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At least 145 records · Page 8Linked to original sources
PubMed1994

Relationship between diabetic autonomic neuropathy and gastric contents.

Delayed gastric emptying secondary to diabetic autonomic neuropathy (DAN) is a recognized risk factor for aspiration pneumonitis. The purpose of this study is to determine whether bedside autonomic function tests (AFTs) would predict gastric contents. Gastric volume and its pH were measured in 36 patients with diabetes mellitus (DM) and 15 nondiabetic patients at induction of general anesthesia for elective ambulatory surgery. Manifestations of autonomic dysfunction were assessed preoperatively in all 51 patients with five commonly used cardiovascular AFTs. According to the results of these five tests, 16 patients with DM met the criteria for the diagnosis and are called "DAN positive." The remaining 20 diabetics did not meet the criteria and are called "DAN negative." Fifteen patients without DM did not meet the criteria and are called "nondiabetics." Diabetic patients were significantly older and more obese than nondiabetics and those with DM more than 10 yr were more often DAN positive. Solid, undigested food particles were found more often in the gastric contents of DAN-positive patients compared to nondiabetics. Gastric liquid volume and pH were similar in diabetic patients (DAN positive and DAN negative) and nondiabetic controls. These results demonstrate that diagnosis of DAN by commonly used cardiovascular AFTs does not predict larger gastric liquid volume or lower pH, but does predict the presence of solid food particles.

Adult↗
PubMedDate not supplied

Autonomic influences on colorectal motility and pelvic surgery.

The nervous control of the motility of the human distal bowel was investigated by two physiological studies of electrical stimulation of sacral parasympathetic outflow in patients with high spinal injuries and in patients with intractable constipation following pelvic surgery. Identical and reproducible motility responses of the left colon, rectum, and anal sphincters were obtained by sequential electrical stimulation of anterior sacral roots S2, S3, and S4 in patients with spinal injury. S2 stimulation provoked isolated low-pressure colorectal contractions. S3 stimulation initiated frequency-dependent high-pressure colorectal motor activity which appeared peristaltic and was enhanced with repetitive stimuli. S4 stimulation increased colonic and rectal tone. Quantitative responses were maximal at the splenic flexure and rectum. Pelvic floor activity was stimulated in increasing magnitude from S2 to S4. These results of distal bowel motility were achieved by an implanted Brindley stimulator. A newer generation of externally active stimulators are envisaged for the control of lower bowel in fecal incontinence. Women with intractable constipation following hysterectomy had significantly increased rectal volume and compliance together with deficits of rectal sensory function. Following stimulation with Prostigmine (neostigmine) a colorectal motility gradient was paradoxically reversed in the patients following hysterectomy, thus constituting a functional obstruction. Denervation supersensitivity was demonstrable in 2 patients tested with carbachol provocation. These findings suggest dysfunction in the autonomic innervation of the hindgut in some patients following hysterectomy.

Adult↗
PubMed1994

Alterations in temporal patterns of heart rate variability after coronary artery bypass graft surgery.

BACKGROUND: Preliminary studies have indicated that autonomic nervous system dysfunction may be present in patients after cardiac surgery. The purpose of this study was to evaluate cardiac autonomic nervous system function, as assessed by analysis of heart rate variability (HRV), in adult patients undergoing uncomplicated coronary artery bypass graft surgery. METHODS: Longitudinal changes in HRV were determined perioperatively by continuous electrocardiographic monitoring in 40 adult patients undergoing elective coronary artery bypass graft surgery and were compared with HRV in two groups of control subjects: 15 patients undergoing nonthoracic major vascular surgery and 19 healthy volunteers. Exclusion criteria were diabetes, renal failure, recent or perioperative myocardial infarction, or use of inotropic drugs. HRV data during electrocardiographically documented episodes of myocardial ischemia were omitted. RESULTS: There were no differences in any measurement of preoperative HRV between groups during the day, but HRV was greater at night (12:00 AM to 5:00 AM) in volunteers than in patients in either surgical group. In the hour after induction of anesthesia (before cardiopulmonary bypass), the components of HRV were decreased compared with those in the preoperative daytime but were similar in the two surgical groups. After surgery, HRV in the group undergoing nonthoracic vascular surgery remained at about the same level as that observed after induction of anesthesia, whereas in the group undergoing coronary artery bypass graft surgery, HRV was further reduced and was approximately 40-50% less than that in the vascular surgery group (P < 0.05). In the coronary artery bypass group, the reduction in HRV compared with the preoperative daytime measurements persisted on postoperative day 5. CONCLUSIONS: HRV is reduced after uncomplicated coronary artery bypass graft surgery. Although we cannot exclude the effects of uncontrolled variables in this reduction of postoperative HRV, the observed changes in HRV did not appear to result from general anesthesia, perioperative stress responses, and other factors associated with the early postoperative period. These data are consistent with the supposition that cardiac autonomic nervous system function is impaired after cardiac surgery.

Autonomic Nervous System↗
PubMed1997

[The diagnostic and clinical aspects of postoperative dysphonias following operations on the thyroid].

Postoperative dysphonia is not rare and in some cases life-treating complication in the thyroid surgery. Its emerge, autonomous, or attended with dysphagia and dyspnea is an early symptom for intraoperative lesion of n. laryngeus recurrens. The investigation is carried out over 21 patients with postoperative dysphonias, operated for euthyroid or hyperthyroid strumas and followed-up for a period of 3-10 months. Analysis of the results indicated that the main reason for postoperative dysphonias in thyroid surgery is the lesion of n. laryngeus recurrens. Along with this one is impressed by the fact that in 30% of the cases dysphonic complaints may owe to nonsurgical reasons.

