Irritable bowel syndrome: more than abdominal pain and bowel habit abnormalities.

BACKGROUND & AIMS: Although irritable bowel syndrome (IBS) can be defined using few symptoms, principal symptoms alone may be inadequate in monitoring disorder severity. Secondary analysis of a published data set was performed to determine if more inclusive symptom measures would better reflect the burden of this disorder. METHODS: From a prospective naturalistic study of 213 patients meeting Rome II criteria, all the data were used from daily questionnaires recorded for 4 weeks, and repeated again after an interval of 4 weeks. The total number of 11 symptoms and intensity grading score of each symptom were analyzed alongside individual symptom intensities by principal component analysis. RESULTS: The trend accounting for the most variance was explained by the intensity of all symptoms together. The second largest trend was explained by differences between IBS bowel habits (constipation and diarrhea). The 2 constipation and 4 diarrhea symptoms closely correlated within each group, but the category of other symptoms were not correlated directly with either, and represent a separate dimension. Other symptoms (pain/discomfort, abdominal uneasiness, flatulence/distension, incomplete evacuation, pain or burning in the stomach) correlated more highly with disease intensity than either constipation or diarrhea symptoms. The sum of all symptoms and their intensity was consistent over each week, although the relative intensity of individual symptoms was more variable. Investigator measures of disease intensity underestimated that reported by patients. CONCLUSIONS: Non-bowel habit symptoms include more than abdominal pain and discomfort, and contribute to the largest component of the total symptom burden. Thus, more than bowel habits and abdominal pain drive IBS symptom severity.

Recent advances in understanding depression in adults with diabetes.

The authors review the science linking depression with diabetes. Some recent heuristic research is identified that highlights progress in the field and is directing future research. Issues in the management of depression in diabetes are outlined, including interactions of depression and insulin resistance.

Gastric residual volume and aspiration in critically ill patients receiving gastric feedings.

BACKGROUND: The helpfulness of bedside assessment of gastric residual volume in the prediction of aspiration has been questioned, as has the volume that signals increased risk of aspiration. OBJECTIVE: To describe the association between gastric residual volumes and aspiration of gastric contents. METHODS: In a prospective study of 206 critically ill patients receiving gastric tube feedings for 3 consecutive days, gastric residual volumes were measured with 60-mL syringes every 4 hours. Measured volumes were categorized into 3 overlapping groups: at least 150 mL, at least 200 mL, and at least 250 mL. Patients were categorized as frequent aspirators if 40% or more of their tracheal secretions were positive for pepsin and as infrequent aspirators if less than 40% of their secretions were positive for pepsin. Gastric residual volumes were compared between the 2 aspiration groups. RESULTS: Approximately 39% of the 206 patients had 1 or more gastric residual volumes of at least 150 mL, 27% had 1 or more volumes of at least 200 mL, and 17% had 1 or more volumes of at least 250 mL. Large-bore tubes identified most of the high volumes. Eighty-nine patients were frequent aspirators. Volumes less than 150 mL were common in both aspiration groups. However, the frequent aspirators had a significantly greater frequency of 2 or more volumes of at least 200 mL and 1 or more volumes of at least 250 mL. CONCLUSIONS: No consistent relationship was found between aspiration and gastric residual volumes. Although aspiration occurs without high gastric residual volumes, it occurs significantly more often when volumes are high.

High somatic symptom burdens and functional gastrointestinal disorders.

