GI complications in patients receiving mechanical ventilation

When should stress ulcer prophylaxis be used in the ICU?

PURPOSE OF REVIEW

To discuss the risk factors and underlying illnesses that play a role in the pathophysiology of stress ulcer, and to evaluate the evidence pertaining to stress ulcer-related bleeding prophylaxis in critically ill patients.

RECENT FINDINGS

The use of stress ulcer prophylaxis is common in critical care medicine and is a major challenge to physicians in the ICU. The mechanism of stress ulcer is believed to be multifactorial, yet remains incompletely understood. The most widely used drugs for stress ulcer prophylaxis are intravenous histamine2-receptor antagonists. They raise gastric pH, but are associated with the development of tolerance, possible drug interactions, and neurologic manifestations. Sucralfate, which can be administered by the nasogastric route, can protect the gastric mucosa without raising pH, but may decrease absorption of concomitantly administered oral medications. Proton pump inhibitors are the most potent acid-inhibiting pharmacologic agents available. Proton pump inhibitors are at least as effective as histamine2-receptor antagonists, as a limited number of clinical trials have demonstrated. However, these trials were small, lacked an active comparator, varied in the number of risk factors, and used a different definition of clinically important bleeding than previously established.

SUMMARY

Routine prophylaxis against stress ulcers in the ICU is not well justified by current evidence. Patients at risk of stress ulcer-related bleeding are most likely to benefit from prophylaxis. Thus, healthcare professionals should continue to evaluate risk and assess the need for stress ulcer-related prophylaxis.

Clinical outcomes in patients with ICU-related pancreatitis

AIM: To identify risk factors predictive of intensive care unit (ICU) mortality in patients with ventilator-related pancreatitis. The clinical outcomes of patients with ventilator-related pancreatitis were compared with those of patients with pancreatitis-related respiratory failure as well as controls.

METHODS: One hundred and forty-eight patients with respiratory failure requiring mechanical ventilation and concomitant acute pancreatitis were identified from a prospectively collected dataset of 9108 consecutive patients admitted with respiratory failure over a period of five years. Sixty patients met the criteria for ventilator-related pancreatitis, and 88 (control patients), for pancreatitis-related respiratory failure.

RESULTS: Mortality rate in ventilator-related pancreatitis was comparable to that in ICU patients without pancreatitis by case-control methodology (P = 0.544). Multivariate logistic regression analysis identified low PaO₂/FiO₂ (OR: 1.032, 95% CI: 1.006-1.059, P = 0.016) as an independent risk factor for mortality in patients with ventilator-related pancreatitis. The mortality rate in patients with ventilator-related pancreatitis was lower than that in patients with acute pancreatitis-related respiratory failure (P < 0.001).

CONCLUSION: We found that low PaO₂/FiO₂ was an independent clinical parameter predictive of ICU mortality in patients with ventilator-related pancreatitis.

Stress-induced ulcer bleeding in critically ill patients

Increased knowledge of risk factors and improved ICU care has decreased the incidence of stress-related bleeding. Not all critically ill patients need prophylaxis for SRMD and withholding such prophylaxis in suitable low-risk candidates is a reasonable and cost-effective approach. Mechanical ventilation for more than 48 hours and coagulopathy are the main risk factors for stress-induced upper GI bleeding. Although intravenous H2RAs can prevent clinically important bleeding, their benefits seem to be limited by the rapid development of tolerance. The availability of intravenous formulations of PPIs makes it possible to critically compare their prophylactic efficacy and safety to different classes of acid-suppressive agents, such as H2RAs, in critically ill patients. The appropriate dose of PPI and the role of newer PPI formulations need to be further defined along with proposed guidelines for the use of intravenous and oral/enteral formulations of PPIs in patients at risk for stress-related mucosal damage.

Effects of different peep levels on mesenteric leukocyte-endothelial interactions in rats during mechanical ventilation

INTRODUCTION

Mechanical ventilation with positive end expiratory pressure (PEEP) improves oxygenation and treats acute pulmonary failure. However, increased intrathoracic pressure may cause regional blood flow alterations that may contribute to mesenteric ischemia and gastrointestinal failure. We investigated the effects of different PEEP levels on mesenteric leukocyte-endothelial interactions.

METHODS

Forty-four male Wistar rats were initially anesthetized (Pentobarbital I.P. 50 mg/kg) and randomly assigned to one of the following groups: 1) NAIVE (only anesthesia; n=9), 2) PEEP 0 (PEEP of 0 cmH2O, n=13), 3) PEEP 5 (PEEP of 5 cmH2O, n=12), and 4) PEEP 10 (PEEP of 10 cmH2O, n=13). Positive end expiratory pressure groups were tracheostomized and mechanically ventilated with a tidal volume of 10 mL/kg, respiratory rate of 70 rpm, and inspired oxygen fraction of 1. Animals were maintained under isoflurane anesthesia. After two hours, laparotomy was performed, and leukocyte-endothelial interactions were evaluated by intravital microscopy.

RESULTS

No significant changes were observed in mean arterial blood pressure among groups during the study. Tracheal peak pressure was smaller in PEEP 5 compared with PEEP 0 and PEEP 10 groups (11, 15, and 16 cmH2O, respectively; p<0.05). After two hours of MV, there were no differences among NAIVE, PEEP 0 and PEEP 5 groups in the number of rollers (118+/-9,127+/-14 and 147+/-26 cells/10 minutes, respectively), adherent leukocytes (3+/-1,3+/-1 and 4+/-2 cells/100 microm venule length, respectively), and migrated leukocytes (2+/-1,2+/-1 and 2+/-1 cells/5,000 microm(2), respectively) at the mesentery. However, the PEEP 10 group exhibited an increase in the number of rolling, adherent and migrated leukocytes (188+/-15 cells / 10 min, 8+/-1 cells / 100 microm and 12+/-1 cells / 5,000 microm(2), respectively; p<0.05).

CONCLUSIONS

High intrathoracic pressure was harmful to mesenteric microcirculation in the experimental model of rats with normal lungs and stable systemic blood pressure, a finding that may have relevance for complications related to mechanical ventilation.

