PubMed Health⌕ Search

Biomedical subjects

C A Gaillard

Publications and source records attributed to C A Gaillard.

At least 19 recordsLinked to original sources
PubMed2004

Disparate systemic and renal blocking properties of angiotensin II antagonists during exogenous angiotensin II administration: implications for treatment.

Generation of angiotensin II (Ang II) contributes to the pathogenesis of cardiovascular diseases. Owing to the existence of high levels of Ang II within the kidney, blockade of the intrarenal Ang II levels may be important since long term outcome seems not only to be related to blood pressure per se. This was a prospective, randomized, double-blind, placebo-controlled study, with crossover design. We examined in 13 patients with mild to moderate hypertension the specific systemic and renal blocking properties of two different Ang II receptor blockers during a wide range of Ang II concentrations, 24 h post dose. The effects were evaluated after 4 weeks treatment with candesartan cilexetil (16 mg OD), losartan (50 mg OD) and placebo using clearance techniques. Candesartan reduced the 24 h blood pressure better than losartan (138(*)/87+/-12/8 vs 145/89+/-12/7 mmHg, (*)P<0.05 vs losartan) and placebo. Despite the lower blood pressure, candesartan attenuated the Ang II-induced response on ERPF and RVR markedly better than losartan or placebo. The GFR decreased, as expected, with placebo, but remained stable with candesartan. The present study demonstrates that in hypertensive patients candesartan and to a lesser degree losartan are effective in blocking the systemic and renal effects of Ang II during a wide range of Ang II infusion rates. Interestingly, 24 h post dose, candesartan effectively diminished the change in ERPF as well as GFR. This sustained renal effect of candesartan may be of importance, especially in pathophysiological circumstances in which (high renal levels of) Ang II contributes to cardiovascular damage.

Adult↗
PubMed2004

Hypertension management in primary care: standard care and attitude towards a disease management model.

INTRODUCTION: Cardiovascular risk control has become one of the hallmarks in the treatment of diabetes and coronary heart disease, yet assessment of individual risk factors is suboptimal. We have designed a new Hypertension Screening Facility (HSF) for the evaluation of cardiovascular risk in hypertensive patients, based on 1) systematic, protocol-driven (WHO/ISH-based) analysis by nurse practitioners, 2) computer-assisted reporting of results and advice, 3) risk assessment using a Decision Support System (DSS), 4) maintenance of the autonomy of the GP. In a pilot study we wanted to investigate this HSF. METHODS: Survey 1 addressed a. how general practitioners deal with hypertension, b. whether they intend to and do use existing clinical guidelines, c. what their opinions are towards changes in the current process of care. In survey 2, we evaluated the attitude of GPs using the HSF. Responses were 43% (51 out of 120) to the first survey and 100% (20 out of 20) to the second. RESULTS: The majority of physicians included lifestyle in their assessment of risk factors and management of hypertension. Consideration of age and a positive family history was extremely high. In contrast, vision disturbances, ECG and microalbuminuria were not often considered. In the absence of additional risk factors, drug treatment was initiated in patients with a mean systolic blood pressure of 162+/-6 over 99+/-4 mmHg. In the presence of risk factors (obesity, smoking and a positive family history of cardiovascular disease) treatment is started at an average blood pressure of 154+/-8 over 96+/-4 mmHg. Opinions towards a change in management of hypertensive patients were generally positive. The opinions about the new HSF and the cardiovascular risk were reported to the general practitioner and considered useful or very useful by 79%. CONCLUSION: The present study thus confirms that cardiovascular risk evaluation by GPs is suboptimal, but there is a positive attitude towards an improvement in their assessment by HSF. The novelty of the HSF is that it respects the autonomy of the GP and brings the expertise to the GP.

Attitude of Health Personnel↗
PubMed2001

Prevention of ventilator-associated pneumonia by oral decontamination: a prospective, randomized, double-blind, placebo-controlled study.

