Intravenous drip anesthesia with pentothal sodium

INTRAVENOUS

DRIP ANESTHESIA

WITH

PENTOTHAL

SODIUM A REPORT

OF 7,694 CASES

GEOFFREY COTTAM,

M.D.

Sioux Falls, South Dakota

T

HE induction of sIeep for the purpose of accompIishing certain therapeutic procedures painIessIy has IargeIy been done through the use of inhaIation of vapors and gases. 1The most idea1 anesthetic is the one that has the widest range of safety and the one that comes nearest to naturaI sIeep without severe after effects. We beIieve that our experience in over 7,000 operations under intravenous pentotha1 sodium, aIone and in combination, wiI1 throw some Iight on this form of anesthesia. l The data for this paper come from a survey of the anesthetic and operative records of McKennan HospitaI and Sioux VaIIey HospitaI, both of which are Iocated in Sioux FaIIs, S. D. The years Surveyed are 1940 to 1946, incIusive, aIthough we began to use pentotha1 cautiousIy when it first became avaiIabIe. In Iooking over our statistics the reader may be surprised to note that 4,656 of the cases reported were major surgery patients and that these incIude nearly every type of genera1 surgica1 procedure. The Iiterature accompanying pentothal sodium soIutions and various previous articIesF4 warn against the use of this anesthetic for major surgery or proIonged procedures. We began using pentotha1 for major operations and proIonged procedures, for the most part, pureIy by accident and circumstance. It came about quite naturaIIy when some of our surgeons wouId scheduIe a minor operation that wouId turn out to be major, or a short operation that wouId become a long one. For instance, a surgeon wouId start what was to be a quick appendectomy and find that he must do a

bowe1 resection instead. Since the condition of the patient wouId seem satisfactory, the anesthetic wouId not be changed. After a few of these accidenta uses of intravenous pentotha1 one prominent and gratifying resuIt was noted, namely, the postoperative course was smoother than after any other anesthetic. There were fewer cases of vomiting and gas pains, and fewer instances of acute diIatation of the stomach. The recovery period was shorter. Quite by accident we Iearned another vaIuabIe piece of information. When one of our surgeons wouId begin an operation under pentotha1 and Iater switch to an inhaIation anesthetic for better abdomina1 reIaxation, we noted the postoperative recovery was much smoother than if we had used an inhaIation anesthetic aIone. As a resuIt we began to use combination anesthetics.5-7 These combinations wouId vary with the surgeon and the task at hand. Our most popuIar form of anesthetic today is a combination of intravenous pentotha1 sodium, oxygen, cycIopropane and curare. This combination constitutes about 45 per cent of a11 genera1 anesthetics given in our two hospitaIs today. We have never been unmindfu1 of the warnings against the use of intravenous pentothaI2,4’8-‘0 and these warnings and dangers we wish to discuss thoroughIy. We think the dangers previousIy reported were due to the improper administration of the anesthetic or to inexperience. We have deveIoped a safe method of administration and, equaIIy important, pre- and postoperative management. We have had no anesthetic deaths and our postoperative compIications are Iess than ever before in 23

24

American

JOU~IMIof Surgery

Cottam-Intravenous

spite of the increased use of pentotha1. The reader wiIl recaI1 that the main dangers of intravenous pentotha1 have been respiratory and vasomotor depression. A discussion of the evoIution of our present method wiI1 show how improper administration produces these dangerous symptoms of respiratory and vasomotor depression and proper administration avoids them. Since the writer was on the anesthetic committee of McKennan HospitaI for the year 1942, operative records were kept with particular reference to respiration, as to rate, ampIitude and cyanosis. Also bIood pressure readings were plotted on charts and postoperative compIications were added to the anesthetic charts. The age incidence was eight to eighty-seven. 11--13 Evolution. We made mistakes at first; we began with the usua1 preoperative orders of no breakfast, enemas and a preoperative hypodermic of morphine and atropine. We found that if the hypodermic was given too near the time of operation some respiratory depression was evident on induction. We avoided this by giving the preoperative hypodermic one hour before operation. Induction. The psychoIogic effect on the patient who knows he is going to get intravenous anesthesia is noteworthy.‘“14 There is a Iack of apprehension often shown because of fear of the smothering sensation under the mask of an inhaIation anesthetic. We began, Iike everyone eIse, with a 3 per cent soIution in a syringe. We noted an absence of vomiting in the first and second stages, but we were at a Ioss to account for frequent regurgitation of stomach contents into the pharynx. This we found was due to singuItus and it is sometimes so miId it can hardIy be detected. NevertheIess, it is so frequent with intravenous induction that we insist that the head of the tabIe be Iowered unti1 the patient is asIeep and we thereby prevent aspiration of stomach contents by gravity and pharyngea1 suction. This is important. At first we had the patient count out Ioud unti1 he couJd no Ionger count. This we found is unnecessary

