The use of NG tubes is just one of many procedures where EPs take a traditional approach that lacks evidence to support it. A closer look at the research shows that the benefits of NG tubes may not outweigh the discomfort.
When I was applying for medical school, there were only five in my hometown of Philadelphia and I applied to all five. When I toured Jefferson Medical College I heard they inserted nasogastric tubes (NG) on each other – I scratched Jefferson off the list.
When it comes to noxious routine ED procedures, the insertion of an NG tube is right at the top of the list. The most effective way to limit the angst of placing an NG tube is to not do them. The literature says NG tubes are usually unneeded in GI bleeding, small bowel obstruction and pancreatitis – three indications that had been routine in the past (and their use for gastric lavage in the setting of suspected overdoses is pretty much a very uncommon circumstance). In the setting that an NG tube is appropriate, anesthetizing the oropharynx with atomized lidocaine can decrease gagging and discomfort.
The great title of the first paper reflects the patient anxiety when advised of the need for an NG tube. This classic paper by Mike Witting focuses on the decreased indications for an NG tube, particularly as it related to upper gastrointestinal bleeding (UGI).
“YOU WANNA DO WHAT?!” MODERN INDICATIONS FOR NASOGASTRIC INTUBATION Witting, M.D., J Emerg Med 33(1):61, July 2007
Nasogastric intubation (NGI) is associated with considerable discomfort and the potential for com- plications. Recent studies have questioned the need for NGI for “traditional” indications. The author, from the University of Maryland, reviews the use of NGI in selected clinical conditions. The evidence supports selective use of NGI in patients with gastrointestinal bleeding. In patients with hematemesis, NGI has not been definitively demonstrated to have positive effects on decision-making. Because endoscopy is the definitive procedure for these patients, this author suggests that decisions about the need for prior NGI be discussed with the endoscopist. If immediate endoscopy is planned, NGI is not likely to be necessary. In the absence of hematemesis, NGI is felt to have little utility in patients without risk factors for an upper GI source of bleeding (black stool color, a BUN/ creatinine ratio above 30, and age below 50). This author suggests that an upper GI source is unlikely in patients without these risk factors and is probable in those with two or more risk factors (for whom a need for NGI should be discussed with the endoscopist), and that NGI is most likely to be useful in patients with a moderate pretest probability of an upper GI source of bleeding (i.e., those with one risk factor). Routine use of NGI is not supported for patients with metastatic small bowel obstruction or paralyticileus, or for the administration of activated charcoal; the author suggests selective use of NGI in such patients. Finally, studies have shown no benefit of NGI (and the possibility of producing more harm than good) in patients with pancreatitis or isolated large bowel obstruction. Techniques to limit the discomfort of NGI and to facilitate the passage of the NG tube are also reviewed. 22 references 11/07 – #23
This next study is a systematic review and meta-analysis of five papers looking at pain relief during NG tube insertion. It compares nebulized lidocaine with saline placebo. Each of the studies individually did not show a statistically significant decrease in pain, however, when combined, statistical power was achieved and a 58% reduction was shown. This is a great example of how small studies may be underpowered to show that true differences exist be- tween therapies. Seems that warming the tube so that it is subtle, using some lidocaine jelly in the nose in advance and using some lidocaine jelly on the tube – all combined with nebulization of lidocaine would seem to be a logical progression.
REDUCING THE PAIN OF NASOGASTRIC TUBE INTUBATION WITH NEBULIZED AND ATOMIZED LIDOCAINE: A SYSTEMATIC REVIEW AND META-ANALYSIS Kuo, Y.W., et al, J Pain Symp Man 40(4):613, October 2010
BACKGROUND: Nasogastric tube insertion has been noted to be one of the most painful procedures performed in the ED. Studies reporting a beneficial effect of aerosolized lidocaine on the discomfort of NG tube insertion have yielded inconclusive results due to methodologic limitations.
METHODS: These Chinese authors performed a systematic review and meta-analysis of five randomized controlled trials (212 subjects) comparing the effects of nebulized lidocaine or placebo on the discomfort of NG tube insertion.
