- Email: [email protected]
Alcohol Withdrawal after Open Aortic Surgery
Alcohol Withdrawal after Open Aortic Surgery Karl A. Illig, MD,1 Matthew Eagleton, MD,1 David Kaufman, MD,2 Sean P. Lyden, MD,1 Cynthia K. Shortell, MD,1 David Waldman, MD, PhD,1 and Richard M. Green, MD,1 Rochester, New York
This study was designed to test the hypothesis that unexpected alcohol withdrawal-like syndrome (AWLS) is more common following aortic, but not other, vascular or nonvascular procedures. All patients undergoing open aortic surgery at our institution in 1997 who survived at least 48 hr were identified, as were those undergoing carotid endarterectomy, infrainguinal bypass, and total colectomy. AWLS was defined as prolonged confusion or agitation and response to conventional treatment for withdrawal, providing that all other sources had been ruled out or a significant history was present. Our results show that, for unknown reasons, AWLS is more common after aortic surgery than after other vascular and high-stress, nonaortic intraabdominal procedures at our institution, and is associated with increased length of stay and morbidity. Because prophylaxis may improve outcome, better efforts to identify patients at risk are required.
INTRODUCTION
PATIENTS AND METHODS
It has long been known that alcohol withdrawal can be precipitated by stressors such as major surgery and, when present, is associated with substantial morbidity. It has been our perception that patients undergoing open aortic operations have a particularly high incidence of withdrawal in the postoperative period. This retrospective review was designed to discover whether this is true, and, if so, what effect this phenomenon has on outcome.
All patients undergoing elective open aortic surgery for repair of abdominal aortic aneurysm or aortoiliac occlusive disease during 1997 at our institution were identified. A retrospective chart review was carried out to identify possible alcohol withdrawal-like syndrome and to document these patients’ postoperative courses. For comparison, patients undergoing carotid endarterectomy, lower extremity bypass, and total colectomy were similarly studied. Only patients who survived more than 48 hr were included. Because these patients were often intubated or otherwise nonverbal and a preoperative history was usually not available until after the fact, we felt that the term alcohol withdrawal-like syndrome (AWLS) was most accurate. AWLS was defined as prolonged confusion or agitation (typically 18 to 24 hr) and response to conventional treatment for withdrawal (clearing of mental status and normalization of overall hemodynamic status), providing that all other sources had been ruled out or a history of significant preoperative alcohol intake was present. The Clinical Institute Withdrawal Assess-
1 Division of Vascular Surgery, University of Rochester Medical Center, Rochester, NY. 2 Division of Critical Care Medicine, University of Rochester Medical Center, Rochester, NY. This study was partially presented in poster form at the 24th World Congress, International Society for Cardiovascular Surgery, Melbourne, Australia, September 12–16, 1999. Correspondence to: K.A. Illig, MD, Division of Vascular Surgery, University of Rochester Medical Center, 601 Elmwood Avenue, Box 652, Rochester, NY 14642, USA, E-mail: [email protected]. Ann Vasc Surg 2001; 15: 332-337 DOI: 10.1007/s100160010083 © Annals of Vascular Surgery Inc. Published online: April 24, 2001
332
Fig. 1. The revised Clinical Institute Withdrawal Assessment for Alcohol scale (CIWA-Ar) used for diagnosis of alcohol withdrawal. Items are scored as shown. The maximum score is 67; a patient scoring <10 can usually be
managed with supportive care alone, while one scoring 20 or more usually needs to be hospitalized. Note that while heart rate and blood pressure are recorded, they are not used for scoring.14
Vol. 15, No. 3, 2001 Alcohol withdrawal after open aortic surgery 333
334
Illig et al.
