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Biomedical subjects

S M Frank

Publications and source records attributed to S M Frank.

48 records · Page 3Linked to original sources
PubMed1994

Core hypothermia and skin-surface temperature gradients. Epidural versus general anesthesia and the effects of age.

BACKGROUND: Inadvertent hypothermia occurs frequently during surgery and may be associated with adverse outcomes. Although various anesthetic agents have been shown to impair thermoregulation, the impairment with regional and general anesthetics has not been directly compared. METHODS: Thirty patients undergoing radical retropubic prostatectomy were randomly allocated to receive epidural (EA, n = 15) or general (GA, n = 15) anesthesia. Tympanic membrane measurements were used to assess core temperature. Forearm and calf skin-surface temperature gradients were used to assess thermoregulatory vasoconstriction (forearm minus fingertip > 4 degrees C and calf minus toe > 6 degrees C). The two groups were compared during the intraoperative and early postoperative periods to identify differences. Subgroup analysis was used to compare core temperatures and skin-surface gradients in younger (< 62 yr of age) and older (> or = 62 yr) patients in the EA and GA groups. RESULTS: Mean tympanic membrane temperatures were similar at all time periods in the EA and GA groups and were nearly identical at the end of the surgical procedure (EA, 35.5 +/- 0.2 degrees C; GA, 35.6 +/- 0.2 degrees C) (P = 0.68). Intraoperatively, the EA group maintained a significant forearm skin-surface gradient compared to the GA group (P = 0.0001), whereas the calf gradients were minimal and were similar between groups. Postoperatively, both groups had comparable positive forearm gradients, whereas calf gradients were greater in the GA group (P = 0.001). Mean core temperatures and forearm gradients were not different between the younger and older patients receiving GA. In those receiving EA, the younger patients had greater mean core temperatures (P = 0.015) and greater forearm gradients (P = 0.05) for most of the perioperative period. CONCLUSIONS: The EA and GA groups had virtually identical core temperature profiles during the intraoperative and post-operative periods. Comparison of skin-surface gradients suggests that EA is associated with less intraoperative upper-body thermoregulatory impairment but greater and persistent post-operative lower-body impairment. During EA, younger patients appeared to maintain thermoregulatory activity relative to the older patients. In patients receiving GA, the age-related differences were minimal.

Aged↗
PubMed1994

Cardiac sympathovagal balance and peripheral sympathetic vasoconstriction: epidural versus general anesthesia.

Both epidural and general anesthetics alter autonomic balance. However, the relative differences between epidural (EA) and general anesthetics (GA) with regard to cardiac and peripheral sympathovagal balance have not been described. Twenty consecutive patients scheduled for radical retropubic prostatectomy were randomized to receive EA (n = 10) or GA (n = 10). Power spectral analysis was performed on the electrocardiographic recordings, with the ratio of low (0.05-0.125 Hz)/high (0.125-0.5 Hz) frequency power used an index of cardiac sympathovagal balance. The forearm minus fingertip skin-surface temperature gradient (> 4 degrees C) was used as an indicator of sympathetically mediated peripheral vasoconstriction. Patients in the EA group demonstrated a significantly greater low/high frequency power ratio and a more frequent incidence of peripheral vasoconstriction than the GA group during the intraoperative period. During the postoperative period, the GA group demonstrated an increase in the low/high ratio and the incidence of vasoconstriction relative to the intraoperative period. Intraoperatively, upper body vasoconstriction appears to be accompanied by a significant shift in cardiac sympathovagal balance toward sympathetic predominance with EA relative to GA. Postoperatively, GA is associated with a shift in the sympathovagal balance toward sympathetic predominance. Further research is required to determine whether this results in cardiovascular compromise in the high-risk patient.

Anesthesia, Epidural↗
PubMed1993

Unintentional hypothermia is associated with postoperative myocardial ischemia. The Perioperative Ischemia Randomized Anesthesia Trial Study Group.

