TIME AND RESOURCES UTILIZED IN PLACING POSTPYLORIC TUBES
Placement of postpyloric enteral tubes may take a considerable amount of time especially when these tubes are placed via endoscopy or fluoroscopic guidance as opposed to bedside techniques. Delays in placing small bowel or duodenal tubes primarily happen when the radiologist or the endoscopist is not available after-hours or during weekends or holidays. Scheduling difficulties with radiology or endoscopy suites also, at times, may contribute to delays in the placement of small bowel tubes. Delays of up to 24 hours to initiate feeds are not uncommon when postpyloric tubes are placed via the endoscopic method.8 Such delays in the initiation of feeds ultimately affect the amount of nutrition a critically ill patient receives during her or his stay in the ICU. Adequately trained ICU staff skilled in placing postpyloric tubes at the bedside, however, ameliorates the need to take the patient to radiology or endoscopy suites for placement of tubes. Median times as low as 6.6 hours from admission to the ICU or initiation of mechanical ventilation to begin feeding while achieving 80% success rate in placement of postpyloric tubes by bedside nurses has been reported.8 Placement of postpyloric tubes at the bedside also forgoes the risks associated with transporting a critically ill patient, along with the paraphernalia of tubes and machines, in and out of the ICU. Cost reductions of greater than 60% have been noted when postpyloric tubes are placed at the bedside by dieticians as opposed to placement by the radiologist under fluoroscopic guidance.9 It is advisable, thus, that an attempt to place a postpyloric feeding tube should ideally be made at the bedside by an adequately trained professional, preferably a nurse or a dietician. If it proves difficult to obtain enteral access at the bedside, only then should alternate means to obtain enteral access be pursued.
ACHIEVING NUTRITIONAL GOALS IN THE CRITICALLY ILL PATIENTS
A number of studies have looked in to whether differences exist in achieving nutritional goals based on whether a patient is fed into the stomach or past the pylorus.
A fair number of studies have found that patients fed past the pylorus received greater amount of nutrition overall10,11,12,13 compared to those fed in to the stomach. Another set of studies, however, found no difference between the 2 groups.14,15 Evidence also exists which shows that those fed past the pylorus received less overall nutrition than those fed in to the stomach.8 One study found no difference over all, but upon a subgroup analysis found that in centers which have previous experience with postpyloric feeding, patients fed via the postpyloric route met nutritional goals more frequently than those fed in to the stomach.14 In a retrospective review of 150 episodes of postpyloric feeding in 146 patients, including 20 patients fed at home for various durations of time, nutritional requirements were met in 90% of the patients.16 The results of these studies are summarized in Table 70–2.
Table 70–2Nutritional outcomes in pyloric versus postpyloric feeding in critically ill patients. |Favorite Table|Download (.pdf) Table 70–2Nutritional outcomes in pyloric versus postpyloric feeding in critically ill patients.
