Portal de Periódicos da CAPES

Struggling toward easier endoscopy

1998; Elsevier BV; Volume: 48; Issue: 4 Linguagem: Inglês

10.1016/s0016-5107(98)70021-5

1097-6779

Mahesh S. Mokhashi, Robert H. Hawes,

Gastrointestinal disorders and treatments

Gastrointestinal endoscopy has undergone tremendous evolution since the development of fiberoptics by Sir Anthony Hopkins1Hopkins H Kapany NS. A flexible fiberscope using static scanning.Nature. 1954; 173: 39-41Crossref Scopus (266) Google Scholar and its incorporation into flexible endoscopes by Basil Hirschowitz.2Hirschowitz BI. Endoscopic examination of the stomach and duodenal cap with the fiberscope.Lancet. 1961; 1: 1074-1078Abstract PubMed Scopus (90) Google Scholar Initially, flexible endoscopy was perceived as a diagnostic tool and in its earliest form was capable only of capturing still photographs (gastrocamera).3Hirschowitz B. A personal history of the fiberscope.Gastroenterology. 1979; 76: 864-869PubMed Scopus (61) Google Scholar Rapidly, however, the cry went out to develop biopsy forceps to obtain mucosal biopsies for histologic evaluation. Colonoscopy was a natural extension of upper endoscopy, but it became immediately apparent that "visualization" alone was insufficient and that "intervention" in the form of polypectomy needed to be an integral part of this procedure. The same evolution from diagnostics to therapeutics occurred with ERCP; the early pioneers initially celebrated successful injection of contrast into the desired duct yet quickly became impatient when they were unable to treat the problem they had just diagnosed. The initial series of diagnostic ERCPs were reported in 1969, and only 3 years later, Classen and Kawai were performing the first sphincterotomy.4Kawai K Akasaka Y Murakami K Tada M Koli Y. Endoscopic sphincterotomy of the ampulla of Vater.Gastrointest Endosc. 1974; 20: 148-151Abstract Full Text PDF PubMed Scopus (669) Google Scholar, 5Demling L Koch H Classen M Belohlavek D Schaffner O Schwamberger K et al.Endoscopic papillotomy and removal of gallstones: animal experiments and first clinical results.Dtsch Med Wochenschr. 1974; 99 ([German]): 2255-2257Crossref PubMed Scopus (64) Google Scholar Since then, "therapeutic" endoscopy seems to have dominated practitioners' thoughts and energies. We have seen a progressive march toward greater sophistication in endoscopic interventions and have enthusiastically embraced the brave new world we call "minimally invasive therapies." Unquestionably the next decade will bring many exciting opportunities in therapeutic endoscopy, but with the adoption of this therapeutic mindset, have we lost a vision for the impact of diagnostic endoscopy? Few persons would attempt to argue (and none would succeed) in convincing clinicians that indirect inspection of the intestinal tract lumen using contrast coating and x-ray imaging is superior to direct inspection (with or without biopsy) in the diagnosis of intestinal disorders. Yet, annually > 500,000 upper gastrointestinal x-rays and > 800,000 barium enemas are performed on Medicare patients alone (personal communication, Paula Higger, Health Care Financing Administration, 1998). If similar statistics were to be explored for non-Medicare patients, the overall figures would more than double. Why is this so? The answer lies in the complexities of performing routine endoscopy combined with the substantially greater direct and indirect costs (and charges) generated by endoscopic procedures compared to barium studies. The cost and encumbrances created by our current practice of diagnostic endoscopy threaten its future. These factors, combined with technologic advances, are fueling the development of alternative diagnostic tests such as virtual endoscopy and magnetic resonance cholangiopancreatography (MRCP). Will these techniques replace diagnostic endoscopy? Our intent in this editorial is to articulate these developments and make a plea that resources be directed toward developing techniques and technologies that will "simplify" (and lower the cost!) of diagnostic endoscopic procedures. If one takes a simple look at how we currently structure diagnostic endoscopy (at least in the United States), the problems become quite apparent. The scenario presented in