UNLABELLED: Colonization of the intestinal tract has been assumed to be important in the pathogenesis of ventilator-associated pneumonia (VAP), but relative impacts of oropharyngeal, gastric, or intestinal colonization have not been elucidated. Our aim was to prevent VAP by modulation of oropharyngeal colonization, without influencing gastric and intestinal colonization and without systemic prophylaxis. In a prospective, randomized, placebo-controlled, double-blind study, 87 patients received topical antimicrobial prophylaxis (gentamicin/ colistin/vancomycin 2% in Orabase, every 6 h) in the oropharynx and 139 patients, divided over two control groups, received placebo (78 patients were studied in the presence of patients receiving topical prophylaxis [control group A] and 61 patients were studied in an intensive care unit where no topical prophylaxis was used [control group B]). Baseline characteristics were comparable in all three groups. Topical prophylaxis eradicated colonization present on admission in oropharynx (75% in study group versus 0% in control group A [p < 0.00001] and 9% in control group B patients [p < 0.00001]) and in trachea (52% versus 22% in A [p = 0.03] and 7% in B [p = 0.004]). Moreover, topical prophylaxis prevented acquired oropharyngeal colonization (10% versus 59% in A [p < 0.00001] and 63% in B [p < 0.00001]). Colonization rates in stomach and intestine were not affected. Incidences of VAP were 10% in study patients, 31% in Group A, and 23% in Group B patients (p = 0.001 and p = 0.04, respectively). This was not associated with shorter durations of ventilation or ICU stay or better survival. Oropharyngeal colonization is of paramount importance in the pathogenesis of VAP, and a targeted approach to prevent colonization at this site is a very effective method of infection prevention. KEYWORDS: cross infection, prevention and control; respiration, artificial, adverse effects; antibiotics, administration and dosage infection control methods; pneumonia, etiology, prevention and control; intubation, intratracheal, adverse effects

Administration, Topical↗
PubMed2000

[What is to be done with vancomycin-resistant enterococcal infections?].

Recently, three epidemics in Dutch hospitals were caused by vancomycin-resistant enterococci (VRE). Although the number of infections was small, spread of colonization was extensive and many infection control measures were necessary to prevent further spread. VRE are relatively avirulent bacteria. However, few, if any, antibiotics are available for treatment of infections caused by VRE and the genetic code for resistance may be transferable to other, more virulent, bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). Although colonization and infection with MRSA have become endemic in many surrounding countries, such a situation has been prevented in the Netherlands by employing an aggressive 'search and destroy' policy. Although many questions regarding the optimal approach of VRE remain unanswered, a similar policy as employed for MRSA will not be possible. In contrast to MRSA, colonization with VRE occurs in the open population, no populations with increased risk for colonization appear to be definable and colonization cannot be eradicated. Based on common sense, a differentiated approach seems indicated in which extensive infection control measures should only be implemented when spread of a single genotype has been demonstrated. A reference laboratory should be created for uniform genotyping.

Anti-Bacterial Agents↗
PubMed2000

[Vancomycin-resistant Enterococcus faecium outbreak in a nephrology ward].

In April 2000, an outbreak of vancomycin-resistant Enterococcus faecium (VRE) was discovered in an internal medicine/nephrology and dialysis ward of the Eemland Hospital, Amersfoort, the Netherlands. Although enterococci are considered relatively non-virulent, VRE are resistant to almost all commercially available antibiotics. Surveillance cultures were obtained from all patients at the ward, all patients visiting the dialysis ward and the environment of patients. VRE were determined and clustering of strains was analysed using molecular genotyping. In all, 12 patients were colonized with the outbreak strain. Transmission of VRE usually occurs via the hands of health care workers. The ward was closed for new admissions, patients were divided in cohorts of colonized and non-colonized patients, and rooms were disinfected after patient discharge. Infection control measures (such as handwashing and use of gloves and gowns) were enforced and prescriptions of vancomycin and cephalosporins were reduced. With these measures the outbreak could be controlled. Epidemiological analysis demonstrated that earlier admission and previous use of ciprofloxacin, amoxicillin and amoxicillin-clavulanic acid were risk factors for colonization. A nearby hospital was a possible source of this outbreak.

