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Khatri P, Babyak M, Croughwell ND, Davis R, White WD, Newman MF, Reves JG, Mark DB, Blumenthal JA. Temperature during coronary artery bypass surgery affects quality of life. Ann Thorac Surg 2001; 71:110-6. [PMID: 11216728 DOI: 10.1016/s0003-4975(00)02350-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The objective of this study was to examine the effects of temperature on a variety of indices of psychologic adjustment and quality of life. METHODS A total of 209 patients randomly received normothermic (warm) or hypothermic (cold) conditions during coronary artery bypass surgery (CABS), and a number of physical, social, and psychologic measures were assessed before as well as 6 weeks and 6 months after CABS. RESULTS Repeated measures analyses of covariance revealed significant temperature group main effects for anxiety (p = 0.008) and depression (p = 0.039), with the normothermic group obtaining lower anxiety and depression levels than the hypothermic group at both 6 weeks and 6 months after surgery. Additionally, among patients who entered the study with higher depression levels, those in the hypothermic group tended to have higher depression scores at follow-up compared with patients in the normothermic condition (p = 0.012). No temperature group differences were observed on other quality of life indices. CONCLUSIONS The results of the present study indicate that hypothermic conditions during CABS are associated with higher levels of emotional distress after CABS than normothermic conditions, particularly for patients with greater stress to begin with.
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Affiliation(s)
- P Khatri
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina 27710, USA
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Abstract
BACKGROUND The glial protein S100beta has been used to estimate cerebral damage in a number of clinical settings. The purpose of this investigation was to determine the correlation between cerebral microemboli and S100beta levels during cardiac operations. METHODS Transcranial Doppler ultrasonography was used to measure emboli in the right middle cerebral artery. Emboli counts (n = 111) were divided into five time periods: (1) incision to aortic cannulation; (2) aortic cannulation to cross-clamp onset; (3) cross-clamp onset to cross-clamp release; (4) cross-clamp release to decannulation; and (5) decannulation to chest closure. The level of S100beta (n = 156) was measured at baseline, at the end of cardiopulmonary bypass, then 150 and 270 minutes after cross-clamp release. RESULTS The level of S100beta correlated with age, cardiopulmonary bypass time, cross-clamp time, and number of emboli at time period 2. Although cardiopulmonary bypass time was univariately associated with S100beta level, it became nonsignificant in a multivariable model that included age and cross-clamp time. CONCLUSIONS The correlation of S100beta level with emboli measured during cannulation (time period 2) supports the hypothesis that cannulation is a high-risk time period for cerebral injury.
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Affiliation(s)
- H P Grocott
- Department of Anesthesiology, Duke Heart Center, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Croughwell ND, Reves JG, White WD, Grocott HP, Baldwin BI, Clements FM, Davis RD, Jones RH, Newman MF. Cardiopulmonary bypass time does not affect cerebral blood flow. Ann Thorac Surg 1998; 65:1226-30. [PMID: 9594842 DOI: 10.1016/s0003-4975(98)00113-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND A time-dependent decline in cerebral blood flow (CBF) has been reported in cardiac surgical patients despite stable pump flows and arterial carbon dioxide tension. Other studies have failed to support these hypothermic cardiopulmonary bypass (CPB) results, showing preservation of CBF during CPB. The purpose of the study was to define the influence of mildly hypothermic CPB duration on CBF. METHODS Cerebral blood flow was measured using xenon-133 washout and alpha-stat blood gas management during nonpulsatile CPB. Cerebral blood flow measurements were made after the initiation of CPB and near the end of bypass during pump flows of 2.4 L.min-1.m-2. RESULTS Fifty-two coronary artery bypass patients were studied. The average time between CBF measurements was 54 +/- 20 minutes (mean +/- standard deviation), with a range of 10 to 100 minutes. Temperature and arterial carbon dioxide tension were controlled: after the initiation of CPB, temperature was 35.5 degrees +/- 0.4 degree C and carbon dioxide tension was 37 +/- 2.8 mm Hg; whereas near the end of bypass temperature was 35.6 degrees +/- 0.5 degree C and carbon dioxide tension was 36 +/- 2.3 mm Hg. We found no correlation between CBF and time on CPB (p = 0.47; r = 0.101), in contrast to other studies suggesting that CPB duration may intrinsically affect CBF. CONCLUSIONS Our experimental results include the following: (1) during mildly hypothermic bypass, CBF does not decrease in relation to time and (2) cerebral flow-metabolism coupling is intact at 35 degrees C.