Gastrointestinal symptoms in intensive care patients

BACKGROUND

Gastrointestinal (GI) problems are not uniformly assessed in intensive care unit (ICU) patients and respective data in available literature are insufficient. We aimed to describe the prevalence, risk factors and importance of different GI symptoms.

METHODS

We prospectively studied all patients hospitalized to the General ICU of Tartu University Hospital in 2004-2007.

RESULTS

Of 1374 patients, 62 were excluded due to missing data. Seven hundred and seventy-five (59.1%) patients had at least one GI symptom at least during 1 day of their stay, while 475 (36.2%) suffered from more than one symptom. Absent or abnormal bowel sounds were documented in 542 patients (41.3%), vomiting/regurgitation in 501 (38.2%), high gastric aspirate volume in 298 (22.7%), diarrhoea in 184 (14.0%), bowel distension in 139 (10.6%) and GI bleeding in 97 (7.4%) patients during their ICU stay. Absent or abnormal bowel sounds and GI bleeding were associated with significantly higher mortality. The number of simultaneous GI symptoms was an independent risk factor for ICU mortality. The ICU length of stay and mortality of patients who had two or more GI symptoms simultaneously were significantly higher than in patients with a maximum of one GI symptom.

CONCLUSION

GI symptoms occur frequently in ICU patients. Absence of bowel sounds and GI bleeding are associated with impaired outcome. Prevalence of GI symptoms at the first day in ICU predicts the mortality of the patients.

Gastrointestinal complications in critically ill patients: what differs between adults and children?

PURPOSE OF REVIEW

The objective of this review has been to analyse and compare the causes, incidence, severity and treatment of gastrointestinal complications in critically ill children and adults.

RECENT FINDINGS

The incidence of gastrointestinal complications in critically ill patients published in the literature is very variable owing to the absence of unified diagnostic criteria both in children and adults. The incidence of gastrointestinal complications related to nutrition appears to be lower in children than in adults, and there are no differences in the incidence of gastrointestinal complications between gastric and transpyloric nutrition except with respect to the volume of gastric residues. The most important risk factors for digestive tract complications are shock and the administration of drugs (catecholamines, sedatives and muscle relaxants). Altered gastrointestinal motility is the principal mechanism underlying an excessive gastric residue, abdominal distension and constipation.

SUMMARY

Gastrointestinal complications limit the efficacy of enteral nutrition in the critically ill patient and can affect morbidity and mortality. Consensus must be reached on the definition of the criteria of excessive gastric residues, constipation and diarrhoea, and studies must be performed that evaluate the efficacy of prokinetic agents on altered gastrointestinal motility and the effects of diet and laxatives on constipation in the critically ill adult and child.

Effects of esomeprazole premedication on gastric pH during laparoscopic surgery

BACKGROUND

The use of CO2 for pneumoperitoneum during laparoscopic surgery provokes a decrement in the gastric pH. Since the incidence rate of PONV increases after laparoscopic surgery, the possibility of lung aspiration of gastric juice with a low pH during a postanesthetic emergence may increase and this could be fatal for the patient. We conducted this study to determine the effects of esomeprazole premedication on inhibiting the decrement of the gastric pH during laparoscopic surgery.

METHODS

40 adult patients with no underlying diseases were chosen and 20 patients each were grouped as C (the control group) and E (the esomeprazole group). In both group, 0.2 mg glycopyrrolate was given intramuscularly 30 minutes prior to the surgery. In group E, esomeprazole was given orally 2 hours prior to the surgery. The pH, PaCO2, and PETCO2 were measured via pH probe, an ABGA and an capnogram at preinsufflation and 15, 30 and 60 minutes after the CO2 insufflation and right before CO2 exhaustion (predeflation).

RESULTS

Comparing the measurements of the gastric pH between group E and group C, all the results showed a significant increase in group E (P < 0.05). The difference of the PaCO2 and PETCO2 in the two groups was not significance.

CONCLUSIONS

In contrast to the decrease in the gastric pH as the PaCO2 and PETCO2 increased in group C, the gastric pH in group E remained high until the end of the surgery despite the increase in the PaCO2 and PETCO2. Esomeprazole premedication seem to have an effect for inhibiting the gastric pH decrement regardless of the increase in the PaCO2 and PETCO2 during laparoscopic surgery.

Incidence and risk factors of upper gastrointestinal bleeding in mechanically ventilated children

OBJECTIVE

To identify the incidence and factors related to upper gastrointestinal (UGI) bleeding in children requiring mechanical ventilation for longer than 48 hrs.

DESIGN

Prospective analytic study.

SETTING

Ten-bed-pediatric intensive care unit of a tertiary care University Hospital.

PATIENTS

A total of 110 patients requiring mechanical ventilation for longer than 48 hrs from January 1, 2005 to December 31, 2005.

MEASUREMENTS AND RESULTS

UGI bleeding was defined by evidence of blood in nasogastric aspirates, hematemesis, or melena within 5 days of pediatric intensive care unit admission. We prospectively collected data on patient demographics, admission diagnosis, operative status, and pediatric risk of mortality score. UGI bleeding and the potential risk factors including organ failure, coagulopathy, maximum ventilator setting, enteral feeding, stress ulcer prophylaxis as well as sedation were daily monitored. Of the 110 patients who required mechanical ventilation for >48 hrs, the incidence of UGI bleeding was 51.8%, in which 3.6% of the cases presented with clinically significant bleeding (shock, requiring blood transfusion and/or surgery). Significant risk factors were thrombocytopenia, prolonged partial thromboplastin time, organ failure, high pressure ventilator setting >/=25 cm H2O, and pediatric risk of mortality score >/= 10 using univariate analysis. However, the independent factors of UGI bleeding in the multivariate analysis were organ failure (relative risk = 2.85, 95% confidence interval 1.18-6.92) and high pressure ventilator setting >/=25 cm H2O (relative risk = 3.73, 95% confidence interval 1.59-8.72).

CONCLUSION

The incidence of UGI bleeding is high in children requiring mechanical ventilation. Organ failure and high pressure ventilator setting are significant risk factors for UGI bleeding.

