special article incidence and management of...

SPECIAL ARTICLEThe Incidence and Management of "Medical"Complications Foilowing Cardiac Operations

By JOHN F. WILLIAMS, JR., M.D., ANDREW G. MoRRow, M.D., AND

EUGENE BRAUNWALD, M.D.

THE DIRECT MORTALITY associatedwith operations upon the heart and great

vessels has steadily declined as surgeons havebecome more familiar with the operativemanagement of various congenital and ac-

quired malformations, and as improvementshave been made in methods of preoperativepreparation, the conduct of cardiopulmonarybypass, and in postoperative management.Nevertheless, complications secondary to theoperation, usually occurring in the early post-operative period, may still represent seriousthreats to the patient's survival. These com-

plications involve disturbances in the cardiacrhythm and contractile state, electrolyte bal-ance, as well as in the functions of the renal,pulmonary, gastrointestinal, hematopoietic,or central nervous systems. Because of thenature of these complications, they are man-

aged most effectively by the combined effortsof internist or cardiologist and the cardiovas-cular surgeon, and are frequently termed the"<medical" complications of cardiac operations.Some of these complications are seen only inpostoperative patients; although others mayalso occur in patients who have not beenoperated upon, their manifestations and meth-ods of management may be quite differentwhen they arise during the early postoperativeperiod.

Despite the steadily increasing number ofpatients undergoing corrective cardiac opera-

tions, the incidence of associated complicationsand the setting in which they occur have re-

ceived relatively little attention. The presentreport describes experiences with the "medi-cal' complications that arose in the earlypostoperative period of a consecutive series

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of 150 adult patients who were operatedupon at the National Heart Institute and whowere studied in a prospective manner.

Clinical Material and Definition ofComplications

The 150 patients comprising the study rangedin age from 16 to 63 years (average 38 years).Thirty-seven had congenital heart disease, 87had chronic rheumatic valvular heart disease,four had idiopathic hypertrophic subaortic steno-sis, and one had a myxoma of the right ventricle.Twenty-one patients had isolated aortic valvedisease with pure or predominant stenosis, and inthem it was not possible to determine with cer-tainty whether the lesion was congenital orrheumatic in origin. One hundred thirty-one ofthe operations were performed with the aid oftotal cardiopulmonary bypass, provided by a rotat-ing disc oxygenator and roller pumps; the other19 operations were closed procedures. Total re-placement of the aortic or mitral valve, or both,with a Starr-Edwards prosthesis was carried outin 89 patients (table 1).The 150 patients included in this study all

survived the operative procedure and werereturned to the intensive-care unit. Only compli-cations that occurred before the patient's dis-charge from the hospital were analyzed. Bleed-ing from the operative site, which could not beattributed to a coagulation disorder, was specifi-cally excluded from the compilation.

ResultsA total of 187 "medical" complications oc-

curred in 107 patients (table 1), and were di-rectly responsible for deaths of 15 patients;no such complication occurred in the other 43patients. The incidence of the various compli-cations is summarized in table 2.

I. Arrhythmias

A. Atrial Fibrillation

This arrhythmia occurred in 11 patients, allof whom had been in sinus rhythm before op-

eration. Four of these patients had undergoneCirculation, Volume XXXII, October 1965

From the Cardiology Branch and the Clinic ofSurgery, National Heart Institute, Bethesda, Maryland.

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COMPLICATIONS AFTER CARDIAC SURGERY

Table 1Incidence of Major "Medical" Complications in Various Operative Procedures

No. of No. ofOperative procedure operations complications

A. Acquired valvular diseaseMitral valve replacement (Starr-Edwards)Closed mitral commissurotomyOpen mitral commissurotomyMitral and tricuspid valve replacementAortic valve replacement (Starr-Edwards)Aortic and mitral valve replacementAortic and mitral commissurotomyAortic valve replacement and mitral commissurotomyAortic commissurotomy and mitral valve replacementAortic, mitral, and tricuspid commissurotomy

TotalB. Congenital heart disease

Closure of ostium primum defectClosure of ventricular septal defect (VSD)Closure of VSD and aortic valve replacementCorrection of VSD and infundibular pulmonic stenosisResection of coarctation of the aortaResection of discrete subaortic stenosisCorrection of tetralogy of FallotBlalock procedure for tetralogy of FallotBrock procedure for tetralogy of FallotCorrection of transposition of the great arteriesAortic valve replacement-Marfan's syndrome

TotalC. Pure or predominant aortic stenosis

Aortic valve replacementAortic commissurotomy

TotalD. Others

Ventriculomyotomy for idiopathic hypertrophicsubaortic stenosisResection of myxoma of the right ventricle

