http://doi.org/10.33698/NRF0153 Davinder Kaur , Meenakshi Agnihotri, Sukhpal Kaur, Sandhya Narayanan
Abstract In critically ill patients enteral feeding is given commonly by the nasogastric and orogastricroutes. Enteral feeding is often limited by delayed gastric emptying. Gastric residual volume (GRV) measured at the bedside is widely used as an important marker for gastric emptying. A prospective randomized study design was employed to assess the effect of reintroduction of aspirated gastric contents on gastric emptying in patients receiving nasogastric/orogastric feed in intensive care units. A tool consisting of three parts i.e. identification profile; assessment of physiological status; and assessment of Gastric residual volume; and a protocol on ‘Reintroduction of gastric aspiration’ were developed. Twenty subjects in each test group and control group were studied for five days. The patients are administrated nasogastric/ orogastric feed every three hourly. So, a total of eight hundred observations were there in each group. In the test group, the gastric aspiration was reintroduced after each feed while in control group the routine practice of discarding the gastric aspirate was followed. Gastric residual volume was measured by aspirating the gastric content of the patients three hours after the administration of previous feed. The gastric residual volume of less than or equal to 20%
of the volume of the previous feed was considered normal i.e. no delay in the gastric emptying. However, the delay was considered as mild, moderate and severe as per the gastric residual volume i.e. 21-30%, 31-50% and >50% respectively. Both the groups were homogenous with respect to age, gender, mechanical ventilation, sedation, GCS and drugs affecting gastric motility. The average aspiration volume (mls) calculated with percentage of previous feed in test group was 18.0 (ml) ± 8.0 and in control group it was 25 (ml) ±14.6, (p>0.05). More subjects in test group were in normal range of gastric emptying (92%) compared to control group (87%). Subjects with mechanical ventilation, sedation and drugs which were affecting the gastric motility had non-significant difference in gastric emptying in both the study groups. The other associated problems i.e. vomiting, diarrhea and abdominal pain occured in both the groups after feed. But in test group episodes of tube cloggingoccured more (2.9%). So, it can be concluded that re introducting of gastric aspirate had no effect no gastric emptying.
Keywords: Reintroduction, gastric aspirate, gastric emptying, nasogastric /orogastric feed.
Correspondance at:Davinder Kaur Guru Nanak Mission Hospital, Dhahan Kaleran, Nawanshahr (Punjab) India
Email : davis_d08@yahoo.com
Introduction:Critically ill patients are often given enteral feeding. Enteral feeding is done commonly by the nasogastric and orogastric routes. Early enteral feeding is considered best practice.It benefits ICU patients by decreasing catabolic response to injury, maintaining bowel mucosal integrity, decreasing
Nursing and Midwifery Research Journal, Vol-9, No.2, April 2013 74 translocation of gut bacteria, improving wound healing and reducing septic
complications.1,2 However enteral nutrition method is not exempt from complications. It may lead to gastrointestinal dysmotility that may further result into disturbed gastric emptying in critically ill patients. Food intolerance is an indirect marker of disturbed gastric motility and slow gastric emptying.3 Intolerance in critical ill patients is shown by large gastric residual volume. Gastric residual bvolume is the resultant of stasis of
administered feed and the gastrointestinal secretions. Gastric emptying is affected by many
factors. Gastric emptying is slowed in critical ill patients as compared to healthy adults.
A study conducted by Heyland4 has shown that the problem of delayed gastric emptying is more common in critically ill patients. Slow gastric emptying in critically ill patients result from disturbed motor function of both proximal and distal stomach, but the precise mechanism underlying these disturbancesremain unclear. Several factors related to critical illness have been reported to be associated with gastric dysmotility and feed
intolerance including hyperglycemia, nature of acute illness, mechanical ventilation,sedatives and cytokine release etc.3 Delay in gastric emptying results in many complications. In a review of 253 patients receiving enteral nutrition via tube feedings, thirty patients (11.7%) experienced either gastrointestinal (6.2%), mechanical (3.5%), or metabolic (2.0%) complications.5
The most frequent cause for the failure to meet target feeding goals were slow gastric emptying as indicated by large volume gastric
aspirates,6Regular measurement of gastric residual volume (GRV) during the administration of enteral nutrition has been considered a convenient clinical tool to indicate gastric emptying and success of feeding.7
Studies have shown relationship between gastric emptying and reintroduction or discarding of the gastric aspirate. In study by Udina et al patients in intervention group showed a slightly lower total mean GRV. The number of mild and moderate gastric emptying delay episodes was double in the discard group. Complications were similar in both groups.