Aged↗
PubMed2000

Response of erythropoiesis and iron metabolism to recombinant human erythropoietin in intensive care unit patients.

OBJECTIVES: Critically ill patients often are anemic, which may impair oxygen delivery. Transfusion of red cells and supplementation with vitamins or iron are the usual therapeutic strategies, whereas only sporadic data are available on the use of epoetin alfa in these patients. We investigated endogenous erythropoietin (EPO) production and the response to epoetin alfa in anemic intensive care unit (ICU) patients. DESIGN: Randomized, open trial. SETTING: Multidisciplinary ICU in a single secondary care center. PATIENTS: Thirty-six critically ill patients admitted to the ICU who became anemic (hemoglobin concentration, <11.2 g/dL or <12.1 g/dL in case of cardiac disease) were randomized to one of three study groups. INTERVENTIONS: All patients received folic acid (1 mg) daily. The control group received no additional therapy, the iron group received 20 mg of iron saccharate intravenously (iv) daily for 14 days. The EPO group received iv iron and epoetin alfa (300 IU/kg) subcutaneously on days 1, 3, 5, 7, and 9. MEASUREMENTS AND MAIN RESULTS: Blood and reticulocyte counts were measured daily for 22 days. Serum EPO, C-reactive protein, serum transferrin receptor, and iron variables were measured on days 0, 2, 6, 10, and 21. Blood loss and red cell transfusions were recorded. Serum EPO concentrations were inappropriately low for the degree of anemia at baseline, with no difference between patients with and without renal failure. Exogenous administration of EPO increased EPO concentrations from 23+/-13 to a maximum of 166+/-98 units/L on day 10 (p < .05). Reticulocyte count increased exclusively in the EPO group from 56+/-33 x 10(9)/L to a maximum of 189+/-97 on day 13 (p < .05). Serum transferrin receptor rose only in the EPO group from 3.7+/-1.4 to 8.6+/-3.1 mg/L on day 10 (p < .05) and remained elevated on day 21, indicating an increase in erythropoiesis. Hemoglobin concentration and platelet count remained identical in the three study groups. CONCLUSION: Endogenous EPO concentrations are low in critically ill patients. The bone marrow of these patients is able to respond to exogenous epoetin alfa, as shown by elevated concentrations of reticulocytes and serum transferrin receptors.

Adult↗
PubMed1998

Colonization with Pseudomonas aeruginosa in patients developing ventilator-associated pneumonia.

To determine routes of colonization and genotypic variation of Pseudomonas aeruginosa leading to ventilator-associated pneumonia, colonization of the rectum, stomach, oropharynx, and trachea was studied chronologically in 10 patients. Ninety-one isolates of P aeruginosa were genotyped; seven different genotypes were identified. Patients developing ventilator-associated pneumonia caused by P aeruginosa were colonized at multiple body sites and may be colonized with multiple genotypes. The upper respiratory tract is the predominant initial site of colonization with P aeruginosa.

Humans↗
PubMed1998

Progressive vascular damage in hypertension is associated with increased levels of circulating P-selectin.

