Delirium affects length of hospital stay after lung transplantation.

BACKGROUND: Delirium is relatively common after lung transplantation, although its prevalence and prognostic significance have not been systematically studied. The purpose of the present study was to examine pretransplant predictors of delirium and the short-term impact of delirium on clinical outcomes among lung transplant recipients. METHODS: Participants underwent pretransplant cognitive testing using the Repeatable Battery for the Assessment of Neuropsychological Status and the Trail Making Test. After transplant, delirium was assessed using the Confusion Assessment Method until discharge. RESULTS: Sixty-three patients were transplanted between March and November 2013, of which 23 (37%) developed delirium. Among transplanted patients, 48 patients completed pretransplant cognitive testing. Better pretransplant cognitive function was associated with lower risk of delirium (odds ratio, 0.69 [95% confidence interval 0.48, 0.99], P = .043); and demographic and clinical features including native disease (P = .236), the Charlson comorbidity index (P = .581), and the lung allocation score (P = .871) were unrelated to risk of delirium, although there was a trend for women to experience delirium less frequently (P = .071). The presence (P = .006) and duration (P = .027) of delirium were both associated with longer hospital stays. CONCLUSION: Delirium occurs in more than one-third of patients after lung transplantation. Delirium was associated with poorer pretransplant cognitive functioning and longer hospital stays, after accounting for other medical and demographic factors.

Changes in neurocognitive functioning following lung transplantation.

Although neurocognitive impairment is relatively common among patients with advanced lung disease, little is known regarding changes in neurocognition following lung transplantation. We therefore administered 10 tests of neurocognitive functioning before and 6 months following lung transplantation and sought to identify predictors of change. Among the 49 study participants, native diseases included chronic obstructive pulmonary disease (n = 22), cystic fibrosis (n = 12), nonfibrotic diseases (n = 11) and other (n = 4). Although composite measures of executive function and verbal memory scores were generally within normal limits both before and after lung transplantation, verbal memory performance was slightly better posttransplant compared to baseline (p < 0.0001). Executive function scores improved in younger patients but worsened in older patients (p = 0.03). A minority subset of patients (29%) exhibited significant cognitive decline (i.e. >1 standard deviations on at least 20% of tests) from baseline to posttransplant. Patients who declined were older (p < 0.004) and tended to be less educated (p = 0.07). Lung transplantation, like cardiac revascularization procedures, appears to be associated with cognitive decline in a subset of older patients, which could impact daily functioning posttransplant.

Chronotherapy of ovarian cancer: effect on blood variables and serum cytokines. A case report.

A 7-year-old patient with Stage III-c ovarian cancer was subjected to 8 cycles, approximately four weeks apart, of chronobiologically-optimized treatments with combination of three anti-cancer agents: Four cycles at AM, Cytoxan and PM, cis-Platinum; four cycles at AM, Adriamycin and PM, cis-Platinum. A second look laporoscopy revealed clean intestines, no definite masses in the pelvis area although there was an apparent mass in the right upper pelvis and several slightly enlarged lymph nodes in the base of mesentery. Six cycles of Taxol were administered at about Noon. Seven months remission appeared evident as judged by no changes in monthly examinations, in blood work or in CA-125 marker levels which remained below 12 U/ml. During the eight month the CA-125 marker began to rise, 36 then to 52 U/ml. A second 6 cycle series of Taxol was initiated but the CA-125 marker continued to rise, 57, 65, 72, 86, and 87 U/ml level. The patient declined in spirit, in well-being and expired 2 weeks later, 31 months after the initial diagnosis of cancer. Blood hematology, chemistry, and cytokines variables were analyzed at about weekly intervals. Significant reductions in total WBC, neutrophiles and platelet levels were evident during the second week of all cycle treatments, while increases were noted in serum levels of IL-2, IL-6 and IL-10 following Cytoxan-cis-Platinum-Adriamycin, but not Taxol. After each infusion moderate and temporary increases in RBC levels were noted. The treatments impact on hematology, chemistry, cytokine variables and on the integrity of the patient, are presented and briefly discussed.

