Question

Patient Profile:

Miss B. A 74 year-old woman who lives alone, is admitted to the hospital because of weakness and confusion. She has a history of chronic heart failure and chronic diuretic use.

Objective Data:

•Neurologic: confusion, slow to respond to questions, generalized weakness

•Cardiovascular: blood pressure 90/62, heart rate 112 and irregular, pulses are weak, EKG indicates sinus tachycardia

•Pulmonary: respiration 12 per minute and shallow

•Additional findings: decreased skin turgor and dry mucous membranes

Laboratory Results: Na 141, K 2.5, Cl 85

            Arterial Blood Gases: pH 7.52, PaCO2 45, PaO2 88, HCO3 42

A. Which laboratory results are abnormal and what signs and symptoms can be associated with these abnormal values?

B. Is the pH level acidotic or alkalotic? Is the abnormal pH caused by a respiratory problem or metabolic problem?

Laboratory Test Reference Guide:

Laboratory Test	Normal Range
Sodium (Na)	135 – 145    mEq/L
Potassium (K)	3.5 – 5.0      mEq/L
Chloride (Cl)	97 – 105      mEq/L
Calcium (Ca)	8.5 – 10.5    mg/dl
Phosphate (PO4)	2.5 – 5.0      mg/dl
Magnesium (Mg)	1.8 – 3.0      mEq/L
Blood Urea Nitrogen (BUN)	7 – 18          mg/dl
Creatinine (Crea)	0.7 – 1.2      mg/dl
Glomerular Filtration Rate (GFR)	>60      Normal
	15-60   Kidney Disease
	<15      Renal Failure
Blood Count
White Blood Count (WBC)	4.5 – 10 thousand cells/mcL
Hemoglobin (Hgb)	Men 13 – 17 g/dl, Women 11.7 – 15.5 g/dl
Hematocrit (Hct)	Men 38 – 51%, Women 33 – 45%
Arterial Blood Gases
pH	7.35 – 7.45
PaCO2	35 – 45        mmHg
PaO2	80 – 100      mm Hg
HCO3 (Bicarb)	22 - 26
Oxygen Saturation (O2 sat)	94 – 97%

Acid – Base Balance:

Metabolic Acidosis                            pH low, HCO3 low, PaCO2 may be normal or low

Metabolic Alkalosis                           pH high, HCO3 high, PaCO2 may be normal or high

Respiratory Acidosis                         pH low, PaCO2 high, HCO3 may be normal or high

Respiratory Alkalosis                         pH high, PaCo2 low, HCO3 may be normal or low

Combined (Mixed) Acidosis             pH low, HCO3 low, PaCO2 high

Combined (Mixed) Alkalosis             pH high, HCO3 high, PaCO2 low

Answer 1

1) the values of potassium, chlorine and HCO3 values are abnormal and this is due to metabolic alkalosis which is causing high HCO3 values.

2) the pH is alkalotic and it is abnormal due to metabolic alkalosis