OBJECTIVE: To assess whether increased shedding of adhesion molecules in plasma provides an index for endothelial damage in hypertension. DESIGN AND METHODS: Three groups of hypertensive patients with increasing severity of vascular damage were studied: 20 essential hypertensives, 21 atherosclerotic, renovascular hypertensives and four malignant hypertensives. Twenty healthy subjects were included as a control group. Levels of P-selectin, E-selectin, intracellular adhesion molecule 1, vascular cell adhesion molecule and von Willebrand factor in venous blood were measured, using sandwich-type enzyme-linked immunosorbent assay. RESULTS: For essential hypertensives a trend for increased P-selectin and E-selectin values compared with those in controls was observed (159+/-44 versus 132+/-40 ng/ml, P = 0.062 and 40+/-13 versus 34+/-17 ng/ml, P = 0.055, respectively). P-selectin (210+/-84 ng/ml, P = 0.0021) and E-selectin (42+/-12 ng/ml, P = 0.012) levels in renovascular hypertensives were significantly higher than those in healthy controls. There were no significant increases in circulating levels of intracellular adhesion molecule 1, vascular cell adhesion molecule and von Willebrand factor either in essential hypertensives or in renovascular hypertensives. Marked increases in circulating levels of adhesion molecules and von Willebrand factor relative to those in controls were observed in malignant hypertensives (P-selectin 634+/-332 versus 132+/-40 ng/ml, P = 0.0004; vascular cell adhesion molecule 968+/-187 versus 493+/-139 ng/ml, P = 0.0004; and von Willebrand factor 259+/-75 versus 130+/-72 U/dl, P = 0.016). CONCLUSIONS: Progression of vascular damage in essential, renovascular and malignant hypertension is associated with a rise in circulating levels of P-selectins and, to a lesser extent, E-selectins, whereas levels of intracellular adhesion molecule 1, vascular cell adhesion molecule and von Willebrand factor are elevated only in diseases associated with acute severe vascular damage, including malignant hypertension. Our data suggest that selectins may be useful as indicators of vascular damage in hypertension.

Adult↗
PubMed1998

Cross-colonisation with Pseudomonas aeruginosa of patients in an intensive care unit.

BACKGROUND: Ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa is usually preceded by colonisation of the respiratory tract. During outbreaks, colonisation with P aeruginosa is mainly derived from exogenous sources. The relative importance of different pathways of colonisation of P aeruginosa has rarely been determined in non-epidemic settings. METHODS: In order to determine the importance of exogenous colonisation, all isolates of P aeruginosa obtained by surveillance and clinical cultures from two identical intensive care units (ICUs) were genotyped with pulsed field gel electrophoresis. RESULTS: A total of 100 patients were studied, 44 in ICU 1 and 56 in ICU 2. Twenty three patients were colonised with P aeruginosa, seven at the start of the study or on admission and 16 of the remaining 93 patients became colonised during the study. Eight patients developed VAP due to P aeruginosa. The incidence of respiratory tract colonisation and VAP with P aeruginosa in our ICU was similar to that before and after the study period, and therefore represents an endemic situation. Genotyping of 118 isolates yielded 11 strain types: eight in one patient each, two in three patients each, and one type in eight patients. Based on chronological evaluation and genotypical identity of isolates, eight cases of cross-colonisation were identified. Eight (50%) of 16 episodes of acquired colonisation and two (25%) of eight cases of VAP due to P aeruginosa seemed to be the result of cross-colonisation. CONCLUSIONS: Even in non-epidemic settings cross-colonisation seems to play an important part in the epidemiology of colonisation and infection with P aeruginosa.

Adolescent↗
PubMed1998

Prediction of clinical severity and outcome of ventilator-associated pneumonia. Comparison of simplified acute physiology score with systemic inflammatory mediators.

