhinorrhea noted. There were no oral lesions present and his mucus membranes were sticky. No tears were noted when crying on exam.

A cardiovascular exam revealed tachycardia with no murmur or rubs noted, peripheral pulses are equal bilaterally. No edema was noted, with a capillary refill time of 4 seconds on the soles of his feet.

His lungs were clear to auscultation and were equal bilaterally. No grunting, nasal flaring, or retractions were appreciated at the time of the exam.

Examination of his abdomen revealed a soft, non-distended, non-tender abdomen with no hepatosplenomegaly. He is an uncircumcised male with testes noted to be descended bilaterally.

His skin was warm and dry with no rashes, petechiae, bruises, or jaundice noted. J.D. opened his eyes spontaneously, had a weak cry and weak suck, and moved all extremities equally, but not vigorously.

Plan of care and diagnostic testing in the emergency department

In the emergency department, a full sepsis workup was completed, including a chest radiograph; complete blood count (CBC) with differential blood culture; urinanalysis, urine culture, and lumbar puncture with cerebrospinal fluid studies. A herpes simplex virus polymerase chain reaction, respiratory syncytial virus, and influenza A and B screens were also obtained and sent to the laboratory. He was given two normal saline boluses of 20 mL/kg and was then started on maintenance intravenous fluids.

Current laboratory data (reference ranges are reported in parentheses after the patient values) and radiographic results from the emergency department included a CBC with a white blood cell count of 20.6 thou/L (3.8--14 thou/L), hemoglobin 14.2 g/dL (10--18 g/dL), hematocrit 39% (31--55%), and platelet count of 650 thou/L (150--400 thou/L), with the differential revealing a neutrophil count of 71% (21--40%) and a lymphocyte count of 20% (49--70%).

The basic metabolic panel revealed sodium of 136 mEq/L (135--145 mEq/L), potassium of 3.9 mEq/L (3.5--5.1 mEq/L), chloride of 110 mEq/L (99--111 mEq/L), carbon dioxide of 11 mmol/L (20--24 mmol/L), blood urea nitrogen of 31 mg/dL (5--25 mg/dL), creatinine of 0.4 mg/dL (<0.7 mg/dL), glucose of 94 mg/dL (70--110 mg/dL), and calcium of 13.4 mg/dL (8.5--10.5 mg/dL).

Basic and microscopic urinalysis showed yellow and cloudy urine with a specific gravity of 1.010 (1.015--1.025) and pH of 7.0 (5--6.5); the specimen was negative for glucose, ketones, bilirubin, nitrite, and blood. There was trace protein and moderate leukocyte esterase present in the tested specimen. Microscopic analysis revealed 5 to 10 white blood cells, 1 to 4 red blood cells, and trace bacteria.

The cerebrospinal fluid (CSF) obtained was clear and colorless, with all test values within normal limits. In addition, no bacteria or polymorphonuclear cells were seen. The herpes simplex virus polymerase chain reaction, respiratory syncytial virus screen, and influenza A and B screen were all negative. His chest radiograph was consistent with viral peripheral airway disease.

Admission to the inpatient unit

J.D. was admitted to the General Pediatric floor with the diagnosis of fever. His medications include: ampicillin (Principen) (Apothecon, Inc., Princeton, NJ), gentamicin (Garamycin) (Schering Corp., Kenilworth, NJ), and acyclovir (Zovirax) (GlaxoSmithKline, Research Triangle Park, NC) for empiric sepsis coverage while cultures were pending. Acetaminophen (Tylenol) (Ortho/McNeil, Inc. Pharmaceutical, Raritan, NJ) as needed for fever or pain was also prescribed.

As the herpes simplex virus polymerase chain reaction results came back negative, the acyclovir was discontinued. J.D.'s urine and cerebrospinal fluid cultures continued no growth to date the following day after admission.

After being on the floor for 18 hours, this neonate's clinical status did not improve. J.D. was still lethargic, unwilling to feed, continuing to have emesis after feeding, and beginning to have some respiratory distress (as evidenced by tachypnea, nasal flaring, and increased abdominal breathing). An abdominal ultrasound to rule out pyloric stenosis was negative, but incidentally revealed extensive bilateral nephrocalcinosis and cholelithiasis.

Additional laboratory testing revealed a sodium of 142 mEq/L (135--145 mEq/L), potassium of 1.8 mEq/L (3.5--5.1 mEq/L), chloride of 120 mEq/L (99--111 mEq/L), carbon dioxide of 8 mmol/L (20--24 mmol/L), blood urea nitrogen of 22 mg/dL (5--25 mg/dL), creatinine of 0.4 mg/dL (<0.7 mg/dL), glucose of 114 mg/dL (70--110 mg/dL), and calcium of 13.9 mg/dL (8.5--10.5 mg/dL). A repeat urinanalysis revealed urine pH of 7.5 (5--6.5) and specific gravity of 1.005 (1.015--1.025). A venous blood gas showed pH of 7.21 (7.35--7.45), bicarbonate of 12 mmol/L (21--28 mmol/L), base deficit of −14.6 (−2 to +2), potassium of 1.5 mEq/L (3.5--5 mEq/L), and an ionized calcium of 7.7 mg/dL (4.48--5.28 mg/dL).

Because of the need for electrolyte management and more comprehensive evaluation requiring frequent laboratory monitoring J.D. was transferred to the pediatric intensive care unit. In addition, the endocrinology and nephrology services were consulted to assist with the diagnostic work-up and plan of care.

Case Study Questions

  1. What differential diagnoses are you considering for this infant?

  2. What diagnostic tests are you considering ordering?

  3. What is your assessment and plan for J.D.?

  4. What would be your recommendation for follow-up for this child?


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