BACKGROUND: Hypothermia occurs commonly during surgery and can be associated with increased metabolic demands during rewarming in the postoperative period. Although cardiac complications remain the leading cause of morbidity after anesthesia and surgery, the relationship between unintentional hypothermia and myocardial ischemia during the perioperative period has not been studied. METHODS: One hundred patients undergoing lower extremity vascular reconstruction received continuous Holter monitoring throughout the first 24 h postoperatively. Myocardial ischemia was determined by a cardiologist masked to clinical variables. The patient's sublingual temperature on arrival at the intensive care unit immediately after the surgical procedure was used to divide the patients into two groups: hypothermic (temperature, < 35 degrees C; n = 33) and normothermic (temperature, > or = 35 degrees C; n = 67). The relationship between intentional hypothermia and myocardial ischemia occurring during the first postoperative day was evaluated by univariate and multivariate analyses. RESULTS: A greater percentage of patients had electrocardiographic changes consistent with myocardial ischemia in the hypothermic group (36%, 12 of 33) compared with those in the normothermic group (13%, 9 of 67, P = 0.008). Preoperative risk factors for perioperative cardiac morbidity were similar between the two groups, except for patient age. The mean age was 70 +/- 2 yr and 62 +/- 1 yr in the hypothermic and normothermic groups, respectively (P = 0.001). When subgroup and multivariate analyses were used to adjust for differences in age, temperature remained an independent predictor of ischemia (odds ratio, 1.82 per degree Celsius; 95% confidence interval, 1.09-3.02). The incidence of postoperative angina was greater in the hypothermic group (18%, 6 of 33) than in the normothermic group (1.5%, 1 of 67, P = 0.002). The incidence of PaO2 < 80 mmHg in the arterial blood was greater in the hypothermic group (52%, 17 of 33) than in the normothermic group (30%, 20 of 67, P = 0.03). CONCLUSIONS: Unintentional hypothermia is associated with myocardial ischemia, angina, and PaO2 < 80 mmHg during the early postoperative period in patients undergoing lower extremity vascular surgery.

Adult↗
PubMed1993

Perioperative morbidity in patients randomized to epidural or general anesthesia for lower extremity vascular surgery. Perioperative Ischemia Randomized Anesthesia Trial Study Group.

BACKGROUND: Perioperative morbidity may be modifiable in high risk patients by the anesthesiologist's choice of either regional or general anesthesia. This clinical trial compared outcomes between epidural (EA) and general (GA) anesthesia/analgesia regimens in a group of patients at high risk for cardiac and other morbidity who were undergoing similarly stressful surgical procedures. METHODS: One hundred patients scheduled for elective vascular reconstruction of the lower extremities were randomized to receive either EA for surgery followed by epidural analgesia, or GA for surgery followed by intravenous patient-controlled analgesia. Hemodynamic monitoring, blood pressure, and heart rate limits were determined prior to randomization. Management of anesthesia in the immediate postoperative period was standardized. The data collected included continuous electrocardiographic monitoring from the day before surgery through the third postoperative day, serial electrocardiograms, and cardiac enzymes. Cardiac ischemia, myocardial infarction, unstable angina, and cardiac death were identified by a cardiologist blinded to the type of anesthesia received. Other major morbidity was determined at the time of hospital discharge and at 1 and 6 months after surgery. RESULTS: Eleven patients who received GA required regrafting or an embolectomy during their hospital stay, compared with two patients who received EA. This association of GA with reoperation remained significant after adjustment for baseline differences. Cardiac outcomes were similar in the two groups with respect to perioperative death (1 EA and 1 GA), death within 6 months (4 EA and 3 GA), nonfatal myocardial infarction within 7 days (2 EA and 2 GA), unstable angina (0 EA and 2 GA), and myocardial ischemia following randomization (17 EA and 23 GA). Rates of major infections in the two groups (1 EA and 2 GA), renal failure (3 EA and 3 GA), and pulmonary complications (3 EA and 7 GA) also were similar. CONCLUSIONS: Carefully conducted epidural and general anesthesia appear to be associated with comparable rates of cardiac and most other morbidity in patients undergoing lower extremity vascular surgery. However, compared with general anesthesia, epidural anesthesia is associated with a lower incidence of reoperation for inadequate tissue perfusion and, therefore, may be advantageous for this surgical population.

Aged↗
PubMed1993

The effects of different anesthetic regimens on fibrinolysis and the development of postoperative arterial thrombosis. Perioperative Ischemia Randomized Anesthesia Trial Study Group.