Inflammatory gene polymorphisms and risk of postoperative myocardial infarction after cardiac surgery.

BACKGROUND: The inflammatory response triggered by cardiac surgery with cardiopulmonary bypass (CPB) is a primary mechanism in the pathogenesis of postoperative myocardial infarction (PMI), a multifactorial disorder with significant inter-patient variability poorly predicted by clinical and procedural factors. We tested the hypothesis that candidate gene polymorphisms in inflammatory pathways contribute to risk of PMI after cardiac surgery. METHODS AND RESULTS: We genotyped 48 polymorphisms from 23 candidate genes in a prospective cohort of 434 patients undergoing elective cardiac surgery with CPB. PMI was defined as creatine kinase-MB isoenzyme level > or = 10x upper limit of normal at 24 hours postoperatively. A 2-step analysis strategy was used: marker selection, followed by model building. To minimize false-positive associations, we adjusted for multiple testing by permutation analysis, Bonferroni correction, and controlling the false discovery rate; 52 patients (12%) experienced PMI. After adjusting for multiple comparisons and clinical risk factors, 3 polymorphisms were found to be independent predictors of PMI (adjusted P<0.05; false discovery rate <10%). These gene variants encode the proinflammatory cytokine interleukin 6 (IL6 -572G>C; odds ratio [OR], 2.47), and 2 adhesion molecules: intercellular adhesion molecule-1 (ICAM1 Lys469Glu; OR, 1.88), and E-selectin (SELE 98G>T; OR, 0.16). The inclusion of genotypic information from these polymorphisms improved prediction models for PMI based on traditional risk factors alone (C-statistic 0.764 versus 0.703). CONCLUSIONS: Functional genetic variants in cytokine and leukocyte-endothelial interaction pathways are independently associated with severity of myonecrosis after cardiac surgery. This may aid in preoperative identification of high-risk cardiac surgical patients and development of novel cardioprotective strategies.

Genetic factors contribute to bleeding after cardiac surgery.

BACKGROUND: Postoperative bleeding remains a common, serious problem for cardiac surgery patients, with striking inter-patient variability poorly explained by clinical, procedural, and biological markers. OBJECTIVE: We tested the hypothesis that genetic polymorphisms of coagulation proteins and platelet glycoproteins are associated with bleeding after cardiac surgery. PATIENTS/METHODS: Seven hundred and eighty patients undergoing aortocoronary surgery with cardiopulmonary bypass were studied. Clinical covariates previously associated with bleeding were recorded and DNA isolated from preoperative blood. Matrix Assisted Laser Desorption/Ionization, Time-Of-Flight (MALDI-TOF) mass spectroscopy or polymerase chain reaction were used for genotype analysis. Multivariable linear regression modeling, including all genetic main effects and two-way gene-gene interactions, related clinical and genetic predictors to bleeding from the thorax and mediastinum. RESULTS: Nineteen candidate polymorphisms were assessed; seven [GPIaIIa-52C>T and 807C>T, GPIb alpha 524C>T, tissue factor-603A>G, prothrombin 20210G>A, tissue factor pathway inhibitor-399C>T, and angiotensin converting enzyme (ACE) deletion/insertion] demonstrate significant association with bleeding (P < 0.01). Adding genetic to clinical predictors results improves the model, doubling overall ability to predict bleeding (P < 0.01). CONCLUSIONS: We identified seven genetic polymorphisms associated with bleeding after cardiac surgery. Genetic factors appear primarily independent of, and explain at least as much variation in bleeding as clinical covariates; combining genetic and clinical factors double our ability to predict bleeding after cardiac surgery. Accounting for genotype may be necessary when stratifying risk of bleeding after cardiac surgery.

Cerebral embolization during cardiac surgery: impact of aortic atheroma burden.