Table 1 could be considered a typical sequence of events associated with the performance of diagnostic endoscopy.Table 1Typical sequence of events associated with performance of diagnostic endoscopyNo.Event1Patient is scheduled for the procedure2Patient is registered3Patient is interviewed by a nurse; history (including allergies) is obtained and global clinical assessment is performed4An intravenous catheter is placed5Patient is informed about the procedure and consent is obtained6One or more sets of vital signs are obtained7Patient is moved to the endoscopy suite8Monitoring system is set up, including blood pressure, EKG, pulse and oximeter (CO2 monitoring in the future?)9Benzodiazepine +/- narcotic is drawn up and administered10Endoscopy is performed11Frequent vital signs are obtained until the patient is deemed stable12Patient is moved to the recovery area for a 30- to 90- minute recovery period13Physician and/or nurse provides instructions on post-endoscopy activity14Patient is driven home by a family member or friend15Patient is unable to drive for 12 to 18 hours after the Open table in a new tab The entire sequence of events can take between 1½ to 2 hours and essentially eliminates a day of work (or other activities) for both the patient and the spouse, family member, or friend. The direct and indirect costs are substantial, and physician and facility charges are even higher—all of this for what can be a 3- to 5-minute procedure (esophagogastroduodenoscopy [EGD]). It is no wonder that health care systems are looking for alternative diagnostic modalities. Thus, the question at hand becomes: How can we make diagnostic endoscopy simpler and less costly? Assessment of the real economics of flexible endoscopy has only recently become an important issue. In the past, hospitals (facility fees) and physicians (professional fees) were free to charge what they wished for endoscopic procedures and generally got it from third-party payers. The true cost of endoscopy was for the most part irrelevant, and seldom was the information important enough to justify the time and effort required to calculate the real costs. Rather, hospitals would charge as much as possible, often covering losses from other areas of the hospital on the back of revenues generated from the endoscopy suite. As a result, charges were far from an accurate reflection of true costs. Physicians, on the other hand, would loosely calculate the "work" expended for a particular procedure, often comparing it to an existing one. It was usually a matter of trying to charge as much as would be borne by the third-party payers. However, with the coming of managed care (especially with capitation), knowing the true costs for performing endoscopic procedures has become a critical issue. It is now crucial that hospitals (and endoscopists) know the actual cost of providing an endoscopic service to enter into contractual agreements with managed care groups. Physicians are also having to adjust to "new times" as they see a relentless ratcheting down of the amount they are reimbursed for their endoscopic services. They too must know and understand their "costs of doing business" because they are being asked to join in the risk sharing inherent in capitated contracts. If the economics of diagnostic endoscopy are to be altered, we must understand the root sources of the "costs." When we undertook this exercise, we determined that the facility costs broke down into three categories (see Table 2).Table 2Facility costsCategoryPercentage of total costEquipment40%Supplies22%Labor38% Open table in a new tab Equipment and labor accounted for the majority of the costs. With further analysis, it became clear that the requirement for sedation was responsible for 30% to 50% of the costs. In addition, endoscopy without sedation would lower the indirect costs attributable to loss of work for both patient and "transporter." In 1995 the number of basic diagnostic upper gastrointestinal endoscopies done in non-Federal hospitals alone was almost one million,6Detailed diagnoses and procedures, National Hospital Discharge Survey, 1995. 