Wednesday, November 08, 2006
You Tube, I Tube, No Tube
We experimented on each other in medical school. Practiced drawing blood, poked arteries, even did rectal exams. In one memorable event, we were blindly divided into three groups to take either iodine, potassium, or placebo prior to doing various thyroid investigations. Rumor spread that in the previous year the pharmacy had mistakenly prepared ten times the proper dose of the iodine prep, causing inflamed salivary glands. In our year, one student claimed pain in his parotid gland, and the entire group of which he was a member stopped taking their pills, screwing up the whole experiment, as student after student fell ill with pain and nausea. No surprise: when the code was broken, it was the placebo group. I still wonder if that was the intended lesson.
In the laboratory, we were regaled with samples of stool from people suffering many malodorous maladies; and noted the look of pride on the face of the prof as he displayed the "normal" specimen. On another day, we were to study gastric juices as influenced by various chemicals. This required the passing of NG tubes (nasogastric tubes; stomach tubes), providing, in addition to interesting data, the first experience most of us had had with inserting or wearing such devices. It broke down along these lines: about one third were unable to accept the NG tube at all; another third were able to receive it but couldn't tolerate it long enough to produce the required results; and the final third had no problems with it at all. What's interesting about this is that in my practice, having inserted countless tubes myself, and having ordered them inserted countless more times, it was exceedingly rare (happened a couple of times, max) that in an actual patient it was impossible to pass a tube. I'd guess it reflects, in some mix of the factors, the difference between having a tube passed by someone who knows how to do it; and the impact of being sick, ie, acknowledging a need for having a tube.
I was in the second group. My student partner was unable to negotiate and I was unable to receive the tube without hopeless retching. Finally a lab doc crammed it into me. Over the next hour (it was supposed to remain for four), by some mystery of physics as yet inexplicable, the diameter of the tube grew -- I'll swear it's true -- to that of a garden hose. Before it split my face wide open, I yanked it out, to the consternation of the instructors, but to the everlasting gratitude of my self, my sinuses, my pharynx, and the top of my head. I learned what I needed to know about gastric physiology from a book or two. And I developed an abiding respect for the misery one of those tubes can cause.
Certain dicta were accepted without question in the misty times of my training. Among the most hallowed were those regarding the need for NG tubes in virtually any patient who underwent abdominal surgery. In stony decalogic, it was decreed that the tube went in during the operation and was removed, in the example of gallbladder surgery and most intestinal surgery, on postop day three. Regardless. Data were neither provided nor requested; it's just the way it was. It was not without rationale: manipulation (whether due to surgery or various illnesses) within the abdominal cavity is often followed by a period of reflexive shut-down of peristalsis, the muscular milking action that moves food through the gut. That reflexive shut-down is called ileus, and at its worst it can be quite serious, with backup of intestinal content into the stomach, leading to vomiting and/or aspiration. There's a certain logic to keeping the stomach deflated after surgery until ileus would have resolved. But there was also arbitrariness: three days for a gallbladder, dammit. Not two, not four. Three. And I dutifully ordered them for all of my patients. It wasn't until laparoscopy came around that people started looking askance. Instead of having large and painful incisions, requiring narcotics, limiting ambulation, these patients were up and around and raring to go. Tubes came out in a day or less, and what happened was nothing. Nothing bad. Something was different, people said, about laparoscopy: less trauma, less ileus. Soon, there were no tubes in those patients.
Meanwhile, I and others had been making gallbladder incisions smaller and smaller without scopes. I'd gotten it down to an inch or two, and saw people ready to rumble in hours, as with laparoscopy. No magical mystery of wind in the abdomen: maybe the tubes just weren't necessary. Eventually, after several generations of credulity, studies were actually done: do a given operation with and without NG tubes, see what happens. And it turns out not only that omitting them caused no problems: saving patients the misery of NG tubes actually speeds recovery. Those tubes, used on gazillions of patients for a hundred years were actually causing more harm than good. Being miserable, it turns out, is miserable. Having a tube sucking on stomachs actually invites ileus. Having been criticized in the remote past for removing tubes too soon out of sympathy for my patients, I found myself using them less and less. Strongly held beliefs (to wit: failure to use a tube when sewing bowel together meant ruptured suture lines) fell away like loosed chains. In the latter years of my practice, I stopped using them altogether in elective surgery: even gastric surgery patients awoke hose-less. About the only situation where they remained a part of my practice was bowel obstruction, in which the patients presented with vomiting and distended guts.
The list is long: keep patients in bed for several days after major abdominal surgery; no food until passing gas; nobody goes home till they have a bowel movement (that's a lot of thousand-dollar turds, don't you think?); jello for the first meal after an operation. We surgeons, while wanting the best for our patients, perseverated in untested interventions that made things worse, for no reason other than having been taught wrongly. It may be that the bed rest thing evolved from the days of crappy sutures: getting up and watching your guts spill out has a suppressive impact on recovery. Pneumonia and blood clots in the legs, highly related to immobility, were just part of the risk and were common. They've receded into rarity of late, in large measure because of mobilizing patients immediately: an incision well closed and numbed with local anesthetic means patients are up walking around within hours of the most major surgery. The single most important part of post op management, in my opinion.
It's a welcome trend: looking at things we do with a freshly-peeled eye; dredging up old axioms and considering them anew. "Best practice" is the buzz word du jour, denoting a worthy goal. I'm no historian, no great student of human nature. But I think it all began with those infernal NG tubes. Maybe enough docs, themselves made miserable by them, were willing -- anxious! -- to flush them into the mucoid medical morass; and the ripples washed away much more in the process.