Gastric emptying measurement of liquid nutrients using the (13)C-octanoate breath test in critically ill patients: a comparison with scintigraphy.

PURPOSE: Scintigraphy is considered the most accurate technique for the measurement of gastric emptying (GE) but, for patients in the intensive care unit, it is technically demanding, involves radiation and can interfere with care. The (13)C-octanoate breath test ((13)C-OBT) is a simple, non-invasive technique that does not involve radiation exposure. AIM: To evaluate the performance of the (13)C-OBT in the assessment of GE in critically ill patients. METHODS: The GE was assessed in 33 mechanically ventilated patients (23 M; 54.3 ± 3.0 yrs; APACHE II: 22.0 ± 1.1). Following test meal administration (100 ml Ensure(®)), concurrent scintigraphic measurement and breath samples ((13)C-OBT) were collected over 4 h. Scintigraphic meal retention was determined and the gastric emptying coefficient (GEC) and half emptying time [t50(BT)] were calculated for the (13)C-OBT. Delayed GE was defined as meal retention >13 % at 180 min. RESULTS: Delayed GE was identified in 27/33 patients. Meal retention correlated modestly with t50(BT) (r = 0.55-0.66; P < 0.001) and well with GEC (r = -0.63 to -0.74; P < 0.0001). The strength of agreement between the two techniques was highest between GEC and retention at 120 min. The best cut-off GEC for defining delayed GE was 3.25 (AUC = 0.75; 95 % CI = 0.52-0.99; P = 0.05), with 89 % sensitivity and 67 % specificity to detect delayed GE. The GE was delayed in all (23/23) patients with feed intolerance (GRV > 250 ml) on scintigraphy and 91 % (21/23) patients on (13)C-OBT. CONCLUSION: In critical illness, there was a correlation between (13)C-OBT and gastric scintigraphy, with GEC performing as a better and more sensitive marker of detecting delayed GE than t50. However the relatively wide 95 % confidence intervals suggest that (13)C-OBT is more suitable as a technique to assess GE in a group setting for research studies rather than for individual patients in clinical practice.

Plasma erythromycin concentrations predict feeding outcomes in critically ill patients with feed intolerance.

OBJECTIVE: Motilin receptors are rapidly down-regulated by exposure to erythromycin, and its progressive loss of clinical prokinetic effect may relate to higher plasma drug concentrations. This study aimed to evaluate the relationship between plasma erythromycin concentrations and feeding outcomes in critically ill patients. DESIGN: Observational comparative study. SETTING: Tertiary critical care unit. PATIENTS: Twenty-nine feed-intolerant (gastric residual volume >250 mL) mechanically ventilated, medical critically ill patients. INTERVENTIONS: Patients received intravenous erythromycin 200 mg twice daily for feed intolerance. MEASUREMENTS: Plasma erythromycin concentrations were measured 1 and 7 hrs after drug administration on day 1. Success of enteral feeding, defined as 6-hourly gastric residual volume of ≤ 250 mL with a feeding rate ≥ 40 mL/h, was recorded over 7 days. RESULTS: At day 7, 38% (11 of 29) of patients were feed tolerant. Age, Acute Physiology and Chronic Health Evaluation scores, serum glucose concentrations, and creatinine clearance were comparable between successful and failed feeders. Both plasma erythromycin concentrations at 1 and 7 hrs after drug administration were significantly lower in successfully treated patients compared to treatment failures (1 hr: 3.7 ± 0.8 mg/L vs. 7.0 ± 1.0 mg/L, p = .02; and 7 hr: 0.7 ± 0.3 mg/L vs. 2.8 ± 0.6 mg/L, p = .01). There was a negative correlation between the number of days to failure of feeding and both the 1-hr (r = -.47, p = .049) and 7-hr (r = -.47, p = .050) plasma erythromycin concentrations. A 1-hr plasma concentration of >4.6 mg/L had 72% sensitivity and 72% specificity, and a 7-hr concentration of ≥ 0.5 mg/L had 83% sensitivity and 72% specificity in predicting loss of response to erythromycin. CONCLUSIONS: In critically ill feed-intolerant patients, there is an inverse relationship between plasma erythromycin concentrations and the time to loss of clinical motor effect. This suggests that erythromycin binding to motilin receptors contributes to variations in the duration of prokinetic response. The use of lower doses of erythromycin and tailoring the dose of erythromycin according to plasma concentrations may be useful strategies to reduce erythromycin tachyphylaxis.

