ANESTHESIA AND ANALGESIA . . . Current Researches VOL. 54, No. 1,JAN.-FEB.,1975
65
Anesthesia for Jejunoileal Shunt: Review of 88 Cases RAY McKENZIE, F.F.A.R.C.S (Ens.)”? EDUARDO M. FIGALLO, M.D. BOONRAK TANTlSlRA, M.D. RAJINDAR
K.
WADHWA, M.D.
CEFERINO S. SINCHIOCO, M.D. Pittsburgh, Pennsylvaniat
Experience with 88 obese patients undergoing jejunoileal shunt is reviewed, with emphasis on preoperative preparation and assessment, conduct of anesthesia, postoperative care, and anesthesia-related complications. There was no intraoperative mortality, and postoperative morbidity was minimal. The operation can be
viewed as a short-term answer t o t h e malignancy of massive obesity, since physiologic abnormalities a r e reversible; however, only hospitals t h a t can provide full surgical, medical, endocrinologic, and anesthesia services, backed by modern ancillary investigative ability, should perform this operation.
“Who ever hears of fat men heading a riot, or herding together in turbulent mobs? ’tis your lean, hungry men who -no-no, are continually worrying society, and setting the whole communily by the ears.”
kg. Heights ranged from 152.4 to 188 cm. One 167.8 cm.woman weighed 214.7 kg.154.8 kg. overweight.
WASHINGTON IRVING
S
medical treatment is so often unsuccessful in coping with obesity, and since refinements in surgical technics for jejunoileal bypass have brought considerable sucoess,I-4 anesthesiologists are being called upon more frequently to manage grossly overweight patients for this operation. This paper reports our experience with 88 patients considered suitable candidates for jejunoileal bypass. All patients had failed to reduce their weight despite years of medical treatment. INCE
THE SERIES There were 19 males and 69 females, averaging 70.8 kg. overweight,5 with weights varying from 81.7 to 216.6 kg., mean 136.7
All patients received comprehensive medical, endocrinologic, and surgical work-up. As the series progressed, respiratory function tests, including forced expiratory capacity (FEC), forced expiratory volume (FEV) , maximum expiratory flow rate (MEFR j , and arterial blood gases were performed more frequently (table 1). Shunt TABLE 1 Respiratory Function Test Results N u m b e r of
Normal
patients
tested
Mean
Range
range
FEC, liters
68
3.02
1.1-4.7
3.6-5.2
FEVI,percent
68
79
57-94
66
MEFR, liters
68
403
21
75.1
Paoz,mm.. Hg room air
120-630 400-620 40-95
97
*Director. tDepartment of Anesthesiology, University of Pittsburgh School of Medicine, Magee-Womens HospitaI, Pittsburgh, Pennsylvania 15213. Paper received: 3/1/74 Accepted for publication: 6/18/74
66
.
ANFSTHESIA AND ANALGESIA Current Researches VOL.54, No. 1, JAN.-FEB., 1975
determination was sometimes necessary. In one case, evaluation included radioactive xenon clearance, intravenous ( I.V.) technitium microspheres, and cardiac catheterization to determine the degree of pulmonary hypertension. Coexisting diseases, diagnosed in 83 patients, included 17 hypertensives, 14 diabetics, 29 with fatty infiltration of the liver, 13 osteoarthritics, and 6 with chronic bronchitis. The most serious coniplications were paroxysmal auricular tachycardia (2) , angina ( 2 ) , previous pulmonary infarcts i2, one of whom had undergone inferior vena cava plication) , bronchiectasis ( 1), and Pickwickian syndrome i1) . Preoperatiue Preparation.-The anesthesiologist visited the patient 3 to 5 days preoperatively, when a chart review was made, the patient examined, and special investigations ordered. Preoperative abnormalities of anesthesia significance included: 1. FEC of 1.8 L. was recorded in one patient whose preoperative diagnosis included chronic bronchitis and asthma. Her FEV, was 94 percent, proving that no obstructive element to respiration was present a t the time of testing. Her Pao, on room air was 95 torr, '. while shunt evaluation implied an 11 percent shunt (normal 2.3 percent).
2. FEV, was reduced below 50 percent in 2 patients. Both reacted well to anesthesia despite this evidence of obstructive pulmonary disease. 3. MEFR deficits from predicted values, implying obstruction to expiration, were fniind in fi6 percent of patients.
4. A patient with severe long-standing bronchiectasis, with copious sputum, required inhalation therapy and physiotherapy with a broad-spectrum antibiotic, which produced suitable improvement. 5. Cardiac problems included two with mild right-sided heart failure and one who failed the Master test.
