Nasogastric tubes for small bowel obstruction: more pain than evidence - First10EM (2023)

In my opinion, the use of NG tubes for intestinal obstruction is an anachronism. I grew up hearing literature that said that NG tubes are not beneficial, but that they routinely rank as one of the most painful things we do to our patients. In my opinion, this was a classic example of a medical myth that had been consigned to medical history, along with things like leeches and trephination. However, every time I admit a patient with a bowel obstruction, the topic of NG tubes comes up, so I think we need a quick blog post.

Like many historical medical practices, NG was adopted long before the era of evidence-based medicine. Its use was based on common sense and some pathophysiology, but not evidence. Unfortunately, common sense and the physiology of medicine have always led us astray.

There is no evidence that NG tubes help.

The use of nasogastric tubes to decompress the stomach in small bowel obstruction appears to have originated with Dr. Owen Wangensteen. Over the course of a few decades of intestinal obstruction research, the mortality rate at Massachusetts General Hospital dropped from about 45% in the 1920s to about 20% in the late 1930s. For decades , this decrease in mortality, reported through case series , was the evidence that promoted the widespread use of NG tubes. (Edlich 1996) Obviously, by modern standards, a series of cases in which many changes were dated over many decades, from a time when CT was not available and mortality was dramatically higher, does not count as a very high standard of evidence. high. At best, this is hypothesis generation.

Unfortunately, to the best of my knowledge, this hypothesis has never really been tested. There is not a single randomized trial of any size or quality that addresses this issue. All we have are observational data (and the modern-era observational data seems to conflict with Wangensteen's case series).

There are some important limitations to the observational data, because patients who receive NG tubes are likely to be different from those who are treated without them, but the available observational data do not support a benefit from the use of NG tubes. In a chart review of 290 patients admitted with small bowel obstructions, approximately 20% were treated without an NG tube. The use of the NG tube was associated with worse results in all aspects: longer resolution time, longer hospital stay, and higher rate of complications. Conservative management was successful in 2/3 of the patients and was the same regardless of whether or not an NG was placed. Of note, almost 2/3 of the patients who had a nasogastric tube placed had minimal drainage, indicating that the procedure was unable to help the majority of patients. (Fonseca 2013)

The Best Evidence Topic Reports (Best BET) series covered this topic in 2014, and the only relevant article they identified was Fonseca's 2013 observational study. The bottom line: “There is no scientific evidence for the routine use of nasogastric tubes in adults with occlusion of the small intestine. (Paradise 2014)

Another retrospective chart review included 181 patients with small bowel obstruction, half of whom were treated with nasogastric decompression. There was no association between the use of the NG tube and death, surgery, or bowel resection. NG tube decompression was associated with a longer hospital stay (median 5 vs 3 days, p<0.0001). There were significant baseline differences between groups: nasogastric tubes were used more frequently in elderly patients and in those with malignancy, again severely limiting the value of observational data. (Bermann 2017)

Although somewhat tangential, prophylactic nasogastric tubes have long been used to promote early return of normal bowel function in the setting of ileus after surgery. However, a systematic review of 28 studies including 4000 patients found the exact opposite (ileus resolved more rapidly in patients without NG tube) and concluded that "routine nasogastric decompression does not achieve any of the intended goals and therefore therefore, it should be abandoned in favor of selective therapy via nasogastric tube” (Nelson 2005).

Long story short: We have no idea if NG tubes help. There is simply no quality evidence. Observational data suggest harm from longer hospital stays, longer time to resolution, and more complications, but the data are so weak that they cannot be trusted. We just don't know. Some patients may benefit, but observational data suggest that nasogastric tubes should not be used routinely.

On the other hand, NG tubes clearly cause damage

NG tubes are very painful. They are routinely ranked as one of the worst things we do to patients.