8 In a study conducted by Booker etal among 35 subjects was found that there was no significant difference between the 2 groups for any of the variables. Complications related to enteral feedings were more common in the return group (n = 8), which had 2 episodes of tube clogging and 1
episode of diarrhea and nausea.
9 Literature shows a wide variation in nursing practices, regarding whether the aspirated gastric content should be discarded or instilled back. Some concluded that returning of the gastric contents can lead to clogging of tube and abdominal distension while discarding of the contents can lead to electrolyte disturbance because of removal of digestive gastric juices.10In main ICU of Nehru Hospital, PGI, the patients are administered
nasogastric feed every three hourly. The current practice is to aspirate and discard the gastric contents before each feed is continued.Nursing and Midwifery Research Journal, Vol-9, No.2, April 2013 75 So the present study was planned to assess whether the reintroduction of gastric aspirate
affects the gastric emptying.
Objective: To assess the effect of reintroduction of aspirated gastric content on gastric emptying in patients receiving nasogastric / orogastric feed in critically ill patients.
Materials and Methods:This prospective randomized controlled trial was conducted in main ICU of Nehru hospital,PGIMER, Chandigarh.The main ICU is a 12 bedded unit. The patients with different disorders requiring intensive care are admitted here. Majority are fed through nasogastric or
orogastric tube. Institutional ethics committee approval was sought and written informed consent was obtained from the patients’
attendant.
Allpatients admitted in the ICU,age more than 12 years and those who were getting enteral feed either through nasogastric orogastric routes were in included in the study. However, the patient on continuous aspiration and having undergone gastric surgery were excluded. A computer generated random list and sealed envelope were used to randomize patients to gastric aspirate discard or return group.
A tool consisting of three parts i.e. identification profile (part A); assessment of physiological status (part B); assessment of Gastric residual volume (Part C); and aprotocol on ‘Reintroduction of gastric aspiration’were developed after reviewing the
relevant literature and consultation with the experts. The identification profile consisted of information regarding patients’ age, sex, CR No., bed No. and the diagnosis. The physiological status assessment proforma contained the items like need of mechanical ventilation, sedative drugs, Glasgow Coma Scale (GCS) score, and the drugs slowing or increasing motility.The Gastric residual volume assessment tool was used to measure the abdominal girth before and after each feed, to assess the amount and color of aspirate content, amount of aspirate reintroduced,
amount of feed, and to document the other associated problems like vomiting, diarrhea, and clogging of tube. Content validity of each
tool was established by circulating the tool among the experts in the deptt of intensive care and nursing education.
The protocol on ‘Reintroduction of gastric aspiration’ consisted of the steps reintroduction of the gastric content in the patients. The main steps were positioning the patient, aspirating the gastric content, noting the colour and amount of aspiration, and deciding whether to reintroduce or to discard the gastric content etc. After consulting the experts from ICU and review of previous literature it was determined that maximum aspirate volume in test group to be instilled back was up to a maximum of 50% of previous feed. If the volume obtained
from the aspiration was greater than 50%, any surplus amount was discarded.Twenty subjects in each test group and control group were studied for five days.The patients were administered nasogastric/ orogastric feed every three hourly. So, a total Nursing and Midwifery Research Journal, Vol-9, No.2, April 2013 76 of eight hundred observations were there in each group. However, for the parameters like assessing the GCS, the various drugs the patients was getting and whether the patient is on mechanical ventilator, the observation was once per day. So, a total of 100
observations were there. In the test group, the gastric aspiration was reintroduced after each feed while in control group the routine practice of
discarding the gastric aspirate was followed.After assessing the vital signs, abdominal girth and amount of feed, gastric residual volume was checked every 3 hourly by aspirating the gastric content by using 10cc syringe. The stomach was considered empty when no more gastric aspirate content could be obtained. The gastric residual volume of less than or equal to 20% of the volume of the previous feed was considered normal i.e.