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Affiliation(s)
- N D Croughwell
- Department of Anesthesiology, Duke Heart Center, Duke University Hospital, Durham, North Carolina, USA
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Amory DW, Croughwell ND, Kirchner JL, Blumenthal JA, White WD, Gerstle L, Rohatgi A, Baudet B, Grocott H, Newman MF. THE QUANTITATIVE ELECTROENCEPHALOGRAM (QEEG). Anesth Analg 1998. [DOI: 10.1213/00000539-199804001-00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Newman MF, Croughwell ND, White WD, Sanderson I, Spillane W, Reves JG. Pharmacologic electroencephalographic suppression during cardiopulmonary bypass: a comparison of thiopental and isoflurane. Anesth Analg 1998; 86:246-51. [PMID: 9459227 DOI: 10.1097/00000539-199802000-00005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED In this study, we examined the cerebral oxygenation effects of two methods of pharmacologic burst suppression during cardiopulmonary bypass (CPB) in valvular heart surgery patients. Patients were randomly entered into one of three groups: control (n = 13, fentanyl and midazolam), control plus burst suppression doses of thiopental (n = 15), or control plus burst suppression doses of isoflurane (n = 16). Burst suppression (80% suppression) was accomplished in the thiopental and isoflurane groups 15 min before aortic cannulation and was maintained through aortic decannulation. Cerebral physiologic measurements were made during hypothermia (27-28 degrees C) and on rewarming to 36 degrees C. During hypothermia, burst suppression produced significant (P < 0.005) differences with regard to cerebral vascular resistance (P = 0.003), cerebral arterial venous oxygen difference [C(a-v)O2] (P = 0.032), cerebral blood flow (CBF) (P = 0.009), and cerebral oxygen delivery (P = 0.027). There was a similar pattern on rewarming, with groups differing significantly (P < 0.05) with respect to CBF (P = 0.016), cerebral vascular resistance (P = 0.008), oxygen delivery (P = 0.004), C(a-v)O2 (P = 0.043), and cerebral oxygen extraction (P = 0.046). Rewarming rates were similar among groups. There was no difference in neurologic outcome or requirement for inotropic support among groups. The time to awakening was increased (P = 0.0005) in the thiopental group. The thiopental group had lower cerebral oxygen delivery, but not lower cerebral metabolic rate of oxygen consumption, compared with the control group, resulting in widening C(a-v)O2 during CPB. This lack of coupling of oxygen delivery and consumption suggests that pharmacologic neuroprotective mechanisms are complex and involve more than an improvement in the ratio of global cerebral oxygen supply to demand. IMPLICATIONS This study demonstrates that the balance of cerebral oxygen delivery to consumption during cardiopulmonary bypass is altered differently by thiopental and isoflurane. As others have noted, it seems that cerebral protection is more complex than a simple improvement in the balance of oxygen delivery and consumption.
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Affiliation(s)
- M F Newman
- Department of Anesthesiology, Duke Heart Center, Durham, North Carolina, USA.
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Grocott HP, Amory DW, Lowry E, Croughwell ND, Newman MF. Transcranial Doppler blood flow velocity versus 133Xe clearance cerebral blood flow during mild hypothermic cardiopulmonary bypass. J Clin Monit Comput 1998; 14:35-9. [PMID: 9641854 DOI: 10.1023/a:1007493422230] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Transcranial doppler (TCD) is used during cardiopulmonary bypass (CPB) to assess cerebral emboli and to estimate cerebral perfusion. We sought to compare TCD middle cerebral artery blood flow velocity (Vmca) to 133Xe clearance cerebral blood flow (CBF) measurements during mild hypothermic CPB thus determining its utility in cerebral perfusion assessment. METHODS Thirty-four patients undergoing mild hypothermic CPB (35 degrees C) were studied and had comparisons of Vmca and 133Xe CBF at three time intervals, 10, 30 and 60 min after the institution of CPB. Linear regression analysis was performed on data from each of the 3 intervals as well as for pooled data from all 3 periods. RESULTS The correlation coefficients for the 3 time periods were, r = 0.32 (p = 0.12), r = 0.32 (p = 0.11), r = 0.48 (p = (0.02), respectively. The pooled data correlation had a coefficient of 0.34 (p = 0.003). CONCLUSION These findings suggest that TCD Vmca is a relatively poor correlate of CBF during mild hypothermic CPB.
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Affiliation(s)
- H P Grocott
- Department of Anesthesiology, Duke Heart Center, Duke University Medical Center, Durham, NC 27710, USA
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Tardiff BE, Newman MF, Saunders AM, Strittmatter WJ, Blumenthal JA, White WD, Croughwell ND, Davis RD, Roses AD, Reves JG. Preliminary report of a genetic basis for cognitive decline after cardiac operations. The Neurologic Outcome Research Group of the Duke Heart Center. Ann Thorac Surg 1997; 64:715-20. [PMID: 9307463 DOI: 10.1016/s0003-4975(97)00757-1] [Citation(s) in RCA: 202] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Changes in memory and cognition frequently follow cardiac operations. We hypothesized that patients with the apolipoprotein E-epsilon 4 allele are genetically predisposed to cognitive dysfunction after cardiac operations. METHODS The apolipoprotein E-epsilon 4 allele was evaluated as a predictor variable for postoperative cognitive dysfunction in 65 patients undergoing cardiac bypass grafting at Duke University Medical Center. The primary outcome measure was performance on a cognitive battery administered preoperatively and at 6 weeks postoperatively. RESULTS In a multivariable logistic regression analysis including apolipoprotein E-epsilon 4, preoperative score, age, and years of education, a significant association was found between apolipoprotein E-epsilon 4 and change in cognitive test score in measures of short-term memory at 6 weeks postoperatively. Patients with lower educational levels were more likely to show a decline in cognitive function associated with the apolipoprotein E-epsilon 4 allele. CONCLUSIONS This study suggests that apolipoprotein E genotype is related to cognitive dysfunction after cardiopulmonary bypass. Cardiac surgical patients may be susceptible to deterioration after physiologic stress as a result of impaired genetically determined neuronal mechanisms of maintenance and repair.