In a classic survey of admitted adult patients undergoing various medical procedures, the NG tube was ranked at the top of the list, with an average pain score of 8.8 on a 10-point scale, placing it ahead of all others. mechanical ventilation (8.0). , placement of central lines (6.5), arterial lines (3.4) and Foley catheters (6.2). (Morrison 1998) Although the study numbers are imperfect and there are several potential biases, when patients tell us they are in pain, we must listen. Numerous other studies have confirmed that this is a very painful procedure. (for example, Singer 1999; Cullen 2004)

It is possible to limit the pain associated with NG placement using topical lidocaine, although it is not clear how long the analgesic effect will persist as these tubes are generally left in place for many days. (Kuo 2010) Nasal pain is not the only problem with NG tubes. Patients rate the discomfort of choking at least as high as the nasal pain of insertion. (Singer 1999) Also, pain is not completely eliminated, which means that the harm will still outweigh the benefit if there is no benefit at all.

98% of ER physicians believe NG tube insertion is painful, but only 28% believe the pain relief options they provide are effective, and more than half are dissatisfied with their current practice. (Juhl 2005) This probably explains why ER physicians have been quicker to change their practice around this medical myth than many others where we do not immediately see the harm of our actions (such asstress testoPPI in digestive bleeding).

Use of GN in other conditions

Historically, NGs have been used for many other conditions in emergency medicine, from evaluation of upper GI bleeding to administration of activated charcoal. I won't do an in-depth review of the evidence for these other "indications," largely because there really isn't any evidence.

I think we all know that the NG tube is not accurate in diagnosing upper GI bleeding. I will occasionally use an NG tube as an active bleeding monitor in critically ill patients, but the evidence suggests that routine NG tubes in upper GI bleeds are useless. (Huang 2011; Palamidessi 2010)

I have never heard that the NG tube could be helpful in pancreatitis, but this is apparently a widely held belief in some parts of the world. Once again, the evidence seems to suggest the opposite, with faster recovery in patients randomized to no NG tube. (Sar 1986)

NG is sometimes a useful route for drug delivery and even hydration, but the risks need to be weighed against the benefits. It has often been used for drugs that have no proven benefit (such as charcoal), which only compounds the lack of benefit of the NG tube itself. However, I am happy to place an NG tube if it is the only way to deliver a potentially life-saving medication, such as administering aspirin to an unconscious STEMI patient. (Of course, the damage from NG tubes is also negligible in unconscious patients.)

NG has been suggested as a possible alternative to IV for rehydration in pediatrics, but considering that the pain of an NG tube is considered much greater than the pain of an IV, it seems that NG would be the worst alternative in the vast majority. of the cases. cases cases

Most of the time, I think the role of the NG tube isincrediblylimited in emergency medicine. We have to recognize its significant damage, being one of the most painful procedures we perform on patients. Given this, there is a high burden of proof for those who suggest the practice. We need to see evidence of benefit before putting our patients through this procedure.

Conclusion

This is clearly a harmful procedure. Patients find this more painful than almost anything else we do in medicine. This harm means that we must have evidence of benefit before we can consider this practice ethical. At this point there is no evidence and therefore NG probesit absolutely should not be routinely placed in patients with small bowel obstructions.

This conclusion does not mean that NG tubes offer no benefit. Evidence on the subject is essentially non-existent. We just don't know. But we know that the tubes cause harm, so the burden of proof is on whoever wants to subject patients to that harm. Before using NG tubes, we must demonstrate that there is a benefit that outweighs the known harm. If nasogastric tubes are as important as surgeons seem to think (if there is a large absolute benefit), then it should be fairly easy to demonstrate that benefit in an RCT. However, until we see this RCT, it is unfair to patients to undergo this unproven painful procedure.