13. National Center for Health Statistics, Bethesda (MD)1995Google Scholar and the charges to Medicare for basic diagnostic upper gastrointestinal endoscopies in the year 1996 was $747 million (personal communication, Paula Higger, Health Care Financing Administration, 1998). In 1998 both these figures are expected to be higher. A reduction in costs of only 20% would save the health care system well over 100 million dollars. It is well known that in some cultures conscious sedation is not administered while performing EGD and, in some cases, colonoscopy as well. In most of these situations, sedation is neither routinely offered nor do patients ask for it. In the United States, however, sedation is virtually always offered and seldom refused. This routine use of sedation adds considerably to the burden of endoscopy. Most of the preprocedure documentation and monitoring involved is performed in anticipation of giving patients intravenous medications. Apart from the cost of the medications themselves, time is required to draw them up and administer them safely. The use of controlled substances also contributes to the trend of using registered nurses to assist in endoscopy, further increasing costs. Perhaps most dramatic is the cost created by the mandatory post-procedure recovery and safety issues that prohibit patients from driving until the next morning. The use of sedation dictates the practice of requiring that a designated driver accompany the patient, which means that two people miss a day of work. In fact, some studies have shown that a significant number of patients take the following day off as well after undergoing colonoscopy.7Newcomer MK Jowell PS Williams DM Prasad SM Cotton PB. Determination of work time lost following outpatient colonoscopy.Gastrointest Endosc. 1994; 40 ([abstract]): 30Google Scholar In addition to direct and indirect costs, conventional conscious sedation using benzodiazepines and narcotics has other major disadvantages: The sedation-related mortality rate has been as high as 1 to 6 per 20,000 examinations,8Cotton PB Williams CB. Practical gastrointestinal endoscopy.4th ed. Blackwell Science, Oxford1996Google Scholar and in certain medical situations, conventional sedation may actually be contraindicated. Given all these issues, it is not surprising that through the years endoscopists have been attempting to find alternate solutions without compromising either patient comfort or the quality of the examination. Whereas it is clear that some patients and some procedures will require sedation, the ideal agent would be easy to administer (without requiring skilled personnel), have a rapid onset of action, have a rapid recovery phase, have a predictable and consistent efficacy, and be safe and inexpensive. Unfortunately such an agent does not exist, and in lieu of this, endoscopists have explored alternatives. This effort has progressed from hypnosis,9Jackson JA Middleton WRJ. The use of hypnosis for analgesia in upper gastrointestinal endoscopy.Aust J Clin Exp Hypn. 1978; 6: 27-33Google Scholar acupuncture,10Cahn AM Carayon P Hill C Flamant R. Acupuncture in gastroscopy.Lancet. 1978; 1: 182-183Abstract PubMed Scopus (34) Google Scholar and nitrous oxide11Trojan J Saunders BP Woloshynowych M Debinsky HS Williams CB. Immediate recovery of psychomotor function after patient-administered nitrous oxide/oxygen inhalation during colonoscopy.Endoscopy. 1997; 29: 17-22Crossref PubMed Scopus (41) Google Scholar in the 1970s to relaxation music,12Bampton P Draper B. Effect of relaxation music on patient tolerance of gastrointestinal endoscopic procedures.J Clin Gastroenterol. 1997; 25: 343-345Crossref PubMed Scopus (53) Google Scholar allowing an escort,13Lachter J Wiseman H Lavee Y. Patient stress and patient satisfaction when allowed presence of an accompanying person during endoscopy.Endoscopy. 1996; 28 ([abstract]): S42Google Scholar virtual vision,14Kozarek RA Raltz SL Brandabur JJ Bredfeldt JE Patterson DJ Wolfsen HW et al.Virtual vision for diagnostic and therapeutic esophagogastroduodenoscopy and colonoscopy.Gastrointest Endosc. 1997; 46: 58-60Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar and back to nitrous oxide in the 1990s. None of these alternatives has proved effective for EGD, and nitrous oxide has been the only technique to attract any substantial use for colonoscopy. In a prospective double-blind randomized trial, Cahn et al.10Cahn AM Carayon P Hill C Flamant R. Acupuncture in gastroscopy.Lancet. 