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Affiliation(s)
- B E Tardiff
- Department of Anesthesiology, Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Duke University Medical Center, Durham, North Carolina 27710, USA
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Grocott HP, Newman MF, Croughwell ND, White WD, Lowry E, Reves JG. Continuous jugular venous versus nasopharyngeal temperature monitoring during hypothermic cardiopulmonary bypass for cardiac surgery. J Clin Anesth 1997; 9:312-6. [PMID: 9195355 DOI: 10.1016/s0952-8180(97)00009-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
STUDY OBJECTIVE To compare jugular venous to nasopharyngeal temperature during hypothermic cardiopulmonary bypass (CPB). DESIGN Prospective observational study. SETTING Tertiary care teaching hospital. PATIENTS 5 ASA physical status IV patients (40 to 65 years of age) having cardiac surgery with hypothermic CPB. INTERVENTIONS, MEASUREMENTS AND MAIN RESULTS: Jugular venous and nasopharyngeal temperatures were recorded throughout the procedure with comparisons made during four time periods: pre-CPB, during CPB, during rewarming, and post-CPB. The patients underwent 85.8 +/- 45.8 minutes (mean +/- SD) of hypothermic CPB, cooling to 26.3 +/- 7.6 degrees C (nasopharyngeal) followed by rewarming at 0.35 +/- 0.1 degree C (nasopharyngeal)/min. There was a high degree of precision between the two temperature sites, but marked differences in bias. In particular, temperature bias was more pronounced during rewarming from CPB compared with other time periods (p < 0.05) where jugular venous temperature was greater than nasopharyngeal temperature by 3.4 degrees C. CONCLUSION Nasopharyngeal temperature underestimates jugular venous temperature during rewarming from hypothermic CPB. As a result, the brain may be exposed to periods of hyperthermia, possibly increasing the risk of neurologic injury associated with CPB.
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Affiliation(s)
- H P Grocott
- Department of Anesthesiology, Duke Heart Center, Duke University Medical Center, Durham, NC 27710, USA
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Croughwell ND, Newman MF, Lowry E, Davis RD, Landolfo KP, White WD, Kirchner JL, Mythen MG. Effect of temperature during cardiopulmonary bypass on gastric mucosal perfusion. Br J Anaesth 1997; 78:34-8. [PMID: 9059201 DOI: 10.1093/bja/78.1.34] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The purpose of our study was to prospectively study the splanchnic response to hypothermic and tepid cardiopulmonary bypass (CPB) using alphastat management of arterial blood-gas tensions. Twenty-four patients for elective CABG surgery were allocated randomly to tepid (35-36 degrees C) or hypothermic (30 degrees C) bypass groups. Measurements were made at four times: (1) baseline, (2) stable during CPB (inflow temperature = nasopharyngeal temperature) 30 degrees C for hypothermic patients, bypass +20 min for tepid patients, (3) 10 min before the end of bypass, (4) after bypass, skin closure. Both groups demonstrated a significant reduction in gastric intramucosal pH (pHim) from time 1 to time 4 and there was no difference in the incidence of a low pHim between the tepid and cold groups (4/12 vs 3/12; ns) at time 4. pHim was significantly lower in the tepid groups at time 3 (P = 0.03) but this discrepancy may have been because of an artefactually high pHim in the cold group. There was a significantly higher incidence of postoperative non-cardiac complications in patients who had a low pHim at time 4 (P = 0.0008). Therefore, we conclude that although the temperature during CPB had a transient effect on pHim it is unlikely to be a major determinant in the pathogenesis of gut mucosal hypoperfusion after bypass.
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Affiliation(s)
- N D Croughwell
- Department of Anesthesiology and Surgery, Duke University Medical Center, Durham, NC 27710, USA
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Newman MF, Croughwell ND, White WD, Lowry E, Baldwin BI, Clements FM, Davis RD, Jones RH, Amory DW, Reves JG. Effect of perfusion pressure on cerebral blood flow during normothermic cardiopulmonary bypass. Circulation 1996; 94:II353-7. [PMID: 8901774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND We have recently shown that during hypothermic cardiopulmonary bypass (CPB), cerebral autoregulation has a positive slope such that for every 10 mm Hg change in pressure, a 0.86 mL.100 g-1.min-1 change in cerebral blood flow (CBF) is predicted. The purpose of this study was to define the influence of mean arterial blood pressure (MAP) on CBF during normothermic CPB. METHODS AND RESULTS CBF was measured by use of 133Xe washout and alpha-stat blood gas management during nonpulsatile CPB. CBF measurements were made at a pump flow of 2.4 L.min-1.m-2 at stable normothermia and approximately 15 minutes later after the MAP was increased or decreased > or = 20%. A third data set was recorded after the pressure was returned to the initial value. Forty-five patients were entered into the study. Temperature was held constant. We found a significant effect (P = .016) of change in MAP on change in CBF during normothermic CPB. For a 10 mm Hg increase in MAP, an increase in CBF of 1.78 mL.100 g-1.min-1 is predicted. Along with change in CBF, significant increases in both cerebral metabolic rate and cerebral oxygen delivery were observed. CONCLUSIONS This information, along with our previous data shows that autoregulation during CPB has a positive slope that is greater with normothermia than hypothermia. Although it is unlikely that these small changes in flow are an important primary effect in the development of hypoperfusion, increased metabolic rate with increased CBF may indicate pressure-dependent collateral flow potentially in regions embolized during CPB.
