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Biomedical subjects

S H Rosenbaum

Publications and source records attributed to S H Rosenbaum.

At least 19 recordsLinked to original sources
PubMed2000

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.

Anesthesiology↗
PubMed1998

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.

Analgesia, Patient-Controlled↗
PubMed1997

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.

Abscess↗
PubMed1995

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.

Adult↗
PubMed1995

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.

Aged↗
PubMed1995

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.

Aged↗
PubMed1993

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.

Aged↗
PubMed1993

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.

Aged↗
PubMed1992

Failure of negative dipyridamole thallium scans to predict perioperative myocardial ischaemia and infarction.

Three cases of postoperative myocardial infarction are reported in patients with normal or fixed defects on preoperative dipyridamole thallium scans (interpreted as "negative" for active cardiac ischaemic risk). All patients were monitored with an ambulatory electrocardiographic recorder from the evening before surgery through the first two postoperative days. Two of the patients demonstrated preoperative or early postoperative ischaemia, suggesting that the test was a false negative. The third patient did not demonstrate ischaemia during the period of monitoring, but developed a myocardial infarction during the third postoperative day, suggesting progression of the underlying coronary artery disease. Preoperative dipyridamole thallium imaging may result in false negative scans in selected high-risk populations.

Aged↗
PubMed1992

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.

Anesthesia, Conduction↗