Other FOAMED

Monthly EP: I Declare the End of the NG Reflective Tube

EP Monthly: The NG probe for gastrointestinal bleeding: cruel and unusual punishment

Monthly PE: NG tube pain preventable but not preventable

References

[ PMC free article ] [ PubMed ] Berman DJ, Ijaz H, Alkhunaizi M, Kulie PE, Vaziri K, Richards LM, Meltzer AC. Nasogastric decompression not associated with reduction surgery or intestinal ischemia due to acute small bowel obstruction. J Emerg Med. 2017 December; 35(12): 1919–1921. doi: 10.1016/j.ajem.2017.08.029. Epub 2017 15 August. IDPM:28912083

Cullen L, Taylor D, Taylor S, Chu K. Nebulized lidocaine decreases the discomfort of nasogastric tube insertion: a randomized, double-blind trial. Ann Emerg Med. 2004 Aug; 44(2): 131-7. doi: 10.1016/j.annemerged.2004.03.033. PMID:15278085

Edlich RF, Woods JA. Wangensteen's transformation of the treatment of intestinal obstruction from an empirical art to a scientific discipline. J Emerg Med. 1997 Mar-April;15(2):235-41. doi: 10.1016/s0736-4679(96)00351-4. PMID:9144067

Fonseca AL, Schuster KM, Maung AA, Kaplan LJ, Davis KA. Routine nasogastric decompression in small bowel obstruction: is it really necessary? I am Surgery. April 2013; 79(4): 422-8. PMID:23574854

Huang ES, Karsan S, Kanwal F, Singh I, Makhani M, Spiegel BM. Impact of nasogastric lavage on the outcomes of acute GI bleeding. Endosc. gastrointestinal. 2011 November; 74(5):971-80. doi: 10.1016/j.gie.2011.04.045. Epub Jul 7, 2011. IDPM:21737077

Juhl GA, Conners GP. Practices and attitudes of emergency physicians regarding the anesthetic procedure for nasogastric tube insertion. Emerg Med J. 2005 April; 22(4):243-5. doi: 10.1136/emj.2004.015602. PMID:15788820

Kuo YW, Yen M, Fetzer S, Lee JD. Pain reduction of nasogastric intubation with nebulized and atomized lidocaine: a systematic review and meta-analysis. J Treatment of pain symptoms. 2010 October; 40(4): 613-20. doi: 10.1016/j.jpainsymman.2010.01.025. Epub Aug 3, 2010. PMID:20678892

Morrison RS, Ahronheim JC, Morrison GR, Darling E, Baskin SA, Morris J, Choi C, Meier DE. Pain and discomfort associated with common hospital procedures and experiences. J Treatment of pain symptoms. 1998 February; 15(2):91-101. PMID:9494307

Nelson R, Tse B, Edwards S. Systematic review of prophylactic nasogastric decompression after abdominal operations. Br J Surg. 2005 Jun;92(6):673-80. doi: 10.1002/bjs.5090. PMID:15912492

Palamidessi N, Sinert R, Falzon L, Zehtabchi S. Nasogastric aspiration and lavage in emergency room patients with hematochezia or melena without hematemesis. Acad Emerg Med. 2010 February; 17(2): 126-32. doi: 10.1111/j.1553-2712.2009.00609.x. PMID:20370741

Paradis M. Towards evidence-based emergency medicine: Manchester Royal Infirmary's best bets. BET 1: Is routine nasogastric decompression indicated in small bowel occlusion? Emerg Med J. 2014 Mar;31(3):248-9. doi: 10.1136/emermed-2014-203617.1. PMID:24532357

Sarr MG, Sanfey H, Cameron JL. Randomized prospective study of nasogastric suction in patients with acute pancreatitis. Surgery. 1986 September; 100(3):500-4. PMID:3526610

Singer AJ, Konia N. Comparison of topical anesthetics and vasoconstrictors versus lubricants prior to nasogastric intubation: a randomized controlled trial. Acad Emerg Med. 1999 Mar;6(3):184-90. doi: 10.1111/j.1553-2712.1999.tb00153.x. PMID:10192668

Witting MD. "What do you want to do?!" Modern indications for nasogastric intubation. J Emerg Med. 2007 July; 33(1): 61-4. doi: 10.1016/j.khmermed.2007.02.017. Epub 2007 May 30. PMID:17630077

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