Annals of Vascular Surgery
Table I. Operative results and 30-day mortality in all study patients
Procedures (n) Mortality (%) Anesthetic time (min) Operative time (min) IV fluids (mL) EBL (mL)
AORTA
CEA
COLON
LEBP
p
75 4 222 ± 52 187 ± 51 7643 ± 2653a 2475 ± 2100a
260 2 140 ± 16a 106 ± 20a 1300 ± 390 188 ± 177
50 2 244 ± 101 225 ± 97 4570 ± 2935 640 ± 481
128 4 230 ± 155 216 ± 163 2171 ± 1412 264 ± 184
NS <0.005 vs. alla <0.005 vs. alla <0.02 vs. alla <0.001 vs. alla
AORTA, aortic procedures (aneurysm and aortofemoral bypass); CEA, carotid endarterectomy; COLON, total colectomy; EBL, estimated blood loss; IVF, intravenous fluids; LEBP, lower extremity bypass. Significance was assessed using ANOVA for continuous data and chi-squared analysis for categorical data.
ment for Alcohol (revised) (CIWA-Ar) score was calculated (Fig. 1), but because so many of these patients were intubated and medically unstable, scores were used for informational purposes only and not used to define AWLS. Categorical values were compared using chisquared analysis, while continuous variables were compared using unpaired t-tests and ANOVA, as appropriate.
RESULTS During 1997, a total of 75 patients underwent open aortic surgery—44 for aneurysm and 31 for occlusive disease. Two hundred sixty patients underwent carotid endarterectomy, 128 had lower extremity bypass, and 50 had total colectomy. Anesthetic management was similar in the patients undergoing aortic and colon surgery (general inhalational anesthesia, usually with an epidural catheter for intra- and postoperative analgesia). Those undergoing carotid endarterectomy during this period were managed using light general anesthesia with liberal use of narcotics and lidocaine, while those undergoing lower extremity bypass were split relatively evenly between receiving general and spinal anesthesia. Anesthetic and operative times varied among all groups, the longest being for those undergoing colon resection and the shortest being for those undergoing carotid endarterectomy. Total fluid intake (7643 ± 2653) and estimated blood loss (2475 ± 2100) were significantly greater in those who had aortic surgery than in all others (p < 0.02), although scatter was large in all groups (Table I). The incidence of AWLS was 12% (7 patients) in patients undergoing aortic surgery, 2% in those undergoing total colectomy, and 0 in those undergoing carotid surgery and lower extremity bypass (p < 0.05). In the 75 patients who had aortic surgery, the
presence of AWLS was associated with significantly lengthened intensive care unit (ICU) stay (13 vs. 4 days), more days on mechanical ventilation (10 vs. 2), more days without oral intake (11 vs. 6), and more days spent in the hospital (23 vs. 10) (Table II). There was no mortality in the nine patients with AWLS. Patients with AWLS were slightly older, although this factor did not reach statistical significance. Preoperative albumin levels, prothrombin times, and other liver function tests were not significantly different, although whenever trends were present, they suggested worsened hepatic function in the patients with AWLS (Table II). Negative fluid balance was achieved by postoperative day 3 in patients undergoing aortic surgery as a group, but was delayed until postoperative day 5 in those suffering from AWLS, although again, this difference did not reach statistical significance. In the nine patients with AWLS, the mean CIWA-Ar score was 12.6 ± 4.4 (range, 4 to 16), although only one patient’s score was <10. Most points were accrued because of disorientation, anxiety, and agitation. The most common pattern was increasing agitation on the first postoperative day, followed by hyperdynamic vital signs and increasing agitation and disorientation on postoperative days 1 to 3 despite treatment (alcohol drip in seven patients and benzodiazepines in all nine) begun after agitation was recognized. A history of significant alcohol use (more than two drinks per day) was present prior to symptoms in only four patients. One patient reported abstinence for the previous 10 months and one reported social intake only. The remaining three denied all intake preoperatively, but admitted (either the patient or family) to significant intake after withdrawal was manifest. Three patients in this series were given prophylactic alcohol drips on the basis of a history of significant prior intake. Two did not suffer withdrawal
Vol. 15, No. 3, 2001
Alcohol withdrawal after open aortic surgery 335
Table II. Outcome in patients operated on for aortic disease
Patients (n) Age Days on ventilator Days NPO Days in ICU Days in hospital Mortality Preoperative levels BUN Albumin LDH AST PT INR
AWLS
No AWLS
p
9 73.5 ± 4.5 10.0 ± 9.1 10.9 ± 6.4 13.2 ± 8.2 23.1 ± 12.9 0
66 69.5 ± 8.7 1.7 ± 5.3 6.4 ± 2.1 3.8 ± 5.3 10.4 ± 7.1 5% (3)
NS <0.0002 <0.0002 <0.0001 <0.0001 NS
16.0 ± 3.4 3.8 ± 0.9 328.5 ± 198.4 23.4 ± 14.2 11.9 ± 0.7 1.0 ± 0.1
15.4 ± 6.9 4.8 ± 6.4 412.5 ± 304.5 24.0 ± 7.4 12.6 ± 1.0 1.1 ± 0.1
NS NS NS NS NS (p = 0.12) NS (p = 0.17)
AST, aspartate transaminase; BUN, blood urea nitrogen; ICU, intensive care unit; INR, international normalized ratio; LDH, lactate dehydrogenase; NPO, nothing by mouth; PT, prothrombin time. Morbidity, mortality, and preoperative liver function tests were performed in patients with and without AWLS. Significance was assessed using t-tests for continuous data, and chi-squared test for categorical data.