BACKGROUND & AIMS: Unexplained, multi-system somatic symptoms and syndromes, the hallmark features of somatization, are prevalent in patients with functional gastrointestinal disorders (FGIDs). We studied outpatients attending a gastroenterology clinic to see whether current somatic symptom burdens (a somatization state measure) or number of prior functional diagnoses (a somatization trait measure) could predict the presence of an FGID over structural gastrointestinal disease, and whether the predictive value was dependent on comorbid depression or anxiety disorders. METHODS: Clinical data from 327 consecutive new referrals to an outpatient gastroenterology practice were reviewed, 187 with an FGID and 140 with a structural illness. Somatization state and trait were measured by using self-reported current symptoms and functional diagnoses recorded in the medical history, respectively. Psychiatric comorbidity (depression or anxiety disorders) was extracted from chart review. RESULTS: FGID subjects endorsed more somatization state symptoms, had more somatization trait diagnoses, and had greater likelihood of psychiatric comorbidity (P < .001 for each). Logistic regression analysis adjusting for age and sex differences showed that each of these features independently predicted the likelihood of an FGID over structural disease (P < .05 for each). When high ratings on the somatization measures were present together with psychiatric comorbidity, the positive predictive value exceeded 0.95. CONCLUSIONS: Higher burdens of either current somatic symptoms or functional diagnoses in the medical history are strong predictors of an FGID in outpatients presenting with gastrointestinal complaints. The mechanism is not solely dependent on a relationship with affective disorders, which independently predicts FGID, at least in part, through another path.

Zonisamide or levetiracetam for adults with cyclic vomiting syndrome: a case series.

BACKGROUND & AIMS: Management of cyclic vomiting syndrome in adults is limited by the small number of effective medications for maintenance therapy. The clinical response to treatment with 2 newer antiepileptic drugs was evaluated retrospectively to see whether they might have a prophylactic role in this syndrome. METHODS: Outpatient records from 20 adult patients with cyclic vomiting syndrome attending a university-based practice were reviewed. Each had received zonisamide (median dose, 400 mg/d) or levetiracetam (median dose, 1000 mg/d) because tricyclic antidepressants alone were unsatisfactory as maintenance medications. Outcome was graded from chart review and directed interview; characteristics of the vomiting episodes were compared before and after initiation of antiepileptic drug therapy. RESULTS: At least moderate clinical response was described by 15 (75.0%) subjects, and 4 of these (20.0% of the total) reported symptomatic remission during 9.5 +/- 1.8 months of follow-up. Rate of vomiting episodes decreased from 1.3 +/- 0.3 to 0.5 +/- 0.2 per month (P = .01). Tricyclic antidepressants were discontinued in 11 (61.1%) of the 18 subjects who were still taking the medications when antiepileptic drug therapy was initiated. Moderate or severe side effects were reported by 45.0%, but by switching drugs, intolerance to antiepileptic drug therapy occurred in only 1 subject. CONCLUSIONS: Newer antiepileptic drugs, specifically zonisamide and levetiracetam, appeared beneficial as maintenance medications for nearly three fourths of adults with cyclic vomiting syndrome in this uncontrolled clinical experience. Although side effects occur in a large proportion of subjects, newer antiepileptic drugs might offer an alternative for patients who fail conventional treatment.

Predictors of premature antidepressant discontinuation in functional gastrointestinal disorders.

OBJECTIVES: To identify factors responsible for premature antidepressant discontinuation that would assist in designing management strategies for patients with functional gastrointestinal disorders. Antidepressants are being used increasingly to manage patients with functional gastrointestinal disorders; poor patient adherence to treatment regimens, particularly in the period shortly after antidepressant initiation, is common and interferes with success. METHODS: Clinical records were reviewed from 172 outpatients who attended a university-based practice and who had been prescribed antidepressants to manage their functional gastrointestinal symptoms. Survival analysis methods were used to determine independent predictors of premature antidepressant discontinuation (within 6 months of initiation). Logistic regression analyses were used to see if the same predictors were responsible for side effects or poor treatment response. RESULTS: Premature antidepressant discontinuation occurred in 41 (23.8%) subjects. Somatization features (state or trait) and history of depression or an anxiety disorder were the most significant predictors of premature discontinuation (p < or = .01 for each). Advancing age and female sex also were independent predictors (p < .05 for each). Somatization features and psychiatric illness were each linked to poor treatment response, whereas somatization features most consistently were associated with antidepressant side effects. CONCLUSIONS: Failure to maintain treatment occurs in nearly a quarter of outpatients given antidepressants for functional gastrointestinal disorders. Somatization features and history of depression or anxiety most significantly interfered with treatment by predicting side effects, poor treatment response, and premature antidepressant discontinuation. Management algorithms should include specific strategies targeted at patients with these risk factors for poor treatment adherence.