Monosodium L-glutamate added to a high-energy, high-protein liquid diet promotes gastric emptying

BACKGROUND

Free glutamate activates taste receptors on nerves in the oral cavity to elicit a unique taste known as umami. Recently, umami taste receptors were also found in the gastric mucosa. Although reports suggest that mucosal receptors may respond to free glutamate to modulate gastric function, no evidence of any effect on gastric emptying has been documented.

OBJECTIVE

We hypothesized that glutamate may act as a modulator of gastric function. We studied the effects of L-glutamate enrichment of a protein-rich liquid meal, and similar enrichment of an equicaloric carbohydrate meal or noncaloric water, on gastric emptying.

DESIGN

Ten healthy men were enrolled. Nine of the 10 subjects included in the study ingested all test meals with and without monosodium L-glutamate (MSG), and the remaining subject ingested only the protein-rich meals with and without MSG. All experimental and control liquid meals included [1-(13)C]sodium acetate as a tracer. After a test meal or water was ingested, (13)C breath tests were performed to estimate gastric emptying.

RESULTS

MSG enrichment not only resulted in a significant decrease in the mathematically simulated half-excretion (emptying) time of a protein-rich meal, but also increased the area under the curve (%dose/h) significantly. In contrast, MSG had no significant effect on the gastric emptying of a carbohydrate meal or a noncaloric water meal.

CONCLUSIONS

Enrichment with MSG facilitated gastric emptying of a protein-rich meal exclusively, which suggests that free glutamate is important for protein digestion and may be helpful in the management of delayed gastric emptying.

Gastrointestinal prophylaxis in critically ill patients

Physiologic stress associated with illness and hospitalization is known to result in gastrointestinal ulceration, especially among the critically ill. The complication of this stress-related mucosal disease could be prevented with appropriate application of pharmacologic prophylaxis. Vigilance by the nursing staff is required to properly detect and manage the condition.

Positive pressure ventilation: what is the real cost?

Positive pressure ventilation is a radical departure from the physiology of breathing spontaneously. The immediate physiological consequences of positive pressure ventilation such as haemodynamic changes are recognized, studied, and understood. There are other significant physiological interactions which are less obvious, more insidious, and may only produce complications if ventilation is prolonged. The interaction of positive pressure with airway resistance and alveolar compliance affects distribution of gas flow within the lung. The result is a wide range of ventilation efficacy throughout different areas of the lung, but the pressure differentials between alveolus and interstitium also influence capillary perfusion. The hydrostatic forces across the capillaries associated with the effects of raised venous pressures compound these changes resulting in interstitial fluid sequestration. This is increased by impaired lymphatic drainage which is secondary to raised intrathoracic pressure but also influenced by raised central venous pressure. Ventilation and PEEP promulgate further physiological derangement. In theory, avoiding these physiological disturbances in a rested lung may be better for the lung and other organs. An alternative to positive pressure ventilation might be to investigate oxygen supplementation of a physiologically neutral and rested lung. Abandoning heroic ventilation would be a massive departure from current practice but might be a more rationale approach to future practice.

Stress-related mucosal bleeding in critically ill oncology patients

Objective. To determine the incidence of stress-related mucosal bleeding (SRMB) in a critically ill oncology population receiving stress ulcer prophylaxis (SUP) with either a histamine-2 receptor antagonist (H2RA) or proton pump inhibitor (PPI). Design. Single-center, prospective, observational study.

Setting. Fifty-two bed medical-surgical intensive care unit of an academic oncology institution. Patients. A convenience sample of 100 medical and surgical critically ill oncology patients who received intensive care for more than 24 hours and at least one dose of a H2RA or PPI for prevention of SRMB.

Interventions. None.

Measurements and Main Results. Patients were followed throughout their intensive care unit stay for the development of an overt and/or clinically significant gastrointestinal (GI) bleed. More patients received a PPI (n = 81) in contrast to a H2RA (n = 19) for SUP. Overall, 94 patients (94%) had at least one risk factor for a SRMB with four patients (4%) experiencing an event (overt bleed, n=3; clinically significant bleed, n =1). All cases of GI bleeding occurred in patients receiving a PPI. No ICU deaths were considered directly related to a GI bleed.

Conclusions. The incidence of SRMB among high-risk critically ill oncology patients receiving SUP appears low; further, large-scale trials are needed to confirm this finding. J Oncol Pharm Practice (2009) 15: 9—16.

Gastrointestinal failure score in critically ill patients: a prospective observational study

INTRODUCTION

There are no universally accepted diagnostic criteria for gastrointestinal failure in critically ill patients. In the present study we tested whether the occurrence of food intolerance (FI) and intra-abdominal hypertension (IAH), combined in a 5-grade scoring system for assessment of gastrointestinal function (the Gastrointestinal Failure [GIF] score), predicts mortality. The prognostic value of the GIF score alone and in combination with the Sequential Organ Failure Assessment (SOFA) score is evaluated, and the incidence and outcome of gastrointestinal failure is described relative to the GIF score.

METHODS

A total of 264 subsequently hospitalized patients, who were mechanically ventilated on admission and stayed in the intensive care unit (ICU) for longer than 24 hours, were prospectively studied. GIF score was documented daily as follows: 0 = normal gastrointestinal function; 1 = enteral feeding with under 50% of calculated needs or no feeding 3 days after abdominal surgery; 2 = FI or IAH; 3 = FI and IAH; and 4 = abdominal compartment syndrome (ACS). Admission parameters and mean GIF and SOFA scores for the first 3 days were used to predict ICU outcome.

RESULTS

FI developed in 58.3%, IAH in 27.3%, and both together in 22.7% of patients. The mean GIF score for the first 3 days in the ICU was identified as an independent risk factor for mortality (odds ratio = 3.02, 95% confidence interval = 1.63 to 5.59; P < 0.001). The GIF score integrated into the SOFA score allowed better prediction of ICU mortality than did the SOFA score alone, and was an independent predictor of mortality (odds ratio = 1.49, 95% confidence interval = 1.28 to 1.74; P < 0.001). The development of gastrointestinal failure (FI plus IAH) was associated with significantly higher ICU and 90-day mortality.

CONCLUSION

The GIF score is useful for classifying information on the gastrointestinal system. The mean GIF score during the first 3 days in the ICU had high prognostic value for ICU mortality. Development of gastrointestinal failure is associated with significantly impaired outcome.