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Affiliation(s)
- M F Newman
- Department of Anesthesiology, Duke Heart Center, Durham, NC, USA.
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Newman MF, Croughwell ND, Blumenthal JA, Lowry E, White WD, Reves JG. Cardiopulmonary bypass and the central nervous system: potential for cerebral protection. J Clin Anesth 1996; 8:53S-60S. [PMID: 8695116 DOI: 10.1016/s0952-8180(96)90013-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- M F Newman
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
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Abstract
BACKGROUND Despite the large body of literature documenting the presence of cognitive decline after coronary artery bypass grafting, there is little consensus as to the frequency and extent of cognitive impairment. One potential reason for this lack of agreement is the absence of uniform criteria for assessing cognitive decline. METHODS Two hundred thirty-two patients underwent cognitive testing the day before operation and were examined before discharge, and at 6 weeks and 6 months after grafting. For comparative purposes, five different sets of criteria were used to define cognitive decline. RESULTS There was little agreement between the criteria as to which patients declined at each test period. The incidence of decline ranged from 66% to 15.3% before discharge, 34% to 1.1% at 6 weeks, and 19.4% to 3.4% at 6 months. CONCLUSIONS A large variation in reported incidence of cognitive decline after coronary artery bypass grafting can be attributed to the different criteria used to define cognitive impairment.
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Affiliation(s)
- E P Mahanna
- Department of Psychiatry, Duke University Medical Center, Durham, North Carolina 22710, USA
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Newman MF, Murkin JM, Roach G, Croughwell ND, White WD, Clements FM, Reves JG. Cerebral physiologic effects of burst suppression doses of propofol during nonpulsatile cardiopulmonary bypass. CNS Subgroup of McSPI. Anesth Analg 1995; 81:452-7. [PMID: 7653803 DOI: 10.1097/00000539-199509000-00004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Central nervous system (CNS) complications are common after cardiac surgery. Death due to cardiac causes has decreased, but the number of deaths due to CNS injury has increased. As a first stage in the evaluation of its cerebral protection potential, we evaluated the cerebral physiologic effects of burst suppression doses of propofol during nonpulsatile cardiopulmonary bypass. Thirty patients without history of cerebral vascular disease were randomized to two study groups: control group (n = 15) who received sufentanil and vecuronium, or propofol group (n = 15) who received the control anesthetic and propofol infused to maintain electroencephalogram (EEG) burst suppression. Catheters were placed in the radial artery and right jugular bulb for sampling of systemic arterial and jugular bulb venous blood. 133Xe clearance was used to determine cerebral blood flow (CBF) at the start of normothermic bypass, during stable hypothermia, and when rewarmed to 35-37 degrees C nasopharyngeal temperature. Pharmacologic burst suppression with propofol produced a statistically significant reduction in CBF, cerebral oxygen delivery (DO2), and cerebral metabolic rate (CMRO2) at each measurement interval (P < 0..05 vs control). Cerebral arterial venous oxygen difference (C(a-v)O2), and jugular bulb venous oxygen saturation (SJvO2) were not statistically different between groups, indicating maintenance of cerebral metabolic autoregulation (coupling). The reduction in CBF and CMRO2, prominent during the normothermic phases of cardiopulmonary bypass (CPB), indicates a potential for propofol to reduce cerebral exposure to the embolic load during CPB.
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Affiliation(s)
- M F Newman
- Department of Anesthesiology, Duke Heart Center, Durham, North Carolina 27710, USA
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Newman MF, Kramer D, Croughwell ND, Sanderson I, Blumenthal JA, White WD, Smith LR, Towner EA, Reves JG. Differential age effects of mean arterial pressure and rewarming on cognitive dysfunction after cardiac surgery. Anesth Analg 1995; 81:236-42. [PMID: 7618708 DOI: 10.1097/00000539-199508000-00005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Central nervous system dysfunction is a common consequence of otherwise uncomplicated cardiac surgery. Many mechanisms have been postulated for the cognitive dysfunction that is part of these neurologic sequelae. The purpose of our investigation was to evaluate the effects of mean arterial pressure (MAP) during cardiopulmonary bypass (CPB) and the rate of rewarming on cognitive decline after cardiac surgery. Two hundred thirty-seven patients completed preoperative and predischarge neuropsychologic testing. MAP and temperature were recorded at 1-min intervals using an automated anesthesia record keeper. MAP area less than 50 mm Hg (time and degree of hypotension), as well as the maximal rewarming rate, were determined for each patient. Multivariable linear regression revealed that the rate of rewarming and MAP were unrelated to cognitive decline. However, interactions significantly associated with cognitive decline were found between age and MAP area less than 50 mm Hg on one measure, and between age and rewarming rate in another, identifying susceptibility of the elderly to these factors. Although MAP and rewarming were not the primary determinates of cognitive decline in this surgical population, hypotension and rapid rewarming contributed significantly to cognitive dysfunction in the elderly.