Sertraline for prevention of depression recurrence in diabetes mellitus: a randomized, double-blind, placebo-controlled trial.

CONTEXT: In patients with diabetes mellitus, depression is a prevalent and recurrent problem that adversely affects the medical prognosis. OBJECTIVE: To determine whether maintenance therapy with sertraline hydrochloride prevents recurrence of major depression in patients with diabetes. DESIGN: A randomized, double-blind, placebo-controlled, maintenance treatment trial. Patients who recovered from depression during open-label sertraline treatment continued to receive sertraline (n = 79) or placebo (n = 73) and were followed up for up to 52 weeks or until depression recurred. SETTING: Outpatient clinics at Washington University, St Louis, MO, the University of Washington, Seattle, and the University of Arizona, Tucson. PATIENTS: One hundred fifty-two patients with diabetes (mean age, 52.8 years; 59.9% female; 82.9% with type 2 diabetes) who recovered from major depression (43.3% of those initially assigned) during 16 weeks of open-label treatment with sertraline (mean dose, 117.9 mg/d). INTERVENTION: Sertraline continued at recovery dose or identical-appearing placebo. MAIN OUTCOME MEASURES: The primary outcome was length of time (measured as the number of days after randomization) to recurrence of major depression as defined in DSM-IV. The secondary outcome was glycemic control, which was assessed via serial determinations of glycosylated hemoglobin levels. RESULTS: Sertraline conferred significantly greater prophylaxis against depression recurrence than did placebo (hazard ratio = 0.51; 95% confidence interval, 0.31-0.85; P = .02). Elapsed time before major depression recurred in one third of the patients increased from 57 days in patients who received placebo to 226 days in patients treated with sertraline. Glycosylated hemoglobin levels decreased during the open treatment phase (mean +/- SD glycosylated hemoglobin level reduction, -0.4% +/- 1.4%; P = .002). Glycosylated hemoglobin levels remained significantly lower than baseline during depression-free maintenance (P = .002) and did not differ between treatment groups (P = .90). CONCLUSIONS: In patients with diabetes, maintenance therapy with sertraline prolongs the depression-free interval following recovery from major depression. Depression recovery with sertraline as well as sustained remission with or without treatment are associated with improvements in glycosylated hemoglobin levels for at least 1 year.

Depression, anxiety, and nonalcoholic steatohepatitis.

OBJECTIVE: Nonalcoholic steatohepatitis (NASH) is a morbid liver disease with limited treatment. Depression and anxiety have been associated recently with insulin resistance and inflammatory states, factors that are relevant to the development of NASH. We hypothesized that depression and anxiety would be more prevalent in NASH patients and predict more severe histological findings on liver biopsy. METHODS: Histories of major depressive disorder (MDD) and generalized anxiety disorder (GAD) were determined using a structured interview and DSM-IV criteria in 36 NASH subjects and 36 matched controls without liver disease who had undergone cholecystectomy. Histological changes on liver biopsy in NASH subjects were age-adjusted and compared in subjects with and without psychiatric disorders. A multivariate model incorporating other potential risk factors for NASH (female sex, body mass index, waist-to-hip ratio, and presence of diabetes) was used to determine independent effects of MDD and GAD on severity of histological findings. RESULTS: NASH subjects had significantly increased lifetime rates of MDD (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.4-10.2; p = .018) and GAD (OR 5.0, 95% CI, 1.7-14.9; p = .005). The onset of psychiatric illness preceded diagnosis of liver disease by 18 to 20 years. Each psychiatric disorder was associated with more severe histological features (p < .05 for each), the effect of GAD on fibrosis stage persisting in the multivariate model. CONCLUSIONS: MDD and GAD are overrepresented in NASH subjects and are associated with more advanced liver histological abnormalities. Additional investigation will be required to determine if depression and anxiety affect the development or progression of NASH and serve as modifiable risk factors.

Depression-related hyperglycemia in type 1 diabetes: a mediational approach.