Total

mitral replacement, and four aortic valve re-

placement. One patient had had a closed mi-tral commissurotomy, one closure of an atrialseptal defect, and the other a left ventriculo-myotomy for idiopathic hypertrophic subaorticstenosis. Eight of these 11 episodes occurredduring the first 3 postoperative days, while one

episode each occurred on the fourth, sixth, andthirteenth days. In one patient moderate hy-poxemia may have contributed to the develop-ment of the arrhythmia, whereas in the otherpatients no specific contributing factors were

evident. Since all patients undergoing intra-cardiac operations in this clinic are digitalizedCirculation, Volume XXXII, October 1965

beforehand, treatment of atrial fibrillation re-

quired only supplementary doses of digoxinto control the ventricular rate. Ten of the 11patients subsequently reverted to normal sinusrhythm during their hospitalization withoutspecific administration of antiarrhythmic drugsor electrical conversion.Fourteen patients who had been in atrial

fibrillation at the time of operation developedsinus rhythm when electrical conversion ofventricular fibrillation was carried out prior totermination of cardiopulmonary bypass. Thir-teen of these patients had undergone valvereplacement, and one ventriculomyotomy for

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Table 2Incidence of Postoperative Complications

Types of complications

I. Arrhythmias (total)A. Atrial fibrillationB. Atrial flutterC. Nodal tachycardiaD. Atrioventricular block

1. Complete heart block2. Wenckebach phenomenon3. Electrical asystole

E. Ventricular tachycardiaF. Ventricular fibrillation

II. Congestive heart failureIII. Low cardiac output syndromeIV. Electrolyte disturbances (total)

A. HyperkalemiaB. HypokalemiaC. Hyponatremia

V. Renal complicationsVI. Central nervous system complications (to

A. EmboliB. Acute brain syndrome

VII. InfectionsVIII. Pulmonary complicationsIX. Postpericardiotomy syndromeX. Postperfusion syndromeXI. HemolysisXII. Hemorrhagic diathesisXIII. Gastrointestinal hemorrhageXIV. Hypertension

hypertrophic subaortic stenosis. Eight of these14 patients were placed on maintenance quini-dine; four of them remained in sinus rhythmbut the other four reverted to atrial fibrillation.However, the six patients who were not givenquinidine all reverted to atrial fibrillation.

B. Atrial Flutter

Of the 12 patients who developed thisarrhythmia, five had undergone valve replace-ments, four involving the aortic and one themitral valve. Four patients had had closure ofan atrial septal defect, two closed mitral com-missurotomies, and one an infundibulectomyfor tetralogy of Fallot. In eight patients atrialflutter occurred during the second or thirdpostoperative days; in the others it developedbetween the tenth and twenty-sixth days. Withthe exception of a prolonged period of hypox-emia in one patient, no specific precipitatingfactors were evident. The administration of

Number of patients

46

14563

78

4111613234

1112510

532

44

172224

53

digoxin was successful in controlling the ven-tricular rate and reverting the rhythm to asinus mechanism in eight patients, while fourrequired electroconversion.

C. Nodal TachycardiaFive patients developed nodal tachycardia.

The ventricular rates ranged between 150 and200 per minute, and all episodes occurredduring the first 5 postoperative days. Three pa-tients had undergone aortic valve replace-ments, one both aortic and mitral valve re-placement, and one closure of an atrial septaldefect. In one patient the occurrence of thisarrhythmia was related to the administrationof isoproterenol by nebulization, the arrhyth-mia occurring each time the nebulizer wasused. In another patient severe hypoventila-tion and hypoxemia precipitated nodal tachy-cardia, which reverted to sinus rhythm whenassisted ventilation was provided and addition-

Circulation, Volume XXXII, October 1965

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al digoxin was administered. In the otherthree patients no etiologic factors were found,and sinus rhythm was restored with only in-creased doses of digoxin.Nodal rhythm with ventricular rates be-

tween 60 and 110 per minute at the conclusionof an operation is such a common occurrence,particularly in patients undergoing valve re-placement, that it has not been included as acomplication. Correction of this arrhythmia hasnot been attempted, since it rarely persists forlonger than 48 hours and does not appear toaffect the patient's cardiovascular status ad-versely. It is unlikely that this rhythm is amanifestation of digitalis intoxication, sincedigoxin administration has generally been con-tinued without untoward effect.