|Study ||Patient Type ||Number of Patients ||Results |
|Montecalvo et al ||Mixed, medical, and surgical ||38 ||PP group received higher nutritional intake, P value < 0.05 |
|Kortbeek et al ||Trauma (75% had head injury) ||80 ||PP group reached target feed rate faster than P group. 34 vs 43.8 hours, P value < 0.02 |
|Kearns et al ||Medical ||44 ||%REE higher in PP group. 69% vs 47%, P value < 0.05 |
|Davies et al ||Medical ||73 ||PP group had significantly decreased GRV |
|Montejo et al ||Mixed ||101 ||NSG in caloric intake. Subgroup analysis limited to experienced centers: significantly higher nutritional intake in PP group |
|Jones et al ||Mixed, not all patients critically ill, outpatients included in study also ||150 episode of PP feeding in 146 patients ||Nutritional goals met in 90% of cases |
|White et al ||Medical ||104 ||Pyloric group reached nutritional goals earlier, average daily energy deficit significantly higher in PP group |
|Hsu et al ||Medical ||121 ||Average daily nutritional intake significantly higher in PP group |
|Acosta-Escribano et al ||Severe traumatic brain injury ||104 ||Mean efficacious volume of diet delivered significantly higher in PP group. P value: 0.01 |
|Davies et al ||Mixed, on mechanical ventilation ||181 ||NSG in nutrition delivered |
Meta-analyses that have evaluated this issue have yielded mixed results as well, with some that have reported no difference in achievement of nutritional goals17,18 while others that have reported a signal toward increased nutritional intake with postpyloric feeding.19
PNEUMONIA IN PYLORIC VERSUS POSTPYLORIC FEEDS
Given that critically ill patients have a high incidence of delayed gastric emptying, up to 60% in some studies,7 high GRVs are frequently encountered when these patients are fed in to the stomach. High GRVs are thought to predispose a critically ill patient to a higher chance of developing gastroesophageal reflux, leading to an increased incidence of macroaspiration and microaspiration of gastric contents ultimately resulting in greater incidence of pneumonia. The idea of feeding past the pylorus to decrease reflux, aspiration, and ultimately prevent pneumonia is not an unfounded one. It has been shown in clinical studies that feeding a patient past the pylorus significantly reduces gastroesophageal reflux and results in a trend toward decreased pulmonary aspiration.20 Whether this decreased incidence of reflux and aspiration of gastric contents leads to clinically important outcomes such as decreased incidence of nosocomial and ventilator associated pneumonias, has been extensively debated in multiple studies.
CURRENT EVIDENCE VALUATING RISK OF PNEUMONIA IN PYLORIC VERSUS POSTPYLORIC FEEDING
A number of studies have found no significant difference in the incidence of pneumonia in patients fed via the pyloric versus the postpyloric route.8,11,14,15,21 One of the earlier studies did however show a decreased incidence of pneumonia with postpyloric feeding compared to gastric feeding.10 Two additional studies have also shown a significant decrease in pneumonia with the use of postpyloric feeding as compared to prepyloric feeding.12,13
Mostly, studies evaluating controversies surrounding pyloric versus postpyloric feeding have been relatively small. Given the plausibility of how postpyloric feeding can theoretically decrease the incidence of pneumonia and a number of studies showing both benefit and no benefit at all, a number of meta-analyses been carried out to investigate this issue further. Two of the earlier meta-analyses,17,18 which utilized 9 and 11 studies, respectively; found no difference in rates of pneumonia between the pyloric and postpyloric feeding groups. More recent meta-analyses,19,22 however, both of which are from 2013, with each including 15 studies, did show significant reduction in incidence of pneumonia with postpyloric feeds. Table 70–3 summarizes the results of the studies exploring pneumonia in pyloric versus postpyloric feeding.
Table 70–3Impact of pyloric versus postpyloric feeding on incidence of pneumonia in critically ill patients. |Favorite Table|Download (.pdf) Table 70–3Impact of pyloric versus postpyloric feeding on incidence of pneumonia in critically ill patients.
|Study ||Year of Publication ||Patient Type ||Number of Patients ||Result |
|Montecalvo et al ||1992 ||Mixed medical and surgical ||38 ||2 episodes of pneumonia in gastric vs none in jejunal |
|Kortbeek et al ||1999 ||Trauma (75% had head injury) ||80 ||NSG |
|Kearns et al ||2000 ||Medical ||44 ||NSG |
|Montejo et al ||2002 ||Mixed ||101 ||NSG |
|White et al ||2009 ||Mixed ||104 ||NSG |
|Hsu et al ||2009 ||Medical ||121 ||8.6 vs 3.1 per 1000 ventilator days for P vs PP, P value: 0.01 |
|Acosta-Escribano et al ||2010 ||Severe traumatic brain injury ||104 ||32% vs 57% for PP vs P, P value: 0.01 |
|Davies et al ||2012 ||Mixed, on ventilator ||181 ||NSG |