OBJECTIVE: Depression is linked with hyperglycemia and with an increased risk for diabetes complications, but the mechanisms underlying these relationships have not been established. In this study, we applied mediational analysis methods to determine whether the hyperglycemic effect of depression could be mediated by poor diabetes self-care. METHODS: Depression symptoms and diabetes self-care activity were assessed in a primary care sample of 188 patients with type 1 diabetes by using the Hopkins Symptom Checklist-90 (SCL-90) and the Summary of Diabetes Self-Care Activities (SDSCA). A composite score of self-care activity was formed from SDSCA ratings for diet amount, exercise, and glucose testing. Degree of hyperglycemia (level of glycosylated hemoglobin [HbA1c]), weight, insulin dose, and other clinical characteristics were obtained from electronic medical records. Ordinary least-squares regression was used to determine the effect of depression on HbA1c level controlling for weight and insulin dose. The SDSCA score was then added to the regression model to determine whether it attenuated the effect of depression symptoms on HbA1c level, thus providing suggestive evidence of mediation from these cross-sectional data. RESULTS: Depression symptoms, poor diabetes self-care, and hyperglycemia were correlated with one another in univariate analyses (p <.05). Depression symptoms were associated with higher HbA1c after controlling for weight and insulin dose (parameter estimate for depression 0.53, t = 3.6, p <.001). Inclusion of SDSCA in the model minimally attenuated the effect of depression symptoms (adjusted parameter estimate for depression 0.50, t = 3.3, p = .001). CONCLUSIONS: These findings do not support mediation of the depression-hyperglycemia relationship by diabetes self-care behavior. Other pathways, including psychophysiological mechanisms, should be investigated.

Depression in diabetic patients: the relationship between mood and glycemic control.

PROBLEM: Evidence from prospective and cross-sectional studies demonstrates that the presence of diabetes doubles the risk of comorbid depression. This commonly overlooked comorbidity affects more than one quarter of the diabetic population, making its recognition and treatment in diabetic patients clinically relevant. METHODS: PubMed, PsycINFO, and MEDLINE databases were searched (search words: diabetes, depression, metabolic control, hyperglycemia, hypoglycemia) for articles that evaluated outcomes, relationships, and/or management of comorbid depression and diabetes published between 1980 and 2002. This review represents a synthesis of the findings including treatment recommendations. RESULTS: Concurrent depression is associated with a decrease in metabolic control, poor adherence to medication and diet regimens, a reduction in quality of life, and an increase in health care expenditures. In turn, poor metabolic control may exacerbate depression and diminish response to antidepressant regimens. Psychotherapy and pharmacotherapy are effective in the presence of diabetes; both cognitive behavior therapy and selective serotonin reuptake inhibitors are weight neutral and have been associated with glycemic improvement in some studies. CONCLUSION: Depression is common in both type 1 and type 2 diabetes and has significant effects on the course and outcome of this medical illness. Conventional antidepressant management strategies are effective and the regimen should be tailored to the individual patient. Enhanced efforts toward good glycemic control may also contribute to improvements in mood and perceptions of well-being.

Effect of feeding-tube properties on residual volume measurements in tube-fed patients.

BACKGROUND: The effect of feeding tube size and port configuration on the ability to measure gastric residual volume (GRV) is poorly understood. In addition, there is confusion about the need to measure GRVs during feedings into the small bowel. This study sought to (1) compare the volume of gastric contents obtained from small-diameter feeding tubes and large-diameter sump tubes concurrently positioned in the stomach and (2) describe the distribution of GRVs during small-bowel feedings. METHODS: For the first objective, GRV measurements were made from 10-Fr tubes (n = 645) and 14-Fr or 18-Fr sump tubes (n = 645) concurrently present in 62 critically ill patients. Sixty-milliliter syringes were used to measure GRVs from the 10-Fr tubes; the fluid was returned to the stomach and measurements were repeated from the large-diameter sump tubes. To address the second research objective, 890 GRV measurements were made from 14-Fr or 18-Fr gastric sump tubes (not connected to suction) in 75 critically ill patients who were receiving small-bowel feedings. RESULTS: When GRVs were >50 mL, a linear regression equation indicated that volumes obtained from the large-diameter sump tubes were about 1.5 times greater than those obtained from the small-diameter tubes concurrently present in the stomach, p < .001. Gastric volumes > or =100 mL were found in 11.6% of the 890 measurements made in patients receiving small-bowel feedings; volumes > or =150 mL were found in 5.4% of the measurements. CONCLUSIONS: The findings suggest that GRVs obtained from large-diameter sump tubes are about 1.5 times greater than those obtained from 10-Fr tubes. Large GRVs occur in at least 5% of patients receiving postpyloric feedings.