6. A 43-year-old Pickwickian presented with Pao, of 40 torr and Paco, of 65 torr. Treatment included proscription of smoking, intermittent positive-pressure breathing with 0.25 ml. isoprenaline in 3 ml. normal saline, daily physiotherapy, activity about the hospital for 2 weeks (without any improve*Tom unit of pressure of 1 mm. Hg at On C. and standard gravity.
ment) . Progesterone (100 mg.) administered intramuscularly (I.M.) daily was added to the regime, with reversal of blood-gas values to Pao, 60 torr and Paco, 40 torr.O
A second preoperative uisit on the night before operation established rapport with the patient, permitted review of the chart and of the results of all tests and included assessment of possible difficulty in intubation. I t was not necessary to perform awake intubation on any patients. Explanations included use of endotracheal tubes, following directions, and how to breathe deeply despite pain from the abdominal incision. This indoctrination failed only once. Finally, since each patient had his own particular fears, any remaining questions were encouraged and answered. The Day of Operation.-If, after administration of the I.M. premedication, the patient complained of any respiratory distress, he was placed in a semisitting posture in his bed and then transported to the operating room. On arrival, an I.V. drip of lactated Ringer's + 5 percent glucose was set up via a 16 or 18-gauge cannula. For patients still apprehensive, sedation with l-ml. increments of Innovar@ I.V. was added a s needed.* Two doses usually produced the desired result. Occasionally it was necessary to encourage deep breathing; the patient must not be left alone. Fentanyl 1.V.t is a potent respiratory depressant, reducing the desire to initiate respiration. However, patients will follow a command to breathe deeply. All patients transforrd themselves to thc oprrnting room table. To prevent nerve trauma and postanesthesia position discomfort, they were asked to assume their most comfortable position. The Asteriosonde@ blood-pressure machine was applied and baseline readings recorded a t 1 to 2-minute intervals. With electrocardiographic leads and a Block-Aid@ monitor attached, a baseline blood gas was drawn and preoxygenation by face mask was begun. Znduclion of Anesthesia.-Three mgs. of d-tubocurarine was given 3 minutes before thiamylal induction (dose range 100 to 675 mg.). The mechanics of breathing in the obese require some to be in the semisitting ___ -1 ml. InnovaP contains droperidol 2 5 mg. tanyl 0.05 mg. tl ml. fentanyl contains 0.05 mg. fentanyL
+ fen-
Jejunoileal Shunt.
. . McKenzie, et a1
position. Vasodilation with subsequent reduction in venous return after I.V. barbiturate requires immediate table adjustment at the time a semierect patient goes to sleep. The patient was placed horizontal, with slight elevation of the legs, and an adequate dose of succinylcholine (100 to 150 mg.) was injected slowly. In intubation, the biggest problem was the atraumatic introduction of the blade into the mouth; at times the handle of the laryngoscope had to be laterally rotated to avoid the chest wall. A No. 4 Macintosh blade was of assistance in some, and repeat doses of succinylcholine were required in 6 patients.
67 For the remainder of the operation, relaxation was kept maximal by 15 mg. of curare or 2 mg. of pancuronium, as indicated by the monitor. Maximal relaxation lowers ventilation pressures, and we believe provides better oxygenation. Doses of this magnitude were not given within 45 minutes of the end of operation. At times, 20 to 40 mg. of gallamine provided suitable relaxation for peritoneal closure. Serial radial artery blood samples are mandatory during the operation to confirm adequate oxygenation. Radial artery cannulation preceded by Allen's test7 provided continuous blood-pressure monitoring and blood-gas sampling. Increments of fentanyl were continued at 20 to 30-minute intervals, depending on the clinical assessment of the patient, degree of pupillary constriction, and 5-minute blood pressure and pulse recordings. Bronchospasm occurred twice but was immediately relieved, once by 0.25 percent halothane and once by 0.5 percent enflurane. Of 7 patients not having neuroleptanalgesia, 4 received halothane supplement, while the remaining 3 were given increments of meperidine. All patients were reversed with atropine (1 mg.) and neostigmine (2.5 mg.). This dose was repeated on 10 occasions.
