Rapid sustained recovery after cardiac operations

J

THORAC CARDIOVASC SURG

1990;100:194-7

Rapid sustained recovery after cardiac operations After successful cardiac operations in the early 1980s the most common causes of prolonged hospitalizations were noncardiac disorders. We prevented or quickly corrected these noncardiac disorders after operations in succeeding patients and observed in the foUowing 2 years that the shortest postoperative stays in the hospital were foUowed by the fewest rehospitalizations. In 240 consecutive patients the median length of hospital stay after operation was 4 days. The operations included coronary artery bypass procedures, aortic valve replacements, and mitral valve operations. Six patients (2.5 %) were rehospitalized within 6 months after discharge and five patients (2.1 %) were rehospitalized 6 to 24 months after discharge: Longer initial hospitalizations would not have prevented rehospitalizations. Forty of the 240 patients were discharged on the third postoperative day or earBer (one patient). None died or were rehospitalized in the foUowing 2 years. Prevention or quick correction of noncardiac disorders aUowed rapid recovery after heart operations, and rapid recovery indicated that health would be maintained.

Bernard G. Krohn, MD, FACC, Jerome H. Kay, MD, FACC, Michael A. Mendez, MD, FACC, Pablo Zubiate, MD, FACC, and Gregory L. Kay, MD, FACC, Los Angeles, Calif.

Improved surgical technique and perioperative management help patients recover more quickly now than in the past. This is remarkable because surgery is no longer applied to the less severe cardiac abnormalities, which are now improved by medicine or angioplasty, but is reserved for the most severe abnormalities. However, despite perfect cardiac repairs many patients die or linger in the hospital after the operations because of noncardiac disorders. We observed that noncardiac disorders started as small problems that could be prevented or corrected promptly, but if they were not managed promptly they became difficult or impossible to improve. Furthermore, one problem often begat another; for example, first a patient had gastric irritation, next he did not eat, next he became too weak to walk, and next he had a pulmonary embolus. It appeared that noncardiac disorders required the earliest possible treatment. This study sought to determine if more rapid recovery after cardiac operations and the resulting earlier discharge from the hospital caused any change in subsequent rehospitalization or death rates. In short, did early success From The Hospital of The Good Samaritan, Los Angeles, Calif. Received for publication Dec. 13, 1988. Accepted for publication July 12, 1989. Address for reprints: Bernard G. Krohn, MD, 16250 Woodruff Ave., Bellflower, CA 90706.

12/1/21218

194

mean ultimate success? The study also aimed to see if a simple exercise test could help select patients who were well enough and strong enough to go home and not require rehospitalization in the following 6 months. Methods Selection of patients. On a cardiac surgical service that performs more than 1000 cardiac operations per year, several cardiology services provide perioperative care. This report limits itself to 240 consecutive patients treated by one cardiologist (B.G.K.) from Dec. 1, 1984, through Dec. 31, 1986. These patients were all the patients requiring cardiac operations in this cardiology practice with no exceptions. The surgical.service was a tertiary referral service. Surgical protocol. A membrane oxygenator with moderate systemic cooling was used for cardiopulmonary bypass in all patients requiring a cardiac operation. Cold blood or crystalloid cardioplegia, single dose and multidose, was used at the surgeon's discretion. Patients of all six surgeons on the surgical service were included in this study. Valve repair or replacement was done in a standard manner. Myocardial revascularization was accomplished with autogenous vein or mammary artery conduits. According to the preference of the surgeon, the proximal anastomoses were done first, before cardiopulmonary bypass, or last when on cardiopulmonary bypass. Vasopressors and intraaortic balloon support were used as needed. Perioperative management 1. Before the operation patients were told what to expect and what to do after the operation so that they could participate in the recovery process. 2. Methylprednisolone 5 rug/kg of body weight was given intravenously within 6 hours before the operation to minimize inflammation and resulting soreness. Within 4 hours after oper-