as defined here; one remained asymptomatic and the other suffered only minor, transient confusion. The third, admitting to four to six drinks per day and included in the analysis above, developed severe withdrawal despite prophylaxis.
DISCUSSION These data demonstrate that AWLS is prevalent in patients undergoing open aortic surgery, occurring at our institution in 12% of patients during 1997. Its presence was associated with increased ICU and hospital stay and ventilator dependence, but not mortality in this small sample. Confusion and agitation coupled with autonomic hyperactivity after a lucid, normal interval was the most common presenting symptom complex in this group. Prophylaxis was of benefit in a limited number of patients, but failed in one of the three patients in whom it was attempted. Although most patients eventually admitted to significant intake, this information was infrequently available prior to symptoms. Alcohol withdrawal is caused by abstinence from alcohol intake. Chronic alcohol use down-regulates gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter of the central nervous system, and inhibits the influx of calcium ions through N-methyl-D-aspartate (NMDA) receptors normally activated by excitatory neurotransmitters.1,2 Abstinence thus results in global neuroexci-
tation. The major signs and symptoms initially seen (within 6 to 24 hr after last intake) include generalized autonomic excitation, and take the form of tremulousness and nervousness, tachycardia, hyperthermia, sweating, and tremor, among others. If more severe, seizures can result, and occasionally true delirium tremens, manifest by frank hallucinations, stupor, and even death, can occur.1 Alcohol withdrawal is especially common after operation and in hospitalized patients in general, and has been shown to worsen outcome.3-6 Why this occurs is not known. Certainly part of the effect is the enforced abstinence induced by hospitalization and abdominal surgery, but most would agree that the stress of the acute illness and/or surgical procedure exacerbates the problem. In the particular case of patients undergoing resection of oropharyngeal carcinomas, heavy alcohol use has been shown to be an independent risk factor for the disease itself, and up to 92% of patients so affected have a history of chronic alcohol abuse.7 Unfortunately, all facets of the problem (preoperative identification of those at risk, prophylactic therapy, identification of potential withdrawal, and treatment of established or presumed withdrawal) are all relatively neglected. Several screening tests have been studied and validated, the best being the Alcohol Use Disorders Identification Test (AUDIT), a self-administered 10question checklist (Fig. 2) that requires approxi-
336
Illig et al.