Systemic kinetics of three inflammatory mediators (bactericidal/permeability-increasing protein [BPI], soluble intercellular adhesion molecule [sICAM], and soluble E-selectin [sE-selectin]) were studied during the development of ventilator-associated pneumonia (VAP) (n = 42), diagnosed on quantitative cultures of bronchoscopic samples. From a pool of collected samples, nested samples were used to measure mediators on Days -4, -2, 0, and +2, relative to diagnosis. Correlations between systemic levels of mediators and clinical severity of infection (VAP with or without severe sepsis or septic shock) and patient outcome (mortality at Day 10 after diagnosis) were studied. Predictive values of inflammatory mediators were compared with daily Simplified Acute Physiology Score II (SAPS II) values and the logarithmic number of bacteria in bronchoscopic samples. During the development of VAP, increasing SAPS II scores and rising systemic mediator levels were only found in patients in whom VAP was accompanied with severe sepsis or septic shock. Values of SAPS II and plasma levels of BPI and sE-selectin, but not sICAM, increased from the day of diagnosis on in patients who died within 10 d of diagnosis. Systemic levels of inflammatory mediators did not better predict clinical severity or patient outcome than daily SAPS II scores. The logarithmic number of bacteria in bronchoscopic samples poorly correlated with circulating levels of inflammatory mediators, severity of infection, and patient outcome. Our findings show that a clinical scoring system (SAPS II score) is at least as good as a predictor for the clinical severity of infection and patient outcome, and provide new information on the kinetics of inflammatory mediators during the development of VAP.

APACHE↗
PubMed1997

Natriuretic effect of nitrendipine is preceded by transient systemic and renal hemodynamic effects.

This study investigated whether the acute natriuretic effect of nitrendipine is related to its initial renal hemodynamic effects. We investigated 16 patients (10 men and 6 women, mean age 52 +/- 2 years) with essential hypertension, whose treatment, if any, was stopped 3 weeks before the study. They were admitted to a metabolic ward for 9 days and kept on a constant sodium diet of 55 mmol/day. During two 24-hour experiments, subjects randomly received a single oral dose of placebo/nitrendipine 10 mg (group 1, n = 8) or placebo/nitrendipine 20 mg (group 2, n = 8), according to a double-blind crossover study design. Patients fasted during the experiments, but their sodium intake was ensured by a constant intravenous saline infusion of 2.3 mmol/hr. Mean arterial pressure (MAP) and heart rate were determined for 5 hours following the administration of nitrendipine or placebo. Effective renal plasma flow (ERPF), glomerular filtration rate, active plasma renin concentration, angiotensin II, aldosterone, atrial natriuretic peptide, and catecholamines were determined every hour for 5 hours. Hourly urine collections were used to assess sodium, potassium, and creatinine excretions. Relative to placebo, only in group 2 (nitrendipine 20 mg) was a fall in MAP and a rise in ERPF observed 2 hours after the start of the experiment. The effects, however, lasted only for 1 hour. No such changes were seen in group 1. In neither group did nitrendipine affect hormonal concentrations. Sodium excretion was enhanced after the 20-mg dose of nitrendipine only (p < 0.05). Nitrendipine 20 mg induced a significant increase in sodium excretion, which may be dissociated from its acute hemodynamic effects.

Blood Pressure↗
PubMed1997

Role of colonization of the upper intestinal tract in the pathogenesis of ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is the most frequent infection in mechanically ventilated patients. Colonization of the gastrointestinal tract, especially the stomach, is believed to be important in the pathogenesis of VAP. However, the literature on this topic is full of contradictory evidence. In the present review, we critically assess the existence and importance of the gastropulmonary route of colonization in the pathogenesis of VAP, and we analyze the differences between studies that show different results. Several preventive regimens (e.g., the use of sucralfate for stress ulcer prophylaxis and modulation of enteral feeding) have been used to prevent gastric colonization and decrease the incidence of VAP. However, none of these regimens has been demonstrated to be unequivocally beneficial. Moreover, recent analyses of the sequences of colonization in patients who develop VAP suggest that gastric colonization may be less important in the pathogenesis of VAP than has been assumed. As a result, the impact of other routes of colonization such as cross-colonization or transfer of rectal bacteria via the skin or other vectors to the respiratory tract may have been underestimated. Knowledge of the relative importance of each of these possible routes of colonization is essential for developing effective measures to prevent VAP.

Bacteria↗
PubMed1997

Indications for antibiotic use in ICU patients: a one-year prospective surveillance.