RESULTS: All five studies compared aerosolized lidocaine vs. saline placebo. The five studies were all judged to be of higher methodologic quality. The mean patient age was 59.6 years in the active treatment groups and 55 years in controls, and 58% of the subjects were female. Two studies assessed the effects of administration of 10% lidocaine via a face mask or nasal atomizer, and 4% lidocaine was administered in the remaining three studies. All five studies individually reported a reduction in the pain of NG tube insertion with the active intervention that did not achieve statistical significance, but the pooled effect size was statistically significant (OR 0.423) and consistent with a 57.7% reduction in discomfort with the lidocaine intervention compared with the administration of normal saline.
CONCLUSIONS: One study reported that fewer than one in five patients is pretreated with nebulized anesthetic prior to NG tube insertion in the ED. The findings of this meta-analysis are consistent with a significant reduction in the discomfort of this procedure with administration of nebulized lidocaine. 22 references (email@example.com – no reprints) 4/11 – #15
Now, let’s look at the use of NG lavage or suction in the setting of GI bleeding. It has long been ritual that an NG tube be inserted in patients with UGI bleeding or to ascertain whether positive rectal bleeding is coming from an UGI source. The first study was a chart review of 632 patients presenting with UGI bleeding. 60% had GI lavage performed before endoscopy. No difference in any of multiple outcomes was found in those who had lavage and those who didn’t except that endoscopy was performed more frequently in the NG lavage group (72.3% vs. 60.1%) and was done earlier in the course of treatment. This be- ing the case, it may be best to ask the GI consultant his/ her desire regarding the need for lavage and the timing of endoscopy.
IMPACT OF NASOGASTRIC LAVAGE ON OUTCOMES IN ACUTE GI BLEEDING Huang, E.S., et al, Gastrointest Endosc 74(5):971, November 2011
BACKGROUND: Guidelines for the management of acute nonvariceal upper gastrointestinal bleeding do not address routine performance of nasogastric lavage prior to endoscopy. It has been observed that the beliefs of both academic and community-based providers about routine use of NG lavage in such patients is quite variable.
METHODS: The authors, from the West Los Angeles VA Medical Center, performed an implicit chart review to assess the relationship between performance of NG lavage and clinical outcomes in 632 patients (mean age 63, 98% male) presenting with acute GI bleeding.
RESULTS: NG lavage was performed prior to endoscopy in 193 patients (60%), who were propensity-matched (for 19 variables related to the likelihood of undergoing NG lavage) to 193 patients not so treated. Baseline characteristics were similar in the two groups. In this cohort, there were no statistical intergroup differences in 30-day mortality (11% in the NG lavage group vs. 13% in controls, odds ratio [OR] 0.84, 95% CI 0.37-1.92), the duration of the hospital stay (7.3 vs. 8.1 days), blood transfusion requirements (3.2 vs. 3.0 units of packed red cells) or the need for emergency surgery (3.1% vs. 2.1%). However, endoscopy was performed more frequently in the NG lavage group (72.3% vs. 60.1%), and was done earlier in the course. A finding of bloody aspirate on NG lavage correlated with demonstration of high-risk lesions on endoscopy (OR 2.69), but performance of NG lavage did not.
CONCLUSIONS: In this study, performance of nasogastric lavage in patients with acute GI bleeding was associated with earlier performance of endoscopy, but was unrelated to clinical outcomes. 31 references (firstname.lastname@example.org for reprints) 4/12 – #15
Next, a literature review involving three studies and 533 total patients identified a rate of confirmed upper GI bleeding in the three studies ranged from 32% to 74%. The sensitivity of nasogastric aspiration and lavage in diagnosing upper GI hemorrhage in the three studies was 42%, 68% and 84%, respectively, and corresponding specificities were 91%, 54% and 82%, respectively. Negative predictive values ranged between 61% and 78%, and positive predictive values ranged from 41% to 93%. Due to the limited utility of NG aspiration to exclude UGI bleeding, both upper and lower endoscopy will be required.