Maintenance.-Nitrous oxide-oxygen (4:2) was administered until succinylcholine wore off, when 30 mg. of d-tubocurarine or 6 to 10 mg. of pancuronium was given. Ventilation of 1000 ml. per breath was measured by Wright's respirometer, placed on the expiratory limb of the anesthetic machine. Pressures averaged 40 cm. of water and settled to 35 cm. of water 4 minutes after the curare or 2 to 3 minutes after pancuronium. Automatic blood-pressure monitoring at 1-minute intervals showed one temporary hypotensive episode of 40 percent fall in systolic pressure in a very excited patient, and four transient falls of 25 percent in systolic pressure in two poorly Postoperative Care.-All patients received premedicated patients. Pancuronium used in place of curare prevented this degree of 100 percent oxygen by face mask or endotracheal tube or ventilator for at least 2 systolic fall. hours (table 2 ) . During this time, blood An esophageal stethoscope was inserted" gases were checked. Patients were extuand an Air-Shields@ventilator was attached bated immediately at the end of operation and set to deliver 1100 to 1400 ml., 12 to in 55 cases. A tidal volume of 350 ml. and 14lmin. After 15 minutes, blood gases were a vital capacity of 1000 ml. are our criteria, checked. As the abdomen was prepared, the associated with the reversal of relaxant third (1 ml.) increment of Innovar or fen- (nerve stimulator) and clinical confirmation tanyl was administered in the I.V. to ensure that all the respiratory muscles were active. total analgesia for the abdominal incision. If there was any doubt about the adeiInnovar or fentanyl are maximal 5 minutes following injection, and the timing should quacy of spontaneous ventilation, the endobe such that summation with maximal cu- tracheal tube was left in place, and 100 perrare effect can be avoided.) We rarely ex- cent oxygen given via T-piece and blood ceeded 4 ml. of Innovar, so that the dose of gases repeated. Tidal volume and vital cadroperidol was kept below 10 mg. Above this pacity were checked at 10-minute intervals. dosage, postoperative side effects are likely, and mental uneasiness can be prolonged for All patients were placed in a semisitting 24 hours postoperatively in some patients. position following operation, to gain maxiWe attempt to time the fourth dose of anal- mum diaphragmatic excursion. (The weight gesic so that it is given 5 minutes prior to of the abdominal wall and increased intraperitoneal incision. abdominal pressure make the diaphragm curve convexly upward when they are kept *These patients were monitored by (1) ECG, (2) horizontal.) The Recovery Room staff exBlock-Aid, (3) Respirometer, (4) Esophageal stethoscope, (5) Blood pressure and pulse, (6) horted them to take deep breaths at 15-minute intervals. Skin and blood color.
AXESTHESIA AND ANALGESIA. . . Current Researches VOL.54, NO.1, JAN.-FEB.,1975
68
TABLE 2
Postoperative Ventilatory Support in 88 Bypass Patients tube postoperatively
RerDirator postoperatively
55
16
17
88
2 hr. 45 min.
3 hr. 6 min.
3 hr. 11min.
2 hr. 54 min.
57.1 mg.
63.3 mg.
75.2 mg.
Number of patients
Mean duration of
anesthesia
Endotracheal
N o endotracheal tube postoperatively
Mean dose of curare
(46)
Mean dose of pancuronium
11.1 mg. (9)
Mean dose of fentanyl
6.9 ml. (49)
(
(11) 12.2 mg.
(13)
(5) 6.4 ml. (15)
(4) 7.8 ml. (13)
13 mg.
Whole
series
59.5 mg. (70) 11.5 mg. (18) 6.9 ml. (75)
1 Denotes number of patients in each category.
ANESTHESIA COMPLICATIONS There were no deaths during the operation or during the immediate postoperative period, although 2 patients have since died. A 61-year-old woman developed viral pneumonia 18 months after operation and died in the intensive care unit after 4 days of mechanical ventilation. A 33-year-old man suffered abdominal dehiscence on the 7th postoperative day; at emergency operation, he aspirated vomitus on induction. Pulmonary edema followed, and he died on the 10th postshunt day despite the use of positive end-expiratory pressure. One patient developed atelectasis on the 2nd postoperative day and another developed phlebitis with pulmonary embolus 6 weeks postoperatively. The average postoperative hospital stay was 12.2 days (range 8 to 27).