Opioid-induced constipation in intensive care patients: relief in sight?

Constipation is the most common gastrointestinal complication associated with opioid therapy in chronic pain patients, and also frequently occurs in sedated intensive care unit patients. Conventional therapy may not provide sufficient relief from constipation, which can be severe enough to limit opioid use or the dose. In a recent study on terminally ill patients suffering from laxative-resistant opioid-induced constipation, Thomas and colleagues demonstrated subcutaneous methylnaltrexone to rapidly induce defecation. This appealing result might also have favourable prospects for intensive care patients, as their outcome is often codetermined by recovery of bowel functioning.

Noninvasive mechanical ventilation may be useful in treating patients who fail weaning from invasive mechanical ventilation: a randomized clinical trial

INTRODUCTION

The use of noninvasive positive-pressure mechanical ventilation (NPPV) has been investigated in several acute respiratory failure situations. Questions remain about its benefits when used in weaning patients from invasive mechanical ventilation (IMV). The objective of this study was to evaluate the use of bi-level NPPV for patients who fail weaning from IMV.

METHODS

This experimental randomized clinical trial followed up patients undergoing IMV weaning, under ventilation for more than 48 hours, and who failed a spontaneous breathing T-piece trial. Patients with contraindications to NPPV were excluded. Before T-piece placement, arterial gases, maximal inspiratory pressure, and other parameters of IMV support were measured. During the trial, respiratory rate, tidal volume, minute volume, rapid shallow breathing index, heart rate, arterial blood pressure, and peripheral oxygen saturation were measured at 1 and 30 minutes. After failing a T-piece trial, patients were randomly divided in two groups: (a) those who were extubated and placed on NPPV and (b) those who were returned to IMV. Group results were compared using the Student t test and the chi-square test.

RESULTS

Of 65 patients who failed T-piece trials, 28 were placed on NPPV and 37 were placed on IMV. The ages of patients in the NPPV and IMV groups were 67.6 +/- 15.5 and 59.7 +/- 17.6 years, respectively. Heart disease, post-surgery respiratory failure, and chronic pulmonary disease aggravation were the most frequent causes of IMV use. In both groups, ventilation time before T-piece trial was 7.3 +/- 4.1 days. Heart and respiratory parameters were similar for the two groups at 1 and 30 minutes of T-piece trial. The percentage of complications in the NPPV group was lower (28.6% versus 75.7%), with lower incidences of pneumonia and tracheotomy. Length of stay in the intensive care unit and mortality were not statistically different when comparing the groups.

CONCLUSION

The results suggest that NPPV is a good alternative for ventilation of patients who fail initial weaning attempts. NPPV reduces the incidence of pneumonia associated with mechanical ventilation and the need for tracheotomy.

TRIAL REGISTRATION

CEP HCPA (02-114).

Future expectations in the prophylaxis of intestinal bleeding

Prophylaxis of gastrointestinal bleeding is attempted in widely varying situations. In NSAID-induced peptic ulcer, the advantage of selective cyclooxygenase 2 inhibitors with regard to gastrointestinal damage has yet to be translated into an advantage in overall morbidity. Strategies for primary and secondary prevention of variceal bleeding have been established. Therapy tailored to hepatic venous pressure gradient has the potential to achieve clinical relevance. Several methods have been developed to prevent postpolypectomy bleeding, but their optimal risk-tailored application has yet to be demonstrated. Although octreotide treatment seems to be beneficial in reducing the blood loss from angiodysplasias, controlled studies to determine its optimal use are awaited. Stress-ulcer prophylaxis is commonly applied in critically ill patients. Although data indicate that H2-receptor antagonists and omeprazole are effective in preventing clinically significant bleeding, evidence for an advantage with respect to length of hospital or intensive-care-unit stay, as well as mortality, is still lacking. Since there is misuse of acid-suppressing drugs on regular wards, in-house guidelines may offer the potential for saving costs and reducing inappropriate prescription.

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.

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.

Laxation of critically ill patients with lactulose or polyethylene glycol: a two-center randomized, double-blind, placebo-controlled trial

OBJECTIVE

To study whether lactulose or polyethylene glycol is effective to promote defecation in critically ill patients, whether either of the two is superior, and whether the use of enteral laxatives is related to clinical outcome.

DESIGN

Double-blind, placebo-controlled, randomized study.

SETTING

Two tertiary intensive care units.

PATIENTS

Three hundred and eight consecutive patients with multiple organ failure were included when receiving mechanical ventilation and intravenous circulatory support and when defecation did not occur on day 3 after admission.

INTERVENTIONS

Thrice daily administration of lactulose, polyethylene glycol, or placebo until defecation occurred, to a maximum of 4 days.

MEASUREMENTS AND MAIN RESULTS

The number of patients with defecation during the study period was 32 of 103 (31%) for placebo, 76 of 110 (69%) for lactulose, and 70 of 95 (74%) for polyethylene glycol (p = .001 for lactulose and polyethylene glycol vs. placebo). Lactulose and polyethylene glycol-treated patients produced stools after a median of 36 and 44 hrs, respectively, compared with 75 hrs for the placebo group (p = .001 for lactulose and polyethylene glycol vs. placebo). Length of stay in the intensive care unit was a median of 156 hrs for the lactulose group, 190 hrs for the polyethylene glycol group, and 196 hrs for the placebo group (p = .001). Intestinal pseudoobstruction or Ogilvie's syndrome occurred in 4.1% of patients in the placebo group, 5.5% of patients in the lactulose group, and 1.0% of patients in the polyethylene glycol group. There was no difference in hospital mortality. Administration of morphine was associated with a longer time before first defecation, except in the polyethylene glycol group. For all groups, defecation within 6 days after admission was associated with a shorter length of stay.

CONCLUSIONS

Both lactulose and polyethylene glycol are more effective in promoting defecation than placebo. Patients receiving polyethylene glycol had a slightly lower incidence of acute intestinal pseudoobstruction, whereas length of stay was shorter in lactulose-treated patients. Morphine administration was associated with delayed defecation except in the polyethylene glycol-treated group. Irrespective of study medication, early defecation was associated with a shorter length of stay.

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.