Impact of bolus volume on small intestinal intra-luminal impedance in healthy subjects.

AIM: To assess the impact of bolus volume on the characteristics of small intestinal (SI) impedance signals. METHODS: Concurrent SI manometry-impedance measurements were performed on 12 healthy volunteers to assess the pattern of proximal jejunal fluid bolus movement over a 14 cm-segment. Each subject was given 34 boluses of normal saline (volume from 1 to 30 mL) via the feeding tube placed immediately above the proximal margin of the studied segment. A bolus-induced impedance event occurred if there was > 12% impedance drop from baseline, over > or = 3 consecutive segments within 10 s of bolus injection. A minor or major impedance event was defined as a duration of impedance drop < 60 s or > or = 60 s, respectively. RESULTS: The minimum volume required for a detectable SI impedance event was 2 mL. A direct linear relationship between the SI bolus volume and the occurrence of impedance events was noted until SI bolus volume reached 10 mL, a volume which always produced an impedance flow event. There was a moderate correlation between the bolus volume and the duration of impedance drop (r = 0.63, P < 0.0001) and the number of propagated channels (r = 0.50, P < 0.0001). High volume boluses were associated with more major impedance events (> or = 10 mL boluses = 63%, 3 mL boluses = 17%, and < 3 mL boluses = 0%, P = 0.02). CONCLUSION: Bolus volume had an impact on the type and length of propagation of SI impedance events and a threshold of 2 mL is required to produce an event.

The impact of delaying enteral feeding on gastric emptying, plasma cholecystokinin, and peptide YY concentrations in critically ill patients.

BACKGROUND: Enteral nutrient (EN) deprivation slows gastric emptying (GE) and increases plasma cholecystokinin (CCK) concentrations in healthy humans and may potentially contribute to the delayed GE in the critically ill. This study examined the impact of delayed feeding on GE, plasma CCK, and peptide YY (PYY) concentrations in the critically ill. DESIGN: Randomized controlled trial. SETTING: Mixed medical and surgical intensive care unit (ICU). INTERVENTIONS: Twenty-eight critically ill patients were randomized to receive EN either within 24 hrs of admission ("early feeding": 54.9 +/- 3.3 yrs; Acute Physiology and Chronic Health Evaluation (APACHE) II = 23.0 +/- 1.8) or on day 4 of admission after GE assessment ("delayed feeding": 56.1 +/- 4.2 yrs, APACHE II = 21.7 +/- 1.8). GE of 100 ml of Ensure was measured using scintigraphy on day 4 of admission. Blood was sampled for measurement of plasma CCK, PYY, and glucose concentrations. RESULTS: Demographics, APACHE II score, use of inotrope and morphine sedation were similar between the groups. The mean administered/prescribed caloric ratio in the "early feeding" group was 72 +/- 4%. There were no differences in the retention of meal, intragastric meal distribution, proportion of patients with delayed GE (9/14 vs. 9/14), and plasma CCK and PYY concentrations during fasting and postprandially between the two groups. There was no relationship between the number of calories received and percentage of meal retention at 240 min (p > .05). However, delayed feeding was associated with longer duration of mechanical ventilations (13.7 +/- 1.9 vs. 9.2 +/- .9 days, p = .049) and length of stay in ICU (15.9 +/- 1.9 vs. 11.3 +/- 0.8 days, p = .048), but no difference in mortality. CONCLUSIONS: In critical illness, delayed enteral feeding appears to have little impact on either GE or the enterogastric feedback hormones. However, the association between delayed feeding and increased duration of ventilation and length of stay in the ICU supports the current recommendation that enteral nutrition should be commenced early.