Annals of Vascular Surgery
Fig. 2. The Alcohol Use Disorders Identification Test (AUDIT), used for screening for alcohol dependence. Questions 1 through 8 are scored from 0 to 4, while ques-
tions 9 and 10 are scored as 0, 2, or 4. The maximum score is 40; a score of 8 or more indicates a strong likelihood of harmful alcohol consumption.8
mately 2 min to complete.8 A score of 8 or more indicates a strong likelihood of hazardous or harmful alcohol consumption. AUDIT seems to have little age, gender, or racial bias, and results correlate with next-of-kin reports.9 Multiple other scoring instruments are available as well.10 Recent excessive alcohol use can potentially be quantified biochemically by measuring levels of carbohydratedeficient transferrin (CDT), which is increased after as little as 7 days of heavy drinking.9,11,12 The accuracy and clinical use of this test have yet to be established, however, and its indiscriminate use as a screening tool cannot be advocated. Prophylactic therapy would seem to be of value, providing that the proper therapy and proper patient population to treat can be identified, although our experience is too small to support this directly. When applied in the proper clinical setting, for example, in patients undergoing resection of head and neck tumors, prophylaxis has been shown in limited trials to be of benefit,13 but surprisingly few such reports exist, perhaps because of the problems in identifying patients at risk. Although we favor
direct administration of the “deficient” substance, i.e., alcohol, one randomized trial found no differences between alcohol and several other regimens.5 Unfortunately, the diagnosis of alcohol withdrawal in these patients can be difficult. The most commonly used scoring instrument, CIWA-Ar, is somewhat problematic when applied to patients following abdominal surgery, as they have nasogastric tubes in place and may experience nausea and vomiting (Fig. 1). In addition, many signs or symptoms (such as sweating, headache, anxiety, or disorientation) are extremely common in the early postoperative period, and signs of autonomic hyperactivity, which we feel are quite helpful, are not included.14 An instrument to make this diagnosis more objective in postoperative patients is needed. Treatment of established AWLS is more straightforward. The basic principle is generalized autonomic inhibition, which can be accomplished with benzodiazepines, neuroleptics, or, of course, alcohol.15-18 We have been most pleased with using alcohol in this setting, combined with judicious use of benzodiazepines or beta-blockade for persistent
Vol. 15, No. 3, 2001
autonomic hyperactivity. Alcohol has the advantage of being easily administered either parenterally or enterally with predictable dose-response characteristics, and has the biochemical advantage of exactly replacing the deficiency. We cannot determine why withdrawal seems to be more prevalent in patients undergoing open aortic surgery. One possibility is that the magnitude of metabolic insult combined with the duration of inability to take fluids and nutrition by mouth triggers withdrawal. Anesthetic time, fluid requirements, and blood loss were different among groups, although no evidence exists to implicate these factors in and of themselves. We have not seen alcohol withdrawal symptoms in our patients undergoing endovascular repair; they have much reduced levels of all these stressors. Another possibility is that the prevalence of alcohol abuse might be higher in patients with aortic disease, or that excessive alcohol intake is a risk factor for aneurysm. This question cannot be answered by this study, but will require prospective investigation.
CONCLUSIONS Alcohol withdrawal-like syndrome occurs in 12% of patents undergoing open aortic surgery in our institution, and is associated with substantially increased morbidity. Although recognition of established withdrawal seems to be adequate, diagnostic tools that are applicable to postoperative patients need to be developed, and preoperative screening to better identify patients who would benefit from prophylaxis needs to be improved. REFERENCES 1. Hall W, Zador D. The alcohol withdrawal syndrome. Lancet 1997;349:1897-1900. 2. Greenberg DA. Ethanol and sedatives. Neurol Clin 1993; 11:523-534. 3. Ferguson JA, Suelzer CJ, Eckert GJ, Zhou XH, Dittus RS.
Alcohol withdrawal after open aortic surgery 337
4.
5.
6.
7.
8.
9.
10. 11.
12.
13.
14.
15.
16. 17.
18.