NASOGASTRIC ASPIRATION AND LAVAGE IN EMERGENCY DEPARTMENT PATIENTS WITH HEMATOCHEZIA OR MELENA WITHOUT HEMATEMESIS Palamidessi, N., et al, Acad Emerg Med 17(2):126, February 2010
BACKGROUND: Insertion of a nasogastric tube has been cited as one of the most uncomfortable procedures performed in the ED, and has the potential to produce significant complications. Nasogastric aspiration and lavage is often performed in ED patients to identify or exclude an upper gastrointestinal source of bleeding, but there is uncertainty about its diagnostic value.
METHODS: The authors, from the State University of New York in Brooklyn, performed a literature review to identify studies of the utility of nasogastricaspiration and lavage to identify an upper GI bleeding source in ED patients with hematochezia or melena in the absence of hematemesis. Three retrospective studies that included 533 patients without hematemesis were identified.
RESULTS: The three studies included heterogenous patient populations. Esophagogastroduodenoscopy results were the reference standard in two studies, and the hospital course combined with the results of surgery, endoscopy or other imaging were the reference standard in the third study. The rate of confirmed upper GI bleeding in the three studies ranged from 32% to 74%. The sensitivity of nasogastric aspiration and lavage in diagnosing upper GI hemorrhage in the three studies was 42%, 68% and 84%, respectively, and corresponding specificities were 91%, 54% and 82%, respectively. Negative predictive values ranged between 61% and 78%, and positive predictive values ranged from 41% to 93%.
CONCLUSIONS: Nasogastric aspiration with or without lavage appears to have limited utility in excluding an upper GI source of bleeding in patients with hematochezia or melena without hematemesis. Regardless of the nasogastric aspirate result, both high and low endoscopy will be required for diagnostic confidence. 25 references (email@example.com for reprints) 6/10 – #18
Routine insertion of an NG tube in small bowel obstruction is not defended by the literature. The following small study tries to ascertain which patients may do well without an NG tube, but the small numbers make if very hard to get much in the way of take home. Ultimately, 52 of 290 adults were managed without NG decompression. Nonoperative management was successful for two-thirds of the patients not getting an NG tube.
ROUTINE NASOGASTRIC DECOMPRESSION IN SMALL BOWEL OBSTRUCTION: IS IT REALLY NECESSARY? Fonseca, A.L., et al, Am Surg 79(4):422, April 2013
BACKGROUND: Although nonoperative management of patients with small bowel obstruction (SBO) often includes nasogastric decompression, there are no studies that document a need for this intervention on a routine basis.
METHODS: The authors, from Yale University, per- formed an implicit chart review in 290 adults (average age, 58) admitted with SBO over a five-year period in an attempt to identify those who might be safely managed without an NG tube. The study included patients with adhesive or malignant obstruction, but not those with an obviously incarcerated hernia.
RESULTS: Fifty-five patients (19%) were managed without NG decompression. These patients had a higher rate of abdominal distension and tympany on presentation than those who underwent immediate NG tube insertion. Although most patients in both groups had nausea and/or vomiting on presentation, an NG tube was placed in three-fourths of the patients without nausea and/or vomiting. Most of the patients undergoing NG decompression (63.8%) had minimal NG tube drainage (less than 500ml in 24 hours). Nonoperative management was successful for two-thirds of the patients; the success of conservative management was not associated with NG tube placement. Patients who underwent NG decompression had a longer time to resolution of SBO than those not so managed (3.6 vs. 1.7 days), a longer length of stay (10.2 vs. 3.2 days), a higher complication rate (odds ratio [OR] 19.3), and more frequent discharge to a rehabilitation facility or nursing home. (OR 6.6); it is impossible to assess causality based on these findings, however.
CONCLUSIONS: Some patients hospitalized with small bowel obstruction do well without nasogastric decompression. 29 references (kevin.schuster@yale. edu for reprints) 5/14 – #17
Finally, everybody knows that patients with pancreatitis need an NG tube. The theory is that sucking out the stomach juices that are the stimulus for the pancreas to secrete will put the pancreas at rest and accelerate the recovery process. But is that actually the case? Here is a really old paper that affirms others and suggests that patients with mild to moderate severity don’t benefit from an NG tube and may do better without it.