D. Atrioventricular Block and Asystole

Five patients had complete heart block at theconclusion of the operative procedure, andtemporary stimulating electrodes were insert-ed. Three had undergone aortic valve replace-ment, and one closure of a ventricular septaldefect. These four patients developed sinusrhythm, two within hours of the operation,one on the second, and one on the eighteenthpostoperative day. In the fifth patient, heartblock was persistent following relief of idio-pathic hypertrophic subaortic stenosis, and apermanent pacemaker was inserted.Three patients developed the Wenckebach

phenomenon, which subsided with cessationof digoxin therapy. In two of these patientsthe serum potassium was below 3.5 mEq./L.,and in the third it was normal at the time thearrhythmia began. Two patients exhibited acomplete lack of cardiac electrical activity im-mediately after aortic valve replacement. Tem-porary electrodes were attached to the rightventricle and the heart rate was maintainedwith an external cardiac pacemaker. Both pa-tients developed sinus rhythm within 72 hours,allowing removal of the electrodes.

E. Ventricular TachyeardiaThis arrhythmia occurred in four patients,

frequent premature ventricular contractionshaving preceded the tachycardia in each ofthem. Three patients had had mitral valve re-


placement, and one had undergone closure ofa ventricular septal defect. In three patientsdigitalis intoxication, associated with a lowserum potassium level in one, may have beenthe inciting factor. The fourth patient devel-oped atrial fibrillation with a rapid ventricularresponse that was interrupted by bursts of ven-tricular tachycardia, and after termination ofthe ventricular tachycardia, increased amountsof digoxin were required to control the rapidrate. In three patients the arrhythmia consistedof recurrent episodes of ventricular tachycar-dia of short duration, which were successfullycontrolled with quinidine, procaine amide, orintravenous lidocaine; in the fourth patientventricular tachycardia was refractory to drugsand was treated successfully with electricalcountershock.

F. Ventricular Fibrillation

Excluding the development of ventricularfibrillation as the event terminating othercomplications, this arrhythmia occurred in fourpatients, each of whom exhibited frequentpremature ventricular contractions precedingthe fibrillation. Two patients had undergoneaortic valve replacement, and the othersreplacement of two valves each. A pheo-chromocytoma, unsuspected at the time ofoperation, was probably causally related inone patient, while severe hypertension andhypoxia preceded ventricular fibrillation in an-other. Although all patients were successfullyresuscitated initially by means of externalmassage and electrical countershock, two sub-sequently died of recurrent ventricular fibril-lation, in spite of the prophylactic use of pro-caine amide, quinidine, or lidocaine.

G. Comment

The experience with the patients describedabove indicates that serious arrhythmias area frequent occurrence after cardiac operations.Ventricular extrasystoles were so common inthe early postoperative period, particularlyfollowing valve replacement, that they werenot included in this compilation of major com-plications. It must be emphasized, however,that frequent ventricular extrasystoles preced-ed more serious ventricular arrhythmias (ven-

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tricular fibrillation or tachycardia) in each ofthe eight patients in whom the latter occurred.All but one of these serious ventricular arrhyth-mias occurred in patients who had under-gone replacement of one or more valves. Itis also of interest that 25 per cent (4 of 16) ofthe patients who had undergone closure ofostium secundum atrial septal defects devel-oped atrial flutter, and that 16 of the 23 epi-sodes of atrial flutter and fibrillation occurredwithin the first 3 postoperative days. Althoughthe detection and corrections of abnormalities,such as digitalis intoxication, electrolyte dis-turbances, hypoxia, acidosis, and hypotension,which may produce or contribute to the oc-currence of these arrhythmias, are essential,specific causative factors could not be identi-fied in the majority of patients, particularlythose who developed supraventricular arrhyth-mias. While most arrhythmias can in timebe corrected with appropriate drug therapyor the removal of the inciting causes, thereare some patients in whom the occurrence ofan arrhythmia results in rapid clinical dete-rioration. Since such patients are vulnerable tothe development of severe and possibly ir-reversible hypotension, as well as ventricularfibrillation, when their already abnormal myo-

cardial function is further compromised, theimmediate application of external electricalcountershock can be life saving. In the treat-ment of arrhythmias with digitalis glycosidesthe possibility that patients in the early post-operative period exhibit an increased sensitiv-ity to digitalis should be considered.

II. Congestive Heart FailureFourteen patients, 12 of whom had had

valve replacements, developed an exacerba-tion of congestive heart failure following op-

eration. All had been in heart failure pre-

operatively, but were considered to be wellcompensated at the time of the surgical pro-

cedure. Marked tricuspid regurgitation, whichhad been inadvertently created at operation,was the causative factor in one patient. Con-gestive failure usually was manifested byweight gain and edema with relatively fewpulmonary symptoms and often occurred after

an increase in the dietary sodium intake. Onepatient developed acute pulmonary edema,which responded rapidly to the usual thera-peutic measures. All but two patients werecontrolled adequately with digoxin, sodiumrestriction, and diuretic therapy. These twopatients had marked tricuspid regurgitationand could not be kept free from edema despitea strict cardiotonic regimen. It is of interestthat the majority of patients who suffered fromcongestive failure preoperatively did not de-velop this complication postoperatively, nordid they require diuretic therapy at the timeof discharge from the hospital, even thoughsodium intake at that time was only moderate-ly restricted, usually to 50 mEq./day.