Therapy insight: Prophylaxis of stress-induced gastrointestinal bleeding in critically ill patients

Stress-induced gastrointestinal bleeding is associated with increased morbidity and mortality in critically ill patients. Within the past few decades, the incidence of stress-induced gastrointestinal bleeding has decreased. Prophylaxis of stress-induced gastrointestinal bleeding, which is aimed at preventing morbidity and mortality, has to be achieved with as few adverse effects as possible. Data indicate that not all critically ill patients need prophylaxis for stress-induced gastrointestinal bleeding. The main risk factors associated with clinically important hemorrhage are mechanical ventilation for >48 h, and coagulopathy (thrombocyte count <50/nl, partial thromboplastin time (PTT) >2 times the upper limit of the normal range, international normalized ratio (INR) >1.5). Ranitidine is more effective than sucralfate for the prevention of clinically important bleeding. Immediate-release omeprazole is as effective as cimetidine, and is more efficient at increasing the intragastric pH. As yet, however, there is no firm evidence that any of the drugs used for prophylaxis of stress-induced gastrointestinal bleeding in critically ill patients decrease mortality or the length of hospital stay. When to stop prophylaxis is decided on clinical grounds rather than on the basis of data from clinical studies.

[Chylous ascites complicating domiciliary ventilation by tracheostomy]

INTRODUCTION

Despite the development of non-invasive ventilation there remain indications for domiciliary ventilation by tracheostomy (TDV). The principal complications are mechanical and infective. We report a case of chylous ascites secondary to compression of the thoracic duct by the tracheostomy cuff.

CASE REPORT

A man of 65 had had TDV for over one year. During hospitalisation for possible weening chylous ascites was discovered. The classical causes of this condition were excluded. CT scan of the neck and thorax showed evidence of significant dilatation (over 45 mm) of the upper part of the trachea in association with an over-inflated cuff, leading to compression of the thoracic duct. On reducing the inflation pressure of the cuff the chylous ascites has not recurred.

CONCLUSION

The management of the tracheostomy tube cuff is an important matter for the personel involved in the management of TDV. Regular radiological surveillance is useful to ensure that there is no tracheal dilatation in association with the cuff.

The relationship between blood glucose control and intolerance to enteral feeding during critical illness

OBJECTIVE

To assess the relationship between blood glucose concentrations (BSL) and intolerance to gastric feeding in critically ill patients.

DESIGN

Prospective, case-controlled study.

PATIENTS AND PARTICIPANTS

Two-hourly BSL and insulin requirements over the first 10 days after admission were assessed in 95 consecutive feed-intolerant (NG aspirate > 250 ml during feed) critically ill patients and 50 age-matched, feed-tolerant patients who received feeds for at least 3 days. Patients with diabetes mellitus were excluded. A standard insulin protocol was used to maintain BSL at 5.0-7.9 mmol.

MEASUREMENTS AND RESULTS

The peak BSLs were significantly higher before and during enteral feeding in feed-intolerant patients. The mean and trough BSLs were, however, similar between the two groups on admission, 24 h prior to feeding and for the first 4 days of feeding. The variations in BSLs over 24 h before and during enteral feeding were significantly greater in feed-intolerant patients. A BSL greater than 10 mmol/l was more prevalent in patients with feed intolerance during enteral feeding. The time taken to develop feed intolerance was inversely related to the admission BSL (r= -0.40). The amount of insulin administered before and during enteral feeding was similar between the two groups.

CONCLUSIONS

Feed intolerance in critically ill patients is associated with a greater degree of glycaemic variation, with a greater number of patients with transient hyperglycaemia. These data suggest more intensive insulin therapy may be required to minimize feed intolerance, an issue that warrants further study.

Inappropriate continuation of stress ulcer prophylactic therapy after discharge

BACKGROUND

Medications for stress ulcer prophylaxis are appropriately started in critically ill patients with risks for developing stress ulcers. It is unknown whether these drugs are discontinued once the risk factors are removed.

OBJECTIVE

To assess the duration of stress ulcer prophylactic therapy in critically ill patients.

METHODS

A retrospective chart review was conducted at a multidisciplinary, 24 bed medical/surgical intensive care unit (ICU) of a university-affiliated tertiary referral medical center. Three hundred ninety-four patients fulfilled eligibility criteria during the study period of July 1, 2005, through September 30, 2005. Patients were considered to be appropriately discharged from the hospital on gastric acid suppressants if they met any of the following criteria: continued mechanical ventilation, gastroesophageal reflux disease, peptic ulcer disease, history of gastrointestinal ulceration or bleeding within the past year, prescribed medications used for stress ulcer prophylaxis prior to admission, gastrointestinal bleed during hospitalization, or prescriber indication of reason to continue therapy.

RESULTS

Three hundred fifty-seven patients received stress ulcer prophylaxis during their ICU stay. Of these, 80% continued on gastric acid suppressants on transfer from the ICU, with 60% of the therapy being inappropriate. The percentage of critically ill patients discharged from the hospital with inappropriate prescription of gastric acid suppressants was 24.4%. Based on the average wholesale cost, the total cost for unnecessary gastric acid suppressant therapy within the follow-up period was $13,973.

CONCLUSIONS

Gastric acid suppressant medications initially prescribed for stress ulcer prophylaxis are frequently prescribed inappropriately on discharge for patients who were initially admitted to the medical/surgical ICU.

[Importance of prevention of acute mucosal lesions in patients in intensive care units]

At least three-quarters of critically ill patients develop mucosal lesion as a direct consequence of stress within the first 24 hours following the admission to intensive care unit. These mucosal lesions occur as superficial or deep mucosal lesions which can lead to massive gastrointestinal bleeding and it can put at risk the life of critically ill patient. There are multiple risk factors for the occurence of mucosal lesion such as: respiratory failure requiring mechanical ventilation, sepsis, hypotension, bums, severe trauma, neurotrauma, ileus, coagulopathy, renal and hepatic failure, myocardial infarction etc. The incidence of silent (ocult) bleeding in critically ill patients is almost 100%, but only about 5% of patients have clinically apparent (overt) hemorrhage and 1-2% have clinically significant bleeding which requires blood transfusions. In patients who are at the greatest risk of developing mucosal lesion, prophylactic treatment ought to be started immediately in order to achieve pH4 with adequate perfusion and coagulation. Today several groups of medications are used for the prevention of mucosal gastrointestinal lesion and they include: antacids, sucralfate, hisamine-2 receptor antagonists and proton pump inhibitors.