Diminished functional association between proximal and distal gastric motility in critically ill patients.

OBJECTIVE: This study examined the effects of critical illness on the relationship between proximal and distal gastric motor activity during fasting and duodenal nutrient stimulation. DESIGN: Prospective, case-controlled study. PATIENTS AND PARTICIPANTS: Ten critically ill patients and ten healthy volunteers. INTERVENTIONS: Concurrent proximal gastric (barostat) and antro-pyloro-duodenal (manometry) motility were recorded during fasting and during two 60-min duodenal nutrient infusions (Ensure at 1 kcal/min and 2 kcal/min) in random order, separated by a 2-h wash-out period. RESULTS: Baseline proximal gastric volumes were similar between the two groups. At 10 min nutrient-induced fundic relaxation was lower in patients than healthy subjects (45 +/- 26 vs. 196 +/- 29 ml). In patients the frequency and volume amplitude of fundic waves were also lower. There were fewer propagated antral waves in patients than in healthy subjects during both fasting and nutrient infusion. These were more retrograde, shorter in length and associated with a pyloric contraction. The proportion of fundic waves followed by a distally propagated antral wave was significantly less in patients (0%, 0-8%) than controls 36% (11-44%). CONCLUSIONS: In critical illness, in addition to impairment of proximal and distal gastric motor activity, the association between the two gastric regions is abnormal. This disturbance may interfere with meal distribution and further contribute to slow gastric emptying in these patients.

The effects of sedation on gastric emptying and intra-gastric meal distribution in critical illness.

OBJECTIVE: To evaluate the effects of sedation with morphine and midazolam (M&M) versus propofol on gastric emptying in critically ill patients. DESIGN: Descriptive study. SETTING: Mixed medical and surgical intensive care unit. PATIENTS: Thirty-six unselected, mechanically ventilated, critically ill patients. INTERVENTIONS: Gastric scintigraphic data were analysed retrospectively according to whether patients were receiving M&M (n=20; 14M, 6F) or propofol (n=16; 7M, 9F). Measurements were performed over 4 h after administration of 100 ml of Ensure, labelled with 20 MBq Tc99m. MEASUREMENTS AND RESULTS: Gastric half-emptying time (t1/2) and total and regional (proximal and distal stomach) meal retention (%) were assessed. The median t1/2 of patients receiving M&M (153 (IQR: 72-434) min) was significantly longer than that of patients receiving propofol (58 (34-166) min, p=0.02). Total gastric retention was greater in patients receiving M&M compared to those receiving propofol (p<0.01). Proximal (p=0.02) but not distal (p=0.80) gastric retention was greater in patients who received M&M. Patients who received M&M were more likely to have >or=5% meal retention at 240 min than those treated with propofol (95% (19/20) vs. 56% (9/16); p=0.01). Changes in blood glucose concentrations during the study were similar in the two groups. CONCLUSIONS: In critical illness, patients receiving M&M for sedation are more likely to have slow gastric emptying, and proximal meal retention than those receiving propofol. The apparent beneficial effects of propofol-based sedation need confirmation by a prospective randomised controlled study.

The relationship between gastric emptying, plasma cholecystokinin, and peptide YY in critically ill patients.

