Report of a National Conference on Donation after cardiac death.

A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care. This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States.

Haemodynamic changes induced by hyperbaric bupivacaine during lateral decubitus or supine spinal anaesthesia.

BACKGROUND AND OBJECTIVE: Hypotension, the commonest side-effect of spinal anaesthesia, results from sympathetic denervation. This study compared patient positioning (supine vs. decubitus) on haemodynamic variables during spinal anaesthesia. METHODS: After intravenous crystalloid preloading with 5 mL kg(-1), hyperbaric bupivacaine 0.5% 2.5 mL was injected intrathecally at the L2-3 or L3-4 interspace. Patients were then randomly assigned to be positioned immediately supine and horizontal for 30 min (Group SUP, n = 12), or remained in the lateral decubitus position (fractured hip dependent) for 30 min (Group LAT, n = 14). Systolic blood pressure, mean arterial pressure, and loss of sensation of pinprick sensation were recorded prior to induction of spinal anaesthesia (baseline) and at 1, 2, 3, 5, 10, 15, 30, 45, 60, 90 and 120 min after intrathecal injection. RESULTS: In Group SUP, the percent maximum systolic blood pressure (36 +/- 13%) and percent maximum mean arterial pressure decreases (27 +/- 13%) were significantly greater (P < 0.05) than in Group LAT (30 +/- 8% and 23 +/- 11%, respectively). Additionally, there was a borderline significant delay in the time to maximum systolic blood pressure decrease in Group LAT (38 +/- 30 min) when compared with Group SUP (20 +/- 17 min, P = 0.06), while the total dose of ephedrine required in the SUP group (30 mg) was greater than that required in the LAT group (15 mg, P = 0.05). In Group LAT patients, the mean level of denervation on the operative side extended 2 dermatomes more cephalad than in Group SUP. CONCLUSIONS: Lateral positioning for spinal anaesthesia delays the onset of hypotension, while requiring smaller total doses of vasoconstrictors for blood pressure maintenance.

Activities of daily living and cardiovascular complications following elective, noncardiac surgery.

BACKGROUND: Algorithms for preoperative cardiac evaluation prior to noncardiac surgery use indices of the metabolic equivalent of activities of daily living (METs). We evaluated METs as a predictor of cardiac complications following elective, noncardiac surgery. METHODS: A study was performed in an outpatient university preadmission center METs were estimated prospectively for 5,939 inpatients admitted for elective, noncardiac surgery who underwent a preanesthetic assessment within two months prior to surgery. Cardiac outcomes were retrieved retrospectively from relational databases. Outcomes included death, myocardial infarction, acute congestive failure, arrhythmias, cardiac arrest, acute ischemia, acute renalfailure, stroke, respiratory failure, severe hypertension, peripheral vascular occlusion, and pericardial effusion. Adverse outcomes were correlated with age, gender, surgical procedure, activities, and the American Society of Anesthesiologist's Physical Status (ASA-PS) using receiver operator characteristic curve analysis. RESULTS: 94 of 5,939 (1.6 percent) patients had cardiac complications; 16 died, six from their cardiac complication. 38.3 percent of complications occurred following vascular surgery. Using a multinomial logistic regression analysis, both age and physical status were highly significant predictors (p < 0.001) but METs was not (p = 0. 793). Receiver operator characteristic (ROC) curves were usedfor predictive value of variables. Area of the curves for age versus cardiac complications and death were 0.814 and 0.782; for physical status, 0.744 and 0.803; for METs, 0.664 and 0.524. CONCLUSIONS: METs are not a reliable index for the prediction of adverse cardiac events following elective, noncardiac surgery. Age and physical status are more predictive. Adverse cardiac outcomes are most frequent following vascular surgery.

The traumatic airway: the anesthesiologist's role in the emergency room.

An approach to the airway is addressed in Table 1. A summary of induction/NMB agents and doses is given on Table 2; indications for the different agents are noted on Table 3. The central pharmacological issue is not that any one drug is universally preferred over another. Rather, it is key that one develop a thoughtful rationale for the drugs used, and a plan to get out of trouble if one is suddenly in the sinking situation of a patient with a difficult airway who cannot breathe on his or her own. The backup plan might involve the use of BVM ventilation, blind digital intubation, fiberoptic bronchoscope-aided intubation, retrograde techniques, light wand intubation, laryngeal mask airway techniques, posterior pharyngeal endotracheal tube placement ventilation, or a surgical airway. Most of these approaches are reviewed elsewhere.

The sedative and analgesic sparing effect of music.