DISCUSSION Hypoventilation in the obese has long been recognized8 but is not evident in all patients.g Hackney’s 1959 series of 17 patients averaged Paco, of 66 torr before weight reduction by medical means.lO All agree that there is a reduction of the expiratory reserve volume resulting from decreased chest compliance, raised intra-abdominal pressure, and ventilation perfusion mismatching. The “pure” obesjty patient has no abnormality of FEV or MEFR. Some obese, perhaps following elevation of Pam.,, develop reduced expiratory-center sensitivity.l This possibility has been emphasized by Lyons and Huang,G who reported successful treatment of high resting Paco, with 100 mg. of progesterone I.M. daily in 8 patients. This treatment has been likened to the mild chemical hyperventilation seen during the
luteal phase of the menstrual cycle and hyperventilation during pregnancy. The Paco, again rose following cessation of progesterone therapy. We believe progesterone (100 mg.) I.M. for 2 weeks helped our only Pickwickian, changing the Pao, of 40 torr to 60 torr and Paco, from 65 to 40 torr. The determination of valid blood pressure readings is difficult in the obese. Attempted auscultation over the brachial artery with the blood-pressure cuff around the forearm does not produce readily audible Korotkoff sounds.l, We have found the automatic Doppler Ultrasound accurate and reliable even when the upper arm is huge. The sonic crystals must be placed over the brachial artery-a readily achieved criterion. The automaticity relieves the anesthesiologist of a time-consuming chore in which he often has little faith. Since cannulation provides ready arterial blood sampling as well as accurate recording of blood pressure, we believe this is the method of choice. The cardiovascular status can best be determined by history, chest x-ray of cardiac size, and electrocardiogram with Master test. Those with anginal histories or signs of coronary insufficiency cannot afford bloodpressure falls during operation. l 3 Increased cardiac diameter is common in obesity r e gardless of hypertension.12-14Blood volume and cardiac output both rise in parallel with excess body weight. As the heart rate remains normal, stroke volume and minute work increase. Oxygen consumption also rises with excess weight.12 Bromagel5 has stressed the value of regional procedures for operations on obese patients. Apart from the technical difficulty
69
Jejunoileal Shunt. . . McKenzie, et a1
of placing an epidural catheter correctly in the 400-pounder, the patient is often uncomfortable if poised horizontally atop the 20-inch operating table, and sedation is difficult without dangerously lowering Pao,.s Venti1ation:perfusion relationships are disturbed by anesthesia and intermittent positive-pressure ventilation, but a recent publication illustrates the ability of end-expiratory pressure to achieve adequate oxygenation.lG Neuroleptanalgesia remains our anesthesia of choice, although we have used halothane when indicated, despite a high incidence (29 patients) of fatty infiltration of the liver, proved by biopsy. Follow-up enzyme studies have not been frequent enough to note any differences in enzyme levels postoperatively, nor have 6-monthly liver biopsies detected any ill effect due to halothane. We must stress the value of the shortacting narcotic agent, fentanyl, which adds an element of control over the duration of respiratory depression. Meperidine and morphine, by their longer action, require more frequent ventilator assistance in the postoperative period. Oxygenation has the highest priority. Innovar reduces oxygen c0nsumption.~7Preinduction Innovar appears to maintain oxygenation in obese patients with 33 percent oxygen. Sixty-six percent nitrous oxide provides basic anesthesia, equivalent to 0.5 minimal alveolar concentration (MAC). Total fentanyl dosage (including Innovar) ranged from 2 to 14 ml. (mean 7 ml.) for cases of 2 to 5 hours duration (mean almost 3 hours). A recent reportla determined the 0.5 MAC equivalent of morphine sulfate at 45 mg./sq.m. at the end of 30 minutes. Thus 13.2 ml. of fentanyl would be required to reach 0.5 MAC. This level was not achieved in our patients, yet awareness was not a problem. Had intraoperative Pao, been unsatisfactory, an inhalational anesthetic agent would have been required. Enflurane would have been our agent of choice in these circumstances, in view of its low percentage of biotransformation. Our incremental regime for neuroleptanalgesics (NLA) and confirmed reversal of neuromuscular blockade enables patients to breathe spontaneously from the end of operation, and our impression is that they progres more rapidly than when ventilated mechanically. The total dosage of NLA is
much lower than reported for renal transplants.19 We did not reverse the narcotic in any patient. Finally, teamwork among our departments of Endocrinology, General Surgery, and Anesthesiology enabled performance of 88 procedures without intraoperative mortality. Morbidity related to anesthesia for this operation was minimal, as exemplified by the mean postoperative stay of 12.2 days.
REFERENCES 1. Editorial: Operations for obesity. Brit Med J 4:247-248, 1971
2. Payne J H , DeWind LT: Surgical treatment of obesity. Amer J Surg 1118:141-147, 1969 3. Scott H W Jr, Law D H IV, Sandstead HH, et al: Jejunoileal shunt in surgical treatment of morbid obesity. Ann Surg 171:770-782, 1970
4. Salmon PA: The results of small intestine bypass operations for the treatment of obesity. Surg Gynec Obstet 132:965-979, 1971 5. Desirable weights for men Statist Bull 40:3, 1959
and
women.
6. Lyons HA, Huang CT: Therapeutic use of progesterone in alveolar hypoventilation associated with obesity. Amer J Med 44:881-888, 1968 7. Greenhow DE: Incorrect performance of Allen’s testulnar-artery flow erroneously presumed inadequate. Anesthesiology 37:356-357, 1972 8. Miller WF, Bashour FA:- Cardiopulmonary changes in obesity. Clin Anesth 3:128-139, 1963
9. Barrera F, Reidenberg MM, Winters WL, et al: Ventilation-perfusion relationships in the obese patient. J Appl Physiol 26:420-426, 1969 10. Hackney JD, Crane MG, Collier CC, et al: Syndrome of extreme obesity and hypoventilation: studies of etiology. Ann Intern Med 51:541-552, 1959
11. Burwell CS, Robin ED, Whaley RD, et al: Extreme obesitv associated with alveolar hvDoventilation-a Pickwickian syndrome. Amer J Med 21:811-818, 1956
65
Anesthesia for Jejunoileal Shunt: Review of 88 Cases RAY McKENZIE, F.F.A.R.C.S (Ens.)”? EDUARDO M. FIGALLO, M.D. BOONRAK TANTlSlRA, M.D. RAJINDAR
K.