BACKGROUND: Cholecystokinin (CCK) and peptide YY (PYY) are released in response to intestinal nutrients and play an important physiological role in regulation of gastric emptying (GE). Plasma CCK and PYY concentrations are elevated in critically ill patients, particularly in those with a history of feed intolerance. This study aimed to evaluate the relationship between CCK and PYY concentrations and GE in critical illness. METHODS: GE of 100 mL of Ensure meal (106 kcal, 21% fat) was measured using a 13C-octanoate breath test in 39 mechanically ventilated, critically ill patients (24 males; 55.8 +/- 2.7 years old). Breath samples for 13CO2 levels were collected over the course of 4 hours, and the GE coefficient (GEC) (normal = 3.2 to 3.8) was calculated. Measurements of plasma CCK, PYY, and glucose concentrations were obtained immediately before and at 60 and 120 minutes after administration of Ensure. RESULTS: GE was delayed in 64% (25/39) of the patients. Baseline plasma CCK (8.5 +/- 1.0 versus 6.1 +/- 0.4 pmol/L; P = 0.045) and PYY (22.8 +/- 2.2 versus 15.6 +/- 1.3 pmol/L; P = 0.03) concentrations were higher in patients with delayed GE and were inversely correlated with GEC (CCK: r = -0.33, P = 0.04, and PYY: r = -0.36, P = 0.02). After gastric Ensure, while both plasma CCK (P = 0.03) and PYY (P = 0.02) concentrations were higher in patients with delayed GE, there was a direct relationship between the rise in plasma CCK (r = 0.40, P = 0.01) and PYY (r = 0.42, P < 0.01) from baseline at 60 minutes after the meal and the GEC. CONCLUSION: In critical illness, there is a complex interaction between plasma CCK, PYY, and GE. Whilst plasma CCK and PYY correlated moderately with impaired GE, the pathogenetic role of these gut hormones in delayed GE requires further evaluation with specific antagonists.

Prokinetic therapy for feed intolerance in critical illness: one drug or two?

OBJECTIVE: To compare the efficacy of combination therapy, with erythromycin and metoclopramide, to erythromycin alone in the treatment of feed intolerance in critically ill patients. DESIGN: Randomized, controlled, double-blind trial. SETTING: Mixed medical and surgical intensive care unit. PATIENTS: Seventy-five mechanically ventilated, medical patients with feed intolerance (gastric residual volume > or =250 mL). INTERVENTIONS: Patients received either combination therapy (n = 37; 200 mg of intravenous erythromycin twice daily + 10 mg of intravenous metoclopramide four times daily) or erythromycin alone (n = 38; 200 mg of intravenous erythromycin twice daily) in a prospective, randomized fashion. Gastric feeding was re-commenced and 6-hourly gastric aspirates performed. Patients were studied for 7 days. Successful feeding was defined as a gastric residual volume <250 mL with the feeding rate > or =40 mL/hr, over 7 days. Secondary outcomes included daily caloric intake, vomiting, postpyloric feeding, length of stay, and mortality. MEASUREMENTS AND MAIN RESULTS: Demographic data; use of inotropes, opioids, or benzodiazepines; and pretreatment gastric residual volume were similar between the two groups. The gastric residual volume was significantly lower after 24 hrs of treatment with combination therapy, compared with erythromycin alone (136 +/- 23 mL vs. 293 +/- 45 mL, p = .04). Over the 7 days, patients treated with combination therapy had greater feeding success, received more daily calories, and had a lower requirement for postpyloric feeding, compared with erythromycin alone. Tachyphylaxis occurred in both groups but was less with combination therapy. Sedation, higher pretreatment gastric residual volume, and hypoalbuminemia were significantly associated with a poor response. There was no difference in the length of hospital stay or mortality rate between the groups. Watery diarrhea was more common with combination therapy (20 of 37 vs. 10 of 38, p = .01) but was not associated with enteric infections, including Clostridium difficile. CONCLUSIONS: In critically ill patients with feed intolerance, combination therapy with erythromycin and metoclopramide is more effective than erythromycin alone in improving the delivery of nasogastric nutrition and should be considered as the first-line treatment.

Mechanisms underlying feed intolerance in the critically ill: implications for treatment.