III. Low Cardiac Output SyndromeThe clinical picture presented by patients

with this syndrome, which may be considereda variant of the heart failure state, is character-ized by hypotension, an elevated venous pres-sure, severe vasoconstriction with peripheralcyanosis, and progressive metabolic acidosis.In all five patients who developed this compli-cation it occurred during the first 24 postoper-ative hours. Three of these patients had hadvalve replacements, one closure of a septumsecundum atrial septal defect, and the fifth acorrective operation for complete transpositionof the great arteries. Four patients died, andat autopsy none was found to have cardiactamponade or atrial thrombosis, frequentcauses for the syndrome, and the specific eti-ology could not be determined. VWhile the lowcardiac output syndrome appears to resultfrom myocardial failure, pre-existing severemyocardial disease is not an essential pre-requisite, since one patient had an uncompli-cated atrial septal defect. However, it is ofinterest that this patient, in whom Arfonadwas used to overcome the severe vasoconstric-tion, was also the only survivor in the group.In the management of this serious complica-tion, it is essential to exclude the presence, notonly of cardiac tamponade, but also of hypo-volemia and of metabolic acidosis, which actedas the inciting factor. In addition, inadequatesurgical correction of the underlying defects


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and, in particular, the persistence of severetricuspid regurgitation may be of etiologic im-portance.

IV. Electrolyte DisturbancesA. Hyperkalemia

Seventeen patients developed serum potas-sium levels of 6.0 mEq./L. or greater. Extra-corporeal circulation had been used in all and13 of them had undergone valve replacement.In 16 of these patients hyperkalemia developedduring the first 24 postoperative hours. A di-minished urinary output was considered to bea precipitating or contributing factor in fourpatients, one of whom developed acute renalfailure as a result of hypotension and hemo-globinuria. Three patients, one of whom wasoliguric, were acidotic at the time of their hy-perkalemia. Although serum potassium levelswere determined routinely on two or three oc-casions during the first 24 hours, electrocardio-graphic abnormalities were the first indicationof the development of hyperkalemia in threepatients, two of whom died before attempts atcorrection could be made. A multiplicity offactors, such as extravascular collections ofblood, multiple blood transfusions, hemolysis,and acidosis, in patients in whom renal func-tion is often diminished, probably contributeto the development of these elevated serumpotassium levels. The need for frequent serumpotassium determinations during the first 24postoperative hours is apparent from this ex-perience.

B. HypokalemiaSerum potassium levels of less than 3.5

mEq./L. were recorded in 22 patients. In 16of them hypokalemia developed during thesecond to fourth postoperative days, whereasin two patients each it appeared on the first,tenth, and fifteenth days. In five of the 22patients, hypokalemia was associated with re-spiratory alkalosis while they were receivingrespiratory assistance; five other patients hadreceived an ion exchange resin in the treat-ment of hyperkalemia. In four patients hypo-kalemia was associated with the postoperativeadministration of thiazide diuretics; three ofthem had also received these drugs until at

COrculation, Volume XXXII, October 1965

least 7 days preoperatively. Five patients whodeveloped hypokalemia had received thiazidediuretics in the immediate preoperative peri-od and, although they had also been givensupplementary potassium and had normal se-rum potassium levels at the time of operation,their total body potassium stores may wellhave been reduced. The adrenocortical re-sponse to operation, the development of respir-atory alkalosis, or the administration of agentsto lower elevated serum potassium levels maythen have precipitated hypokalemia.Although the correction of hyperkalemia is

essential, frequent measurements of serum po-tassium are mandatory when potent potassiumdepleting agents are used, as exemplified bythe following brief case report.

B.H., a 23-year-old man, underwent replace-ment of his aortic and mitral valves for severerheumatic valvular disease. He had been re-ceiving chlorothiazide for several months prior tohis admission, but this was discontinued 2 weeksbefore operation. However, he received threeinjections of mercuhydrin during the 10 dayspreceding his operation. The serum electrolyteson the day preceding and on the evening follow-ing operation were normal, and his urinary out-put during the early postoperative period wasadequate. On the morning of the first postopera-tive day his electrocardiogram demonstrated afirst-degree AV block with wide QRS com-plexes. The serum electrolytes were sodium 137mEq./L., potassium 7.7, chloride 99, and carbondioxide 27; the blood urea nitrogen was 30mg. per cent and the pH 7.44. He was given a100-Gm. sodium polystyrene sulfonate enema,but following this the serum potassium remainedelevated at 7.6 mEq./L. He was given an addi-tional 50-Gm. sodium polystyrene sulfonate ene-ma and the serum potassium declined to 6.5mEq./L. and then to 5.1 mEq./L. An electro-cardiogram revealed atrial fibrillation with nar-rowing of the previously widened QRS com-plexes. On the following morning the serumpotassium was 4.5 mEq./L., and the blood ureanitrogen 36 mg. per cent, while during the next2 days the potassium fell to 3.5 and then to 2.5mEq./L., necessitating the oral administration oflarge amounts of supplementary potassium.The electrocardiogram is of limited value in