Risk factors for delirium tremens development. J Gen Intern Med 1996;11:410-414. Foy A, Kay J. The incidence of alcohol-related problems and the risk of alcohol withdrawal in a general hospital population. Drug Alcohol Rev 1995;14:49-54. Spies CD, Dubisz N, Funk W. Prophylaxis of alcohol withdrawal syndrome in alcohol-dependent patients admitted to the intensive care unit after tumor resection. Br J Anaesth 1995;75:734-739. Spies CD, Nordmann A, Brummer G. Intensive care unit stay is prolonged in chronic alcoholic men following tumor resection of the upper digestive tract. Acta Anaesthesiol Scand 1996;40:649-656. Seitz W, Simanowski UA. Ethanol and carcinogenesis of the alimentary tract. Alcohol Clin Exp Res 1986;10(Suppl):33S40S. Saunders JB, Aasland OG, Babor TF, de la Fuente J, Grant M. Development of the Alcohol Use Diserders Identification Test (AUDIT): WHO collaborative project on early detection of persons with harmful alcohol consumption—II. Addiction 1993;88:791-804. Allen JP, Cross GM, Fertig JB, Litten RZ. Screening for alcohol problems in the military: recommended tests. Mil Med 1998;163:9-12. Schorling JB, Buchsbaum DG. Screening for alcohol and drug abuse. Med Clin North Am 1997;81:845-865. Stibler H. Carbohydrate-deficient transferrin in serum: a new marker of potentially harmful alcohol consumption reviewed. Clin Chem 1991;37:2029-2037. Xin Y, Lasker JM, Lieber CS. Serum carbohydrate-deficient transferrin: mechanism of increase after chronic alcohol intake. Hepatology 1995;22:1462-1468. Spies CD, Rommelspacher H. Alcohol withdrawal in the surgical patient: prevention and treatment. Anesth Analg 1999;88:946-954. Sullivan JT, Sykora K, Schneiderman J, Naranjo CA, Sellers E. Assessment of alcohol withdrawal: the revised Clinical Institute Withdrawal Assessment for Alcohol Scale (CIWAAr). Br J Addiction 1989;84:1353-1357. Gower WE, Kersten H. Prevention of alcohol withdrawal symptoms in surgical patients. Surg Gynecol Obstet 1980;151:382-384. Castaneda R, Cushman P. Alcohol withdrawal: a review of clinical management. J Clin Psychiatry 1989;50:278-284. Saitz R, Mayo-Smith MF, Roberts MS, Redmond HA, Bernard DR, Calkins DR. Individualized treatment for alcohol withdrawal. JAMA 1994;272:519-523. Saitz R, O’Malley SS. Pharmacotherapies for alcohol abuse. Med Clin North Am 1997;81:881-907.
This study was designed to test the hypothesis that unexpected alcohol withdrawal-like syndrome (AWLS) is more common following aortic, but not other, vascular or nonvascular procedures. All patients undergoing open aortic surgery at our institution in 1997 who survived at least 48 hr were identified, as were those undergoing carotid endarterectomy, infrainguinal bypass, and total colectomy. AWLS was defined as prolonged confusion or agitation and response to conventional treatment for withdrawal, providing that all other sources had been ruled out or a significant history was present. Our results show that, for unknown reasons, AWLS is more common after aortic surgery than after other vascular and high-stress, nonaortic intraabdominal procedures at our institution, and is associated with increased length of stay and morbidity. Because prophylaxis may improve outcome, better efforts to identify patients at risk are required.
INTRODUCTION
PATIENTS AND METHODS
It has long been known that alcohol withdrawal can be precipitated by stressors such as major surgery and, when present, is associated with substantial morbidity. It has been our perception that patients undergoing open aortic operations have a particularly high incidence of withdrawal in the postoperative period. This retrospective review was designed to discover whether this is true, and, if so, what effect this phenomenon has on outcome.
All patients undergoing elective open aortic surgery for repair of abdominal aortic aneurysm or aortoiliac occlusive disease during 1997 at our institution were identified. A retrospective chart review was carried out to identify possible alcohol withdrawal-like syndrome and to document these patients’ postoperative courses. For comparison, patients undergoing carotid endarterectomy, lower extremity bypass, and total colectomy were similarly studied. Only patients who survived more than 48 hr were included. Because these patients were often intubated or otherwise nonverbal and a preoperative history was usually not available until after the fact, we felt that the term alcohol withdrawal-like syndrome (AWLS) was most accurate. AWLS was defined as prolonged confusion or agitation (typically 18 to 24 hr) and response to conventional treatment for withdrawal (clearing of mental status and normalization of overall hemodynamic status), providing that all other sources had been ruled out or a history of significant preoperative alcohol intake was present. The Clinical Institute Withdrawal Assess-
1 Division of Vascular Surgery, University of Rochester Medical Center, Rochester, NY. 2 Division of Critical Care Medicine, University of Rochester Medical Center, Rochester, NY. This study was partially presented in poster form at the 24th World Congress, International Society for Cardiovascular Surgery, Melbourne, Australia, September 12–16, 1999. Correspondence to: K.A. Illig, MD, Division of Vascular Surgery, University of Rochester Medical Center, 601 Elmwood Avenue, Box 652, Rochester, NY 14642, USA, E-mail: [email protected]. Ann Vasc Surg 2001; 15: 332-337 DOI: 10.1007/s100160010083 © Annals of Vascular Surgery Inc. Published online: April 24, 2001
332
Fig. 1. The revised Clinical Institute Withdrawal Assessment for Alcohol scale (CIWA-Ar) used for diagnosis of alcohol withdrawal. Items are scored as shown. The maximum score is 67; a patient scoring <10 can usually be
managed with supportive care alone, while one scoring 20 or more usually needs to be hospitalized. Note that while heart rate and blood pressure are recorded, they are not used for scoring.14
Vol. 15, No. 3, 2001 Alcohol withdrawal after open aortic surgery 333
334
Illig et al.