Volume 100 Number 2 August 1990

Sustained recovery after cardiac operations 1 9 5

Table I. Deaths within 30 days ofoperation Initial diagnosis

I. Coronary artery disease, hypertension, obstructivelung disease, chronic nephropathy, carotid artery obstruction 2. Coronary artery disease status post triple coronary bypass surgery 5 years previously; hypertension; chronic pulmonary disease 3. Recent nontransmural myocardial infarction with persistent ischemia, congestive heart failure, diabetes mellitus, hypertension, nephropathy 4. Bacterial endocarditis with ruptured sinus of Valsalva,septicemia,

Ejection fraction

0.65

0.50

Cause of death

Postoperative chronic bleeding with cardiac tamponade Angiographic dissection of arteries.

New acute myocardial infarction

Endocarditis, septicemia, pneumonitis.

pneumonitis

5. Coronary artery disease, ischemia, shock

0.30

Shock

ation 6 mg of dexamethasone was given intravenously, followed by four doses of dexamethasone 2 mg each given 6 hours apart. 3. Prophylactic cephalosporin antibiotic was administered perioperatively. 4. Patients were extubated as early as possible, even if this meant extubation during the night. 5. The night of operation patients were encouraged to sit on the edge of the bed and, if possible, to stand next to the bed or to sit in a chair. 6. Digoxin was given intravenously, 12llg/kg of lean body weight within 6 hours after operation, to prevent fast ventricular rates resulting from supraventricular tachycardias, other than sinus tachycardia. Peak body digoxin stores were raised to 15llg/kg oflean body weight on the first day after operation and maintained there unless a supraventricular tachycardia developed, at which time peak body stores were raised to 17 or 19 Ilg/kg of lean body weight to slow the ventricular rate. I -3 7. Serum potassium was kept at approximately 4 mEq/L throughout the postoperative period, patients receiving 8 mEq of potassium chloride in a wax matrix pill twice a day while the serum potassium was at this desired level. 8. Adequate analgesia was provided intravenously for 24 hours followed by oral analgesics (usually oxycodone plus acetaminophen) . 9. Fluid intake was restricted to 500 to 1000 ml for at least 24 hours after operation to minimize visceral edema. 10. Food intake and uptake were promoted by giving all patients whatever food they could swallowstarting shortly after

Table II. Mortality rate in 240 consecutive patients No. Deaths in hospital Deaths within 6 mo after discharge Sudden cardiac death Hepatitis Pancreatic cancer Deaths 6-24 mo after discharge Cardiac Noncardiac

5 3

%

2 1.5

II 5

2

6

2.5

extubation, regardless of known metabolic or cardiovascular diseases. When appetite improved, appropriate therapeutic diets were ordered. 11. Metoclopramide 10 mg four times a day and cimetidine 300 mg four times a day were given first intravenously and then orally during the first 3 postoperative days. 12. Exercise testing was performed on the third postoperative day or sooner. Exercise test. The cardiologist, counting the patient's pulse, walked along with the patient 200 feet at the pace of a visitor. The criteria for passing were as follows: I. Increase in heart rate of less than 15 beats per minute 2. No abnormalities in the telemetered electrocardiogram during exercise 3. No undue fatigue or dyspnea

Criteria for a patient to be eligible for discharge home

I. Stable cardiac rhythm 2. Oral temperature of 99.2° F or lower 3. Stable hematocrit level of 25% or higher (hemoglobin value of 8 gm/dl or higher) 4. Oral intake of at least 1000 calories per day 5. Successful completion of exercise test 6. Absence of significant wound problems 7. Absence of active complications 8. Confident desire to go home 9. Ability to report progress from home adequately to physician by telephone Factors not contraindicating discharge. Poor left ventricular function, valvular heart operation, advanced age, previous cardiac operation, leukocytosis,hypertension, diabetes mellitus, and chronic obstructive lung disease, individually or in combination, were not considered contraindications for discharge. Follow-up after discharge. All patients called one of us (B.G.K.) on the telephone daily for I week after discharge. Patients reported progress, including daily temperature readings, and received advice needed.