the diagnosis of altered serum potassium lev-els, since both abnormally elevated and de-pressed levels have been found in patientswhose electrocardiograms did not reveal char-

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acteristic changes. In addition, electrocardio-graphic findings suggestive of alterations inpotassium concentration occur relatively fre-quently after cardiac operations in patientswith normal serum potassium concentrations.

C. HyponatremiaSerum sodium concentrations of less than

130 mEq./L. occurred in 24 patients. In 22patients hyponatremia was probably due tooverhydration, since these patients gainedweight postoperatively, and the urinary sodi-um excretions determined in several were lessthan 5 mEq./L. at a time when the serumsodium concentration was falling. Althoughthe fluid intake was usually restricted to 1,000to 1,800 ml. a day during the first postopera-tive days, even this amount of fluid was evi-dently a greater load than these patients werecapable of excreting. Two patients had serumsodium levels below 130 mEq./L. prior tooperation, and developed even lower concen-trations postoperatively. Further restriction offluid intake, and the occasional use of a mer-curial diuretic, resulted in the restoration ofnormal serum sodium concentrations in all butthree of the 22 patients. The three patientswith persistent postoperative hyponatremia allhad marked residual tricuspid regurgitation.

In only two patients was hyponatremia con-sidered a result of sodium loss. One patienthad intestinal losses of sodium during an epi-sode of small bowel obstruction, while in theother excessive urinary sodium losses occurredin the diuretic phase after a transient periodof renal failure.

V. Renal ComplicationsRenal complications occurred in seven pa-

tients, five of whom developed renal failurecharacterized by symptomatic azotemia, withblood urea nitrogen levels exceeding 100 mg.per cent. In these five patients the occurrenceof renal failure was unexpected, and not pre-dictable, from their preceding clinical courses.None had antecedent renal disease; three ofthem had short periods of hypotension duringthe first postoperative day, which respondedrapidly to blood replacement, but in retro-spect may have been responsible for the sub-

sequent development of renal insufficiency. Inspite of azotemia, these patients were neveranuric; one of them never excreted less than500 ml. of urine a day (fig. 1) and the urinaryoutput in the other four patients never fellbelow 300 to 500 ml. a day. Hemoglobinuriawas present in only one patient, and only twodeveloped hyperkalemia. These episodes ofrenal failure were somewhat unusual in that anumber of other patients with urinary out-puts of less than 500 ml. a day, or with hypo-tension of equal or greater severity than thatwhich occurred in these five patients, did notdevelop significant azotemia. Since the urinaryoutput was between 1 and 2 liters a day andthe serum potassium was normal by the timethe blood urea nitrogen exceeded the highestlevel that is commonly observed in the earlypostoperative period (50 mg. per cent), themanagement of the renal insufficiency con-sisted mainly of maintaining an appropriatefluid intake and restricting the administrationof those drugs excreted by the kidney, par-ticularly digoxin and streptomycin. These fivepatients did not develop the massive diuresisor electrolyte abnormalities often seen duringthe recovery phase of acute tubular necrosis,and all recovered from the episode of renalfailure.

In addition to the five patients with tran-sient renal failure described above, one patientdeveloped a rapid nodal tachycardia, resultingin hypotension and subsequently in acute renalinsufficiency. He eventually died of general-ized Candidiasis following peritoneal dialysis.The other patient developed a hemothorax,hypotension, transient oliguria, a blood ureanitrogen of 110 mg. per cent, and symptomsof azotemia, but recovered with conservativemanagement.