WADHWA, M.D.
CEFERINO S. SINCHIOCO, M.D. Pittsburgh, Pennsylvaniat
Experience with 88 obese patients undergoing jejunoileal shunt is reviewed, with emphasis on preoperative preparation and assessment, conduct of anesthesia, postoperative care, and anesthesia-related complications. There was no intraoperative mortality, and postoperative morbidity was minimal. The operation can be
viewed as a short-term answer t o t h e malignancy of massive obesity, since physiologic abnormalities a r e reversible; however, only hospitals t h a t can provide full surgical, medical, endocrinologic, and anesthesia services, backed by modern ancillary investigative ability, should perform this operation.
“Who ever hears of fat men heading a riot, or herding together in turbulent mobs? ’tis your lean, hungry men who -no-no, are continually worrying society, and setting the whole communily by the ears.”
kg. Heights ranged from 152.4 to 188 cm. One 167.8 cm.woman weighed 214.7 kg.154.8 kg. overweight.
WASHINGTON IRVING
S
medical treatment is so often unsuccessful in coping with obesity, and since refinements in surgical technics for jejunoileal bypass have brought considerable sucoess,I-4 anesthesiologists are being called upon more frequently to manage grossly overweight patients for this operation. This paper reports our experience with 88 patients considered suitable candidates for jejunoileal bypass. All patients had failed to reduce their weight despite years of medical treatment. INCE
THE SERIES There were 19 males and 69 females, averaging 70.8 kg. overweight,5 with weights varying from 81.7 to 216.6 kg., mean 136.7
All patients received comprehensive medical, endocrinologic, and surgical work-up. As the series progressed, respiratory function tests, including forced expiratory capacity (FEC), forced expiratory volume (FEV) , maximum expiratory flow rate (MEFR j , and arterial blood gases were performed more frequently (table 1). Shunt TABLE 1 Respiratory Function Test Results N u m b e r of
Normal
patients
tested
Mean
Range
range
FEC, liters
68
3.02
1.1-4.7
3.6-5.2
FEVI,percent
68
79
57-94
66
MEFR, liters
68
403
21
75.1
Paoz,mm.. Hg room air
120-630 400-620 40-95
97
*Director. tDepartment of Anesthesiology, University of Pittsburgh School of Medicine, Magee-Womens HospitaI, Pittsburgh, Pennsylvania 15213. Paper received: 3/1/74 Accepted for publication: 6/18/74
66
.
ANFSTHESIA AND ANALGESIA Current Researches VOL.54, No. 1, JAN.-FEB., 1975
determination was sometimes necessary. In one case, evaluation included radioactive xenon clearance, intravenous ( I.V.) technitium microspheres, and cardiac catheterization to determine the degree of pulmonary hypertension. Coexisting diseases, diagnosed in 83 patients, included 17 hypertensives, 14 diabetics, 29 with fatty infiltration of the liver, 13 osteoarthritics, and 6 with chronic bronchitis. The most serious coniplications were paroxysmal auricular tachycardia (2) , angina ( 2 ) , previous pulmonary infarcts i2, one of whom had undergone inferior vena cava plication) , bronchiectasis ( 1), and Pickwickian syndrome i1) . Preoperatiue Preparation.-The anesthesiologist visited the patient 3 to 5 days preoperatively, when a chart review was made, the patient examined, and special investigations ordered. Preoperative abnormalities of anesthesia significance included: 1. FEC of 1.8 L. was recorded in one patient whose preoperative diagnosis included chronic bronchitis and asthma. Her FEV, was 94 percent, proving that no obstructive element to respiration was present a t the time of testing. Her Pao, on room air was 95 torr, '. while shunt evaluation implied an 11 percent shunt (normal 2.3 percent).
2. FEV, was reduced below 50 percent in 2 patients. Both reacted well to anesthesia despite this evidence of obstructive pulmonary disease. 3. MEFR deficits from predicted values, implying obstruction to expiration, were fniind in fi6 percent of patients.
4. A patient with severe long-standing bronchiectasis, with copious sputum, required inhalation therapy and physiotherapy with a broad-spectrum antibiotic, which produced suitable improvement. 5. Cardiac problems included two with mild right-sided heart failure and one who failed the Master test.