Routine discharge medications

I. Analgesics included acetaminophen 325 mg four times a day for I week and propoxyphene hydrochloride 65 mg every 4 hours if needed in addition to acetaminophen to relieve pain for all patients. 2. Flurazepam 30 mg was given at night if needed. 3. Ferrous sulfate 324 mg pills were given twice a day after meals if the hematocrit level was below 32%. 4. Digoxin (peak body stores) 10 Ilg/kg oflean body weight for 2 months was given for patients with low ejection fractions and patients with heart failure before or after operation. All patients who had regular sinus rhythm when they entered the

The Journal of Thoracic and Cardiovascular Surgery

1 9 6 Krohn et al.

Table III. Rehospitalization after 240 heart

Table IV. Patients discharged on third day after

operations

heart operations

Within 6 mo after discharge Postpericardiotomy syndrome Arrhythmias New obstruction in artery Congestive heart failure Total 6-24 mo after discharge Acute myocardial infarction Heart failure Noncardiac chest pain Total

2 2 I

1

6 (2.5%) 3 I

Year

Patients on service ofB.G.K.

Patients discharged on third day

1983 (December) 1984 1985 1986 Totals

4 107 63 68 240

7 5 27 40

I

1

5 (2.1 %)

hospital went home with regular sinus rhythm. Nevertheless, if they hadsupraventricular tachycardia (other thansinus tachycardia) during hospitalization, with a heart rate faster than70 beats/min, these patients were given daily digoxin to maintain peak body stores at 15 ILg/kg oflean body weight for 1 week at home. Patients who hadatrialfibrillation before andafterhospitalization were given enough digoxin tokeep ventricular rates slower than 100 beats/min. 5. Dipyridamole 75mgthree times a dayplus aspirin 80mg daily was given to patients who had undergone myocardial revascularization. 6. Warfarin was given topatients who hadundergone valvular operations. Results

Of the 240 patients who had operations during this study, five died, for a hospitalmortality rate of 2.1%.The causesof death in the hospitaland the preoperative diagnosesare listed in Table I. In the first 6 months after discharge, three patients (1.5%) died of causes shown in Table II and six patients (2.5%) were rehospitalized for causes shown in Table III. Table II also gives the causes of death and the mortality rate in the first 2 years after discharge from the hospital: Six patients died (14%). Table III also givesthe rehospitalizations in the first 2 years after discharge: 11 patients (4.7%).Lengthsof stay in the hospitalafter operation for 235 of the original 240 patients are givenin Fig. 1:The median was 4 days. The patients in Fig. 1 include 12 who had mitral valveoperations:Three of these weredischargedon the fourth postoperative day and the rest between the fifth and tenth postoperative days.Three patientshad operationson both the aortic and mitral valves. Twenty-five patients had aortic valve replacement, including nine who also had coronary artery bypassgrafts insertedand three whoalso had a mitral valve operation. Forty patients were discharged on the third day after the operation, exceptingone who was discharged on the secondday. Three of the 40 had aortic valvereplacement. The mean number of grafts per patient was 2.53 ± 0.95 (standard deviation). Mean ejection fraction of the left

ventriclewas 0.59 ± 0.13 (standard deviation); four had an ejectionfraction of 0.35 or less. Sevenoperationswere done as emergencies after unsuccessful coronary angioplasties. Before operation 16 patients had hypertension, two diabetes mellitus, nine previous myocardial infarction,and four previous coronaryartery bypassoperations. The 40 patients dischargedon the third day after operation were all men, excepting one woman. Thirty-five percent wereaged 60 to 69 years,noneolder.After discharge all patients were free of angina pectoris and able to resume active lives without rehospitalization in the following 2 years. These 40 werea youngersubsetof our whole set of 240 patients in which 20%were 65 years of age or older:Five were 75 to 79 years old, and the mean postoperative day of dischargefor these five was 6.2 days. One 71-year-old woman who had mitral valvereplacement went horneon the seventhday after operation.One 71-year-old man had the aortic valve replaced and had one coronary artery bypassgraft inserted;he wasdischargedon the fourthday after operation. Sixteen patients aged 65 or older were dischargedon the fourth or third day after operationand werealiveand well2 yearslater withoutrehospitalization. Discussion