Verification of inefficacy of the glucose method in detecting aspiration associated with tube feedings.

While some authors believe that testing for glucose in suctioned tracheal secretions can be used to detect aspiration of glucose-containing formula, others disagree. Previous evaluative studies of the glucose method's efficacy have lacked adequate statistical power and a gold standard for aspiration. In this animal study, a gold standard for aspiration was used and possessed sufficient statistical power to address the glucose method's sensitivity and specificity. As such, the results from the study provide the clinician with useful data to decide if the glucose method is appropriate for use in clinical settings.

Chest pain in patients with cardiac and noncardiac disease.

OBJECTIVE: To describe factors influencing chest pain expression in patients with cardiac or noncardiac disease. METHODS: The authors conducted a case presentation and review of literature. RESULTS: Causes of chest pain are diverse. Psychologic factors influence chest pain expression commonly in patients with or without cardiac disease. CONCLUSIONS: Physicians and other therapists must be aware of psychologic influences on chest pain expression to provide optimal treatment to their patients.

Depression and coronary heart disease in women with diabetes.

OBJECTIVE: The protective effects of female gender on the appearance and course of coronary heart disease (CHD) in nondiabetic subjects are diminished in the presence of diabetes. Depression predicts onset of and poor outcome from CHD in nondiabetic populations. We hypothesized that the doubled rates of depression in female diabetic patients could help explain the high prevalence of CHD in women with diabetes. METHOD: Seventy-six female type 1 and type 2 diabetic patients with (N=16) or without (N=60) active major depression (DSM-III) at index evaluation underwent systematic annual investigation of diabetes and its complications for up to 10 years. Occurrences of CHD and other macrovascular complications were examined in relation to depression status using survival analysis statistics. A multivariate model incorporating other CHD risk factors (age, duration of diabetes, body mass index, glycosylated hemoglobin, and presence of hypertension, hyperlipidemia, or tobacco use) was used to determine independent effects of depression on outcome. RESULTS: Development of CHD was significantly more rapid in the depressed subset (p<0.01 between 10-year curves), an effect that persisted after controlling for base-line differences in body mass index. Depression also was retained as an independent predictor of CHD in the multivariate model with an age-adjusted hazard ratio of 5.2 (95% CI: 1.4-18.9; p=.01). In contrast, depression did not predict the development of clinically apparent peripheral or cerebrovascular disease. CONCLUSIONS: In this sample of diabetic women, major depression was an independent risk factor that accelerated the development of CHD. Depression recognition and management may improve outcomes from diabetes in this gender subgroup.

Efficacy of dye-stained enteral formula in detecting pulmonary aspiration.