Malnutrition is associated with poor outcomes in critically ill patients. Although nutritional support is yet to be proven to improve mortality in non-malnourished critically ill patients, early enteral feeding is considered best practice. However, enteral feeding is often limited by delayed gastric emptying. The best method to clinically identify delayed gastric emptying and feed intolerance is unclear. Gastric residual volume (GRV) measured at the bedside is widely used as a surrogate marker for gastric emptying, but the value of GRV measurement has recently been disputed. While the mechanisms underlying delayed gastric emptying require further investigation, recent research has given a better appreciation of the pathophysiology. A number of pharmacological strategies are available to improve the success of feeding. Recent data suggest a combination of intravenous metoclopramide and erythromycin to be the most successful treatment, but novel drug therapies should be explored. Simpler methods to access the duodenum and more distal small bowel for feed delivery are also under investigation. This review summarises current understanding of the factors responsible for, and mechanisms underlying feed intolerance in critical illness, together with the evidence for current practices. Areas requiring further research are also highlighted.

Erythromycin is more effective than metoclopramide in the treatment of feed intolerance in critical illness.

OBJECTIVE: This study aimed to a) compare the efficacy of metoclopramide and erythromycin in the treatment of feed intolerance in critical illness; and b) determine the effectiveness of "rescue" combination therapy in patients who fail monotherapy. DESIGN: Randomized controlled trial. SETTING: Level III mixed medical and surgical intensive care unit. PATIENTS: Ninety mechanically ventilated, medical patients with feed-intolerance (gastric residual volume>or=250 mL). INTERVENTIONS: Patients received either metoclopramide 10 mg intravenously four times daily (n=45) or erythromycin 200 mg intravenously twice a day (n=45) in a double-blind, randomized fashion. After the first dose, nasogastric feeding was commenced and 6-hourly nasogastric aspirates were performed. If a gastric residual volume>or=250 mL recurred on treatment, open-label, combination therapy was given. Patients were studied for 7 days. Successful feeding was defined as 6-hourly gastric residual volume<250 mL with a feeding rate>or=40 mL/hr. MEASUREMENTS AND MAIN RESULTS: Demographic data, blood glucose levels, and use of inotropes, opioids, and benzodiazepines were similar between the two groups. After 24 hrs of treatment, both monotherapies reduced the mean gastric residual volume (metoclopramide, 830+/-32 mL to 435+/-30 mL, p<.0001; erythromycin, 798+/-33 mL to 201+/-19 mL, p<.0001) and improved the proportion of patients with successful feeding (metoclopramide=62% and erythromycin=87%). Treatment with erythromycin was more effective than metoclopramide, but the effectiveness of both treatments declined rapidly over time. In patients who failed monotherapy, rescue combination therapy was highly effective (day 1=92%) and maintained its effectiveness for the study duration (day 6=67%). High pretreatment gastric residual volume was associated with poor response to prokinetic therapy. CONCLUSIONS: In critical illness, erythromycin is more effective than metoclopramide in treating feed intolerance, but the rapid decline in effectiveness renders both treatments suboptimal. Rescue combination therapy is highly effective, and further study is required to examine its role as the first-line therapy.

Proximal gastric motility in critically ill patients with type 2 diabetes mellitus.

AIM: To investigate the proximal gastric motor response to duodenal nutrients in critically ill patients with long-standing type 2 diabetes mellitus. METHODS: Proximal gastric motility was assessed (using a barostat) in 10 critically ill patients with type 2 diabetes mellitus (59 +/- 3 years) during two 60-min duodenal infusions of Ensure (1 and 2 kcal/min), in random order, separated by 2 h fasting. Data were compared with 15 non-diabetic critically ill patients (48 +/- 5 years) and 10 healthy volunteers (28 +/- 3 years). RESULTS: Baseline proximal gastric volumes were similar between the three groups. In diabetic patients, proximal gastric relaxation during 1 kcal/min nutrient infusion was similar to non-diabetic patients and healthy controls. In contrast, relaxation during 2 kcal/min infusion was initially reduced in diabetic patients (P < 0.05) but increased to a level similar to healthy humans, unlike non-diabetic patients where relaxation was impaired throughout the infusion. Duodenal nutrient stimulation reduced the fundic wave frequency in a dose-dependent fashion in both the critically ill diabetic patients and healthy subjects, but not in critically ill patients without diabetes. Fundic wave frequency in diabetic patients and healthy subjects was greater than in non-diabetic patients. CONCLUSION: In patients with diabetes mellitus, proximal gastric motility is less disturbed than non-diabetic patients during critical illness, suggesting that these patients may not be at greater risk of delayed gastric emptying.