BACKGROUND: Aortic atheromatous disease is known to be associated with an increased risk of perioperative stroke in the setting of cardiac surgery. In this study, we sought to determine the relationship between cerebral microemboli and aortic atheroma burden in patients undergoing cardiac surgery. METHODS: Transoesophageal echocardiographic images of the ascending, arch and descending aorta were evaluated in 128 patients to determine the aortic atheroma burden. Transcranial Doppler (TCD) of the right middle cerebral artery was performed in order to measure cerebral embolic load during surgery. Using multivariate linear regression, the numbers of emboli were compared with the atheroma burden. RESULTS: After controlling for age, cardiopulmonary bypass time and the number of bypass grafts, cerebral emboli were significantly associated with atheroma in the ascending aorta (R2=0.11, P=0.02) and aortic arch (P=0.013). However, there was no association between emboli and descending aortic atheroma burden (R2=0.05, P=0.20). CONCLUSIONS: We demonstrate a positive relationship between TCD-detected cerebral emboli and the atheromatous burden of the ascending aorta and aortic arch. Previously demonstrated associations between TCD-detectable cerebral emboli and adverse cerebral outcome may be related to the presence of significant aortic atheromatous disease.

Report of the substudy assessing the impact of neurocognitive function on quality of life 5 years after cardiac surgery.

BACKGROUND AND PURPOSE: The importance of perioperative cognitive decline has long been debated. We recently demonstrated a significant correlation between perioperative cognitive decline and long-term cognitive dysfunction. Despite this association, some still question the importance of these changes in cognitive function to the quality of life of patients and their families. The purpose of our investigation was to determine the association between cognitive dysfunction and long-term quality of life after cardiac surgery. METHODS: After institutional review board approval and patient informed consent, 261 patients undergoing cardiac surgery with cardiopulmonary bypass were enrolled and followed for 5 years. Cognitive function was measured with a battery of tests at baseline, discharge, and 6 weeks and 5 years postoperatively. Quality of life was assessed with well-validated, standardized assessments at the 5-year end point. RESULTS: Our results demonstrate significant correlations between cognitive function and quality of life in patients after cardiac surgery. Lower 5-year overall cognitive function scores were associated with lower general health and a less productive working status. Multivariable logistic and linear regression controlling for age, sex, education, and diabetes confirmed this strong association in the majority of areas of quality of life. CONCLUSIONS: Five years after cardiac surgery, there is a strong relationship between neurocognitive functioning and quality of life. This has important social and financial implications for preoperative evaluation and postoperative care of patients undergoing cardiac surgery.

Effect of apolipoprotein E genotype on cerebral autoregulation during cardiopulmonary bypass.

BACKGROUND AND PURPOSE: The presence of the apolipoprotein E epsilon4 (apoE4) allele has been associated with cognitive decline after cardiac surgery. We compared autoregulation of cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO(2)), and arterial-venous oxygen content difference [C(A-V)O(2)], during cardiopulmonary bypass (CPB) in patients with and without the apoE4 allele to help define the mechanism of association with cognitive decline. METHODS: One hundred fifty-four patients underwent coronary artery bypass grafting with CPB, nonpulsatile flow, and alpha-stat management. CBF was measured by using (133)Xe washout methods. C(A-V)O(2), CMRO(2), and oxygen delivery were calculated. Pressure-flow autoregulation was tested by using 2 CBF measurements at stable hypothermia: the first at stable mean arterial pressure (MAP) and the second 15 minutes later, when MAP had increased or decreased >/=20%. Metabolism-flow autoregulation was tested by varying the temperature and measuring the coupling of CBF and CMRO(2). RESULTS: In patients with (n=41) or without (n=113) the apoE4 allele, there were no differences in CBF, CMRO(2), C(A-V)O(2), pressure-flow and metabolism-flow autoregulation corrected for age, gender, non-insulin-dependent diabetes, hemoglobin, CPB time, and temperature. CONCLUSIONS: We conclude that apoE genotype does not affect global CBF and oxygen delivery/extraction during CPB, which suggests that other mechanisms are responsible for the apoE isoform-related neurocognitive dysfunction seen in patients undergoing CPB.