Risk of Clostridium difficile diarrhoea in critically ill patients treated with erythromycin-based prokinetic therapy for feed intolerance

OBJECTIVE

To determine the incidence of Clostridium difficile (CD) diarrhoea in feed-intolerant, critically ill patients who received erythromycin-based prokinetic therapy.

DESIGN AND SETTING

Prospective observational study in a mixed intensive care unit.

METHODS

The development of diarrhoea (> 3 loose, liquid stool per day with an estimated total volume > or = 250ml/day) was assessed in 180 consecutive critically ill patients who received prokinetic therapy (erythromycin only, n = 53; metoclopramide, n 37; combination erythromycin/metoclopramide, n = 90) for feed intolerance. Stool microscopy, culture and CD toxin assay were performed in all patients who developed diarrhoea during and after prokinetic therapy. Diarrhoea was deemed to be related to CD infection if CD toxin was detected.

RESULTS

Demographics, antibiotic use and admission diagnosis were similar amongst the three patients groups. Diarrhoea developed in 72 (40%) patients, 9.9 +/- 0.8 days after commencement of therapy, none of whom was positive for CD toxin or bacterial infection. Parasitic infections were found in four aboriginal men from an area endemic for these infections. Diarrhoea was most prevalent in patients who received combination therapy (49%) and was more common than in those who received erythromycin alone (30%) and metoclopramide alone (32%). Diarrhoea was short-lasting with a mean duration of 3.6 +/- 1.2 days.

CONCLUSIONS

In critical illness, diarrhoea following the administration of erythromycin at prokinetic doses is not associated with CD but may be related to pro-motility effects of the agent. Prokinetic therapy should be stopped at the onset of diarrhoea and prophylactic use should be strictly avoided.

Risk of Clostridium difficile diarrhoea in critically ill patients treated with erythromycin-based prokinetic therapy for feed intolerance

OBJECTIVE

To determine the incidence of Clostridium difficile (CD) diarrhoea in feed-intolerant, critically ill patients who received erythromycin-based prokinetic therapy.

DESIGN AND SETTING

Prospective observational study in a mixed intensive care unit.

METHODS

The development of diarrhoea (> 3 loose, liquid stool per day with an estimated total volume > or = 250ml/day) was assessed in 180 consecutive critically ill patients who received prokinetic therapy (erythromycin only, n = 53; metoclopramide, n 37; combination erythromycin/metoclopramide, n = 90) for feed intolerance. Stool microscopy, culture and CD toxin assay were performed in all patients who developed diarrhoea during and after prokinetic therapy. Diarrhoea was deemed to be related to CD infection if CD toxin was detected.

RESULTS

Demographics, antibiotic use and admission diagnosis were similar amongst the three patients groups. Diarrhoea developed in 72 (40%) patients, 9.9 +/- 0.8 days after commencement of therapy, none of whom was positive for CD toxin or bacterial infection. Parasitic infections were found in four aboriginal men from an area endemic for these infections. Diarrhoea was most prevalent in patients who received combination therapy (49%) and was more common than in those who received erythromycin alone (30%) and metoclopramide alone (32%). Diarrhoea was short-lasting with a mean duration of 3.6 +/- 1.2 days.

CONCLUSIONS

In critical illness, diarrhoea following the administration of erythromycin at prokinetic doses is not associated with CD but may be related to pro-motility effects of the agent. Prokinetic therapy should be stopped at the onset of diarrhoea and prophylactic use should be strictly avoided.

Stress ulcer prophylaxis in hospitalized patients not in intensive care units

PURPOSE

A review is presented of the evidence behind the current use of therapies for the prevention of stress-related mucosal disease and bleeding in the nonintensive care unit (ICU), general medicine population.

SUMMARY

The use of proton pump inhibitors and histamine H2-receptor antagonists for the prevention of stress ulcers has been well-defined in critical care patients. In 1999, the American Society of Health-System Pharmacists (ASHP) published guidelines on the use of stress ulcer prophylaxis in medical, surgical, respiratory, and pediatric ICU patients. In recent years, the practice of stress ulcer prophylaxis has become increasingly more common in general medicine patients, with little to no evidence to support it. Multiple risk factors have been identified for the development of stress ulcers, such as major trauma, severe head injury, multiple organ failure, burns covering more than 25-30% of the body, and major surgical procedures. Multiple studies have demonstrated the overuse of acid-suppressive therapy (AST), with as many as 71% of patients admitted to the hospital receiving some form of treatment. While many practitioners view AST to be harmless, its use is not without risks. Subsequently, a significant number of patients are discharged home on these medications, increasing economic cost and potentially increasing the risk of pneumonia or Clostridium difficile-associated disease.

CONCLUSION

AST is commonly misused in hospitals, with as many as 71% of patients in general medicine wards receiving some sort of AST without an appropriate indication. Anticoagulant therapy has been identified as a risk factor for GI bleeding in hospitalized patients, but prophylaxis with AST has not been found to lower that risk. Although PPIs, H2-antagonists, and antacids are often viewed as safe, patients--particularly those with complicated disease states and complex drug regimens--should not be unduly exposed to the adverse effects and drug interactions associated with those agents. Many such patients treated with the drugs while hospitalized continue to receive AST as outpatients. The cost of inappropriate stress ulcer prophylaxis in medicine patients was found in one trial to exceed $111,000 for one year. The use of AST for the prevention of stress ulcers in general medicine patients is currently not recommended or supported in the clinical literature.

Stress-related mucosal disease in the intensive care unit: an update on prophylaxis

Gastric ulcers have been known to develop in critically ill patients secondary to physiological stress since the 19th century. It is only relatively recently that stress ulcer prophylaxis has become an established routine practice in the intensive care unit. Numerous terms have been used to describe stress ulcers, but stress-related mucosal disease (SRMD) is commonly used. Significant morbidity and mortality in critically ill patients is caused by SRMD and related bleedings, but the incidence depends on the definition of bleeding. Pathophysiology of SRMD is multifactorial and involves a complex set of interactions that causes a breakdown of mucosal proactive defenses, leading to ulceration. Critically ill patients are at an increased risk for developing SRMD and subsequent bleeding secondary to several risk factors. To minimize stress-related mucosal bleeding, several regimens have been used. This article presents an update on the incidence, pathophysiology, risk factors, and prophylaxis of SRMD.