STUDY OBJECTIVE: To determine the extent to which a mixture of human gastric juice and enteral formula stained with two concentrations of FD&C Blue No. 1 food dye (0.8 and 1.5 mL/L) is visible in suctioned tracheobronchial secretions following three forced small-volume pulmonary aspirations over a 6-h period in an animal model. DESIGN: Experimental 2 x 3 repeated measures. SETTING: Animal laboratory and an acute care hospital. PARTICIPANTS: Ninety New Zealand white rabbits weighing approximately 3 kg each, and 90 acutely ill adults who furnished gastric juice. INTERVENTIONS: A mixture of human gastric juice and enteral formula stained with 0.8 or 1.5 mL of dye per liter was instilled intratracheally over a 30-min period into anesthetized intubated animals at baseline, 2 h, and 4 h. A total of 0.4 mL/kg of the mixture was instilled at each session. Ninety minutes after each instillation, suctioned secretions were examined for visible dye and blood. MEASUREMENTS AND RESULTS: Dye was visible in 46.3% of the secretions (125 of 270). The concentration of dye had no significant effect on dye visibility. Blood that was present in 114 of 270 of the secretions (42.2%) interfered with dye visibility in all but two secretions. For reasons unknown, even in the absence of blood, dye visibility decreased from 90.2% (55 of 61 secretions) after the first aspiration event to only 61% (25 of 41 secretions) after the third aspiration event. CONCLUSIONS: Findings from this animal model study do not support the use of the dye method to detect repeated small-volume aspirations. For clinicians who choose to use the dye method in selected situations, it appears that a dye concentration of 0.8 mL/L may be as effective in detecting aspiration as a 1.5 mL/L concentration.

Patients with upright reflux have less favorable postoperative outcomes after laparoscopic antireflux surgery than those with supine reflux.

The aim of this study was to compare symptomatic outcomes after laparoscopic antireflux surgery in patients with upright vs. supine reflux. A prospective database was used to assess postoperative clinical outcomes in relation to positional patterns of reflux in 117 patients. Supine reflux was present in 31%, upright in 24%, and the remaining 44% had bipositional reflux. Preoperatively there were no differences in the frequency of typical or atypical symptoms between groups. At a mean follow-up of 18 +/- 11 months postoperatively, there were marked differences in symptoms between groups. Patients with upright reflux noted significantly more heartburn, chest pain, odynophagia, and bloating postoperatively when compared to patients with supine and bipositional reflux (P < 0.05). According to visual analog scales, patients with upright reflux expressed less satisfaction with operative results, ascribing more symptoms to the esophagus and stomach, when compared to those with supine reflux (P < 0.05). Although all patients reported improvement, the extent of the relief from preoperative symptoms was less in patients with upright reflux (P < 0.05). When asked if, in retrospect, they favored operative therapy, the patients with upright reflux were less enthusiastic (P < 0.05). Although antireflux surgery eliminates reflux in nearly all patients, postoperative symptomatic outcome is related to the preoperative pattern of reflux. Although all patients showed symptomatic improvement, the extent of that improvement was significantly less in patients with upright reflux. These patients should be carefully counseled preoperatively regarding expected symptomatic outcomes.

Treatment of depression in diabetes: impact on mood and medical outcome.

Depression is prevalent as a co-morbid condition in diabetes. The efficacy of depression treatment with either pharmacological agents or psychotherapy has been demonstrated in the few available controlled trials. Depression has been associated with poor glycemic control and with accelerated rates of coronary heart disease in diabetic patients. Reported depression treatment trials demonstrate benefits of depression remission on glycemic control as well as mood and the potential for improvement in the course and outcome of diabetes. Because adverse effects of pharmacological agents on glycemic control have been observed, optimal therapies that improve both depression and measures of diabetes are still being sought. This review critically examines the efficacy of depression treatment in diabetes patients, the effects of depression treatment on the medical condition, and methodological issues important in the performance of treatment trials in the patient population.

Prevalence of anxiety in adults with diabetes: a systematic review.

BACKGROUND: Anxiety is associated with decreased functioning and quality of life. It may have added importance in diabetes for its potential adverse effects on regimen adherence and glycemic control. OBJECTIVE: To estimate the prevalence of clinically significant anxiety in adults with diabetes. RESEARCH DESIGN AND METHODS: MEDLINE and PsycINFO databases and published reference lists were searched to identify studies that determined the prevalence of anxiety in diabetes from threshold scores on self-report measures or from diagnostic interviews. Prevalence was calculated as an aggregate mean weighted by the combined number of subjects in the included studies. RESULTS: Eighteen studies having a combined population (N) of 4076 (2584 diabetic subjects, 1492 controls) satisfied the inclusion criteria. Most did not adjust for the effects of moderator variables such as gender, and only one was community-based. Generalized anxiety disorder (GAD) was present in 14% of patients with diabetes. The subsyndromal presentation of anxiety disorder not otherwise specified and of elevated anxiety symptoms were found in 27% and 40%, respectively, of patients with diabetes. The prevalence of elevated symptoms was significantly higher in women compared to men (55.3% vs. 32.9%, P<.0001) and similar in patients with Type 1 vs. Type 2 diabetes (41.3% vs. 42.2%, P=.80). CONCLUSION: GAD is present in 14% and elevated symptoms of anxiety in 40% of patients with diabetes who participate in clinical studies. Additional epidemiological studies are needed to determine the prevalence of anxiety in the broader population of persons with diabetes.