BACKGROUND: The purpose of this clinical trial was to compare the effects of different anesthetic and analgesic regimens on hemostatic function and postoperative arterial thrombotic complications. METHODS: Ninety-five patients scheduled for elective lower extremity vascular reconstruction were randomized to receive either epidural anesthesia followed by epidural fentanyl (RA) or general anesthesia followed by intravenous morphine (GA). Intraoperative and postoperative care were controlled by protocol using predetermined limits for heart rate, blood pressure, and other monitoring criteria. Data collection included serial physical examinations, electrocardiograms, and cardiac isoenzymes to detect arterial thrombosis (defined as unstable angina, myocardial infarction, or vascular graft occlusion requiring reoperation). Fibrinogen, plasminogen activator inhibitor-1 (PAI-1), and D-dimer levels were measured preoperatively and at 24 and 72 h postoperatively. RESULTS: Preoperative fibrinogen levels were similar in both groups, remained unchanged after 24 h, and increased equally (45%) in the first 72 h postoperatively. PAI-1 levels in the GA group increased from 13.6 +/- 2.1 activity units (AU)/ml to 20.2 +/- 2.6 AU/ml at 24 h and returned to baseline at 72 h. In contrast, PAI-1 levels in the RA group remained unchanged over time. Twenty-two of 95 patients (23%) had postoperative arterial thrombosis, 17 of whom had received GA and 5 of whom, RA. Preoperative PAI-1 levels were higher in patients who developed postoperative arterial thrombosis (20.5 +/- 3.6 AU/ml vs. 11.2 +/- 1.4 AU/ml). Multiple logistic regression analysis indicated that GA and preoperative PAI-1 levels were predictive of postoperative arterial thrombotic complications. CONCLUSIONS: Impaired fibrinolysis may be related causally to postoperative arterial thrombosis. Because RA combined with epidural fentanyl analgesia appears to prevent postoperative inhibition of fibrinolysis, this form of perioperative management may decrease the risk of arterial thrombotic complications in patients undergoing lower extremity revascularization.

Aged↗
PubMed1993

Determinants of catecholamine and cortisol responses to lower extremity revascularization. The PIRAT Study Group.

BACKGROUND: Surgical trauma elicits diffuse changes in hormonal secretion and autonomic nervous system activity. Despite studies demonstrating modulation of the stress response by different anesthetic/analgesic regimens, little is known regarding the determinants of catecholamine and cortisol responses to surgery. METHODS: Plasma catecholamines and cortisol secretion data were obtained from 60 patients undergoing lower extremity revascularization. Patients were randomized to receive either general anesthesia combined with patient-controlled intravenous morphine (GA) or epidural anesthesia combined with epidural fentanyl analgesia (RA). All aspects of intra- and postoperative clinical care were defined by written protocol. Plasma catecholamines were measured before induction, intraoperatively, and for the first 18 h postoperatively (by HPLC). Urine cortisol was measured intra- and postoperatively using RIA. Data were evaluated using univariate and multivariate analyses to evaluate demographic and perioperative variables as determinants of stress hormone secretion. RESULTS: Plasma catecholamines increased during skin closure in the GA group, and remained higher relative to the RA group in the postoperative period. Multivariate analysis indicated that age and anesthetic regimen predicted increases in catecholamines during skin closure (P < 0.005), although duration of surgery, blood loss, and body temperature were not correlated. Early postoperative norepinephrine concentrations were correlated with pain score and duration of surgery (P < 0.004), but not with anesthetic management, blood loss, or body temperature. All postoperative norepinephrine levels were highly correlated (r = 0.7) with norepinephrine levels during skin closure. Cortisol excretion was higher postoperatively than intraoperatively. No patient or perioperative variable predicted cortisol excretion, and cortisol excretion was not correlated with catecholamine levels at any time. CONCLUSIONS: These data indicate that patient factors, such as age and inherent sympathetic responsivity, are important determinants of the catecholamine response to surgery. Modulation of the norepinephrine response by regional anesthesia/analgesia appears to be related, in part, to superior analgesia. The lack of correlation between catecholamine and cortisol secretion indicates that the stress response may consist of discrete systems responding to different stimuli.

Adult↗
PubMed1992

Epidural versus general anesthesia, ambient operating room temperature, and patient age as predictors of inadvertent hypothermia.