PROSPECTIVE, RANDOMIZED TRIAL OF NASOGASTRIC SUCTION IN PATIENTS WITH ACUTE PANCREATITIS Sarr, M.G., Surgery 100(3):500, September 1986
Nasogastric suction has traditionally been employed in the management of patients with acute pancreatitis. This random, prospective, controlled study, from the Johns Hopkins Hospital in Baltimore, analyzed the effects of NG suction in 60 patients with a diagnosis of mild (59) or moderate (1) acutepancreatitis. Twenty-nine patients were managed with at least 48 hours of nasogastric intubation (mean, 4.4 days) in conjunction with low, intermittent suction, and 31 comparable patients were managed without NG suction. Analysis of the hospital courses of these patients indicated that the duration of fever, abdominal tenderness, and absence of bowel sounds and bowel movements, the need for narcotics and IV fluid therapy, and the prevalence of serious complications of acute pancreatitis were comparable in the two treatment groups. Patients managed with NG suction resumed oral intake 5.0 days after admission, compared to 3.9 days in patients managed without NG suction (p<0.01). The patients managed with NG suction had a longer duration of hyperamylasemia and a longer duration of hospitalization than patients managed without this modality, but these differences did not achieve statistical significance. The conclusions of this study confirm the data of other investigators who have demonstrated no benefit associated with routine use of NG suction in patients with acute pancreatitis of mild to moderate severity, but may not apply to individuals with severe pancreatitis. 20 references 3/87-#23
There are lots of ED procedures that have been ingrained into our psyche as “standard of care” – often without good evidence to support their use. For the benefit of our patients emergency providers need to be willing to shine the searchlight of scientific inquiry at many of the dogmas to which we adhere.
After Spinal Cord Injury
What is the Bowel and What Does it Do?
The bowel is the last portion of your digestive tract and is sometimes called the large intestine or colon. The digestive tract as a whole is a hollow tube that extends from the mouth to the anus.
The function of the digestive system is to take food into the body and to get rid of waste. The bowel is where the waste products of eating are stored until they are emptied from the body in the form of a bowel movement (stool, feces).
A bowel movement happens when the rectum (last portion of the bowel) becomes full of stool and the muscle around the anus (anal sphincter) opens.
With a spinal cord injury, damage can occur to the nerves that allow a person to control bowel movements. If the spinal cord injury is above the T-12 level, the ability to feel when the rectum is full may be lost. The anal sphincter muscle remains tight, however, and bowel movements will occur on a reflex basis. This means that when the rectum is full, the defecation reflex will occur, emptying the bowel. This type of bowel problem is called an upper motor neuron or reflex bowel. It can be managed by causing the defecation reflex to occur at a socially appropriate time and place.
A spinal cord injury below the T-12 level may damage the defecation reflex and relax the anal sphincter muscle. This is known as a lower motor neuron or flaccid bowel. Management of this type of bowel problem may require more frequent attempts to empty the bowel and bearing down or manual removal of stool.
Both types of neurogenic bowel can be managed successfully to prevent unplanned bowel movements and other bowel problems such as constipation, diarrhea and impaction.
Methods for Emptying the Bowel:
Each person’s bowel program should be individualized to fit his/her own needs. The type of disease or nerve damage (for example, upper or lower motor neuron) should be taken into account as well as other factors. Components of a bowel program can include any combination of the following:
Physical removal of the stool from the rectum. This can be combined with a bearing down technique called a Valsalva maneuver (avoid this technique if you have a heart condition).
Circular motion with the index finger in the rectum, which causes the anal sphincter to relax.
Dulcolax (stimulates the nerve endings in the rectum, causing a contraction of the bowel) or glycerine (draws water into the stool to stimulate evacuation).
Softens, lubricates, and draws water into the stool to stimulate evacuation.