Drip

Anesthesia

JULY, 1948

and prevents a more rapid induction. The Ioss of the cornea1 reffex is i good guide that the patient is asIeep.15 In addition, the abdomina1 skin is pinched with tissue forceps in the Iine of the purposed incision. Loss of the pain reflex is an exceIIent sign that the incision can be made. Operation. We were disturbed during the operation by the fact that the anesthetic was not an even one. The respirations wouId at times get shaIIow, the bIood pressure wouId faI1 and at times sIight cyanosis wouId appear. These symptoms would be evident every time the anesthetist wouId use another syringe fuI1 of anesthetic. On the other hand, if the intravenous injection was not given frequentIy, the patient wouId tend to come out of the anesthetic.16-l7 FrankIy, it appeared that the anesthesia wouId .be too deep one minute and too Iight the next. On conferring with our head anesthetist on this unevenness, she suggested that a more even anesthetic might be obtained in a continuous intravenous drip apparatus1v1”1g with a cIamp on the tubing. We were delighted to find that this did away with the unevenness of the anesthetic and we promptIy discarded the syringe and wiI1 not permit its use. Another fact became of interest to us. Some patients sIept for such Iong intervaIs afterward even when smaI1 amounts were given for short procedures. We decided to try weaker soIutions and that definiteIy answered this probIem. Now we never use a soIution that is stronger than I per cent and in very young or very oId peopIe we’ frequentIy use $5 per cent. The average strength of the anesthetic used now in both hospitals is I per cent and the patients wake up promptIy. These points cannot be stressed too much: Pentothal given by syringe is dangerous and soIution strengths above I per cent are not safe. On the other hand, the intravenous drip method with soIution strengths of. I per cent and beIow are not dangerous and can be administered by any average anesthetist. With the syringe method you are pouring into the blood

VOL. L.XXVI, No. I

Cottam-Intravenous

stream and respiratory center far too much potent soIution, far too rapidIy and at uneven intervaIs. Under such circumstances the respiratory center does not wake up as fast as the cornea1 reflex and muscuIar movements. In the sIower, more even intravenous drip method of I per cent soIution at 60 drips a minute the respiratory center keeps pace with the cornea1 reflex and muscular movements so that the anesthetist has more accurate guides to the condition of the respiratory center and thereby avoids disaster. Postoperative Care. We had a run of pulmonary compIications for a whiIe. None of these proved serious but our incidence of atelectasis and postoperative pneumonia, or at Ieast cyanosis, was sIightIy increased. This was found to be caused by the same troubIe that we first had on induction. When the patient is coming out of intravenous anesthesia, we frequently noted miId contractions of the diaphragm which brought up stomach contents to an insensitive pharynx and Iarynx, with subsequent puImonary aspiration. To prevent this we ordered the foot of the bed raised on a11 postoperative patients and instructed a nurse to stand by with an aspirator and tongue bIade unti1 the patient was fuIIy awake. We did this in a11 types of cases, even thyroidectomies, thereby ignoring an old dictum to elevate rather than Iower the operative part.20 One side effect of raising the foot of the bed in a11 postoperative cases is of extreme interest. Our incidence of puImonary embolism promptIy decreased. Our explanation of this seemed to be that elevation of the foot of the bed did not aIIow stagnation of bIood in the veins of the Iower extremities where it couId cIot. In addition, the patients awake very soon after the operation and stir around. We began to encourage patients to move about as soon as they were awake and they now are activeIy hyperventiIated by deep breathing, Ieg and arm exercises and frequent turning. Now that such sutures as tantaIum wire and cotton are in vogue. some of our surgeons