To elucidate the multifactorial nature of perioperative changes in body temperature, the influence of several clinical variables, including anesthetic technique, ambient operating room temperature, and age, were evaluated. Perioperative oral sublingual temperatures were measured in 97 patients undergoing lower extremity vascular surgery randomized to receive either general (GA) or epidural (EA) anesthesia. Surgery and anesthesia were performed in operating rooms (OR) with a relatively warm mean ambient temperature (24.5 +/- 0.4 degrees C) (GA, n = 30; EA, n = 33) or relatively cold mean ambient temperature (21.3 +/- 0.3 degrees C) (GA, n = 21; EA, n = 13). Patients were 35-94 yr old, with a mean age of 64.5 +/- 1.1 yr. A regression analysis was performed to determine the variables that correlated with intraoperative decrease in temperature and postoperative rewarming rate. The major correlates of greater intraoperative decrease in temperature were 1) GA (P = 0.003); 2) cold ambient OR temperature (P = 0.07); and 3) advancing patient age (P = 0.03). There was significant interaction between ambient OR temperature and type of anesthesia (P = 0.03): there was a greater intraoperative decrease in temperature with GA compared to EA in a cold OR but a similar decrease with GA and EA in a warm OR. The data also suggest an interaction between type of anesthesia and patient age (P = 0.06), showing a greater decrease in temperature with GA compared to EA in the younger patients, but a similar decrease between GA and EA in older patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Right- and left-arm blood pressure discrepancies in vascular surgery patients.

To identify a relationship between atherosclerotic vascular disease and differences in blood pressure between the right and left arms, blood pressure differences between arms were measured in patients with peripheral vascular disease (PVD, n = 58), in patients with coronary artery disease (CAD, n = 38), and in patients with no evidence of atherosclerotic disease, who served as a control group (n = 38). The incidence and magnitude of right and left arm pressure difference determined by the oscillometric technique were compared between the patient groups. The incidence of systolic pressure difference greater than or equal to 20 mmHg between arms in patients with PVD (21%) was greater than that in either those with CAD (3%) (P less than or equal to 0.05) or control subjects (0%) (P less than 0.01). The incidence of systolic pressure difference greater than or equal to 45 mmHg between arms in patients with PVD (10%) was greater than that in either those with CAD (0%) (P less than 0.05) or control subjects (0%) (P less than 0.05). Patients with PVD also had a greater incidence of right and left arm difference than did those with CAD or controls for mean and diastolic blood pressures. Of all patients with a systolic difference greater than 10 mmHg, neither the right nor the left arm blood pressure was consistently higher: 21 of 35 (60%) had a higher pressure in the right arm, and 14 of 35 (40%) had a higher pressure in the left arm (P = 0.33). Gender, diabetes, hypertension, smoking, and age were not associated with a difference in blood pressure between the right and left arms.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1976

Linguistic performance in vulnerable and autistic children and their mothers.

The authors studied the language patterns of schizophrenic mothers and their 4-year-old children, and compared them with the speech of normal mothers and children and normal mothers with autistic children. They found that children of schizophrenic mothers showed lags in language development and language distortions less severe than but in some ways similar to those seen in autistic children. Schizophrenic mothers were more likely to produce more deficient and/or distorted language in interactions with their children. Mothers of autistic children produced language that was equal to or above that of mothers of normal children on most parameters and adjusted their language to the chronological rather than the linguistic age of the child.

Autistic Disorder↗
PubMedDate not supplied

Perioperative rate-related silent myocardial ischemia and postoperative death.

A case is presented that demonstrates heart rate (HR)--related silent myocardial ischemia occurring preoperatively, subsiding intraoperatively, then recurring and leading to a post-operative cardiac death in a patient undergoing peripheral vascular surgery. This case illustrates that patients may have an ischemic threshold for HR whereby recurrent depression of the ST segment may occur during increase of HR to rates as low as 80 to 85 beats per minute (bpm), even in the absence of acute blood pressure (BP) changes. Myocardial ischemia may be HR related; however, the authors are not aware of a case that demonstrates repeated episodes of rate-related ischemia occurring at HRs well below the 100 bpm traditional definition of tachycardia. The authors conclude that patients at risk for perioperative myocardial ischemia should be identified and the hemodynamic management of these patients should include control of HR. This implies control of the physiologic variables that influence HR, along with the use of beta-adrenergic blockers. This case also demonstrates the value of Holter monitoring for ischemia, which, when done preoperatively, can detect patients at risk for unfavorable cardiac outcomes. Ischemia monitoring also may be useful during the intraoperative and postoperative periods, a time when ischemia is often silent and undetected. The early recognition of ischemia would allow for anti-ischemic interventions, which could decrease the morbidity and mortality of patients at risk for perioperative cardiac complications.

Arrhythmias, Cardiac↗