title: Comparison of two methods of measuring gastric pH.
abstract: OBJECTIVE
  To assess the agreement between two methods of measuring gastric pH in critically ill patients (multiple band litmus paper-tested aspirations versus a meter-read probe located in the tip of a nasogastric tube) and to compare nurse satisfaction with both methods of measuring pH.
  
  
  METHODS
  Prospective, correlational, nonprobability sample.
  
  
  METHODS
  Mid-Atlantic, semirural Veterans Affairs Medical Center.
  
  
  METHODS
  39 male, surgical, critical care patients, who were nasogastrically intubated in the operating room and received nothing by mouth. NURSES: Twenty-seven registered nurses on the medical-surgical intensive care staff.
  
  
  METHODS
  Differences in pH units as determined by two methods of measurement and nurse satisfaction scores.
  
  
  METHODS
  Litmus paper-tested aspirations versus a meter-read probe located in the tip of the nasogastric tube, measured every 2 hours for 48 hours. A nurse satisfaction assessment form for both measurement methods at entry, 6 months, and 12 months.
  
  
  RESULTS
  All measures of association, Pearson's r (0.79), the concordance coefficient (0.74), and eta (0.88), were high. The concordance coefficient measures indicated sufficient agreement between the two methods at the initial and 24 hour measurement times (Cb) = 0.97, 0.97, and 0.94), but not at 48 hours. The meter method indicated prophylaxis was needed when the paper did not, more often than did the paper method (9.3% vs 5.2%). A significant difference between methods was found only at the last reading at 48 hours (z = -2.24, p < .0249). MANOVA revealed that nurses' preference for the meter method was significant (F = 139.48, df = 1.18) and increased over time (F = 4.77, df = 2,36).
  
  
  CONCLUSIONS
  The gastric probe method of measuring pH is an accurate substitution up to 48 hours for the litmus-paper aspiration method in the postoperative patient who is receiving nothing by mouth. Nurses prefer the gastric probe method of measuring pH over the litmus-paper method because they judge it to be safer, faster, and more accurate.
authors.affiliation: Georgetown University School of Nursing, Washington, D.C.
authors.forename: K M
authors.initials: KM
authors.lastname: Neill
authors.forename: K T
authors.initials: KT
authors.lastname: Rice
authors.forename: H L
authors.initials: HL
authors.lastname: Ahern
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005745:Gastric Acidity Determination; D006801:Humans; D007441:Intubation, Gastrointestinal; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011934:Reagent Strips
chemical_list: D011934:Reagent Strips