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Affiliation(s)
- M F Newman
- Duke Heart Center, Department of Anesthesiology, NC, USA
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Abstract
Systemic venous oxygen saturation is clinically used as an indicator of a satisfactory oxygen supply demand balance on cardiopulmonary bypass (CBP). Cerebral desaturation has been associated with postoperative cognitive dysfunction and has an incidence of 17% to 23% on bypass. We tested the hypothesis that systemic venous saturation did not correlate with jugular bulb venous saturation. Blood was drawn from the radial artery, jugular bulb catheter, and venous return line for determination of pH, oxygen tension and saturation, and carbon dioxide tension at four times during bypass: warm 1 (following initiation of CPB); cold 1 (stable hypothermia); cold 2 (hypothermia prior to rewarm); and warm 2 (nasopharyngeal temperature 36 degrees C to 37 degrees C). Correlations of jugular bulb and systemic venous saturation at cold 1 were r = 0.29, r2 = 0.08, and p = 0.0005, and at warm 2 were r = 0.22, r2 = 0.05, and p = 0.007. We conclude that systemic saturation is a poor indicator of cerebral saturation. The poor association of jugular and systemic pump venous saturations underscores our inability to evaluate adequacy of cerebral perfusion. Jugular saturation is lower than pump venous return blood, especially at times of lower oxygen delivery, thus either continuous invasive or noninvasive evaluation of cerebral oxygenation is required to evaluate the adequacy of cerebral perfusion.
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Affiliation(s)
- N D Croughwell
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Abstract
This report reviews critical issues facing investigators interested in neuropsychologic sequelae after cardiac operations: (1) experimental design; (2) selective attrition; (3) selection of instruments; (4) moderating factors; (5) definitions of cognitive decline; (6) statistical analysis; and (7) clinical significance. Implications for further research in the area are discussed.
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Affiliation(s)
- J A Blumenthal
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina 27710, USA
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Newman MF, Croughwell ND, Blumenthal JA, Lowry E, White WD, Spillane W, Davis RD, Glower DD, Smith LR, Mahanna EP. Predictors of cognitive decline after cardiac operation. Ann Thorac Surg 1995; 59:1326-30. [PMID: 7733762 DOI: 10.1016/0003-4975(95)00076-w] [Citation(s) in RCA: 160] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Despite major advances in cardiopulmonary bypass technology, surgical techniques, and anesthesia management, central nervous system complications remain a common problem after cardiopulmonary bypass. The etiology of neuropsychologic dysfunction after cardiopulmonary bypass remains unresolved and is probably multifactorial. Demographic predictors of cognitive decline include age and years of education; perioperative factors including number of cerebral emboli, temperature, mean arterial pressure, and jugular bulb oxygen saturation have varying predictive power. Recent data suggest a genetic predisposition for cognitive decline after cardiac surgery in patients possessing the apolipoprotein E epsilon-4 allele, known to be associated with late-onset and sporadic forms of Alzheimer's disease. Predicting patients at risk for cognitive decline allows the possibility of many important interventions. Predictive power and weapons to reduce cellular injury associated with neurologic insults lend hope of a future ability to markedly decrease the impact of cardiopulmonary bypass on short-term and long-term neurologic, cognitive, and quality-of-life outcomes.
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Affiliation(s)
- M F Newman
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
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Croughwell ND, Newman MF, Blumenthal JA, White WD, Lewis JB, Frasco PE, Smith LR, Thyrum EA, Hurwitz BJ, Leone BJ. Jugular bulb saturation and cognitive dysfunction after cardiopulmonary bypass. Ann Thorac Surg 1994; 58:1702-8. [PMID: 7979740 DOI: 10.1016/0003-4975(94)91666-7] [Citation(s) in RCA: 185] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Inadequate cerebral oxygenation during cardiopulmonary bypass may lead to postoperative cognitive dysfunction in patients undergoing cardiac operations. A psychological test battery was administered to 255 patients before cardiac operation and just before hospital discharge. Postoperative impairment was defined as a decline of more than one standard deviation in 20% of tests. Variables significantly (p < 0.05) associated with postoperative cognitive impairment are baseline psychometric scores, largest arterial-venous oxygen difference, and years of education. Jugular bulb hemoglobin saturation is significant if it replaces arterial-venous oxygen difference in the model. Factors correlated with jugular bulb saturation at normothermia were cerebral metabolic rate of oxygen consumption (r = -0.6; p < 0.0005), cerebral blood flow (r = 0.4; p < 0.0005), oxygen delivery (r = 0.4; p < 0.0005), and mean arterial pressure (r = 0.15; p < 0.05). Three measures were significantly related to desaturation at normothermia and at hypothermia as well: greater cerebral oxygen extraction, greater arterial-venous oxygen difference, and lower ratio of cerebral blood flow to arterial-venous oxygen difference. We conclude that cerebral venous desaturation occurs during cardiopulmonary bypass in 17% to 23% of people and is associated with impaired postoperative cognitive test performance.