VI. Complications Involving the CentralNervous System

A. Cerebral EmboliFive patients suffered cerebral emboli, four

had had valve replacement; one the mitralvalve, two the aortic valve, and one bothmitral and aortic. The fifth patient had aclosed mitral commissurotomy. One patient


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MARCH

BUNMGMS %

(0) Ii

KmEq/L(1)

FLUI DN TAKEcc/DAY

URINEVOLUMEcc/DAY

Urine Urfine Urine urineNo 22 No 36 WI2/ NG29K'60 A65 K/if5 A20

mEq/L m4ql mEq/LZ mEq/L

Figure 1

Blood urea nitrogen (BUN), serum potassium concentration (K), fluid intake, and urinaryvolume in a patient who unexpectedly developed azotemia following aortic valve replace-ment. CR, serum creatinine; NR, not recorded.

never regained consciousness following aorticvalve replacement and remained in a decere-brate condition until his death, which was at-tributed to air emboli. The patient undergo-ing mitral commissurotomy developed atrialflutter, then atrial fibrillation, and eventuallynormal sinus rhythm. She then became ataxicand developed a right facial weakness, butrecovered with only mild residual signs. Allpatients undergoing mitral valve replacementreceived anticoagulants (warfarin), but twosuch patients (one of whom also had hisaortic valve replaced) had the sudden onsetof localized neurologic abnormalities fromwhich they recovered completely. Anticoagu-lants had been discontinued prior to the epi-sode in one patient because of the presence of

a hemothorax, and in the other patient the


prothrombin time was only slightly above thecontrol value on the day the cerebral embolusoccurred. The fifth patient was thought tohave suffered a cerebral embolism on thefifteenth day following aortic valve replace-ment. Treatment with anticoagulants was theninitiated, but she died 10 days later; a massivecerebral hemorrhage was found at necropsy.

B. Acute Brain Syndrome

Three patients, two of whom had mitralvalve replacements and one a combined aorticand mitral valve replacement, developed dis-orientation, impairment of recent memory,short attention span, confabulation, hallucina-tions, and delusions. The syndrome developedbetween the fourth and sixth day, and persist-ed for 2 to 7 days. No patient had a history of

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neuropsychiatric disorder prior to operation,and none had disturbances of serum electro-lytes, blood gases, or other obvious factorsthat could have been responsible for theiraltered cerebral function. Treatment with tran-quilizers and sedatives was effective in control-ling the symptoms in each instance.

VII. Infections

Four patients acquired infections, and allultimately succumbed to this complication.Two patients died from disseminated Candi-diasis; in one of them, as already noted, Can-dida peritonitis occurred during peritoneal di-alysis for acute renal failure, while the otherdeveloped a pulmonary infection with thefungus prior to its dissemination. One patientdeveloped a generalized infection due to anorganism in the Serratia group from a primarypulmonary focus. The fourth patient developedan ultimately fatal infection at the site of in-sertion of a Starr-Edwards aortic prosthesis.The aortic valve had been replaced with aTeflon Muller prosthesis a year previously, andthe patient had active Staphylococcus albusendocarditis on admission. He was treated for6 weeks with appropriate antibiotics, with anapparent clinical cure, and because the Teflonvalve was regurgitant, it was replaced with aStarr-Edwards prosthesis. Six weeks followingthis operation, however, and in spite of con-tinuous antibiotic administration, he developedrecurrent endocarditis due to the same or-ganism.The occurrence of fever in the postopera-

tive period always suggests the possibility ofbacterial endocarditis, and the problem isfurther compounded by the fact that splinterhemorrhages are noted in approximately 25per cent of our patients in the early postopera-tive period. Although fever commonly per-sisted or recurred after the first few postopera-tive days, this was clearly attributable toinfection in only four patients, and to bacterialendocarditis in only one; in each of these 4patients the diagnosis was easily established.In this clinic penicillin and streptomycin aregiven prophylactically to all patients before

and for 7 days after cardiac operations, butthe relatively low incidence of infection inthese 150 patients is principally attributable tothe aseptic technics applied at operation andthe relatively unique surgical environment pro-vided in the Clinical Center.

VIII. Pulmonary ComplicationsExcluding the pulmonary infections de-

scribed above, 11 patients developed pulmo-nary complications. Five patients evidencedsevere hypoventilation postoperatively; threewith no evidence of antecedent parenchymalpulmonary disease required tracheostomy andrespiratory assistance and a fourth such patientwas successfully managed with positive-pres-sure breathing alone. The fifth patient withhypoventilation had obstructive emphysema,required prolonged respiratory assistance, buteventually recovered. Two patients, one withand the other without a history of bronchospas-tic disease, developed severe bronchospasmpostoperatively; the use of bronchodilatorsparenterally and by nebulization controlledthe spasm. Four patients appeared to havelarge intrapulmonary right-to-left shunts, sincethey remained hypoxemic despite the use ofhigh concentrations of oxygen under positivepressure through a tracheostomy, with suffl-cient ventilation to produce hypocapnia andalkalosis. Three of these patients subsequentlysuccumbed, two from arrhythmias and onefrom a disseminated infection.