6. A 43-year-old Pickwickian presented with Pao, of 40 torr and Paco, of 65 torr. Treatment included proscription of smoking, intermittent positive-pressure breathing with 0.25 ml. isoprenaline in 3 ml. normal saline, daily physiotherapy, activity about the hospital for 2 weeks (without any improve*Tom unit of pressure of 1 mm. Hg at On C. and standard gravity.
ment) . Progesterone (100 mg.) administered intramuscularly (I.M.) daily was added to the regime, with reversal of blood-gas values to Pao, 60 torr and Paco, 40 torr.O
A second preoperative uisit on the night before operation established rapport with the patient, permitted review of the chart and of the results of all tests and included assessment of possible difficulty in intubation. I t was not necessary to perform awake intubation on any patients. Explanations included use of endotracheal tubes, following directions, and how to breathe deeply despite pain from the abdominal incision. This indoctrination failed only once. Finally, since each patient had his own particular fears, any remaining questions were encouraged and answered. The Day of Operation.-If, after administration of the I.M. premedication, the patient complained of any respiratory distress, he was placed in a semisitting posture in his bed and then transported to the operating room. On arrival, an I.V. drip of lactated Ringer's + 5 percent glucose was set up via a 16 or 18-gauge cannula. For patients still apprehensive, sedation with l-ml. increments of Innovar@ I.V. was added a s needed.* Two doses usually produced the desired result. Occasionally it was necessary to encourage deep breathing; the patient must not be left alone. Fentanyl 1.V.t is a potent respiratory depressant, reducing the desire to initiate respiration. However, patients will follow a command to breathe deeply. All patients transforrd themselves to thc oprrnting room table. To prevent nerve trauma and postanesthesia position discomfort, they were asked to assume their most comfortable position. The Asteriosonde@ blood-pressure machine was applied and baseline readings recorded a t 1 to 2-minute intervals. With electrocardiographic leads and a Block-Aid@ monitor attached, a baseline blood gas was drawn and preoxygenation by face mask was begun. Znduclion of Anesthesia.-Three mgs. of d-tubocurarine was given 3 minutes before thiamylal induction (dose range 100 to 675 mg.). The mechanics of breathing in the obese require some to be in the semisitting ___ -1 ml. InnovaP contains droperidol 2 5 mg. tanyl 0.05 mg. tl ml. fentanyl contains 0.05 mg. fentanyL
+ fen-
Jejunoileal Shunt.
. . McKenzie, et a1
position. Vasodilation with subsequent reduction in venous return after I.V. barbiturate requires immediate table adjustment at the time a semierect patient goes to sleep. The patient was placed horizontal, with slight elevation of the legs, and an adequate dose of succinylcholine (100 to 150 mg.) was injected slowly. In intubation, the biggest problem was the atraumatic introduction of the blade into the mouth; at times the handle of the laryngoscope had to be laterally rotated to avoid the chest wall. A No. 4 Macintosh blade was of assistance in some, and repeat doses of succinylcholine were required in 6 patients.
67 For the remainder of the operation, relaxation was kept maximal by 15 mg. of curare or 2 mg. of pancuronium, as indicated by the monitor. Maximal relaxation lowers ventilation pressures, and we believe provides better oxygenation. Doses of this magnitude were not given within 45 minutes of the end of operation. At times, 20 to 40 mg. of gallamine provided suitable relaxation for peritoneal closure. Serial radial artery blood samples are mandatory during the operation to confirm adequate oxygenation. Radial artery cannulation preceded by Allen's test7 provided continuous blood-pressure monitoring and blood-gas sampling. Increments of fentanyl were continued at 20 to 30-minute intervals, depending on the clinical assessment of the patient, degree of pupillary constriction, and 5-minute blood pressure and pulse recordings. Bronchospasm occurred twice but was immediately relieved, once by 0.25 percent halothane and once by 0.5 percent enflurane. Of 7 patients not having neuroleptanalgesia, 4 received halothane supplement, while the remaining 3 were given increments of meperidine. All patients were reversed with atropine (1 mg.) and neostigmine (2.5 mg.). This dose was repeated on 10 occasions.