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Affiliation(s)
- N D Croughwell
- Department of Anesthesiology, Duke University Hospital, Durham, North Carolina 27710
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19
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Newman MF, Croughwell ND, Blumenthal JA, White WD, Lewis JB, Smith LR, Frasco P, Towner EA, Schell RM, Hurwitz BJ. Effect of aging on cerebral autoregulation during cardiopulmonary bypass. Association with postoperative cognitive dysfunction. Circulation 1994; 90:II243-9. [PMID: 7955260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Age is a predictor of cognitive dysfunction after cardiac surgery, but the mechanism is unknown. The purpose of our study was to determine whether age-related decrements in cognition are associated with cerebral blood flow (CBF) autoregulation during cardiopulmonary bypass (CPB). METHODS AND RESULTS Cognitive function testing was completed before surgery and before hospital discharge in 215 patients undergoing elective coronary artery bypass grafting (CABG) surgery. The battery consisted of seven tests with nine measures designed to evaluate memory, mood changes, and visuomotor speed and function. Pressure-flow and metabolic-flow cerebral autoregulation during hypothermic cardiopulmonary bypass were determined using the 133Xe clearance CBF method and radial artery and jugular bulb effluent to calculate cerebral metabolic rate (CMRO2) and cerebral AV difference (C[AV]O2). Pressure-flow autoregulation was tested by using two CBF measurements at stable hypothermia: one at stable mean arterial pressure (MAP) and the second 15 minutes later when MAP had increased or decreased > or = 20%. Metabolism-flow autoregulation was tested by varying the temperature (CMRO2) and measuring the coupling of CBF and CMRO2. Individual patient autoregulation was correlated with changes in cognitive measures. Cognitive performance declined in 6 of 9 measures after CABG surgery. Age predicted cognitive decline in 7 of 9 measures; short-term memory showed the greatest effect of age. Pressure-flow autoregulation during hypothermic CPB showed a small but significant (P < .0001) effect of pressure on CBF. There was no effect of age on the slope of CBF response to changes in MAP (pressure-flow autoregulation). There was a major effect of temperature on CBF during CPB (P < .0001). Coupling CBF and CMRO2 with changing temperature was unaffected by age. Changes in cognition were not associated with measures of cerebral autoregulation. However, increasing C(AV)O2 is associated with cognitive deficits in 5 of 9 measures; these associations were independent of age. CONCLUSIONS Increased age predisposes to impaired cognition after cardiac surgery. This decline in cognitive function in the elderly is not associated with age-related changes in cerebral blood flow autoregulation. The association of increased oxygen extraction with decline in some measures of cognitive function suggests that an imbalance in cerebral tissue oxygen supply, which is unrelated to age, contributes to acute cognitive dysfunction after cardiac surgery. Cognitive dysfunction after CPB in the elderly cannot be explained by impaired CBF autoregulation.
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Affiliation(s)
- M F Newman
- Department of Anesthesiology, Duke Heart Center, Durham, NC
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20
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Kern FH, Ungerleider RM, Reves JG, Quill T, Smith LR, Baldwin B, Croughwell ND, Greeley WJ. Effect of altering pump flow rate on cerebral blood flow and metabolism in infants and children. Ann Thorac Surg 1993; 56:1366-72. [PMID: 8267438 DOI: 10.1016/0003-4975(93)90683-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of reduced pump flow rate (PFR) on cerebral blood flow, cerebral oxygen consumption (CMRO2), oxygen extraction, cerebral vascular resistance, and total body vascular resistance were examined in 27 pediatric patients during hypothermic cardiopulmonary bypass (hCPB). During steady state hCPB the extracorporeal flows were randomly adjusted to a conventional PFR and a reduced PFR for each patient. The reduced pump flow rates were dictated by surgical needs. Cerebral blood flow measured using Xenon 133 clearance, and CMRO2 and oxygen extraction were calculated. Our results demonstrated that cerebral blood flow and CMRO2 are unchanged if pump flow rates are reduced by 35% to 45% of conventional PFRs at moderate and deep hypothermic temperatures. Reductions in PFR of 45%-70% from conventional PFRs affect the brain differently during either moderate or deep hCPB. At moderate hCPB (26 degrees to 29 degrees C), reductions in PFRs of 45% to 70% resulted in a significant decrease in cerebral blood flow and CMRO2, whereas oxygen extraction increased in a compensatory manner. During deep hCPB (18 degrees to 22 degrees C), PFR reductions of 45% to 70% of conventional PFR significantly reduced cerebral blood flow and CMRO2 but did not increase oxygen extraction, suggesting that at deep hypothermic temperatures, cerebral blood flow and CMRO2 exceed cerebral metabolic needs. Cerebral vascular resistance increased significantly with decreasing temperature but was not affected by pump flow reductions. We have derived indices for minimal acceptable low-flow cardiopulmonary bypass based on the known effects of temperature on cerebral metabolism and have speculated on its utility based on our limited data and a literature review.