1978; 1: 182-183Abstract PubMed Scopus (34) Google Scholar from France compared the effect of acupuncture with placebo in 90 patients undergoing unsedated EGD. Patient tolerance was significantly better in the acupuncture group. In a German study evaluating the analgesic effect of acupuncture in 36 patients undergoing colonoscopy, the group that received acupuncture experienced lesser pain and needed a lesser amount of analgesics and sedatives compared to the placebo group.15Li CK Nauck M Loser C Folsch UR Creutzfeldt W. Acupuncture for lessening pain during colonoscopy.Dtsch Med Wochenschr. 1991; 116: 367-370Crossref PubMed Scopus (18) Google Scholar In 1978, in an uncontrolled pilot study, Jackson and Middleton9Jackson JA Middleton WRJ. The use of hypnosis for analgesia in upper gastrointestinal endoscopy.Aust J Clin Exp Hypn. 1978; 6: 27-33Google Scholar from Australia evaluated hypnosis as an alternative to the use of diazepam. In 10 of the 12 patients he studied, endoscopy was completed with hypnosis alone. Studies support the view that hypnosis influences the reaction component rather than the perception of pain per se, and as a result it alters a major factor in the total pain experience.16Barber TX. "Hypnosis," analgesia, and the placebo effect.JAMA. 1960; 172: 680-683Crossref PubMed Scopus (13) Google Scholar In 1994, Cadranel et al.17Cadranel JF Benhamou Y Zylberberg P Novello P Luciani F Valla D et al.Hypnotic relaxation: A new sedative tool for colonoscopy?.J Clin Gastroenterol. 1994; 18: 127-129Crossref PubMed Scopus (31) Google Scholar from France investigated hypnotic relaxation as a potential method of sedation before and during colonoscopy. Of the 24 patients in the study, hypnosis resulted in moderate or deep sedation in only 50% of patients. Compared to the group unable to be hypnotized, successful sedation with hypnosis was associated with a reduction in pain intensity, an increase in the number of colonoscopies that reached the cecum, and increased acceptance of the idea of another examination under the same circumstances. However, hypnosis and acupuncture both have several major disadvantages: (1) both require the presence of skilled personnel; (2) both are time-consuming to administer compared with intravenous sedation; (3) neither is as consistent in its effect on patients as chemical agents; and (4) neither is appropriate for all patients. Endoscopists have tried having patients listen to relaxation music played through headphones while they undergo EGD. Although this technique reduced anxiety levels,18Hsu RK Veridiano M Linciardi J Soares P Stefani C Leung J. The impact of music on the anxiety level of patients undergoing outpatient endoscopy—a prospective randomized controlled study.Gastrointest Endosc. 1998; 47 ([abstract]): AB52Google Scholar it failed to have any impact on the overall tolerance score.12Bampton P Draper B. Effect of relaxation music on patient tolerance of gastrointestinal endoscopic procedures.J Clin Gastroenterol. 1997; 25: 343-345Crossref PubMed Scopus (53) Google Scholar In a small, uncontrolled pilot study, Kozarek et al.14Kozarek RA Raltz SL Brandabur JJ Bredfeldt JE Patterson DJ Wolfsen HW et al.Virtual vision for diagnostic and therapeutic esophagogastroduodenoscopy and colonoscopy.Gastrointest Endosc. 1997; 46: 58-60Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar investigated the role of Virtual Vision as a distraction technique to improve patient tolerance of endoscopy. Virtual Vision is an integrated audiovisual system consisting of a modified pair of sunglasses and a 1-inch liquid crystal display screen that accepts signals from a video transmitter, in this case from a video endoscope (a television or videocassette recorder could be substituted). Of the 14 patients who visualized their endoscopic procedure with Virtual Vision while having the procedure done under conventional sedation, 92% believed that Virtual Vision improved their procedural tolerance and 75% believed that it was a valuable distraction technique. Ninety-two percent indicated that they would prefer to use Virtual Vision again if they required a repeat endoscopy. Most patients appear very resistant to the idea of unconventional alternatives to drug-induced sedation. When offered a choice between pharmacologic sedation, hypnosis, and acupuncture, no patient chose the latter two as forms of sedation for EGD.19Probert CSJ Jayanthi V Quinn J Mayberry JF. Information requirements and sedation preferences of patients undergoing endoscopy of the upper gastrointestinal tract.Endoscopy. 