Maintenance.-Nitrous oxide-oxygen (4:2) was administered until succinylcholine wore off, when 30 mg. of d-tubocurarine or 6 to 10 mg. of pancuronium was given. Ventilation of 1000 ml. per breath was measured by Wright's respirometer, placed on the expiratory limb of the anesthetic machine. Pressures averaged 40 cm. of water and settled to 35 cm. of water 4 minutes after the curare or 2 to 3 minutes after pancuronium. Automatic blood-pressure monitoring at 1-minute intervals showed one temporary hypotensive episode of 40 percent fall in systolic pressure in a very excited patient, and four transient falls of 25 percent in systolic pressure in two poorly Postoperative Care.-All patients received premedicated patients. Pancuronium used in place of curare prevented this degree of 100 percent oxygen by face mask or endotracheal tube or ventilator for at least 2 systolic fall. hours (table 2 ) . During this time, blood An esophageal stethoscope was inserted" gases were checked. Patients were extuand an Air-Shields@ventilator was attached bated immediately at the end of operation and set to deliver 1100 to 1400 ml., 12 to in 55 cases. A tidal volume of 350 ml. and 14lmin. After 15 minutes, blood gases were a vital capacity of 1000 ml. are our criteria, checked. As the abdomen was prepared, the associated with the reversal of relaxant third (1 ml.) increment of Innovar or fen- (nerve stimulator) and clinical confirmation tanyl was administered in the I.V. to ensure that all the respiratory muscles were active. total analgesia for the abdominal incision. If there was any doubt about the adeiInnovar or fentanyl are maximal 5 minutes following injection, and the timing should quacy of spontaneous ventilation, the endobe such that summation with maximal cu- tracheal tube was left in place, and 100 perrare effect can be avoided.) We rarely ex- cent oxygen given via T-piece and blood ceeded 4 ml. of Innovar, so that the dose of gases repeated. Tidal volume and vital cadroperidol was kept below 10 mg. Above this pacity were checked at 10-minute intervals. dosage, postoperative side effects are likely, and mental uneasiness can be prolonged for All patients were placed in a semisitting 24 hours postoperatively in some patients. position following operation, to gain maxiWe attempt to time the fourth dose of anal- mum diaphragmatic excursion. (The weight gesic so that it is given 5 minutes prior to of the abdominal wall and increased intraperitoneal incision. abdominal pressure make the diaphragm curve convexly upward when they are kept *These patients were monitored by (1) ECG, (2) horizontal.) The Recovery Room staff exBlock-Aid, (3) Respirometer, (4) Esophageal stethoscope, (5) Blood pressure and pulse, (6) horted them to take deep breaths at 15-minute intervals. Skin and blood color.
AXESTHESIA AND ANALGESIA. . . Current Researches VOL.54, NO.1, JAN.-FEB.,1975
68
TABLE 2
Postoperative Ventilatory Support in 88 Bypass Patients tube postoperatively
RerDirator postoperatively
55
16
17
88
2 hr. 45 min.
3 hr. 6 min.
3 hr. 11min.
2 hr. 54 min.
57.1 mg.
63.3 mg.
75.2 mg.
Number of patients
Mean duration of
anesthesia
Endotracheal
N o endotracheal tube postoperatively
Mean dose of curare
(46)
Mean dose of pancuronium
11.1 mg. (9)
Mean dose of fentanyl
6.9 ml. (49)
(
(11) 12.2 mg.
(13)
(5) 6.4 ml. (15)
(4) 7.8 ml. (13)
13 mg.
Whole
series
59.5 mg. (70) 11.5 mg. (18) 6.9 ml. (75)
1 Denotes number of patients in each category.
ANESTHESIA COMPLICATIONS There were no deaths during the operation or during the immediate postoperative period, although 2 patients have since died. A 61-year-old woman developed viral pneumonia 18 months after operation and died in the intensive care unit after 4 days of mechanical ventilation. A 33-year-old man suffered abdominal dehiscence on the 7th postoperative day; at emergency operation, he aspirated vomitus on induction. Pulmonary edema followed, and he died on the 10th postshunt day despite the use of positive end-expiratory pressure. One patient developed atelectasis on the 2nd postoperative day and another developed phlebitis with pulmonary embolus 6 weeks postoperatively. The average postoperative hospital stay was 12.2 days (range 8 to 27).