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Affiliation(s)
- F H Kern
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710
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21
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Abstract
Although much has been learned about cerebral physiology during CPB in the past decade, the role of alterations in CBF and CMRO2 during CPB and the unfortunately common occurrence of neuropsychologic injury still is understood incompletely. It is apparent that during CPB temperature, anesthetic depth, CMRO2, and PaCO2 are the major factors that effect CBF. The systemic pressure, pump flow, and flow character (pulsatile versus nonpulsatile) have little influence on CBF within the bounds of usual clinical practice. Although cerebral autoregulation is characteristically preserved during CPB, untreated hypertension, profound hypothermia, pH-stat blood gas management, diabetes, and certain neurologic disorders may impair this important link between cerebral blood flow nutrient supply and metabolic demand (Figure 5). During stable moderate hypothermic CPB with alpha-stat management of arterial blood gases, hypothermia is the most important factor altering cerebral metabolic parameters. Autoregulation is intact and CBF follows cerebral metabolism. Despite wide variations in perfusion flow and systemic arterial pressure, CBF is unchanged. Populations of patients have been identified with altered cerebral autoregulation. To what degree the impairment of cerebral autoregulation contributes to postoperative neuropsychologic dysfunction is unknown. It must be emphasized that not the absolute level of CBF, but the appropriateness of oxygen delivery to demand is paramount. However, the assumption that the control of cerebral oxygen and nutrient supply and demand will prevent neurologic injury during CPB is simplistic. A better understanding of CBF, CMRO2, autoregulation and mechanism(s) of cerebral injury during CPB has lead to a scientific basis for many of the decisions made regarding extracorporeal perfusion.
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Affiliation(s)
- R M Schell
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
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22
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Abstract
Esmolol hydrochloride was administered by constant-rate continuous infusion to 10 patients undergoing hypothermic cardiopulmonary bypass for coronary artery revascularization surgery. After a suitable loading dose, the esmolol infusion was started approximately 30 minutes before bypass and was stopped 10 minutes after termination of bypass. Esmolol concentrations were measured in arterial and venous blood samples collected before and after bypass and in samples taken from the inflow and outflow ports of the membrane oxygenator during bypass. Blood esmolol concentrations increased during hypothermia in a manner that correlated significantly and inversely with temperature. All patients were separated from the extracorporeal circulation without difficulty, and the average arterial esmolol concentration was slightly below the prebypass concentration within minutes of discontinuing bypass. Esmolol disappeared from the blood rapidly on terminating the infusion. There was no difference between esmolol concentrations measured simultaneously from the inflow and outflow ports of the membrane oxygenator during bypass, but radial arterial esmolol concentrations before and after bypass were on average about sevenfold higher than forearm venous esmolol concentrations during the esmolol infusion. The results of this study lead to two important conclusions: (1) in vivo clearance of esmolol demonstrates acute temperature dependence and (2) esmolol is removed irreversibly as it passes through the microcirculation of the hand, making measurement of peripheral esmolol concentrations markedly dependent on sampling site (arterial versus venous).
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Affiliation(s)
- J R Jacobs
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710
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Abstract
The objective of this study was to characterize cerebral venous effluent during normothermic nonpulsatile cardiopulmonary bypass. Thirty-one (23%) of 133 patients met desaturation criteria (defined as jugular bulb venous oxygen saturation less than or equal to 50% or jugular bulb venous oxygen tension less than or equal to 25 mm Hg) during normothermic cardiopulmonary bypass (after hypothermic cardiopulmonary bypass at 27 degrees to 28 degrees C). Cerebral blood flow, calculated using xenon 133 clearance methodology, was significantly (p less than 0.005) higher in the saturated group (33.7 +/- 10.3 mL.100 g-1.min-1) than in the desaturated group (26.2 +/- 6.9 mL.100 g-1.min-1), whereas the cerebral metabolic rate for oxygen was significantly lower (p less than 0.005) in the saturated group (1.28 +/- 0.39 mL.100 g-.min-1) than in the desaturated group (1.52 +/- 0.36 mL.100 g-1.min-1) at normothermia. The arteriovenous oxygen difference at normothermia was lower in the saturated group (3.92 +/- 1.12 mL/dL) than in the desaturated group (5.97 +/- 1.05 mL/dL). Neuropsychological testing was performed in 74 of the 133 patients preoperatively and on day 7 postoperatively. There was a general decline in mean scores of all tests postoperatively in both groups with no significant difference between the groups. We conclude that cerebral venous desaturation represents a global imbalance in cerebral oxygen supply-demand that occurs during normothermic cardiopulmonary bypass and may represent transient cerebral ischemia. These episodes, however, are not associated with impared neuropsychological test performance as compared with the performance of patients with no evidence of desaturation.
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Affiliation(s)
- N D Croughwell
- Department of Anesthesiology, Duke University Hospital, Durham, North Carolina
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Reves JG, Croughwell ND, Hawkins E, Smith LR, Jacobs JR, Rankin S, Lowe J, VanTrigt P. Esmolol for treatment of intraoperative tachycardia and/or hypertension in patients having cardiac operations. Bolus loading technique. J Thorac Cardiovasc Surg 1990; 100:221-7. [PMID: 1974664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Esmolol, administered as a bolus followed by continuous infusion, was used to treat the occurrence of transient tachycardia and hypertension or tachycardia alone before cardiopulmonary bypass in 45 patients. The study was conducted in two phases. Phase I (15 patients) was a dose-finding study and phase II (30 patients) was a randomized, double-blind, placebo-controlled efficacy study. All patients received the last dose of their usual beta-adrenergic blocker the night before the operation and were anesthetized with midazolam, vecuronium, and enflurane in oxygen. Treatment criteria were either a systolic blood pressure greater than 140 mm Hg and a heart rate greater than 70 or a heart rate greater than 80 beats/min. In phase I, graduated doses of esmolol were given to successive patients. A dose of 80 mg followed by a 12 mg/min infusion was declared effective. Phase II patients were randomized to receive esmolol (n = 16) or placebo (n = 14). Hemodynamic data were collected at baseline and 1, 3, 5, and 10 minutes after the administration of esmolol. Plasma norepinephrine was measured at baseline, 1, and 10 minutes. Esmolol significantly (p less than 0.05) reduced heart rate at 1, 3, 5, and 10 minutes but did not change blood pressure, pulmonary artery diastolic pressure, right atrial pressure, cardiac output, or systemic vascular resistance. Our results show that a bolus loading dose of esmolol is safe and effective in the treatment of tachycardia in patients with ischemic heart disease and that esmolol rapidly blocks the beta-adrenergic effects of norepinephrine associated with surgical stress.