Bispectral analysis during cardiopulmonary bypass: the effect of hypothermia on the hypnotic state.

STUDY OBJECTIVE: To evaluate the hypothesis that the bispectral index (BIS) is not affected by the hypothermia that is associated with cardiopulmonary bypass (CPB). DESIGN: Prospective, observational study. SETTING: Cardiac surgical operating suite of a university medical center. PATIENTS: 100 patients undergoing cardiac surgery requiring CPB. INTERVENTIONS: A constant effect site concentration of 2.2 ng/mL for fentanyl and 60 ng/mL for midazolam was maintained throughout surgery using a computer-assisted continuous infusion technique. MEASUREMENTS: The BIS value, percent isoflurane administered, predicted brain concentrations of midazolam and fentanyl, and nasopharyngeal temperature were recorded before CPB, at 15 minutes after the onset of CPB, at placement of the aortic cross-clamp, at start of rewarming, on separation from CPB, and 15 minutes after the end of CPB. Data were analyzed using a repeated-measures mixed-effects method, taking into account temperature, age, and predicted level of each anesthetic. MAIN RESULTS: A significant overall association between temperature and BIS was observed independent of patient age, predicted brain midazolam or fentanyl concentration, percent isoflurane administered, and surgical time point (p < 0.001). The BIS is estimated to decrease by 1.12 units for each degree Celsius decrease in body temperature. CONCLUSIONS: Hypothermia decreases the BIS by 1.12 units per degree Celsius decline in temperature.

Platelet PlA2 polymorphism enhances risk of neurocognitive decline after cardiopulmonary bypass. Multicenter Study of Perioperative Ischemia (McSPI) Research Group.

BACKGROUND: Neurocognitive decline, often produced by atherosclerotic plaque embolization, remains a frequent complication of cardiopulmonary bypass. Plaque fragments may initiate local thrombosis, which, in turn, aggravates the embolic insult. Prothrombotic genetic factors may exacerbate this process. We investigated whether the PlA2 polymorphism of platelet GPIIIa, a prothrombotic risk factor in other cardiovascular settings, is associated with early neurocognitive decline after cardiopulmonary bypass. METHODS: Neurocognitive changes were evaluated by the Mini-Mental State Examination administered preoperatively and on postoperative day 4 and the PlA genotype determined in 70 patients undergoing cardiopulmonary bypass. RESULTS: Forty-nine patients were PlA1/A1, and 21 were PlA1/A2 or PlA2/A2. Fifty-two patients (74%) demonstrated post-cardiopulmonary bypass neurocognitive decline, of which 34 were PlA1/A1 and 18 were PlA1/A2 or PlA2/A2 Multivariate analysis revealed that the PlA2 genotype and baseline Mini-Mental State Examination were significantly associated with greater neurocognitive decline (decreased Mini-Mental State Examination scores, p = 0.036 and 0.024, respectively). CONCLUSIONS: This study demonstrates a link between the PlA2 allele of platelet GPIIIa and more severe neurocognitive decline after cardiopulmonary bypass. Although the mechanism is unknown, it could represent exacerbation of platelet-dependent thrombotic processes associated with plaque embolism.

The concordance of intraoperative left ventricular wall-motion abnormalities and electrocardiographic S-T segment changes: association with outcome after coronary revascularization. Multicenter Study of Perioperative Ischemia (McSPI) Research Group.