1991; 23: 218-219Crossref PubMed Scopus (27) Google Scholar Eighty percent of the patients who were offered Virtual Vision declined to participate in the trial.20Kozarek IRA Brandabur JJ Jiranek GC Raltz SL. Prospective trial using virtual vision for diagnostic and therapeutic endoscopy.Gastrointest Endosc. 1997; 45 ([abstract]): AB51Abstract Full Text PDF Scopus (1) Google Scholar Behavioral modifications provided through booklets21Lanius M Zimmermann P Heegewaldt H Fischer HM Rohde H. Do patient information booklets have any influence on anxiety levels on patients having gastroscopy or colonoscopy?.Z Gastroenterol. 1990; 28: 651-655PubMed Google Scholar or videotapes,22Agre P Kurtz RC Krauss BJ. A randomized trial using videotape to present consent information for colonoscopy.Gastrointest Endosc. 1994; 40: 271-276Abstract Full Text Full Text PDF PubMed Scopus (120) Google Scholar cognitive-behavioral strategies to reduce stress and alter thoughts and evaluations surrounding the "invasive" event,23Ludwick-Rosenthal R Neufeld RWJ. Stress management during noxious medical procedures: An evaluative review of outcome studies.Psychol Bull. 1988; 104: 326-342Crossref PubMed Scopus (85) Google Scholar and modeling24Shipley RH Butt JH Horwitz B Farbry JE. Preparation for a stressful medical procedure: effect of amount of stimulus preexposure and coping style.J Consult Clin Psychol. 1978; 46: 499-507Crossref PubMed Scopus (95) Google Scholar, 25Shipley RH Butt JH Horwitz EA. Preparation to reexperience a stressful medical examination: effect of repetitious videotape exposure and coping style.J Consult Clin Psychol. 1979; 47: 485-492Crossref PubMed Scopus (55) Google Scholar to teach patients how to cope successfully during a distressing medical procedure have all been tried. At this time, however, they can be recommended only as complementary techniques to analgesia and sedation rather than as stand-alone alternatives. A premixed 50% nitrous oxide and oxygen mixture (Entonox) was introduced commercially into the United Kingdom by the British Oxygen Company in 1965.26Cole PV. Apparatus for the relief of pain in labour.Br J Anaesth. 1968; 40: 683-691Crossref Scopus (4) Google Scholar Since then it has been extensively used to provide analgesia in the specialties of dentistry, obstetrics, and emergency medicine. In a 1972 report from Denmark, Ruben27Ruben H. Nitrous oxide analgesia in dentistry.Br Dent J. 1972; 132: 195-196Crossref PubMed Scopus (31) Google Scholar estimated that more than 3,000,000 patients experienced nitrous oxide–induced analgesia without a single major adverse effect. The use of nitrous oxide/oxygen mixtures was first reported in the United States in 1976 by Thompson and Lown,28Thompson PL Lown B. Nitrous oxide as an analgesic in acute myocardial infarction.JAMA. 1976; 235: 924-927Crossref PubMed Scopus (35) Google Scholar who used a 35% concentration of nitrous oxide mixed with oxygen for patients with myocardial ischemic pain. The first study of the use of Entonox in fiberoptic colonoscopy was performed by Bennett et al.29Bennett JA Salmon PR Branch RA Baskett PJF Read AEA. The use of inhalational analgesia during fibre-optic colonoscopy.Anaesthesia. 1971; 26: 294-297Crossref PubMed Scopus (13) Google Scholar from the United Kingdom in 1971. In this study, 23 patients either received no premedication or were given a variety of oral and parenteral agents. The other 26 patients self-administered Entonox using a demand apparatus. The results of this experiment were impressive in that 23 of 26 patients from the Entonox group experienced marked analgesia as opposed to only 11 of 23 patients in the other group. The three failures in the Entonox group were believed to result from inadequate inhalation by the patients rather than a lack of effect from the gas. Although specific recovery times were not given, it was concluded that in view of the