Elective tracheostomy was almost routinelyemployed in those patients with severe pul-monary hypertension or with evidence of pre-ceding pulmonary disease, or in those in whomthe operation was exceptionally long. Thesepatients were ventilated with a Bird respirator,supplying moist air or 40 per cent oxygen. Insome patients surface active agents and bron-chodilators were added to the nebulizer. As-sisted ventilation, when necessary, was usuallygiven for the first 3 or 4 postoperative days.This procedure has been found to be of un-questioned benefit in preventing hypoventila-tion and its attendant complications, and iscurrently administered by an Engstrom rather


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than a Bird respirator. The judicious use ofanalgesics to diminish incisional pain, frequentdeep coughing, deep breathing, and tracheo-bronchial suction are routine measures usedin the early postoperative period to diminishpulmonary complications.

IX. Postpericardiotomy SyndromeSixteen (11 per cent) of the patients in this

series developed the postpericardiotomy syn-drome. Included in this category are patientswho evidenced recurrence of exacerbation offever and otherwise unexplained pleural orpericardial friction rubs after the seventh post-operative day. The over-all incidence of thepostpericardiotomy syndrome was undoubted-ly higher than 11 per cent, since the syndromemay first develop months after operation, andlong after the patient's discharge from the hos-pital. The syndrome varied in severity, fromone characterized by mild chest pain and feverof a few days' duration to one consisting of re-current episodes of high fever, severe chestpain, and arthralgias. However, all patientswere treated successfully with salicylatesalone; anticoagulants were continued withoutapparent ill effect even when loud pericardialfriction rubs were present.

X. Postperfusion SyndromeThis syndrome, characterized by fever,

splenomegaly, and atypical lymphocytes in theperipheral blood, and a negative heterophiltiter, occurred in a 21-year-old woman follow-ing aortic valve replacement. Approximately4 weeks after operation the patient developedfever followed in a week by splenomegaly,splinter hemorrhages, and petechiae. Althoughrepeated blood cultures were sterile, the pa-tient was treated for bacterial endocarditisuntil many atypical lymphocytes appeared inthe peripheral blood 2 weeks after the onsetof her illness. When salicylates were substitut-ed for the antibiotics, her fever promptly dis-appeared and she recovered. As with the post-pericardiotomy syndrome, the incidence of the"postperfusion syndrome" is undoubtedlyhigher than actually observed, since its onsetusually occurs after the patient's discharge.Circulation, Volume XXXII, October 1965

XI. HemolysisThree patients (two who had undergone mi-

tral valve replacement and one aortic replace-ment) developed rapidly falling hematocritvalues, reticulocytosis, and bilirubinemia withnegative Coombs tests during the first 48 post-operative hours. In two of these patients hemo-globinuria was noted. No specific etiology forthe hemolysis could be established. In onepatient the administration of radioactive redcells revealed a shortened life span of donorcells, indicating that mechanical trauma tocells at the time of operation or exchangewith abnormal cells was not responsible. Bloodreplacement and the infusion of mannitol tomaintain a large urinary output was employedin these three patients. No apparent depressionof renal function occurred, and in each patientthe hemolysis eventually ceased.

XII. Hemorrhagic DiathesisAlthough bleeding from the operative sites

occurred in all patients, in some this was ex-cessive and necessitated reexploration. In thevast majority, no definite bleeding point couldbe found, and bleeding ceased after the evac-uation of the existing hemothorax. However,the possibility of abnormalities in the clottingmechanism must be considered in all patientsin whom postoperative bleeding is excessive.In this series, two patients with excessive post-operative bleeding were found to have majorclotting abnormalities. One continued to bleedafter reexploration and was found to havemarked thrombocytopenia; the bleedingceased only after platelet transfusions. Theother patient developed a generalized bleedingdiathesis 1 week after operation. Abnormali-ties in all stages of the clotting mechanismwere found, and this patient was consideredto have a circulating anticoagulant; the ad-ministration of fresh blood resulted in cessa-tion of bleeding.

XIII. Gastrointestinal BleedingThree male patients, who had undergone

valve replacements, developed melena duringthe first postoperative week. None had a his-tory suggestive of peptic ulcer or of previous

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gastrointestinal bleeding or laboratory evi-dence of clotting abnormalities. The gastricaspirate contained blood in only one of thesepatients. All three patients required bloodreplacement and were treated with an ulcerregimen; the melena subsided in 5 to 7 daysand did not recur.

XIV. HypertensionThree patients without previous hyperten-

sion, two with aortic valve prostheses and onewith aortic and mitral prostheses, developedmarked arterial hypertension (> 180/110)shortly after the conclusion of the operation. Inone patient this was associated with hypoven-tilation and hypoxia; no cause could be foundin the other two, in whom hypertension neces-sitated the continuous infusion of Arfonad for24 hours; thereafter the arterial pressure re-mained normal. A fourth patient had mildparadoxical hypertension after resection of acoarctation of the aorta; this was not accom-panied by abdominal pain and disappearedwithout specific therapy in the course of thefirst postoperative day.