BACKGROUND: Transesophageal echocardiography (TEE) and Holter electrocardiography (ECG) are used to detect intraoperative ischemia during coronary artery bypass graft surgery (CABG). Concordance of these modalities and sensitivity as indicators of adverse perioperative cardiac outcomes are poorly defined. The authors tried to determine whether routine use of Holter ECG and TEE in patients with CABGs has clinical value in identifying those patients in whom myocardial infarction (MI) is likely to develop. METHODS: A total of 351 patients with CABG and both ECG- and TEE-evaluable data were examined for the occurrence of ischemia and infarction. The TEE and five-lead Holter ECGs were performed continuously during cardiac surgery. The incidence of MI (creatine kinase-MB > or = 100 ng/ml) within 12 h of arrival in the intensive care [ICU] unit, new ECG Q wave on ICU admission or on the morning of postoperative day 1, or both, were recorded. RESULTS: Electrocardiographic or TEE evidence of intraoperative ischemia was present in 126 (36%) patients. The concordance between modalities was poor (positive concordance = 17%; Kappa statistic = 0.13). Myocardial infarction occurred in 62 (17%) patients, and 32 (52%) of them had previous intraoperative ischemia. Of these, 28 (88%) were identified by TEE, whereas 13 (41%) were identified by ECG. Prediction of MI was greater for TEE compared with ECG. CONCLUSIONS: Wall-motion abnormalities detected by TEE are more common than S-T segment changes detected by ECG, and concordance between the two modalities is low. One half of patients with MI had preceding ECG or TEE ischemia. Logistic regression revealed that TEE is twice as predictive as ECG in identifying patients who have MI.

Lymphocyte and monocyte subset changes during cardiopulmonary bypass: effects of aging and gender.

Complications of cardiopulmonary bypass (CPB) may be associated with either immune suppression or immune activation, but the specific effects of CPB on many lymphocyte and monocyte subsets are unclear. In addition, the increasing age of patients undergoing cardiac surgery raises the possibility of even greater effects on the immune system in elderly patients. We measured immunophenotypic alterations of circulating lymphocytes and monocytes after CPB in male and female cardiac surgery patients who were either younger than 60 or older than 75 years of age. The total lymphocyte counts in all patients decreased postoperatively; older patients had significantly lower counts at all time points. The absolute decline was greatest among T cells and particularly CD4+ T cells, which reached an average nadir of 251 cells/microl on postoperative day 1 in the older patients. The percentages of CD8+, CD4+CD45RA+, and CD4+CD45RO+ T cells did not change significantly, whereas the percentages of B cells and natural killer cells increased. Both T and B lymphocytes and monocytes showed evidence of activation, with increased percentages of CD3+HLADr+, CD3+IL2R+, and CD19+CD23+ lymphocytes and increased expression of CD11b on monocytes. By contrast, expression of class II major histocompatibility antigen (HLADr) monocytes decreased significantly. We conclude that CPB produces a profound alteration in the pool of circulating lymphocytes and monocytes, evidenced by decreased numbers of lymphocyte subsets including CD4+ cells and decreased expression of monocyte surface membrane proteins important for antigen presentation; CPB also activates a variety of specific circulating mononuclear cell subsets. Older patients showed patterns of lymphocyte and monocyte activation comparable to those of younger patients; however, they had consistently lower lymphocyte numbers and a trend toward decreased monocyte HLADr expression, potentially placing them at greater risk for infectious complications. Gender had no effect.

Atrial fibrillation following coronary artery bypass graft surgery: predictors, outcomes, and resource utilization. MultiCenter Study of Perioperative Ischemia Research Group.