Feed intolerance in critical illness is associated with increased basal and nutrient-stimulated plasma cholecystokinin concentrations.

OBJECTIVE: Delayed gastric emptying and intolerance to gastric feeding occur frequently in the critically ill. In these patients, gastric motor responses to nutrients are disturbed. Cholecystokinin (CCK) slows gastric emptying. The aim of this study was to determine plasma CCK concentrations during fasting and in response to small-intestine nutrient infusion in critically ill patients. DESIGN: Randomized, controlled trial. SETTING: Level 3, mixed medical and surgical intensive care unit. SUBJECTS: A total of 31 mechanically ventilated, critically ill patients (23 men, 51 +/- 3 yrs) and 28 healthy subjects (21 men, 43 +/- 2 yrs). INTERVENTIONS: Subjects received two 60-min duodenal infusions of Ensure (complete balanced nutrition), at 1 and 2 kcal/min, in a randomized, single-blind fashion. The nutrient infusions were separated by a 2-hr "washout" period. Blood samples for measurement of plasma CCK concentrations were obtained immediately before and every 20 mins during nutrient infusion. MEASUREMENTS AND MAIN RESULTS: Baseline and nutrient-stimulated plasma CCK concentrations were higher in critically ill patients compared with healthy subjects (p < .001). The magnitude of the rise in plasma CCK in response to nutrients was also greater in the critically ill (p < .01). Of the 23 patients who received enteral nutrition before the study, nine were intolerant of gastric feeding. In these patients, both the baseline plasma CCK concentration and the magnitude of CCK increase during nutrient infusions were greater than in patients with feed tolerance (p < .002). Impaired renal function was associated with an increased baseline CCK concentration but had no effect on the CCK response to nutrients. CONCLUSIONS: Both fasting and nutrient-stimulated plasma CCK concentrations are increased in critically ill patients, particularly in those with feed intolerance. This may provide a humoral mechanism for delayed gastric emptying seen in critical illness.

Fasting and nutrient-stimulated plasma peptide-YY levels are elevated in critical illness and associated with feed intolerance: an observational, controlled study.

INTRODUCTION: Delayed gastric emptying and feed intolerance occur frequently in the critically ill. In these patients, gastric motor responses to nutrients are disturbed. Peptide YY (PYY) slows gastric emptying. The aim of this study was to determine fasting and nutrient-stimulated plasma PYY concentrations and their relationship to cholecystokinin (CCK) in critically ill patients. METHODS: Studies were performed in 19 unselected mechanically ventilated critically ill patients (12 males; 48 +/- 7 years old) in a randomised, single-blind fashion. Subjects received a 60-minute duodenal infusion of Ensure at either 1 or 2 kcal/minute. Blood samples were collected at baseline and at 20, 40, 60, and 180 minutes following commencement of the nutrient infusion for the measurement of plasma PYY and CCK concentrations (using radioimmunoassay). Patient data were compared to 24 healthy subjects (17 males; 43 +/- 2 years old). RESULTS: Fasting PYY concentration was higher in patients (P < 0.05), particularly in those with feed intolerance (P < 0.05). Plasma PYY concentrations were higher in patients during nutrient infusion (area under the curve [AUC] at 1 kcal/minute: 2,265 +/- 718 versus 1,125 +/- 138 pmol/l.min, P < 0.05; at 2 kcal/minute: 2,276 +/- 303 versus 1,378 +/- 210 pmol/l.min, P = 0.01) compared to healthy subjects. The magnitude of PYY elevation was greater in patients during the 1 kcal/minute infusion (AUC: 441 +/- 153 versus 186 +/- 58 pmol/l.min, P < 0.05), but not the 2 kcal/minute infusion. Fasting and nutrient-stimulated plasma CCK concentrations were higher in patients (P < 0.05). There was a relationship between plasma PYY and CCK concentrations during fasting (r = 0.52, P < 0.05) and nutrient infusion (r = 0.98, P < 0.0001). CONCLUSION: In critical illness, both fasting and nutrient-stimulated plasma PYY concentrations are elevated, particularly in patients with feed intolerance, in conjunction with increased CCK concentrations.