Drip Anesthesia

American

~~~~~~~

of surgery25

have their patients who have undergone major operative procedures in a chair the day after operation. Two other precautions against emboIism may have heIped us, however. First, we never put a tight strap across the knees on the operating tabIe because Ioose ankIe hobbies hoId the patient SatisfactoriIy. Second, piIIows under the knees postoperativeIy are strictIy forbidden. Our incidence of puImonary emboIism as found at postmortem in the two hospitaIs is a fairIy accurate index because we average 38 per cent postmortems in a11 deaths at Sioux Valley Hospital and 32 per cent at McKennan Hospital. Table I shows the incidence of postoperative puImonary emboIism. TABLE

I

Cent ,940 1941 ,942 1943 194419451946

,:;.:,:;i:;

The higher incidence of embohsm at Sioux VaIIey is justified because most of the elderly prostatic resections and severe accident cases go to this hospita1. AIso it is a larger hospita1 and more operations are done there. Pentothal Alone. As to the use of pentothal alone for major operations, patients vary in their toIerance4~8-10 to the anesthetic; and when we find a patient who is not tolerating intravenous pentotha1 weI1, we switch to any type of inhaIation anesthetic that benefits the patient. AI1 types of inhaIation anesthetics can be given with pentotha1 or interchanged with it. Most patients react we11 to pentotha1, however, and we have no hesitency in using it aIone for major procedures regardIess of the Iength or formidability of operation. Another reason for adding or changing to an inhaIation anesthetic is to get more abdomina1 reIaxation and it is better to switch than to overdose with pentotha1. PentothaI does not aIways give enough abdominal reIaxation and curare is too

26

A merican

Journal

of Surgery

Cottam-Intravenous

transient for an operation requiring proIonged abdominal reIaxation. When pentothal is used alone, curare is given in opening the peritoneum and at cIosing. To ihustrate, the Figures for 1946 at McKennan Hospital show that there was a total of 2,739 surgical procedures and 647 of these, such as opening clostomies, etc., required no anesthetic. 1 here were 2,092 anesthetics of a11 kinds given. Of this tota1, I, 154 or better than 50 per cent were intravenous aIone or in combination, and the remainder (938) Iess than 50 per cent were other anesthetics. Considering the Iarge number of tonsiIIectomies done under ether and IocaI anesthetics, this is a good percentage. Glancing at the figures for major anesthetics, which number a tota of 978 with 676 of these under pentotha1 alone or in combination, one sees that better than 68 per cent of a11 major operations were done under pentotha1 aIone or in combination. (TabIe II.) Breaking this down further, we hnd that 237 of the totaI, or 24 per cent of our major operations are done under pentotha1 aIone. TABLE II MCKENNANHOSPITAL 1946 Total surgical procedures. . 2,739 Procedures without anesthesia. 647 Total anesthetics.. . 2,092 (incIuding local) Intravenous anesthesia. 1,154 (alone or in combination) Other anesthesias.. 938 Anesthesia in major operations. 978 Anesthesia in minor operations. I, I 14 Intravenous anesthesia in major 676 (237 were inoperations. travenous alone) Other anesthesia in major operations........................ 202 (generaI) Intravenous anesthesia in minor 488 (272 were inoperations. travenous atone) Other anesthesia in minor opera736 (genera1 and tions. local)

A great deaI has been written about the danger of giving too much pentotha12’s-10~21 or giving it in proIonged operations. We have given as much as 66 gr. (4.290 Gm.) without III effect. We note in going over our records that many of our formidabIe major operations in which pentotha1 aIone was used Iasted three or four hours. When a mask or nasa1 catheter can be used, we

Drip

Anesthesia

JULY,1948