Annals of Vascular Surgery
Table I. Operative results and 30-day mortality in all study patients
Procedures (n) Mortality (%) Anesthetic time (min) Operative time (min) IV fluids (mL) EBL (mL)
AORTA
CEA
COLON
LEBP
p
75 4 222 ± 52 187 ± 51 7643 ± 2653a 2475 ± 2100a
260 2 140 ± 16a 106 ± 20a 1300 ± 390 188 ± 177
50 2 244 ± 101 225 ± 97 4570 ± 2935 640 ± 481
128 4 230 ± 155 216 ± 163 2171 ± 1412 264 ± 184
NS <0.005 vs. alla <0.005 vs. alla <0.02 vs. alla <0.001 vs. alla
AORTA, aortic procedures (aneurysm and aortofemoral bypass); CEA, carotid endarterectomy; COLON, total colectomy; EBL, estimated blood loss; IVF, intravenous fluids; LEBP, lower extremity bypass. Significance was assessed using ANOVA for continuous data and chi-squared analysis for categorical data.
ment for Alcohol (revised) (CIWA-Ar) score was calculated (Fig. 1), but because so many of these patients were intubated and medically unstable, scores were used for informational purposes only and not used to define AWLS. Categorical values were compared using chisquared analysis, while continuous variables were compared using unpaired t-tests and ANOVA, as appropriate.
RESULTS During 1997, a total of 75 patients underwent open aortic surgery—44 for aneurysm and 31 for occlusive disease. Two hundred sixty patients underwent carotid endarterectomy, 128 had lower extremity bypass, and 50 had total colectomy. Anesthetic management was similar in the patients undergoing aortic and colon surgery (general inhalational anesthesia, usually with an epidural catheter for intra- and postoperative analgesia). Those undergoing carotid endarterectomy during this period were managed using light general anesthesia with liberal use of narcotics and lidocaine, while those undergoing lower extremity bypass were split relatively evenly between receiving general and spinal anesthesia. Anesthetic and operative times varied among all groups, the longest being for those undergoing colon resection and the shortest being for those undergoing carotid endarterectomy. Total fluid intake (7643 ± 2653) and estimated blood loss (2475 ± 2100) were significantly greater in those who had aortic surgery than in all others (p < 0.02), although scatter was large in all groups (Table I). The incidence of AWLS was 12% (7 patients) in patients undergoing aortic surgery, 2% in those undergoing total colectomy, and 0 in those undergoing carotid surgery and lower extremity bypass (p < 0.05). In the 75 patients who had aortic surgery, the
presence of AWLS was associated with significantly lengthened intensive care unit (ICU) stay (13 vs. 4 days), more days on mechanical ventilation (10 vs. 2), more days without oral intake (11 vs. 6), and more days spent in the hospital (23 vs. 10) (Table II). There was no mortality in the nine patients with AWLS. Patients with AWLS were slightly older, although this factor did not reach statistical significance. Preoperative albumin levels, prothrombin times, and other liver function tests were not significantly different, although whenever trends were present, they suggested worsened hepatic function in the patients with AWLS (Table II). Negative fluid balance was achieved by postoperative day 3 in patients undergoing aortic surgery as a group, but was delayed until postoperative day 5 in those suffering from AWLS, although again, this difference did not reach statistical significance. In the nine patients with AWLS, the mean CIWA-Ar score was 12.6 ± 4.4 (range, 4 to 16), although only one patient’s score was <10. Most points were accrued because of disorientation, anxiety, and agitation. The most common pattern was increasing agitation on the first postoperative day, followed by hyperdynamic vital signs and increasing agitation and disorientation on postoperative days 1 to 3 despite treatment (alcohol drip in seven patients and benzodiazepines in all nine) begun after agitation was recognized. A history of significant alcohol use (more than two drinks per day) was present prior to symptoms in only four patients. One patient reported abstinence for the previous 10 months and one reported social intake only. The remaining three denied all intake preoperatively, but admitted (either the patient or family) to significant intake after withdrawal was manifest. Three patients in this series were given prophylactic alcohol drips on the basis of a history of significant prior intake. Two did not suffer withdrawal