Detection of pepsin in tracheal secretions after forced small-volume aspirations of gastric juice.

BACKGROUND: Detecting small-volume aspirations of gastric contents is an important but difficult task. A potentially useful method for this purpose is assaying tracheal secretions for pepsin, an expected constituent of gastric juice. METHODS: A 2-group experimental design was used. The primary subjects were 161 experimental and 21 control New Zealand white rabbits; 161 acutely ill humans provided the gastric juice used in the project. The animals were anesthetized before being intubated and mechanically ventilated. Three separate boluses of human gastric juice mixed with dye-stained enteral formula were instilled into the experimental animals' tracheas; the 21 control animals received only 0.9% sodium chloride solution. At the beginning of each experiment, 0.4 mL/kg of the substance was infused over a 30-minute period; the infusion was then stopped and 90 minutes were allowed to elapse before endotracheal suctioning was performed. This procedure was repeated at hour 2 and hour 4. After completion of the multiple aspiration portion of the study, 23 additional animals were subjected to a single aspiration of 0.4 mL/kg of a mixture of human gastric juice and dye-stained enteral formula; secretions were obtained at 2 hours, 4 hours, and 6 hours. An immunoassay was used to test for pepsin in all of the tracheal secretions. RESULTS: In the 3-aspiration group, pepsin was found in all of the secretions from 92.5% (149/161) of the experimental animals; in contrast, no pepsin was found in any of the secretions from the 20 control animals. In the single-aspiration group, pepsin was found in all of the tracheal secretions from the 23 animals at 2 hours and 4 hours and 21 of the 23 animals at 6 hours. CONCLUSIONS: The immunoassay used in this animal model study was able to detect pepsin in >90% of the experimental animals' tracheal secretions after multiple or single forced aspirations of gastric juice. The extent to which pepsin can be detected in the tracheal secretions of acutely ill tube-fed humans requires investigation, as does the extent to which clinical outcomes are affected by pepsin-positive tracheal secretions.

Pepsin as a marker for pulmonary aspiration.

BACKGROUND: Although assessment for aspiration of small volumes of gastric contents in tube-fed patients receiving mechanical ventilation is important, available methods for this purpose are not wholly satisfactory. A potential method is immunoassay of tracheal secretions for the gastric enzyme pepsin. OBJECTIVES: To determine the frequency with which pepsin in suctioned tracheal secretions from acutely ill, tube-fed patients receiving mechanical ventilation could be detected via an immunoassay. METHODS: A convenience sample of 136 specimens of suctioned tracheal secretions was collected from 30 acutely ill, tube-fed adults receiving mechanical ventilation. Multiple samples were obtained from 26 of the 30 patients (range, 2-11 per subject). An immunoassay with rooster polyclonal antibodies to purified human pepsin was used to detect pepsin in the secretions. RESULTS: Fourteen specimens tested positive for pepsin. Secretions from 5 patients accounted for the 14 pepsin-positive results. A significant relationship was found between the position of the head of the bed and the presence of pepsin in tracheal secretions (P<.001). Of the 14 pepsin-positive specimens, 13 (92.9%) were obtained from subjects in a flat position. CONCLUSIONS: A pepsin immunoassay can be used to detect pepsin in human tracheal secretions. If pepsin in tracheal secretions is considered an indicator of aspiration of gastric contents, aspiration occurred in 5 of the 30 subjects. A flat position is strongly associated with the presence of pepsin in tracheal secretions.