usuaIIy give IOO per cent oxygen throughout the operation when pentotha1 aIone is administered. We rareIy give picrotoxin and only occasionally administer metrazo1. lh Pentotbal in Combination. 4,5,7,l:i,lY.24,25 I do not have the statistics for Sioux VaIIey HospitaI for 1946 but the anesthetic trend is the same in both hospitals. One can see from our statistics at the McKennan HospitaI for 1946 that 44 per cent of the intravenous anesthetics were given in combination with an inhalation anesthetic. The reason for this is apparent when one remembers that most genera1 surgery is done in the abdomen where muscuIar reIaxation is needed. Our procedure is usuaIIy an induction with pentothaI-oxygen and a gradua1 conversion to cyclopropane. We use a No. 20 needIe and have a Y tube connection, with the pentothal on one limb of the Y and norma sahne or 5 per cent gIucose hooked on the other Iimb of the Y. Thus, we frequentIy give fluids during the operation and none has to be given postoperativeIy. There are roIIer stops on each Iimb of the Y so that each Iimb may be shut off or sIowed instantIy if desired. If bIood must be given during the operation, one Iimb of the Y is disconnected and attached to the bIood bottIe. In formidabIe procedures in which shock is sure to deveIop we do not wait for signs of shock but start the transfusion earIy in the operation. Any intravenous medication required during the operation is administered directly through the steriIe rubber tubing which goes to the arm vein. We have purposeIy emphasized the use of this anesthetic in major14-17 operations and have not cIassified a11 the minor procedures because they are reIativeIy unimportant in this discussion, since intravenous used for minor anesthesia is wideIy but not for major procedures. In our cIassification of major procedures some headings wiI1 need a word of expIanation. (TabIe For instance, under the heading III.) “combined operations” are Iisted operations that incIude more than one procedure,

Cottam-Intravenous

Var.. LXXVI, No. I

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such as choIecystectomy and appendectomy, hysterectomy and appendectomy or Iaparotomy and vagina1 combination. Unare der the heading “bowel resections” incIuded traumatic Iesions and acute obstructions principaIIy. The brain operations TABLE III McKennan 1qospita1

AbdominaI adhesions ........ Abdominoperineal resections. ............ Appendectomy. Bowel resection. ........... Brain operations., .......... Cesarean section. ...........

24 I 953 ‘3 3 14 97 I

ChoIecystectomy........... Cholecystgastrostomy....... Combined operations ........ ExpIoratory Iaparotomy ..... ....... Eye operation-major Gastrectomy............... Gastroenterostomy......... Hernia repair. ............. Hysterectomy. .............

348 21 26

Laminectomy .............. Lobectomy (thyroid). ....... Mastectomy. ..............

Sioux Valley Hospital

‘5 6 808 I2 I 13 78 0 321 16 15 6 IO

Unclassified major surgery ... Uretera calculus removed . .

Total intravenous

anesthetic<

45

47

I

6;

283 148 5 99

35’ 313 17 120

::

38 I73

I 0

2,340 I,01 1

-I

37 41 IO

3 92 2

I

SpIenectomy............... Kidney stone. ............. Total majors. .............. Minor operations. ..........

66;

259 82

165 12 21 16 IO7

Thyroidectomy .............

39 7 1,761 25 4 27 I75

4 ‘4 290 89 I 2

0

I

Nephrectomy .............. Orthopedic operations-majo] PeIvic Iaparotomy .......... Perforated peptic ulcer repail Prostatic resection ..........

rota1

3.35

1

0

I I 2,316 2,027 4,355

24 549 171

I

I 2

1 4,656 3,038 7,694

comprise extradura1 and subdura1 hematomas, depressed fractures with dural tears and foreign body penetrations. The Iaparotomies cover mostly expIoratory inoperable carcinomas or paIliative operations for carcinoma. SUMMARY I.

A survey of the use of intravenous pentothal sodium alone and in combination has been given with particuIar emphasis on major surgery.