Vol. 15, No. 3, 2001
Alcohol withdrawal after open aortic surgery 335
Table II. Outcome in patients operated on for aortic disease
Patients (n) Age Days on ventilator Days NPO Days in ICU Days in hospital Mortality Preoperative levels BUN Albumin LDH AST PT INR
AWLS
No AWLS
p
9 73.5 ± 4.5 10.0 ± 9.1 10.9 ± 6.4 13.2 ± 8.2 23.1 ± 12.9 0
66 69.5 ± 8.7 1.7 ± 5.3 6.4 ± 2.1 3.8 ± 5.3 10.4 ± 7.1 5% (3)
NS <0.0002 <0.0002 <0.0001 <0.0001 NS
16.0 ± 3.4 3.8 ± 0.9 328.5 ± 198.4 23.4 ± 14.2 11.9 ± 0.7 1.0 ± 0.1
15.4 ± 6.9 4.8 ± 6.4 412.5 ± 304.5 24.0 ± 7.4 12.6 ± 1.0 1.1 ± 0.1
NS NS NS NS NS (p = 0.12) NS (p = 0.17)
AST, aspartate transaminase; BUN, blood urea nitrogen; ICU, intensive care unit; INR, international normalized ratio; LDH, lactate dehydrogenase; NPO, nothing by mouth; PT, prothrombin time. Morbidity, mortality, and preoperative liver function tests were performed in patients with and without AWLS. Significance was assessed using t-tests for continuous data, and chi-squared test for categorical data.
as defined here; one remained asymptomatic and the other suffered only minor, transient confusion. The third, admitting to four to six drinks per day and included in the analysis above, developed severe withdrawal despite prophylaxis.
DISCUSSION These data demonstrate that AWLS is prevalent in patients undergoing open aortic surgery, occurring at our institution in 12% of patients during 1997. Its presence was associated with increased ICU and hospital stay and ventilator dependence, but not mortality in this small sample. Confusion and agitation coupled with autonomic hyperactivity after a lucid, normal interval was the most common presenting symptom complex in this group. Prophylaxis was of benefit in a limited number of patients, but failed in one of the three patients in whom it was attempted. Although most patients eventually admitted to significant intake, this information was infrequently available prior to symptoms. Alcohol withdrawal is caused by abstinence from alcohol intake. Chronic alcohol use down-regulates gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter of the central nervous system, and inhibits the influx of calcium ions through N-methyl-D-aspartate (NMDA) receptors normally activated by excitatory neurotransmitters.1,2 Abstinence thus results in global neuroexci-
tation. The major signs and symptoms initially seen (within 6 to 24 hr after last intake) include generalized autonomic excitation, and take the form of tremulousness and nervousness, tachycardia, hyperthermia, sweating, and tremor, among others. If more severe, seizures can result, and occasionally true delirium tremens, manifest by frank hallucinations, stupor, and even death, can occur.1 Alcohol withdrawal is especially common after operation and in hospitalized patients in general, and has been shown to worsen outcome.3-6 Why this occurs is not known. Certainly part of the effect is the enforced abstinence induced by hospitalization and abdominal surgery, but most would agree that the stress of the acute illness and/or surgical procedure exacerbates the problem. In the particular case of patients undergoing resection of oropharyngeal carcinomas, heavy alcohol use has been shown to be an independent risk factor for the disease itself, and up to 92% of patients so affected have a history of chronic alcohol abuse.7 Unfortunately, all facets of the problem (preoperative identification of those at risk, prophylactic therapy, identification of potential withdrawal, and treatment of established or presumed withdrawal) are all relatively neglected. Several screening tests have been studied and validated, the best being the Alcohol Use Disorders Identification Test (AUDIT), a self-administered 10question checklist (Fig. 2) that requires approxi-
336
Illig et al.