BACKGROUND: To determine whether music influences intraoperative sedative and analgesic requirements, two randomized controlled trials were performed. METHODS: In phase 1, 35 adults undergoing urologic procedures with spinal anesthesia and patient-controlled intravenous propofol sedation were randomly assigned to hear favorable intraoperative music via headset or to have no music. In phase 2, 43 adults undergoing lithotripsy treatment of renal or ureteral calculi and receiving patient-controlled intravenous opioid analgesia were randomly assigned to either a music or no-music group. The effect of music on sedatives and analgesics requirements, recovery room duration, and adverse outcomes was assessed. RESULTS: In phase 1, patients in the music group required significantly less propofol for sedation than patients in the control group (0 [0-150] mg vs. 90 [0-240] mg, median[range]; P < 0.001). These findings persisted after adjusting for duration of surgery (0.3+/-0.1 mg/min vs. 1.6+/-0.4 mg/min; P < 0.001). Similarly, in phase 2, patients who listened to music had a significant reduction in alfentanil requirements (1,600 [0-4,250] microg vs. 3,900 [0-7,200] microg; P = 0.005). This persisted after adjusting for duration of surgery (52+/-9 microg/min vs. 119 +/-16 microg/min, mean +/- SD, P < 0.001). Duration of stay in the postanesthesia care unit and the rate of adverse events was similar in both groups (P = NS). CONCLUSIONS: Use of intraoperative music in awake patients decreases patient-controlled sedative and analgesic requirements. It should be noted, however, that patients in the no-music group did not use a headset during operation. Thus, the decrease in sedative and analgesic requirements could be caused by elimination of ambient operating room noise and not by the effects of music.

Patient awareness during general anesthesia: a shocking outcome.

Patient awareness under minimal anesthesia may include the painful impulses of a nerve stimulator used for the monitoring of muscle relaxation. We present a case where discomfort from nerve stimulation was greater than that caused by the surgical incision or the endotracheal tube.

Preoperative dipyridamole thallium imaging and ambulatory electrocardiographic monitoring as a predictor of perioperative cardiac events and long-term outcome.

BACKGROUND: Dipyridamole thallium imaging (DTI) and ambulatory electrocardiography (AEGC) have been advocated as means to stratify risk before vascular surgery. The purpose of this study was to compare the predictive value of both tests in noncardiac surgery patients for perioperative cardiac morbidity and long-term mortality. METHODS: One hundred eighty patients were referred to the nuclear cardiology laboratory for DTI before noncardiac surgery. In patients with normal electrocardiograms and who consented, an ambulatory electrocardiogram was recorded for 24 h. DTI results were classified as negative, positive, or strongly positive (included in positive). Patients were assessed for a minimum of 12 months, and Kaplan-Meier cardiovascular survival curves were constructed with a log-rank statistic of equality with P < 0.05 significant. RESULTS: One hundred nine patients had both tests and then underwent surgery, sustaining 10 perioperative cardiac events (cardiac death, myocardial infarction, or symptomatic ischemia). The positive predictive values for DTI (18%) and AECG (25%) were similar, as were the likelihood ratios for positive tests (DTI = 2.1, AECG = 3.3). The likelihood ratios of a negative test were also similar (DTI = 0.45, AECG = 0.48). A strongly positive thallium defect had a somewhat greater likelihood ratio (3.5) for in-hospital events and was the only test result associated with a significantly worse long-term cardiac survival. CONCLUSIONS: AECG and DTI demonstrated a similar, although lower than initially reported, ability to stratify risk and predict short-term outcome. Only quantitative dipyridamole thallium also had predictive value for long-term prognosis.

Thrombocytopenia in pregnant women who use cocaine.

OBJECTIVE: Our purpose was to determine the prevalence of cocaine-associated thrombocytopenia. STUDY DESIGN: This cohort study was conducted in an inner-city prenatal center. A total of 1907 patients were screened by the Mother's Project, which is an intervention project for inner-city cocaine-abusing parturients. Platelet counts were grouped by illicit drug usage. RESULTS: Platelet counts were available in 37% (709) of subjects; there were no differences between subjects with available platelet counts and those without on illicit drug use or other demographic measures. Five groups were defined: drug-free group (n = 331), cocaine group (n = 104), cocaine and opiates group (n = 11), opiates group (n = 18), and other-drug group (n = 236). Nineteen subjects had a low platelet count (< 150 x 10(9)/L). The medical records of all subjects with a low platelet count were reviewed for any medical condition known to be associated with thrombocytopenia, and two subjects were excluded. The rate of thrombocytopenia in the drug-free group was 1.5%, whereas the rate in the cocaine group was 6.7% (relative risk 4.4, p < 0.05). Because of the reported association of thrombocytopenia with seropositive human immunodeficiency virus status, seropositive women were excluded from the analysis. Even after human immunodeficiency virus status adjustments for the estimated rate, the cocaine-using group continued to have a significantly higher rate of thrombocytopenia (5.4% to 7.2% vs 1.23% to 1.26%, p < 0.05 to p < 0.005). CONCLUSIONS: These results indicate that cocaine use is an independent risk factor for thrombocytopenia in an inner-city parturient population.