The high prevalence of nosocomial infections in critically ill ICU patients is associated with high antibiotic consumption. Besides its economic impact, there is the constant threat of selection and induction of antibiotic resistance. Surveillance studies recording the incidence of infections, antibiotic use, and antimicrobial susceptibilities of pathogens supply vital information regarding infection control and prevention of antibiotic resistance. In order to analyse antibiotic consumption we recorded antibiotic use in a general ICU during one year by categorizing the indications for antibiotic use into three groups; (i) prophylaxis; (ii) therapy for a bacteriologically proven infection (BPI); (iii) therapy for a non-bacteriologically proven infection (non-BPI). Bronchoscopic techniques were used to diagnose pneumonia. In practice, BPI must be treated, but a proportion of antibiotics prescribed for non-BPI may be unnecessary. The subdivision in BPI and non-BPI may help to identify these cases. In all, 515 patients were admitted to ICU and 36% of these had at least one infection. Of all infections, 53% were ICU-acquired and 99% of these occurred in intubated patients. Antibiotics were prescribed in 61% of admissions. Of all antibiotics prescribed for therapy, 49% were for respiratory tract infections, 19% for abdominal infections and 13% for sepsis eci. Categorized by indication, 59% of all antibiotic prescriptions were for BPI, 28% for non-BPI and 13% for prophylaxis. A theoretical reduction of 25% in the number of non-BPI prescriptions would result only in a 7% decrease of total antibiotic use. We conclude that almost all antibiotics prescribed were for intubated patients and for BPI. Respiratory infections were the single most common infection and accounted for 49% of all antibiotics used. Therefore, in our setting, prevention of respiratory tract infections is probably the most effective mode to reduce antibiotic use.

Adolescent↗
PubMed1997

The systemic inflammatory response in the development of ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is the most frequent occurring infection among mechanically ventilated patients. The clinical presentation of VAP ranges from relatively benign to a severe illness with septic shock. The influence of VAP on patient outcome has not been elucidated and its effects on the inflammatory response of the host are unknown. In a case-control study, the systemic inflammatory response was investigated in patients developing VAP as compared with control patients matched on duration of mechanical ventilation and underlying diseases. Patients developing VAP (n = 42) were matched to a single control (without VAP), who was matched on seven variables. VAP was diagnosed with bronchoscopic techniques. The inflammatory response, reflected by circulating levels of interleukin-6 (IL-6) and interleukin-8 (IL-8), was determined on the day of diagnosis (or day of matching for controls), 4 and 2 d before diagnosis, and 2 d after diagnosis. The development of VAP was not associated with an increase in circulating levels of IL-6 or IL-8. Among patients in which VAP was associated with a clinical presentation of severe sepsis or septic shock (n = 10), IL-6 and IL-8 levels increased and were higher than in the corresponding controls. Moreover, 60% of cases with severe sepsis or septic shock died as compared with 20% of their matched controls (p = 0.06). Mortality rates were similar in patients with uncomplicated VAP and their matched controls (25% and 34%, respectively). High circulating levels of IL-6 and IL-8 were associated with higher mortality rates. The clinical picture of VAP can be subdivided into different types, ranging from uncomplicated to an infection associated with severe sepsis or septic shock, elevated circulating levels of IL-6 and IL-8, and an increased mortality rate.

Bronchoalveolar Lavage Fluid↗
PubMed1997

Implementation of bronchoscopic techniques in the diagnosis of ventilator-associated pneumonia to reduce antibiotic use.