Most people perform their bowel program at a time of day that fits in with their prior bowel habits and current lifestyle. The program usually begins with insertion of either a suppository or a mini-enema, followed by a waiting period of approximately 15-20 minutes to allow the stimulant to work. This part of the program should, preferably, be done on the commode or toilet seat.
After the waiting period, digital stimulation is done every 10-15 minutes until the rectum is empty. In order to avoid damage to the delicate rectal tissue, no more than four digital stimulations should be performed in any one session. Those with a flaccid bowel frequently omit the suppository or mini-enema and start their bowel programs with digital stimulation or manual removal. Most bowel programs require 30-60 minutes to complete.
Bowel programs vary from person to person according to their individual preferences and needs. Some people use only half of a suppository, some require two suppositories, and some use no suppository or mini-enema at all. Some choose to do the entire program in bed, while others sit on the toilet from the beginning. Some find that the program works better if they can eat or drink a warm beverage while it is in progress, others find that this is not helpful. What is most important is that you discover what works best for you.
Factors That Can Affect Success:
Any one of the factors listed below, or a combination of factors, can affect the success of a bowel program. Changing one factor may produce results almost immediately, or it may take several days to see the results. Changing more than one factor at a time makes it difficult to determine the effects of individual factors, and may increase the time it takes to develop a stable bowel program.
Previous Bowel History
What have your bowel habits been in the past?
Do you do your bowel program in the morning or evening? At the same time every day? After a meal or warm beverage? What is the interval between programs — half a day, one day or two days? (You should do a bowel program at least every 2-3 days to reduce your risk of constipation, impaction and colon cancer.)
Privacy and Comfort
Does someone else share your bathroom? Do you have enough time to complete your program?
Has your appetite been affected? Are you able to relax?
Where do you do your program — on a commode chair, raised toilet seat, on the toilet, or in bed? It will probably work better when you are sitting up because of gravity.
How much and what type of fluid do you drink? (Prune juice or orange juice can stimulate the bowels, or another type of fruit juice may work best for you.)
How much fiber or bulk (such as fruits and vegetables, bran, whole grain breads and cereals) do you eat? Some foods (such as dairy products, white potatoes, white bread and bananas) can contribute to constipation, while others (such as excess amounts of fruit, caffeine, or spicy foods) may soften the stool or cause diarrhea.
Some medicines (such as codeine, Ditropan, probanthine, and aluminum-based antacids like Aludrox) can cause constipation, while others (including some antibiotics, such as ampicillin, and magnesium-based antacids such as Mylanta and Maalox) can cause diarrhea. Consult your health care provider for information about the medications you are taking.
A case of the flu, a cold or an intestinal infection may affect your bowel program while you are ill. (Even if your digestive system is not directly affected, your eating habits, fluid intake or mobility may change, which can alter your bowel program.)
Activity Level / Mobility
How much exercise do you get? How much time do you spend out of bed?
Hot weather increases the evaporation of body fluids, which can lead to dehydration and constipation.
Massaging the lower abdomen in a circular, clockwise motion from right to left increases bowel activity.
Valsalva (bearing down)
This technique is not recommended for patients with cardiac problems.
Assistive / Adaptive Devices
Devices such as a suppository inserter, finger extension or digital stimulator may be required to assist you in establishing a successful bowel program.
What to Avoid:
Regular Use of Stimulant Laxatives
These include bisacodyl (Dulcolax) tablets, phenolphthalein (Ex-Lax), cascara, senna and magnesium citrate. Laxative use on a regular basis will cause your bowels to become dependent on them. When this happens the bowel will not work well without the laxative, and eventually the “lazy bowel” that results will require more and stronger laxatives to work at all. An occasional small dose of a mild laxative, such as Milk of Magnesia or an herbal laxative, can be used to treat constipation if other measures have not worked. (We recommend that you use no more than three doses per month.)
Any full-size enema (such as Fleet’s, soap suds or tap water) is too irritating to the bowel to be used on a regular basis and will cause the same problem with dependence as a stimulant laxative. A “mini-enema”, which has only a few drops of liquid stool softener, does not fall into this category and can be used regularly. Occasionally, your health care provider may prescribe a full-size enema as preparation for a medical procedure or for treatment of severe constipation.