The main causesof rehospitalization" and death- after cardiac operationswerefailureof noncardiacorgans.For patients under 69 years of age the rate of rehospitalizations in the first 6 months after discharge was 24%.4 In our study, deaths after discharge also resulted mostly from noncardiac causes. The mortality rates for our patients were similar to those reported by the collaborative university study." Longer hospitalization would not have preventedthe deaths in our patients. In contrast to the patients in other studies,our patients required rehospitalization onlyto treat cardiac problems. The rehospitalization rate in the first 6 months after discharge in our study was 2.5o/0---0ne tenth the aforementioned rate. The exercisetests performedon the third postoperative days successfully identified patients who were well

Volume 100 Number 2 August 1990

Sustained recovery after cardiac operations 1 9 7

N 100, U M

94

J

B E R

o

80

60

F P

A

40 .

T I

E

N T

S

20

o o +---+--t 2

2 3

4

5

2

2

0

0

2

6 7 8 9 10 11 12 13 14 15 16 17 18 24 27 114 DAYS IN HOSPITAL AFTER OPERATION

Fig. 1. Hospital stay of 235 patients after operation: median = 4 days.

enough to go home. These patients continued to recover, and by telephone they reported that they were glad to be home. In many hospitals postoperative stays after coronary artery bypass operations are now shorter than the previously reported 10.8 days" and 10.2 days.' Table IV shows that in our series each year a higher percentage of patients is being discharged on the third day after operation. Patients who passed the exercise test on the third or fourth day after operation were more robust than those who passed it on the seventh day or later. Prognosis depended not on condition before operation but on condition after operation. Patients discharged on the third postoperative day (including one discharged on the second postoperative day) had the lowest subsequent morbidity and mortality rates. This fits the general propositions that prognosis is best for well persons, and it is better to get well sooner rather than later. The 16 patients aged 65 or older who were discharged on the fourth or third day after operation demonstrated that rapid sustained recovery was not reserved for the young. The patients presented herein are not identical with the patients in the reader's hospital. Nevertheless, it seems likely that in most hospitals the patients who recovered most rapidly subsequently had lower morbidity and mortality rates. In the present study the rapid recovery resulted in part from preventing or quickly correcting disorders of noncariliac organs.

AddenduQl After this study was completed, maximum treadmill cardiopulmonary tests were preformed on fivepatients on the third day after coronary artery bypass operations just before they went home. All patients exercised to maximum predicted heart rates, with no angina pectoris and no ischemic changes in the electrocardiograms, and none required rehospitalization or died in the following 2 years. REFERENCES 1. Jelliffe RW. An improved method of digoxin therapy. Ann Intern Med 1968;69:703-17. 2. Jelliffe RW. Digitalis therapy: simple formulas to plan and adjust dosage regimens. MD Comput 1984;1:36-42. 3. Krohn BG, Saenz JM, Eto KK. The critical dose of digoxin for treating supraventricular tachycardias after heart surgery. Chest 1989;95:729-34. 4. Stanton BA, Jenkins CD, Goldstein RL, et al. Hospital readmissions among survivors six months after myocardial revascularization. JAMA 1985;253:3568-73. 5. Acinapura AJ, Rose DM, Cunningham IN, et al. Coronary artery bypass in septuagenarians. Circulation 1988;78(Pt 2):1179-84. 6. Roberts AJ, Woodhall DD, Conti CR, et al. Mortality, morbidity, and cost-accounting related to coronary artery bypass graft surgery in the elderly. Ann Thorac Surg 1985;39:426-32. 7. Wagner DP, Wineland TD, Knaus W A. The hidden costs of treating severely ill patients: charges and resource consumption in an intensive care unit. Health Care Rev Fin Fall 1983;5:81-6.