In intensive care units, a large proportion of antibiotics are prescribed for presumed episodes of ventilator-associated pneumonia (VAP). VAP is usually diagnosed on a combination of clinical, radiographic, and microbiologic criteria with a high sensitivity but low specificity for VAP. As a result, patients may receive antibiotics unnecessarily. Specificity can be increased by the addition of quantitative cultures of samples of protected specimen brush (PSB) and bronchoalveolar lavage (BAL) to the diagnostic criteria. We prospectively analyzed the effects of implementation of PSB and BAL in the diagnosis of VAP on antibiotic prescription. PSB and/or BAL were performed in patients who fulfilled the clinical, radiographic, and microbiologic criteria for VAP. Based on quantitative cultures of PSB and/or BAL, patients were categorized into three groups: VAP microbiologically proven (Group 1; n = 72); clinical suspicion of VAP not confirmed microbiologically (Group 2; n = 66); and patients in whom bronchoscopy could not be performed (Group 3; n = 17). In Group 1, antibiotic therapy was instituted empirically in 40 patients (56%) (Group 1a) and after obtaining culture results in the other 32 patients (Group lb). Adjustment of therapy, based on culture results, occurred in 14 (35%) patients in Group la. In Group 2 empiric therapy was instituted in 34 (52%) patients (Group 2a) and dIscontinued within 48 h in 17 of them (50%). In Group 3, 17 (100%) patients were treated with antibiotics. Among the 66 patients in whom a clinical suspicion of VAP was not confirmed, only 18 (27%) were treated with antibiotics, and antibiotic therapy was withheld in 48 (35%) of 138 patients who underwent bronchoscopy. Withholding of antibiotic therapy had no negative effect on the recurrence of a clinical suspicion of VAP or on mortality rates. We conclude that addition of bronchoscopic techniques to the criteria for VAP may help to reduce antibiotic use. However, the definite benefits and cost-effectiveness of these techniques should be analyzed in a randomized study.

Anti-Bacterial Agents↗
PubMed1996

Assessment of gastric acidity in intensive care patients: intermittent pH registration cannot replace continuous pH monitoring.

OBJECTIVE: To test the accuracy of colour-scaled indicator papers to measure pH values and to study the correlation between this method of measuring gastric juice pH once daily and 24-h continuous intragastric pH monitoring in intensive care patients. DESIGN: The accuracy of indicator papers was tested in the laboratory using colourless solutions and aspirated gastric juice and was then verified with a laboratory pH meter. Continuous intragastric pH monitoring was performed in mechanically ventilated ICU patients. Percentages of time with a pH value <3.0 and median pH values by 24-h continuous intragastric pH monitoring were compared to pH values measured once daily with indicator paper. SETTING: A mixed ICU. PATIENTS: A total of 150 measurements were taken by continuous pH monitoring in 91 mechanically ventilated ICU patients. MEASUREMENTS AND RESULTS: The correlation between the pH measured with the indicator paper and subsequently verified with a laboratory pH meter in colourless solutions was 0.96 [regression coefficient (RC) 0.98, 95% confidence interval (CI) 0.91-1.05]. Measured in gastric juice it was 0.95 (RC 0.95, 95% CI 0.88-1.01). The correlation between median pH values, determined with 24-h continuous intragastric pH monitoring, and values measured with indicator papers was 0.39 (RC 0.43, 95% CI 0.26-0.59). The mean difference in pH, as determined by the analysis of Bland and Altman], was 0.9 with a SD of 4.7. The correlation between the percentage of time with pH < 3.0, as obtained with continuous registration, and median gastric pH values (also obtained with continuous registration) was -0.94 (RC-0.06, 95% CI-0.06- -0.05); the correlation between the time and gastric pH values (measured with indicator paper) was-0.40 (RC-0.02, 95% CI-0.03- -0.02). CONCLUSION: The colour-scaled indicator paper is an accurate method of measuring pH values, but there is a poor correlation between gastric pH values measured once daily and a total measurement derived from 24-h continuous intragastric pH monitoring. Changes in intragastric pH values cannot be accurately studied when measuring acidity once daily. The influence of various treatment regimens on intragastric acidity in relation to the development of gastric colonization and nosocomial pneumonia should be investigated either with continuous intragastric monitoring or with frequent measurements in aspirated gastric juice.

Adult↗