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Affiliation(s)
- J G Reves
- Department of Anesthesiology, Heart Center, Duke University Medical Center, Durham, NC 27710
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Croughwell ND, Reves JG, Will CJ, Kasson BJ, Goodman DK. Safety of rapid administration of flumazenil in patients with ischaemic heart disease. Acta Anaesthesiol Scand Suppl 1990; 92:55-8; discussion 78. [PMID: 2109470 DOI: 10.1111/j.1399-6576.1990.tb03185.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The purpose of this study was to determine if higher (36 micrograms.kg-1) doses of flumazenil (a new benzodiazepine (BZ) antagonist) produced an effect on haemodynamics. Twelve patients with class III-IV angina were entered into this double-blind randomised placebo-controlled study. BZ were withheld for 2 weeks prior to surgery. Patients were placed on an ambulatory monitor 18 h prior to surgery to record changes in heart rate rhythm and ST segment changes. The patients were given secobarbital 100-200 mg and morphine 0.12 mg.kg-1 90 min prior to surgery. Flumazenil or placebo was given in divided doses every 3 min (1 mg, 1 mg, 1 mg). Complete haemodynamic profiles were obtained at baseline and 2 min following each injection of flumazenil. Flumazenil produced a minimal but statistically significant reduction in systolic blood pressure (147 +/- 13.9 to 137 +/- 18.4 mmHg) and diastolic blood pressure (74 +/- 14.8 to 67 +/- 13 mmHg). There was no consistent effect on heart rate, pulmonary capillary wedge pressure or cardiac index. We conclude that flumazenil is safe when administered in relatively high doses to patients with ischaemic heart disease who have not received benzodiazepines.
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Croughwell ND, Reves JG, Will CJ, Kasson BJ, Goodman DK. SAFETY OF RAPIDLY ADMINISTERED FLUMAZENIL IN PATIENTS WITH ISCHEMIC HEART DISEASE. Anesth Analg 1990. [DOI: 10.1213/00000539-199002001-00073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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de Bruijn NP, Hlatky MA, Jacobs JR, Clements FM, Croughwell ND, Davis D, Flezzani P, Hill RF, Hinohara T, Kates RA. General anesthesia during percutaneous transluminary coronary angioplasty for acute myocardial infarction: results of a randomized controlled clinical trial. Anesth Analg 1989; 68:201-7. [PMID: 2521988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Acutely ill patients with myocardial infarction may require immediate cardiac catheterization and coronary angioplasty to achieve myocardial reperfusion. To determine the feasibility of using general anesthesia under these circumstances, a randomized clinical trial was performed. Of 50 patients, 25 received anesthesia and 25 receive intravenous sedation. There were transient increases in heart rate and blood pressure after tracheal intubation in the anesthetized patients, followed by significant and sustained decreases below baseline values once steady state anesthesia was attained. Arterial oxygenation was significantly improved in anesthetized patients. There were no serious complications due to anesthesia, but the small sample size limited the power of the study to detect differences in morbidity or mortality. Patients strongly preferred anesthesia. These results show that general anesthesia is feasible in patients undergoing interventional cardiac catheterization during acute myocardial infarction, when pain, anxiety or agitation do not respond adequately to conventional measures.
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Affiliation(s)
- N P de Bruijn
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
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Flezzani P, Croughwell ND, McIntyre RW, Reves JG. Isoflurane decreases the cortisol response to cardiopulmonary bypass. Anesth Analg 1986; 65:1117-22. [PMID: 3767009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Eighteen patients with normal left ventricular function scheduled for elective myocardial revascularization were anesthetized with fentanyl (52-58 micrograms/kg). At the beginning of hypothermic cardiopulmonary bypass (CPB) they were assigned to a control (C) group (n = 6) that did not receive further anesthesia, or to a group given either 1% isoflurane (n = 6) or 2% isoflurane (n = 6). Blood samples for measurement of total plasma cortisol concentrations were obtained before, during, and after CPB. Hemodynamic measurements before and after CPB were not different among groups. Patients in group C required higher infusion rates of sodium nitroprusside (P less than or equal to 0.05) and patients given 2% isoflurane received more phenylephrine (P less than or equal to 0.05) to keep mean arterial pressure at 50 +/- 10 mm Hg during CPB. Isoflurane caused a dose-related decrease in total plasma cortisol concentrations during and after CPB. We conclude that increased depth of anesthesia attenuates the cortisol (stress) response to cardiopulmonary bypass.
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