Annals of Vascular Surgery
Fig. 2. The Alcohol Use Disorders Identification Test (AUDIT), used for screening for alcohol dependence. Questions 1 through 8 are scored from 0 to 4, while ques-
tions 9 and 10 are scored as 0, 2, or 4. The maximum score is 40; a score of 8 or more indicates a strong likelihood of harmful alcohol consumption.8
mately 2 min to complete.8 A score of 8 or more indicates a strong likelihood of hazardous or harmful alcohol consumption. AUDIT seems to have little age, gender, or racial bias, and results correlate with next-of-kin reports.9 Multiple other scoring instruments are available as well.10 Recent excessive alcohol use can potentially be quantified biochemically by measuring levels of carbohydratedeficient transferrin (CDT), which is increased after as little as 7 days of heavy drinking.9,11,12 The accuracy and clinical use of this test have yet to be established, however, and its indiscriminate use as a screening tool cannot be advocated. Prophylactic therapy would seem to be of value, providing that the proper therapy and proper patient population to treat can be identified, although our experience is too small to support this directly. When applied in the proper clinical setting, for example, in patients undergoing resection of head and neck tumors, prophylaxis has been shown in limited trials to be of benefit,13 but surprisingly few such reports exist, perhaps because of the problems in identifying patients at risk. Although we favor
direct administration of the “deficient” substance, i.e., alcohol, one randomized trial found no differences between alcohol and several other regimens.5 Unfortunately, the diagnosis of alcohol withdrawal in these patients can be difficult. The most commonly used scoring instrument, CIWA-Ar, is somewhat problematic when applied to patients following abdominal surgery, as they have nasogastric tubes in place and may experience nausea and vomiting (Fig. 1). In addition, many signs or symptoms (such as sweating, headache, anxiety, or disorientation) are extremely common in the early postoperative period, and signs of autonomic hyperactivity, which we feel are quite helpful, are not included.14 An instrument to make this diagnosis more objective in postoperative patients is needed. Treatment of established AWLS is more straightforward. The basic principle is generalized autonomic inhibition, which can be accomplished with benzodiazepines, neuroleptics, or, of course, alcohol.15-18 We have been most pleased with using alcohol in this setting, combined with judicious use of benzodiazepines or beta-blockade for persistent
Vol. 15, No. 3, 2001
autonomic hyperactivity. Alcohol has the advantage of being easily administered either parenterally or enterally with predictable dose-response characteristics, and has the biochemical advantage of exactly replacing the deficiency. We cannot determine why withdrawal seems to be more prevalent in patients undergoing open aortic surgery. One possibility is that the magnitude of metabolic insult combined with the duration of inability to take fluids and nutrition by mouth triggers withdrawal. Anesthetic time, fluid requirements, and blood loss were different among groups, although no evidence exists to implicate these factors in and of themselves. We have not seen alcohol withdrawal symptoms in our patients undergoing endovascular repair; they have much reduced levels of all these stressors. Another possibility is that the prevalence of alcohol abuse might be higher in patients with aortic disease, or that excessive alcohol intake is a risk factor for aneurysm. This question cannot be answered by this study, but will require prospective investigation.
CONCLUSIONS Alcohol withdrawal-like syndrome occurs in 12% of patents undergoing open aortic surgery in our institution, and is associated with substantially increased morbidity. Although recognition of established withdrawal seems to be adequate, diagnostic tools that are applicable to postoperative patients need to be developed, and preoperative screening to better identify patients who would benefit from prophylaxis needs to be improved. REFERENCES 1. Hall W, Zador D. The alcohol withdrawal syndrome. Lancet 1997;349:1897-1900. 2. Greenberg DA. Ethanol and sedatives. Neurol Clin 1993; 11:523-534. 3. Ferguson JA, Suelzer CJ, Eckert GJ, Zhou XH, Dittus RS.
Alcohol withdrawal after open aortic surgery 337
4.
5.
6.
7.
8.
9.
10. 11.
12.
13.
14.
15.
16. 17.
18.
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