rapid recovery following withdrawal of the inhalation, colonoscopy could be safely undertaken as an outpatient procedure. Interest in the use of nitrous oxide for analgesia during endoscopy waned in the 1980s but has been rekindled in the 1990s; this renewed interest is perhaps related to the managed care environment and the need for shorter acting agents for endoscopic sedation. In the early 1990s a number of studies reported favorable results with the use of nitrous oxide analgesia for colonoscopy.11Trojan J Saunders BP Woloshynowych M Debinsky HS Williams CB. Immediate recovery of psychomotor function after patient-administered nitrous oxide/oxygen inhalation during colonoscopy.Endoscopy. 1997; 29: 17-22Crossref PubMed Scopus (41) Google Scholar, 30Lindblom A Jansson O Jeppsson B Tornebrandt K Benoni C Hedenbro JL. Nitrous oxide for colonoscopy discomfort: a randomized double-blind study.Endoscopy. 1994; 26: 283-286Crossref PubMed Scopus (40) Google Scholar, 31Notini-Gudmarsson AK Dolk A Jakobsson J Johansson C. Nitrous oxide: a valuable alternative for pain relief and sedation during routine colonoscopy.Endoscopy. 1996; 28: 283-287Crossref PubMed Scopus (46) Google Scholar, 32Saunders BP Fukumoto M Halligan S Masaki T Love S Williams CB. Patient-administered nitrous oxide/oxygen inhalation provides effective sedation and analgesia for colonoscopy.Gastrointest Endosc. 1994; 40: 418-421Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar Saunders et al.,32Saunders BP Fukumoto M Halligan S Masaki T Love S Williams CB. Patient-administered nitrous oxide/oxygen inhalation provides effective sedation and analgesia for colonoscopy.Gastrointest Endosc. 1994; 40: 418-421Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar from London, in a double-blind, randomized, placebo-controlled study of 89 patients, showed that the analgesia and overall side-effect profiles for the Entonox group and the conventional sedation group were comparable. However, duration of stay within the recovery area was significantly longer in the group receiving conventional intravenous sedation (median, 60 minutes) than in the nitrous oxide/oxygen group (median, 32 minutes) or placebo (median, 36 minutes). The same group confirmed their previous findings in another well-designed randomized study.10Cahn AM Carayon P Hill C Flamant R. Acupuncture in gastroscopy.Lancet. 1978; 1: 182-183Abstract PubMed Scopus (34) Google Scholar By clinical observation and elaborate psychomotor testing, patients in the nitrous oxide group recovered faster than did those who received conventional sedation. Reportedly, Saunder's group routinely offers inhalation-induced analgesia for colonoscopy to patients who appear cooperative and not overly anxious. Similar encouraging results with nitrous oxide analgesia for colonoscopy have been reported in two Swedish studies.30Lindblom A Jansson O Jeppsson B Tornebrandt K Benoni C Hedenbro JL. Nitrous oxide for colonoscopy discomfort: a randomized double-blind study.Endoscopy. 1994; 26: 283-286Crossref PubMed Scopus (40) Google Scholar, 31Notini-Gudmarsson AK Dolk A Jakobsson J Johansson C. Nitrous oxide: a valuable alternative for pain relief and sedation during routine colonoscopy.Endoscopy. 1996; 28: 283-287Crossref PubMed Scopus (46) Google Scholar However, an Israeli study33Fich A Efrat R Sperber AD Wengrower D Goldin E. Nitrous oxide inhalation as sedation for flexible sigmoidoscopy.Gastrointest Endosc. 1997; 45: 10-12Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar failed to demonstrate any advantage of inhaling a nitrous oxide/oxygen mixture over inhaling oxygen alone when providing analgesia to patients undergoing sigmoidoscopy. A difference in the inhalation technique was cited by the authors as a possible explanation for the lack of analgesic effectiveness of nitrous oxide in this study as opposed to the findings in all other studies.In none of these studies were any major complications with the use of nitrous oxide/oxygen mixture reported, and several studies have shown that it is safe and effective in patients with cardiac disease.34Kerr F Hoskins MR Brown MG. A double-blind trial of patient controlled nitrous-oxide/oxygen analgesia in myocardial infarction.Lancet. 