OBJECTIVE: To determine the incidence, predictors, and cost of atrial fibrillation and flutter (AFIB) following coronary artery bypass graft (CABG) surgery. DESIGN: Prospective observational study (MultiCenter Study of Perioperative Ischemia). SETTING: Twenty-four university-affiliated hospitals in the United States from 1991 to 1993. SUBJECTS: A total of 2417 patients undergoing CABG with or without concurrent valvular surgery selected using a systematic sampling interval. MEASUREMENTS: Detailed preoperative, intraoperative, and postoperative data collected on standardized reporting forms. RESULTS: The overall incidence of postoperative AFIB was 27 percent. Independent predictors of postoperative AFIB included advanced age (odds ratio [OR], 1.24 per 5-year increase; 95 percent confidence interval [CI], 1.18-1.31); male sex (OR, 1.41; 95 percent CI, 1.09-1.81); a history of AFIB (OR, 2.28; 95 percent CI, 1.74-3.00); a history of congestive heart failure (OR, 1.31; 95 percent CI, 1.04-1.64); and a precardiopulmonary bypass heart rate of more than 100 beats per minute (OR, 1.59; 95 percent CI, 1.00-2.55). Surgical practices such as pulmonary vein venting (OR, 1.44; 95 percent CI, 1.13-1.83); bicaval venous cannulation (OR, 1.40; 95 percent CI, 1.04-1.89); postoperative atrial pacing (OR, 1.27; 95 percent CI, 1.00-1.62); and longer cross-clamp times (OR, 1.06 per 15 minutes; 95 percent CI, 1.00-1.11) also were identified as independent predictors of postoperative AFIB. Patients with postoperative AFIB remained an average of 13 hours longer in the intensive care unit and 2.0 days longer in the ward when compared with patients without AFIB. CONCLUSION: Postoperative AFIB is common after CABG surgery and has a significant effect on both intensive care unit and overall hospital length of stay. In addition to expected demographic factors, certain surgical practices increase the risk of postoperative AFIB. Randomized controlled trials are necessary to determine if modification of these surgical practices, especially in patients at high risk, would decrease the incidence of postoperative AFIB.

Acadesine inhibits neutrophil CD11b up-regulation in vitro and during in vivo cardiopulmonary bypass.

Granulocyte adhesion to ischemic tissue, mediated in large part by beta 2 integrin receptors, is important in the pathophysiology of reperfusion injury. Acadesine, a drug that modulates adenosine levels in ischemic tissue, has been shown to reduce reperfusion injury in animal models of ischemia. The purpose of this study was to measure changes in granulocyte CD11b/CD18 in an in vitro assay and in an in vivo trial of acadesine administered during cardiopulmonary bypass to determine whether this agent might modulate up-regulation of this adhesion receptor. In vitro, whole blood was incubated with acadesine or control diluent, stimulated with N-formyl-methionyl-leucyl-phenylalanine, and granulocyte CD11b measured. Acadesine significantly (p < 0.01) inhibited N-formyl-methionyl-leucyl-phenylalanine-induced granulocyte CD11b up-regulation by a mean of 61%. In similar experiments, adenosine also inhibited N-formyl-methionyl-leucyl-phenylalanine-induced granulocyte CD11b up-regulation (p < 0.01). In vivo, 34 patients at our institution participating in a multicenter trial of acadesine during cardiopulmonary bypass were randomized to placebo, low-dose, or high-dose acadesine infusion perioperatively. Combining low- and high-dose treatment groups, there was significant (p = 0.05) inhibition of granulocyte CD11b up-regulation in patients receiving acadesine; granulocyte CD11b expression in the acadesine group peaked at 2.8 times baseline versus 4.3 for placebo. By contrast, monocyte CD11b up-regulation (peaking after cardiopulmonary bypass at 3 times baseline) was not affected by acadesine. Acadesine and adenosine inhibit up-regulation of granulocyte CD11b in vitro, and acadesine is capable of a similar inhibition during in vivo cardiopulmonary bypass. This inhibition may contribute to the ability of these agents to decrease in vivo reperfusion injury.

ST segment depression during labor and delivery.