no delay in the gastric emptying. However, the delay was considered as mild, moderate, and severe as per the gastric residual volume i.e. 21-30%, 31-50%, and >50% respectively.Exact measurement of the amount aspirated and returned was recorded. All the patients in the study were with semi fowler’s position with head raised at 30°.After reinserting the aspirate the feed was administered to the patient. Tube was flushed with 30 ml of water. Abdominal girth was measured. Patients were prospectively monitored for vomiting, abdominal distension (checking abdominal circumference following standardized procedure), and diarrhea (three or more soft blob like, mushy or liquid stools/ 24 hrs). Investigator also gathered data on patient’s medications that were affecting gastric emptying along with other general data of interest.Data was analyzed using descriptive statistics (percentage, mean, and Standard Deviation) and inferential statistics (x2t test,and Mann Whitney test). A p value of 0.05
was taken as a threshold to test the significance level.
Results:Identification profile of the subjects in test and control groups Out of total 20 subjects enrolled in each group the mean age of the subjects in the test group was 41.8 yrs±15.7 with range being19-67 yrs. The mean age in the control group 42.3 yrs±14.3 was ranging from 19-
64 years.65% subjects in the test group were males and in control group there were 14(70%) males. Both groups were comparable as per the age and sex wise distribution of the subjects. Distribution of patients’ observations as per mechanical ventilation, GCS and drugs affecting gastric motility Total 100 observations were made in each group ( daily one observation for five days for 20 patients) related to GCS score,
drugs administration affecting gastric motility and type of ventilation. Eighty percent patients in test group and 78% in control group were
on mechanical ventilation. As per GCS of patients 44% in test group and 36% were in control group fall in the moderate category of consciousness. Eighty two percent observations in test group and 77% Nursing and Midwifery Research Journal, Vol-9, No.2, April 2013 77
observations in control group were made in patients receiving drugs that decrease gastric motility like opoids, barbiturates and atropine
drugs. In test group all the subjects were on prokineticdrugs (like ranitidine, metoclopramide and cizsapride) during all
study days. Both the groups were comparable as per these parameters (Table 1).
Table 1:Distribution of the subjects as per mechanical ventilation, GCS and drugs affecting gastric motility. N=200
Study Groups:Variables Test Control X2
n=100* n=100* df,
p value
Mechanical Yes 80 78 0.121
Ventilation No 20 22 1, 0.728
Sedation Yes 69 66 0.205
No 31 34 1, 0.651
GCS
Severe (<8) 34 33 1.490
2, 0.475
Moderate (8-11) 44 36
Mild (12-15) 22 28
Drugs Yes 82 77 0.767
delaying
gastric No 18 23 1, 0.381
motility
Drugs Yes 100 99 1.005
increasing
gastric No 0 1 1,0.316
motility
*20 patients in each group followed up for five
days so (20×5)=100 observations
Comparison of gastric emptying on the basis of gastric residual volume in both groups Total 800 observations were taken on each group of patients i.e. 8 feeds per day (3 houry feed) for 5 days to 20 patients each in test and control group. In test group, more (91.7%) observations were in normal range of gastric residual volume compared to the control group (86.9%). Observations with mild(21-30% ) increased gastric residual
volume of previous feed, were more in control group (9%) than in test group (6.9%). In moderately increased gastric residual volume