1975; 1: 1397Abstract PubMed Scopus (24) Google Scholar, 35Baskett PJF Eltringham RJ Bennett JA. An assessment of oxygen tensions obtained with pre-mixed 50% nitrous oxide and oxygen mixture (Entonox) used for pain relief.Anaesthesia. 1973; 28: 449-450Crossref PubMed Scopus (9) Google Scholar, 36Mitchell MM Prakash O O'Rulf EN. Nitrous oxide does not induce myocardial ischemia in patients with ischemic heart disease and poor ventricular function.Anesthesiology. 1989; 71: 526-534Crossref PubMed Scopus (25) Google ScholarClearly no current technique or pharmacologic agent is a worthy substitute for conventional sedation with the possible exception of nitrous oxide in some patients undergoing colonoscopy. In light of this fact, perhaps the equipment and technique for diagnostic EGD should be reviewed. Tolerance for an endoscopic procedure is likely to be dependent on numerous factors. EGD elicits primarily gagging and retching, whereas colonoscopy causes pain by stretching and distending the colon. To make EGD tolerable without sedation, the technique must reduce gagging. It is assumed that this symptom is caused by pressure from the endoscope shaft on the posterior pharynx and greater curve of the stomach. If so, perhaps gagging could be reduced by decreasing the outer diameter of the endoscope. Recent technologic advances have made reducing the diameter of upper endoscopes possible. In the early 1970s, small-caliber fiberoptic endoscopes (7.5 to 8 mm in diameter) were developed primarily for use in pediatrics and were found to be safe and effective.37Akasaka Y Misaki F Miyoaka T Nakajima M Kawai K. Endoscopy in pediatric patients with upper gastrointestinal bleeding.Gastrointest Endosc. 1977; 23: 199-200Abstract Full Text PDF PubMed Scopus (13) Google Scholar, 38Chang M Wang T Hsu J Wang C Yu J. Endoscopic examination of the upper gastrointestinal tract in infancy.Gastrointest Endosc. 1983; 29: 15-17Abstract Full Text PDF PubMed Scopus (25) Google Scholar, 39Prolla JC Diehi AS Bemvenuti GA Loguercio SV Magalhaes DS Silveira TR. Upper gastrointestinal fiberoptic endoscopy in pediatric patients.Gastrointest Endosc. 1983; 29: 279-281Abstract Full Text PDF PubMed Scopus (15) Google Scholar Reports of their use in adults followed.40Gleason WA Danis RK. Gastroscopy per gastrostomy: another indication for the use of a small diameter flexible fibreoptic endoscope.Gastrointest Endosc. 1976; 23: 76-77Abstract Full Text PDF PubMed Scopus (4) Google Scholar, 41Mogan GR Gottfried EB Waye JD. A technique for emergency upper gastrointestinal endoscopy in adults using a small caliber endoscope (GIF-P2).Gastrointest Endosc. 1980; 26: 126-127Abstract Full Text PDF PubMed Scopus (3) Google Scholar, 42Urakami Y Nokihara M Kishi S Seifert E. The GIF-P2 as a panendoscope.Gastrointest Endosc. 1979; 25: 88-91Abstract Full Text PDF PubMed Scopus (3) Google Scholar The "shrink" continues, and recently a new class of instruments with external diameters of 4.0 to 6.0 mm has been developed. With instruments of this caliber, transnasal43Dean R Dua K Massey B Berger W Hogan WJ Shaker R. A comparative study of unsedated transnasal esophagogastroduodenoscopy and conventional EGD.Gastrointest Endosc. 1996; 44: 422-424Abstract Full Text Full Text PDF PubMed Scopus (152) Google Scholar and transmaxillary44DeGregorio BT Poorman JC Katon RM. Peroral ultrathin endoscopy in adult patients.Gastrointest Endosc. 1997; 45: 303-306Abstract Full Text Full Text PDF PubMed Scopus (25) Google Scholar, 45Grier JF Goldman DE Gholson CF. Transmaxillary, percutaneous endoscopic gastrostomy.Gastrointest Endosc. 1994; 40 ([letter]): 778-779PubMed Google Scholar routes for intubation are possible. Smaller caliber endoscopes have been shown to have good patient tolerance44DeGregorio BT Poorman JC Katon RM. Peroral ultrathin endoscopy in adult patients.Gastrointest Endosc. 1997; 45: 303-306Abstract Full Text Full Text PDF PubMed Scopus (25) Google Scholar, 46Mulcahy HE Kelly P Banks M Farthing MJG Fairclough PD Kumar P. Factors associated with tolerance to unsedated upper gastrointestinal endoscopy.Gastrointest Endosc. 1998; 47 ([abstract]): AB56Google Scholar, 47Zaman A Hapke R Sahagun G Katon RM. Unsedated peroral endoscopy with a new video ultra (UT) endoscope: patient acceptance, tolerance and diagnostic ac