Prevention of gastrointestinal complications in the critically ill patient

Common pathophysiologic changes associated with critical illness directly contribute to the development of gastrointestinal (GI) complications. In addition, supportive interventions such as mechanical ventilation and vasopressors increase the risk of GI complications. Early, specific signs of GI complications are rarely present; therefore, because of late or missed diagnosis, morbidity and mortality related to these complications can be high. This article aims to review the pathophysiology of GI dysfunction and describe an approach to evaluate the abdomen in the critically ill patient. Risk can be limited by understanding individual patient characteristics, thoughtfully evaluating the risk-benefit profile of all interventions, and implementing preventive strategies.

Gastric feed intolerance is not increased in critically ill patients with type II diabetes mellitus

OBJECTIVE

To examine the occurrence of feed intolerance in critically ill patients with previously diagnosed type II diabetes mellitus (DM) who received prolonged gastric feeding.

DESIGN AND SETTING

Retrospective study in a level 3 mixed ICU.

PATIENTS

All mechanically ventilated, enterally fed patients (n = 649), with (n = 118) and without type II DM (n = 531) admitted between January 2003 and July 2005.

INTERVENTIONS

Patients with at least 72 h of gastric feeding were identified by review of case notes and ICU charts. The proportion that developed feed intolerance was determined. All patient received insulin therapy.

RESULTS

The proportion of patients requiring gastric feeding for at least 72 h was similar between patients with and without DM (42%, 50/118, vs. 42%, 222/531). Data from patients with DM were also compared with a group of 50 patients matched for age, sex and APACHE II score, selected from the total non-diabetic group. The occurrence of feed intolerance (DM 52% vs. matched non-DM 50% vs. unselected non-diabetic 58%) and the time taken to develop feed intolerance (DM 62.6 +/- 43.8 h vs. matched non-DM 45.3 +/- 54.6 vs. unselected non-diabetic 50.6 +/- 59.5) were similar amongst the three groups. Feed intolerance was associated with a greater use of morphine/midazolam and vasopressor support, a lower feeding rate and a longer ICU length of stay.

CONCLUSIONS

In critically ill patients who require prolonged enteral nutrition, a prior history of DM type II does not appear to be a further risk factor for feed intolerance.

The impact of admission diagnosis on gastric emptying in critically ill patients

Introduction

Disturbed gastric emptying (GE) occurs commonly in critically ill patients. Admission diagnoses are believed to influence the incidence of delayed GE and subsequent feed intolerance. Although patients with burns and head injury are considered to be at greater risk, the true incidence has not been determined by examination of patient groups of sufficient number. This study aimed to evaluate the impact of admission diagnosis on GE in critically ill patients.

Methods

A retrospective review of patient demographics, diagnosis, intensive care unit (ICU) admission details, GE, and enteral feeding was performed on an unselected cohort of 132 mechanically ventilated patients (94 males, 38 females; age 54 ± 1.2 years; admission Acute Physiology and Chronic Health Evaluation II [APACHE II] score of 22 ± 1) who had undergone GE assessment by ¹³C-octanoic acid breath test. Delayed GE was defined as GE coefficient (GEC) of less than 3.20 and/or gastric half-emptying time (t50) of more than 140 minutes.

Results

Overall, 60% of the patients had delayed GE and a mean GEC of 2.9 ± 0.1 and t50 of 163 ± 7 minutes. On univariate analysis, GE correlated significantly with older age, higher admission APACHE II scores, longer length of stay in ICU prior to GE measurement, higher respiratory rate, higher FiO₂ (fraction of inspired oxygen), and higher serum creatinine. After these factors were controlled for, there was a modest relationship between admission diagnosis and GE (r = 0.48; P = 0.02). The highest occurrence of delayed GE was observed in patients with head injuries, burns, multi-system trauma, and sepsis. Delayed GE was least common in patients with myocardial injury and non-gastrointestinal post-operative respiratory failure. Patients with delayed GE received fewer feeds and stayed longer in ICU and hospital compared to those with normal GE.

Conclusion

Admission diagnosis has a modest impact on GE in critically ill patients, even after controlling for factors such as age, illness severity, and medication, which are known to influence this function.

Negative pressure ventilation in pediatric critical care setting

Invasive ventilation is associated with both pulmonary and non-pulmonary complications. There has been a renewed interest in the use of negative pressure ventilation (NPV) for various medical conditions to minimise the complications associated with positive pressure ventilation. The routine use of NPV in an ICU setting still requires further studies and research. In this article, the authors review the clinical applications of NPV together with associated risks and limitations. Case reports of patients with cardiac, neuromuscular and respiratory diseases managed with NPV on our unit are described. NPV improved the clinical condition in each of these patients and decreased the requirement for invasive therapy.

Gastrointestinal motility and prokinetics in the critically ill

PURPOSE OF REVIEW

Enteral nutrition is frequently unsuccessful in the critically ill due to gastrointestinal dysfunction. Current treatment strategies are often disappointing. In this article upper gastrointestinal function in health together with abnormalities seen during critical illness are reviewed, and potential therapeutic options summarized.

RECENT FINDINGS

Reflux oesophagitis occurs frequently due to reduced or absent lower oesophageal sphincter tone. In the stomach a number of motor patterns contribute to slow gastric emptying. The fundus has reduced compliance, there are less frequent contractions in both the proximal and distal stomach, isolated pyloric activity is increased and the organization of duodenal motor activity is abnormal. In response to nutrients, enterogastric feedback is enhanced, fundic relaxation and subsequent recovery is delayed, antral motility is further reduced and localized pyloric contractions stimulated. Elevated concentrations of hormones such as cholecystokinin and peptide YY are potential mediators for these phenomena. Rapid tachyphylaxis occurs with the commonly used prokinetics, metoclopramide and erythromycin, and novel agents are under investigation. Independent of gastric emptying, nutrient absorption is reduced.