Skipping or Changing the Time of Your Program
Your bowels will move more predictably if your bowel care program is carried out on a regular, predictable schedule. Skipping your program can also result in constipation or accidents.
The more tense you are, the more difficult it will be for you to empty your bowels. A hurried program will increase the likelihood of an unplanned bowel movement later in the day.
More than Four Digital Stimulations at a Time
This can cause trauma to the rectum, resulting in hemorrhoids or fissures (cracks or breaks in the skin).
They can damage the rectal tissue and cause bleeding, even through a glove.
What to do if…
Stool is too Hard (Constipation)
Do your bowel program on a daily basis until constipation resolves. Add or increase the dose of a stool softener (such as DOSS or colace). Add or increase the dose of psyllium hydro-mucilloid (such as Metamucil or Citrucel). Increase your fluid intake (this is essential if you are increasing psyllium). Increase your activity level and your intake of dietary fiber. Avoid foods that can harden your stool, such as bananas and cheese.
Stool is Liquid or Runny (Diarrhea)
Temporarily discontinue the use of any stool softeners. Continue your bowel program at the regular time and frequency. (If you are having accidents, increase the frequency of your program.) Try adding or increasing the dose of psyllium hydro-mucilloid (Metamucil, Citrucel), which adds bulk to liquid stool. If the diarrhea seems to be related to an acute viral or bacterial illness, change to a liquids only or very bland diet for 24 hours (avoid milk, however). If diarrhea persists for more than 24 hours or if you have a fever or blood in your stool, consult your health care provider.
A frequent cause of diarrhea is a blockage or impaction of stool (liquid stool leaks out around the blockage). Evaluate whether you may have this problem. Have you had small hard stools recently? Or have you had no results from the past several programs? If you suspect impaction, consult your health care provider.
Frequent Bowel Accidents
Be sure your rectum is completely empty at the end of your program. Increase the frequency of your program (some people with a flaccid bowel may need to empty their bowels twice daily). Try using only half of a suppository. Evaluate stool consistency — if it’s too hard or too soft, see above. Monitor your diet for any foods that may over stimulate your bowel, such as spicy foods.
If you notice a clear, sticky, sometimes odorous drainage from the rectum, try switching from a suppository to a mini-enema, or using only half of a suppository, or try eliminating suppositories or mini-enemas completely and begin your program with digital stimulation only. Avoid hard stools.
No Results in 3–4 Days
Treat constipation as recommended above. If there are no results in three days, take 30 cc. of Milk of Magnesia or a single dose of an herbal laxative at bedtime. Do your bowel program in the morning. If there are still no results, repeat the dose of Milk of Magnesia or herbal laxative the next evening. If there are no results in the morning, consult your health care provider.
Keep your stool soft. Be very careful to do digital stimulation gently and with sufficient lubrication, and keep your fingernails short. If you have known hemorrhoids, you may treat them with an over-the-counter hemorrhoidal preparation such as Anusol or Anusol HC. If bleeding persists or is more than a few drops, consult your health care provider.
Avoid constipation. Increase the frequency of your bowel programs. Avoid gas-forming foods, such as beans, corn,onions, peppers, radishes, cauliflower, sauerkraut, turnips, cucumbers, apples, melons and others that you may have noticed seem to increase your own gas. Try simethicone tablets to help relieve discomfort from gas in your stomach.
Bowel Program Takes a Long Time to Complete
Try switching from a suppository to mini-enemas. Increase your intake of dietary fiber and add or increase the dose of psyllium hydromucilloid. Try switching your program to a different time, and be sure you schedule it after a meal to help increase intestinal peristalsis.
Autonomic Dysrefexia During Bowel Program
Use xylocaine jelly (available by prescription from your health care provider) for digital stimulation. You may also need to insert some of the jelly into your rectum before beginning the program. Keep your stool as soft as possible. If dysreflexia persists, consult your health care provider. You may need medication to treat or prevent this condition.