DISCUSSION Hypoventilation in the obese has long been recognized8 but is not evident in all patients.g Hackney’s 1959 series of 17 patients averaged Paco, of 66 torr before weight reduction by medical means.lO All agree that there is a reduction of the expiratory reserve volume resulting from decreased chest compliance, raised intra-abdominal pressure, and ventilation perfusion mismatching. The “pure” obesjty patient has no abnormality of FEV or MEFR. Some obese, perhaps following elevation of Pam.,, develop reduced expiratory-center sensitivity.l This possibility has been emphasized by Lyons and Huang,G who reported successful treatment of high resting Paco, with 100 mg. of progesterone I.M. daily in 8 patients. This treatment has been likened to the mild chemical hyperventilation seen during the
luteal phase of the menstrual cycle and hyperventilation during pregnancy. The Paco, again rose following cessation of progesterone therapy. We believe progesterone (100 mg.) I.M. for 2 weeks helped our only Pickwickian, changing the Pao, of 40 torr to 60 torr and Paco, from 65 to 40 torr. The determination of valid blood pressure readings is difficult in the obese. Attempted auscultation over the brachial artery with the blood-pressure cuff around the forearm does not produce readily audible Korotkoff sounds.l, We have found the automatic Doppler Ultrasound accurate and reliable even when the upper arm is huge. The sonic crystals must be placed over the brachial artery-a readily achieved criterion. The automaticity relieves the anesthesiologist of a time-consuming chore in which he often has little faith. Since cannulation provides ready arterial blood sampling as well as accurate recording of blood pressure, we believe this is the method of choice. The cardiovascular status can best be determined by history, chest x-ray of cardiac size, and electrocardiogram with Master test. Those with anginal histories or signs of coronary insufficiency cannot afford bloodpressure falls during operation. l 3 Increased cardiac diameter is common in obesity r e gardless of hypertension.12-14Blood volume and cardiac output both rise in parallel with excess body weight. As the heart rate remains normal, stroke volume and minute work increase. Oxygen consumption also rises with excess weight.12 Bromagel5 has stressed the value of regional procedures for operations on obese patients. Apart from the technical difficulty
69
Jejunoileal Shunt. . . McKenzie, et a1
of placing an epidural catheter correctly in the 400-pounder, the patient is often uncomfortable if poised horizontally atop the 20-inch operating table, and sedation is difficult without dangerously lowering Pao,.s Venti1ation:perfusion relationships are disturbed by anesthesia and intermittent positive-pressure ventilation, but a recent publication illustrates the ability of end-expiratory pressure to achieve adequate oxygenation.lG Neuroleptanalgesia remains our anesthesia of choice, although we have used halothane when indicated, despite a high incidence (29 patients) of fatty infiltration of the liver, proved by biopsy. Follow-up enzyme studies have not been frequent enough to note any differences in enzyme levels postoperatively, nor have 6-monthly liver biopsies detected any ill effect due to halothane. We must stress the value of the shortacting narcotic agent, fentanyl, which adds an element of control over the duration of respiratory depression. Meperidine and morphine, by their longer action, require more frequent ventilator assistance in the postoperative period. Oxygenation has the highest priority. Innovar reduces oxygen c0nsumption.~7Preinduction Innovar appears to maintain oxygenation in obese patients with 33 percent oxygen. Sixty-six percent nitrous oxide provides basic anesthesia, equivalent to 0.5 minimal alveolar concentration (MAC). Total fentanyl dosage (including Innovar) ranged from 2 to 14 ml. (mean 7 ml.) for cases of 2 to 5 hours duration (mean almost 3 hours). A recent reportla determined the 0.5 MAC equivalent of morphine sulfate at 45 mg./sq.m. at the end of 30 minutes. Thus 13.2 ml. of fentanyl would be required to reach 0.5 MAC. This level was not achieved in our patients, yet awareness was not a problem. Had intraoperative Pao, been unsatisfactory, an inhalational anesthetic agent would have been required. Enflurane would have been our agent of choice in these circumstances, in view of its low percentage of biotransformation. Our incremental regime for neuroleptanalgesics (NLA) and confirmed reversal of neuromuscular blockade enables patients to breathe spontaneously from the end of operation, and our impression is that they progres more rapidly than when ventilated mechanically. The total dosage of NLA is
much lower than reported for renal transplants.19 We did not reverse the narcotic in any patient. Finally, teamwork among our departments of Endocrinology, General Surgery, and Anesthesiology enabled performance of 88 procedures without intraoperative mortality. Morbidity related to anesthesia for this operation was minimal, as exemplified by the mean postoperative stay of 12.2 days.
REFERENCES 1. Editorial: Operations for obesity. Brit Med J 4:247-248, 1971
2. Payne J H , DeWind LT: Surgical treatment of obesity. Amer J Surg 1118:141-147, 1969 3. Scott H W Jr, Law D H IV, Sandstead HH, et al: Jejunoileal shunt in surgical treatment of morbid obesity. Ann Surg 171:770-782, 1970
4. Salmon PA: The results of small intestine bypass operations for the treatment of obesity. Surg Gynec Obstet 132:965-979, 1971 5. Desirable weights for men Statist Bull 40:3, 1959
and
women.
6. Lyons HA, Huang CT: Therapeutic use of progesterone in alveolar hypoventilation associated with obesity. Amer J Med 44:881-888, 1968 7. Greenhow DE: Incorrect performance of Allen’s testulnar-artery flow erroneously presumed inadequate. Anesthesiology 37:356-357, 1972 8. Miller WF, Bashour FA:- Cardiopulmonary changes in obesity. Clin Anesth 3:128-139, 1963
9. Barrera F, Reidenberg MM, Winters WL, et al: Ventilation-perfusion relationships in the obese patient. J Appl Physiol 26:420-426, 1969 10. Hackney JD, Crane MG, Collier CC, et al: Syndrome of extreme obesity and hypoventilation: studies of etiology. Ann Intern Med 51:541-552, 1959
11. Burwell CS, Robin ED, Whaley RD, et al: Extreme obesitv associated with alveolar hvDoventilation-a Pickwickian syndrome. Amer J Med 21:811-818, 1956