SUMMARY

There has been considerable progress in understanding the pathogenesis of mechanisms causing feed intolerance in critical illness, but this is yet to be translated into therapeutic benefit.

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.

Esophagitis in frail elderly people

INTRODUCTION

We studied the clinical course of elderly patients acutely hospitalized for various diseases, assessing any differences between patients with and without esophagitis.

STUDY

A case-control study on the presence of esophagitis was conducted on the clinical records of all in-patients undergoing gastroduodenoscopy at Padova Geriatric Hospital from 1997 to 2001. Data were examined on 338 sex-matched patients: 169 with a diagnosis of esophagitis and 169 with a negative endoscopy.

RESULTS

Admissions for acute respiratory disorders [odds ratios (OR) 2.68; 95% confidence interval (CI) 0.89-8.01], a remote diagnosis of esophagitis (OR 11.34; 95%CI 2.68-48.07), obesity (OR 3.36; 95%CI 0.91-12.48), and being bedridden (OR 6.84; 95%CI 3.27-14.29) were found to be independent risk factors for the presence of esophagitis. The symptoms prompting the endoscopic diagnoses included: gastrointestinal bleeding (OR 7.61; 95%CI 2.76-21.0), heartburn (OR 4.58; 95%CI 1.86-11.28), and cough (OR 3.59; 95%CI 1.34-9.62). Steroids (OR 2.68; 95%CI 1.11-6.44) and calcium antagonists (OR 1.50; 95%CI 0.79-2.87) were associated with esophagitis as risk factors, whereas proton pump inhibitors (OR 0.46; 95%CI 0.25-0.87), nitrates (OR 0.14; 95%CI 0.02-0.78), and sucralfate in males (OR 0.09; 95%CI 0.01-0.92) were associated as protective factors. Patients with esophagitis were discharged with an endocrinologic/metabolic-type diagnosis. Deaths were significantly higher among patients with esophagitis (25 vs. 9); more severe esophagitis was characterized by a higher Charlson comorbidity index and a greater presence of anorexia and nausea.

CONCLUSIONS

These findings seem to substantiate the theory that esophagitis is a characteristic which exacerbates frailty in hospitalized elderly people and its identification may be helpful in these patients.

The use of erythromycin as a gastrointestinal prokinetic agent in adult critical care: benefits versus risks

Erythromycin A, the first macrolide, was introduced in the 1950s and after years of clinical experience it still remains a commonly relied upon antibiotic. In the past, pharmacodynamic characteristics of macrolides beyond antimicrobial action such as anti-inflammatory and immune-modulating properties have been of scientific and clinical interest. The function of erythromycin as a prokinetic agent has also been investigated for a range of gastrointestinal motility disorders and more recently within the context of critically ill patients. Prokinetic agents are drugs that increase contractile force and accelerate intraluminal transit. Whilst the anti-inflammatory action may be a desirable side effect to its antibiotic action, using erythromycin A merely for its prokinetic effect alone raises the concern about promoting emergence of macrolide resistance. The objectives of this review article are: (i) to briefly summarize the modes and epidemiology of macrolide resistance, particularly in respect to that found in the Streptococcus species (a potential reservoir for the dissemination of macrolide resistance on the critical care unit); (ii) to discuss in this context the evidence for conditions promoting bacterial resistance against macrolides; and (iii) to assess the potential clinical benefit of using erythromycin A as a prokinetic versus the risks of promoting emergence of macrolide resistance in the clinical setting. We conclude, that in view of the growing weight of evidence demonstrating the potential epidemiological impact of the increased use of macrolides upon the spread of resistance, versus a lack of sufficient and convincing evidence that erythromycin A is a superior prokinetic agent to potential alternatives in the critically ill patient population, at this stage we do not advocate the use of erythromycin A as a prokinetic agent in critically ill patients unless they have failed all other treatment for impaired gastrointestinal dysmotility and are intolerant of metoclopramide. Further large and methodologically robust studies are needed to ascertain the effectiveness of erythromycin A and other alternative agents in the critically ill.

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.

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.

Diarrhoea in the critically ill

PURPOSE OF REVIEW

The purpose of this review is to update the knowledge on diarrhoea, a common problem in critically ill patients. Epidemiological data will be discussed, with special emphasis on diarrhoea in tube-fed patients and during antibiotic therapy. The possible preventive and therapeutic measures will be presented.

RECENT FINDINGS

The need for concise definitions of diarrhoea was recently re-emphasized. The use of pump-driven continuous instead of intermittent enteral feeding is less often associated with diarrhoea. The discontinuation of enteral feeding during diarrhoea is not justified. Clostridium difficile-associated diarrhoea is frequent during antibiotic therapy with quinolones and cephalosporins. Formulas enriched with water-soluble fibres are probably effective to prevent diarrhoea, and promising data on the modulation of gut microflora with probiotics and prebiotics were recently released.

SUMMARY

Diarrhoea is common in critically ill patients, especially when sepsis and hypoalbuminaemia are present, and during enteral feeding and antibiotic therapy. The management of diarrhoea includes generous hydration, compensation for the loss of electrolytes, antidiarrheal oral medications, the continuation of enteral feeding, and metronidazole or glycopeptides in the case of moderate to severe C. difficile colitis. The place of enteral formulas enriched with water-soluble fibres, probiotics and prebiotics is not yet fully defined.

Gastrointestinal dysfunction following cardiac surgery

Cardiac surgery is associated with a low incidence of GI complications, but with a disproportionate mortality. A number of risk factors have become established which identify patients at risk. CPB is associated with profound reductions in mucosal blood flow. Mesenteric perfusion is altered by primary endothelial dysfunction, which may further be exacerbated by the use of vasoconstrictors during CPB; inflammatory mediators can 'prime' the mesenteric vasculature. Cardiac surgery with or without CPB is associated with increased tissue oxygen demands, particularly by the splanchnic bed. The disparity in general and regional oxygen supply and demand results in the development of mucosal hypoxia and this cannot be attributed to CPB alone. This injury is measurable by reductions in both absorptive and barrier functions of the gut. Protection may be conferred by modulating the perfusion protocol during bypass and pharmacological interventions which modify the inflammatory response to surgery.

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.