ECG changes suggestive of myocardial ischemia are common during cesarean delivery under regional anesthesia. To determine the time course, duration, and significance of these ECG changes, we monitored 111 parturients with continuous ambulatory ECG (Holter) during and after cesarean delivery. Twenty-two parturients undergoing vaginal delivery were similarly monitored. ST segment depression was present in 25% of patients undergoing cesarean delivery but was not found in those patients delivering vaginally. ST segment elevation was not detected in either group. The incidence of ST segment depression during cesarean delivery was similar with epidural (29%), spinal (17%), and general (18%) anesthesia, occurring most commonly in the 30 min following delivery (P less than 0.001). Transthoracic echocardiographic imaging was performed in 23 patients undergoing cesarean section. Five of the 23 patients had seven episodes of intraoperative ST segment depression. Regional wall motion abnormalities were not present in any patient. A decrease in ejection fraction area greater than 15% from baseline or from previous interval ejection fraction area was present during four episodes of ST change. Three episodes of ST depression were not associated with significant decreases in ejection fraction area. Precordial Doppler monitoring for detection of venous air embolism in 25 patients revealed no association between the occurrence of venous air embolism and ST segment depression. We conclude that although significant myocardial impairment during cesarean delivery does not occur, episodes of ST depression may not all be merely an artifact of parturition.

Modulation of platelet surface adhesion receptors during cardiopulmonary bypass.

Alterations in platelet receptors critical to adhesion may play a role in the pathogenesis of the qualitative platelet defect associated with cardiopulmonary bypass. Using flow cytometry, we measured changes in the following platelet surface adhesive proteins: the von Willebrand factor receptor, glycoprotein Ib; the fibrinogen receptor, glycoprotein IIb/IIIa; the thrombospondin receptor, glycoprotein IV; the adhesive glycoprotein granule membrane protein 140, whose expression also reflects platelet activation and alpha-granule release; and, as a control, the nonreceptor protein HLA, A,B,C. Glycoprotein Ib decreased during cardiopulmonary bypass (P less than 0.05) and reached a nadir at 72% (P less than 0.05) of its baseline value at 2-4 h after bypass. This decrease correlated (r = 0.76) with the magnitude of platelet activation (alpha-granule release) in any given patient, but even platelets that were not activated demonstrated a decrease in glycoprotein Ib expression. Glycoprotein IIb/IIIa also decreased in both the activated (47% of baseline, P less than 0.01) and unactivated (63% of baseline, P less than 0.01) subsets of platelets at the end of cardiopulmonary bypass. Glycoprotein IV and HLA A,B,C did not decrease, but instead increased 2-4 h after cardiopulmonary bypass (P less than 0.05). We conclude that cardiopulmonary bypass produces selective decreases in surface glycoproteins Ib and IIb/IIIa as well as in platelet activation; that these two alterations are temporally but not necessarily mechanistically linked; and that these changes have the potential to adversely affect platelet function.

Emergency tracheal intubation in the postanesthesia care unit: physician error or patient disease?

Inadequate airway maintenance has been a major factor in perioperative morbidity. To determine the incidence and etiology of emergency tracheal intubations in the postanesthesia care unit (PACU), we retrospectively reviewed 13,593 consecutive admissions to our PACU from October 1986 through October 1988. Twenty-six patients (26/13,593 = 0.19%) required the insertion of an endotracheal tube while in the PACU. Seventy-seven percent (20/26) of the intubations occurred within 1 h of extubation and/or admission to the PACU. Intubation was more common at the extremes of age; 54% of those intubated were more than 60 yr old (P = 0.003); 19% were less than 3 yr old (P less than 0.05). Twenty-three percent of the intubated patients had undergone otolaryngologic procedures (P = 0.008). Interestingly, 73% of the intubations occurred during the months of January through June (P = 0.016). Median PACU admission scores were lower for the intubated group (P less than 0.001). There was no association between intubation and gender (P = 0.74), anesthetic technique (P = 0.41), or anesthetic agent (P = 0.49). Of the 26 intubations, 18 (69%) were considered to be directly related to anesthetic management. Despite the extremely low incidence of emergency tracheal intubation in a heterogeneous group of patients admitted to our PACU, preventable anesthesia-related etiologic factors including excessive sedative or anesthetic effect, inappropriate fluid management, persistent muscle relaxant effect, and upper airway obstruction contributed to the majority of these intubations.