category, that is gastric aspirate volume of 31-50% of previous feed, control group had more (4.1%) observations than in test
group(1.4%). (Figure 1)
100
80
60
40
20
0
91.7% 86.9%
6.9% 9% 1.4% 4%
normal mild moderate
%Observation
Gastic emptying delay
test
control
Figure 1 : Gastric emptying on the basis of
gastric residual volume measurement
Nursing and Midwifery Research Journal, Vol-9, No.2, April 2013 78 Average aspiration volume between both the study groups
The average aspirate volume was 18.0±8.0 ml in test group and 25±14.6 ml in control group. Aspirated volume was also calculated as per the percentage of the volume of previous feeds which varied from 100 ml to 350 ml, in different patients and at different times. It showed that average aspiration percent of previous feed volume in test group was 7.3±3.2 while in control group it was found 9.6±4.8. Mann Whitney U test was
applied to evaluate the difference of aspiration volume between both the groups. It was statistically insignificant (p>0.05). (Table 2)
Table 2: Average aspiration volume among the both study groups N=1600
Study Groups
Variable Test Control p value
(n=800) (n=800) (Mann
Whitney
U test)
Average Mean±SD 18.0±8.0 25.0±14.6 0.11
aspiration Range 10.2-49.0 5.5-60.5
absolute Mean rank 17.5 23.5
volume Sum of 349.50 470.50
(ml) Ranks
Average Mean±SD 7.3±3.2 9.6±4.8 0.14
aspiration Range 4.1-19.6 2.1-20.4
volume Mean rank 17.6 23.4
percent Sum of 351.5 468.5
of previous Ranks
feed
amount
Problems observed in patients after each
feed in the both groups
The problems observed in test group
were nausea and vomiting (1.4%), diarrhea
(12%), tube clogging (2.9%) and others
(abdominal fullness and abdominal pain)(1.1%) where as in control group the problems observed were nausea and vomiting (2.1%), diarrhea (11.6%), tube clogging (0.6%) and others (abdominal fullness and abdominal pain) (1.7%) The episodes of tube clogging were significantly
more in test group as compared to control group( p<.0.001) Other problems were comparable in both the groups. (Table3)
Table 3:Problemsobserved in patients after
each feed in the both groups N=1600
Problems Test Group Control X
2
(n=800) group df, p
(n=800) Value
Nausea 11 (1.4%) 17 (2.1) 1.3
and 1,0.25
Vomiting
Diarrhea 96 (12%) 93 (11.6%) 0.05
1,0.81
Clogging 23 (2.9%) 5 (0.6%) 11.78
Others 9 (1.1%) 14 (1.7%) 1.1
1, 0.29
*Only presence of problems are shown in table.
**Abdominal fullness, abdominal pain 20 patients in each group were followed up for 5 days with eight observations per day.(20×5×8=800)
Difference in mean abdominal girth before and after giving feed in both the groups In test group, the difference in mean abdominal girth before and after giving feed was 1(cm)±0.23. However, in the control group it was 1.12(cms)±0.32. The difference between both the groups was statistical
insignificant (p>0.05). (Table 4)
Nursing and Midwifery Research Journal, Vol-9, No.2, April 2013 79
Table 4: Mean abdominal girth difference
between both thegroups N=1600
Abdominal Test Control t, df,
girth Group Group p-value
n=800 n=800
Difference 1 (cms) 1.12 cm -1.479, 38
in mean ± 0.23 ± 0.32 0.08
abdominal
Girth
Discussion
There has always been a confusion whether to reintroduce the gastric content or to discard it before giving the next feed in the patients who are on nasogastric or orogastric method of enteral nutrition.Literature shows a wide variation regarding the topic.Reintroduction of the gastric contents
leading to clogging of tube and abdominal distension while discarding of the contents leading to electrolyte disturbance has been documented.