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of surgery 27

2. Over 7,000 cases have been cited, 4,656 of which were major procedures. There were no anesthetic deaths or serious complications that can be attributed to the anesthetic. 3. A safe preoperative, operative and postoperative routine has been outIined. 4. The advantages of intravenous anesthetics, aIone or in combination, compared to other anesthetics aIone or in combination are: (a) quicker, smoother induction without anxiety on the part of the patient. (b) quicker, smoother postoperative recovery with much Iess nausea and vomiting, gas pains or acute diIatation of the stomach; (c) fewer compIications post0perativeIy. 5. In the Iight of our experience we are incIined to beIieve that most disturbances with intravenous anesthetics are due to improper pre- and postoperative management and faulty administration. REFERENCES I. NARAT, J. K. and GIRALDI, E. Anesthesia, intravenous drip pentotha1 in major surgery. Am. J. Surg., 66: 178, 1944. 2. SCHLAEPFER, K. PentothaI sodium anesthesia in major surgery and its dangers. J. Internat. Coil. Surgeons, 8: 121, 1945. 3. PICKRELL, K. L. and RICHARDS, R. K. Pentothalmetrazo1 antagonism. Ann. Surg., 121: 495, 1945. 4. LUNDY, J. S. and TOUHY, E. B., Newer trends in intravenous anesthesia. Minnesota Med., 26: 349, 1943. 5. BRODY, J. The use of curare in sodium pentothalnitrous oxide-oxygen anesthesia. Anesthesiology, 6: 381, 1945. 6. BORROMEA, M. Intocostrin (curare) with pentotha1 sodium anesthesia. (Read at the Annual Meeting of the American Association of the Nurse Anesthetists of IIIinois, Chicago, March 22, 1945.) 7. LEE, J. A. Combined spinal and pentothal anesthesia in gynecoIogy. Anestb. w Analg., 23: 161, 1945. 8. LEES, J. Idiosyncrasy to pentotha1 sodium. Lancer, 2: 57, 1943. 9. CLAUSEN, R. J. Idiosyncrasy to pentotha1 sodium. LCtnCet,2: 117, 1943. IO. ROBERTS, F. W. Idiosyncrasy to pentotha1 sodium. ihUt, 2: 57, 1943. I I. BAIRD, J. W. Geriatrics and anesthesia. Anestbesiology, 4: 17, 1943. 12. WATTS, E. H. Anesthesia in the aged. Canad. M. A. J., 53: 20, 1945. 13. HAUGEN, F. P. Hypertension: management of the anesthesia period. Anestb. @ Analg., 22: 152, ‘943.

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A merican Journal of Surgery

14. HOLLY, J. D. Pentothal

Cottam-Intravenous

sodium procedures. Am. J. Surg., 62: 15. PAQUET, A. Pentothal anesthesia at the Lava1 Hospital. Anesth.

in major surgical 13, 1943. for thoracoplasty CYA&g., 22: 350,

1943. 16. RANDOLPH, H. and KOBERT, L. The use of pentothal sodium anesthesia in thoracic surgery. J. A. M. A., 121: 1215, 1943. 17. SCHUTT, C. H. Notes regarding the use of intravenous sodium pentothal anesthesia in major surgical cases. Surgery, 18: 43, 1945. 18. STEVENS, E. J. PentothaI sodium; its use in continuous intravenous anesthesia and a method of preserving it in soIution. Anesthesiology, 6: 376, 1945. 19. CYRILLA, M. Continuous drip pentothal with supplementary anesthesia. J. Missouri M. A., 42: 694, 1945.

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Anesthesia

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20. HERANGE, H. L. Anesthesia for head and neck surgery with high frequency eIectrosurgica1 unit. Anesth. CYAnalg., 24: I 19, 1945. 21. HUNTER, A. R. Dangers of pentothal sodium anesthesia. Lancer, r : 46, ,943. 22. FRENCH, E. A. Pentothal sodium oxygen anesthesia in major surgery. Am. J. Surg., 61: 16, 1943. 23. WHITACRE, R. and SANKEY, B. Hypertension: complications and choice of anesthesia. Anestb. &+ Analg., 22: gg, 1943. 24. RI-~-~ER,D. PentothaI sodium anesthesia in general surgery: (a new method of combining it with nitrous oxide and oxygen). Anestb CYAnalg., 24: 25.

205, 1945. MCCANN, J. C. Anesthesia by combined intravenous pentothal sodium and IocaI nerve block. New England J. Med., 233: 55, 1945.