Postoperative myocardial ischemia: etiology of cardiac morbidity or manifestation of underlying disease?

STUDY OBJECTIVE: To determine the relationship between postoperative ST segment changes and clinically apparent cardiac morbidity in noncardiac surgery patients. DESIGN: Prospective, cohort study. SETTING: General inpatient and intensive care units at a tertiary care hospital. PATIENTS: 145 high-risk noncardiac surgery patients. MEASUREMENTS AND MAIN RESULTS: Patients were monitored for ST segment changes using ambulatory electrocardiographic (ECG) recorders from the end of the surgical period for up to the third postoperative day. Patients were evaluated for a clinically apparent cardiac event (cardiac death or myocardial infarction) by daily 12-lead ECGs, and CK-MB isoenzymes, as clinically indicated. Nine patients sustained a clinically apparent cardiac event, 7 of whom had a cardiac event during the period in which they were monitored by ambulatory ECG. All 7 patients who sustained a cardiac event during the monitoring period had at least one episode of myocardial ischemia, which persisted for a minimum of 30 minutes either prior to or at the same time of the event, with no morbidity occurring in the group of patients who had only short durations of myocardial ischemia. Three of the patients with events had continuous ST segment changes, while the other patients had transient ST segment changes. CONCLUSIONS: These observations suggest that clinically apparent cardiac events are associated with prolonged ST segment changes detected on ambulatory ECG recorders. The cardiac ischemia leading to prolonged postoperative ST segment changes may itself result in cardiac morbidity, or it may be a reflection of underlying pathophysiology.

Relationship between postoperative anemia and cardiac morbidity in high-risk vascular patients in the intensive care unit.

OBJECTIVE: To determine if postoperative anemia is associated with postoperative myocardial ischemia and morbid cardiac events DESIGN: Case control study. SETTING: Postanesthesia care unit and surgical intensive care unit. PATIENTS: A total of 27 high-risk patients undergoing infra-inguinal arterial bypass procedures. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After informed consent, patients were continuously monitored by ambulatory electrocardiographic recorders from the evening before surgery up to 80 hrs during the postoperative period. Myocardial ischemia was defined as > or = 1 mm of horizontal or downsloping ST depression or > or = 2 mm ST segment elevation persisting for at least 60 secs on the ambulatory electrocardiogram. Morbid cardiac events were defined as: cardiac death, myocardial infarction, unstable angina, and ischemic pulmonary edema. Using a receiver operating characteristic curve, a hematocrit of 28% was determined to be the best threshold hematocrit value below which morbid cardiac events were most likely to occur. Statistical significance between hematocrit and cardiac outcome was determined by Fisher's exact test where appropriate. Thirteen of 27 patients had a hematocrit < 28%. Of these 13 patients, ten demonstrated postoperative myocardial ischemia and six sustained a morbid cardiac event. Of 14 patients with a hematocrit > or = 28%, two displayed myocardial ischemia and none sustained a morbid cardiac event. A hematocrit of < 28% was significantly associated with myocardial ischemia (p = .001) and morbid cardiac events (p = .0058). No significant differences in baseline heart rate and heart rate at the onset of myocardial ischemia were noted between the anemic and nonanemic patients. CONCLUSIONS: This study suggests that postoperative anemia may play a role in postoperative myocardial ischemia and cardiac morbidity.

Approximate entropy of heart rate as a correlate of postoperative ventricular dysfunction.

BACKGROUND: Instantaneous changes in the heart rate, i.e., heart rate variation, traditionally have been quantified by the standard deviation of a series of intervals between successive heart beats. Approximate entropy provides another measure of variability by calculating the logarithmic likelihood that patterns that are similar remain similar on the next incremental comparisons. Approximate entropy is a nonnegative number that will distinguish data sets by their amount of regularity, with larger numbers indicating more randomness. We hypothesized that a decrease in the approximate entropy of heart rate would be associated with postoperative ventricular dysfunction (e.g., myocardial infarction, unstable angina, congestive heart failure, prolonged inotropic support). METHODS: Twenty-three high-risk noncardiac patients were continuously monitored by ambulatory electrocardiographic recorders from the evening before surgery up to 80 h during the postoperative period: 9 demonstrated postoperative ventricular dysfunction, and 14 had an uncomplicated postoperative course. Hourly approximate entropy average values were calculated. RESULTS: Approximate entropy was high (> 0.7) in all but two patients preoperatively. Postoperative approximate entropy <0.55 had a sensitivity of 88% and a specificity of 71% for being associated with postoperative ventricular dysfunction; preoperative approximate entropy values were not significantly different between the two groups. CONCLUSIONS: These results suggest that changes in approximate entropy can distinguish between patients who sustained poor outcome and those who had an uncomplicated course.