10 Present study is an effort to assess the effects of reintroduction (test group) and discarding the aspirated content (control group) on gastric emptying and other complications. Twenty subjects were studied in each group for five days. Gastric aspirate protocol was used in test group. In test group before giving NG/OG feed gastric aspirate was reintroduced. In the current study no participant in either group suffered from
severe delay in gastric emptying. More patients in the intervention group (91.75%) were in normal range of gastric emptying compared to control group (86.87%). In the same way less patients in intervention group presented with mildly (6.8%) and moderately (1.37%) delayed gastric emptying. In control group these episodes were 9% and 4.12% respectively. This shows that reintroducing the gastric aspirate does not increase the total gastric residual volume (GRV) and has an effect in maintaining GRV at physiological levels. The results of this study are similar to
the findings of the study done by Udina et al9 who found that delayed gastric emptying episodes are about 50% fewer if the aspirated contents are reintroduced than when the contents are discarded. The results of the current study are also consistent with the study by Booker et al8 that showed that more patients in discard group had moderate or mild gastric emptying delay compared to reintroduce group. Also a few patients had
severe gastric emptying delay in discard group but no subject was found to have severe gastric emptying delay in reintroduce group.Based on the results of present study it can be recommended that gastric aspirate should be reintroduced to the patients. These are similar to the recommendations given by Williams and Lesile.1Patients on enteral feed were monitored for various complications like nausea and vomiting (if patient was conscious), diarrhea and abdominal pain etc. Overall rate of complications was similar in both groups (17.4% in test group and 16.1% in control group). These findings were similar with findings of Udina et al in which patients have equal episodes of vomiting and diarrhea in
both the study groups.9 In the current study episodes of tube clogging were few but were significantly more Nursing and Midwifery Research Journal, Vol-9, No.2, April 2013 80 in test group (2.9%) than control group (0.6%). Williams and Leslie5 have recommended that of feeding tubes should be flushed after feed with water. We followed these recommendations and flushed the tube with 30 ml of water after each feed. Udine et
al did not have any episode of tube clogging.6 This could be due to continuous administration of feed using a pump delivery
system.Increased mean abdominal girth after feed which was measured to identify the abdominal distension was more in control group(1.1cms±0.3) as compared to test group(0.9cms±0.2) which is same as the findings of study conducted by Udina et al in which the abdominal distension documented more in control group, though it was not statistical different (p=0.07)9
Conclusion:So in present study there was no significant difference in episodes of gastric emptying in both groups. Further studies may
be needed with longer follow up of the patients and new methods of measuring gastric residual volume. So, as such as per the results
of the present study, no recommendation could be made for the nursing practitioners regarding reinserting or discarding the gastric
aspiration.
References
1. Williams TA, Leslie GD.A review of the nursing care of enteral feeding tubes in critically ill adults: part I. Intensive Crit Care Nurs 2004
Dec;20(6): 330-343.
2. Moore FA, Feliciano DV, Andrassy RJ,McArdle AH,Booth FV,Morgenstein-Wagner TB et al. Early enteral feeding,compared with
parenteral, reduces postoperative septic complications.The results of a meta-analysis. Ann of Surg 1992;216:172-183
3. Nguyen NQ,MeiPN , Chapman M ,Fraser R , Hallway HR. The impact of admission diagnosis on gastric emptying in critical ill patients.Crit care 2007: 11(1):R16.
4. Heyland DK, Tougas G, King D, Cook DJ.Impaired gastric emptying in mechanically ventilated, critically ill patients.Intensive Care Med 1996 Dec; 22(12):1339-44.
5. Cataldi-Betcher EL, Murray H, Seltzer MH, Jones KW,Complications Occurring during Enteral Nutrition Support: A Prospective Study.JParenter Enteral Nutr 1983;7:546-552
6. De Beaux, Chapman M, Fraser R. Enteral nutrition in the critically ill: a prospective survey in an Australian intensive care unit. Anaesth
Intensive Care. 2001 Dec;29(6):619-2
7. Deane A, Chapman MJ, Fraser RJ, Bryant LK, Burgstad C, Nguyen NQ.Mechanisms underlying feed intolerance in the critically
ill:Implications for treatment. World J Gastroenterology 2007 August 7; 13(29): 3909-
3917
8. Booker KJ, Niedringhaus L, Eden B, Arnold JS.Comparison of 2 methods of managing gastric residual volumes from feeding tubes.Am
J Crit Care 2000 Sep;9(5):318-24.
9. U ve-UdinaME,Valls-Miró C, Carreño- GraneroA,Martinez-EstalelleG,Monterde -Prat D, Domingo -Felici CM et al.To return or to discard?
Randomized trial on gastric residual volume management .Intensive Crit care Nurs 2009;25:
258-267.
10. Marshall AP, West SH. Enteral feeding in the critically ill: are nursing practices contributing to hypocaloric feeding? Intensive Crit Care
Nurs2006;22(2):95-105