ConclusionsIn designing this analysis of "medical" com-

plications of cardiac operations, it was con-sidered important to make the observations ina prospective, rather than a retrospective man-

ner. In addition, every operation performedupon an adult patient was included, in orderto provide a truly representative 7iew of theincidence, clinical and laboratory manifesta-tions, response to therapy, and relative hazardof the complications occurring in cardiac surg-ical patients.The major conclusion from this survey is

that serious "medical" complications are com-mon in the early postoperative period, in thisseries occurring 187 times in 107 patients; thecourses of only 43 (29 per cent) of the 150patients were free from such complications.The relative danger of the "medical" complica-tions is reflected by the 15 deaths that occurredas their direct results. Thus, 10 per cent of thepatients operated upon and 14 per cent ofthose who developed one or more major com-plication ultimately succumbed (table 3). Itis clear, therefore, that "medical" complicationsconstitute an important, if not the most im-portant, cause of death in patients undergoingcardiac operations. In addition, even whennonfatal, these complications add to morbidityand to the length of hospital stay, and mayresult in long-term damage to the organ systeminvolved.

It is also evident that "medical" complica-tions occur more frequently, and are morehazardous, in patients who have had a valvereplacement. Thus, in 59 per cent of the pa-

Table 3Operative Procedures and Causes of Death in Patients Who Died of "Medical" Complications

Operative procedure

Aortic valve replacementAortic valve replacementAortic valve replacementAortic valve replacementAortic valve replacementAortic valve replacementAortic valve replacementMitral valve replacementMitral valve replacementMitral, tricuspid valve replacementAortic valve replacement, closure of VSDResection of coarctation of the aortaVentriculomyotomy for idiopathic hypertrophic

subaortic stenosisBrock procedure, tetralogy of FallotCorrection of transposition of the great arteries

Cause of death

Infection-disseminated candidiasisInfection-serratia septicemiaInfection-Staphylococcus albus endocarditisArrhythmia-ventricular fibrillationCerebral hemorrhageSuspected air emboliLow cardiac output syndromeLow cardiac output syndromeLow cardiac output syndromeArrhythmia-ventricular fibrillationHyperkalemiaHyperkalemiaSudden death-probable arrhythmiaInfection-disseminated candidiasisLow cardiac output syndrome


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tients a prosthetic valve was inserted, but 73per cent of the deaths and 70 per cent of thecomplications occurred in this group. Undoubt-edly, these patients were older, and in generaltheir cardiac disease was more advanced thanthe patients undergoing other operative pro-cedures. In addition, it seems likely that thelonger durations of anesthesia, operation, andcardiopulmonary bypass in patients requiringvalve replacement also contributed to the in-creased incidence of postoperative complica-tions in these patients.Although the occurrence of many of the com-

plications described herein would not -eauseundue alarm in the usual medical patient,prompt and vigorous therapy is often necessarywhen they occur in the postoperative cardiacsurgical patient, whose cardiovascular statusmay often be in precarious balance for severaldays or even weeks. An awareness of thehazards and clinical manifestations of these

complications, and close cooperation betweensurgeon and internist, are mandatory if thesepatients are to enjoy the ultimate benefits oftheir corrective operative procedures. Finally,it should also be emphasized that although theonly "medical" complications considered in thisanalysis were those occurring during the earlypostoperative period, i.e., during the patient'shospitalization, such complications are by nomeans limited to this period. Indeed, most ofthe difficulties experienced by these patientsfollowing their discharge might be consideredto be more of a "medical" rather than a "surgi-cal" nature. Embolization, hemolytic anemia,and hemorrhage resulting from anticoagulantsin patients with prosthetic valves, the develop-ment of serum hepatitis, the persistence ofmyocardial failure, pulmonary hypertension,and tricuspid regurgitation are problems thatare most frequently dealt with in the late post-operative period.

Learn to LearnNo school of medicine is worthy of the name that does not teach its students how to

learn from experience as well as before experience, how to observe and reason wisely,and how to compare their work with what has been observed and thought elsewhere,by others and in other times. He teaches best who shows his students how to learn:not what to think in 1953 but how to think and how to learn to think in that longstretch of days awaiting you till, let us say, the year 2000.-ALAN GREEG, M.D. ForFuture Doctors. Chicago, The University of Chicago Press, 1957, p. 50.


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JOHN F. WILLIAMS, JR., ANDREW G. MORROW and EUGENE BRAUNWALDOperations

The Incidence and Management of "Medical" Complications Following Cardiac

Print ISSN: 0009-7322. Online ISSN: 1524-4539 Copyright © 1965 American Heart Association, Inc. All rights reserved.

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