Proximal gastric response to small intestinal nutrients is abnormal in mechanically ventilated critically ill patients.

AIM: To determine the response of the proximal stomach to small intestinal nutrients in critically ill patients. METHODS: Proximal gastric motility was measured in 13 critically ill patients (49.3 +/- 4.7 years) and 12 healthy volunteers (27.7 +/- 2.9 years) using a barostat technique. Recordings were performed at baseline, during a 60-min intra-duodenal infusion of Ensure (2 kcal/min), and for 2 h following the infusion. Minimum distending pressure (MDP), intra-bag volume and fundic wave activity were determined. RESULTS: The MDP was higher in patients (11.7 +/- 1.1 vs 7.8 +/- 0.7 mmHg; P < 0.01). Baseline intra-bag volumes were similar in the 2 groups. In healthy subjects, a 'bimodal' proximal gastric volume response was observed. In patients, the initial increase in proximal gastric volume was small and delayed, but eventually reached a maximal volume similar to that of healthy subjects. In healthy subjects, the proximal gastric volume rapidly returned to baseline level after nutrient infusion (median 18 min). In contrast, the recovery of volume to baseline was delayed in critically ill patients (median 106 min). In 6 patients, the volume had not returned to baseline level 2 hours after nutrient infusion. In patients, fundic volume waves were less frequent (P < 0.05) and had lower amplitude (P < 0.001), compared to healthy subjects. CONCLUSION: In critical illness, proximal gastric motor responses to small intestinal nutrient stimulation are abnormal.

Long-standing type II diabetes mellitus is not a risk factor for slow gastric emptying in critically ill patients.

OBJECTIVE: Delayed gastric emptying (GE) is common both in critical illness and in patients with diabetes mellitus (DM). The effect of DM on the incidence of slow GE in these patients is unknown. We evaluated the effect of DM on liquid GE in critically ill patients. METHODS: Retrospective analysis of GE using a standard [13C]octanoic acid breath test in 12 type 2 DM patients compared with (a) 44 critically ill patients without DM, including (b) a subgroup of 15 age- and sex-matched patients and (c) 15 healthy volunteers. We determined the gastric emptying coefficient (GEC) and the gastric half-emptying time (t50). Mean APACHE II scores, blood glucose levels and use of morphine were similar between patient groups. RESULTS: GE was faster in critically ill patients with DM (t50 122 +/- 11 min, GEC: 3.8 +/- 0.3) than in patients without DM (t50 168 +/- 16 min, GEC 2.8 +/- 0.1) and in age- and sex-matched controls (t50 165 +/- 13 min, GEC 2.7 +/- 0.2) and was similar to that in healthy volunteers (t50 148 +/- 13 min, GEC 3.5 +/- 0.1). The proportion of patients with slow emptying (GEC < 3.2) was greater in non-DM (all = 56%, matched = 60%) than in DM patients (25%) and healthy subjects (26%). CONCLUSION: Long-standing type diabetes mellitus is not a risk factor for slow GE in critically ill patients.