Anesthesia↗
PubMed2006

Pre-operative measurement of heart rate variability predicts hypotension during general anesthesia.

BACKGROUND: Peri-operative hymodynamic instability is one of the major concerns for anesthesiologists when performing general anesthesia for individuals with autonomic dysfunction. The purpose of this study was to examine the potential usage of pre-operative measurement of heart rate variability (HRV) in identifying which individuals, with or without diabetes, may be at risk of blood pressure (BP) instability during general anesthesia. METHODS: We studied 46 patients with diabetes and 87 patients without diabetes ASA class II or III undergoing elective surgery. Participants' cardiovascular autonomic function and HRV were assessed pre-operatively, and hymodynamic parameters were monitored continuously intra-operatively by an independent observer. RESULTS: Only 6% of the participants were classified as having cardiovascular autonomic neuropathy (CAN) based on traditional autonomic function tests whereas 15% experienced hypotension. Total power (TP, P = 0.006), low frequency (LF, P = 0.012) and high frequency (HF, P = 0.028) were significantly lower in individuals who experienced hypotension compared with those who did not. Multivariate logistic regression analysis revealed that TP [odds ratio (OR) = 0.15, 95% confidence interval (CI) = 0.05-0.47, P = 0.001] independently predicted the incidence of hypotension, indicating that each log ms2 increase in total HRV lowers the incidence of hypotension during general anesthesia by 0.15 times. After stepwise multiple linear regression analysis (R2= 11.5%), HF (beta = -11.1, SE = 2.79, P < 0.001) was the only independent determinant of the magnitude of systolic blood pressure (SBP) reduction at the 15th min after tracheal intubation. CONCLUSIONS: Spectral analysis of HRV is a sensitive method for detecting individuals who may be at risk of BP instability during general anesthesia but may not have apparent CAN according to traditional tests of autonomic function.

Adult↗
PubMed2006

Evaluation of the cardiovascular risk in patients with subclinical Cushing syndrome before and after surgery.

BACKGROUND: The widespread use of ultrasound, computerized tomography, and magnetic resonance imaging has led to an increase in the number of incidental adrenal masses identified. Asymptomatic incidentally discovered adrenal masses may indicate that subclinical Cushing syndrome (SCS) is not uncommon. We aimed to evaluate the cardiovascular risk of patients with SCS before and after surgery. METHODS: An autonomous cortisol-producing tumor was detected in 11 of 94 patients with adrenal incidentaloma between 1995 and 2005. Twenty-eight patients suffering from classical Cushing syndrome (CS) associated with unilateral adrenocortical adenoma, who were treated at our department in the same period, served as a control group. Cardiovascular risk factors such as blood pressure, body mass index, and lipid profile were evaluated before and 1 year after surgery. RESULTS: The frequency of hypertension (61% versus 63%), obesity (46% versus 55%), diabetes mellitus (50% versus 36%), hypercholesterolemia (39% versus 36%), and low HDL cholesterol (28% versus 36%) were not significantly different between CS and SCS patients, respectively. Adverse cardiovascular risk profile improved 1 year after adrenalectomy in both groups, although the changes were not significant with respect to body mass index, frequency of diabetes, and hyperlipidemia in SCS patients. But frequency of systolic/diastolic hypertension decreased significantly in this group. CONCLUSIONS: These findings indicate that the increased incidence of cardiovascular risk factors commonly observed in classical CS, is also present in SCS. Unilateral adrenalectomy does not always lead to significant improvements in cardiovascular risk profile in SCS.

Adrenal Cortex Neoplasms↗
PubMed2003

Outcome of epilepsy surgery correlates with sympathetic modulation and neuroimaging of the heart.

Temporal lobe epilepsy (TLE) is frequently associated with sympathetic over-activity. Single photon emission computed tomography (SPECT) with 123iodine-meta-iodobenzylguanidine (MIBG), a norepinephrine analogue, showed reduced tracer uptake in cardiac sympathetic nerve endings, indicating myocardial catecholamine disturbance. We investigated whether outcome of epilepsy surgery correlates with cardiac autonomic function in TLE patients. We studied 16 TLE patients before and after epilepsy surgery. We recorded heart rate (HR) and determined sympathetic and parasympathetic cardiac modulation as powers of low (LF, 0.04-0.15 Hz) and high frequency (HF, 0.15-0.5 Hz) heart rate oscillations. The LF/HF-ratio was calculated as index of sympathovagal balance. Cardiac MIBG uptake was assessed with MIBG-SPECT and compared to control data. After surgery, eight patients were seizure-free and eight had persistent seizures. Sympathetic LF-power and LF/HF-ratio were higher in patients who had persistent seizures than in patients who became seizure-free. After surgery, both parameters decreased in seizure-free patients but increased in patients with persistent seizures. MIBG uptake was lower in patients than controls and even lower in the patient subgroup who had persistent seizures. In this subgroup, MIBG uptake further decreased after surgery (P<0.05). Sympathetic cardiac modulation decreased in TLE patients after successful surgery, but further increased if seizures persisted. Reduction of cardiac MIBG uptake progressed after surgery in patients with persistent seizures. Interference of epileptogenic discharges with autonomic neuronal transmission might account for sympathetic cardiac over-stimulation and reduced MIBG uptake. Both findings are possible risk factors for sudden unexplained death and might be relevant for risk stratification in epilepsy patients.

3-Iodobenzylguanidine↗
PubMed2004

Heart rate variability following coronary artery bypass graft surgery as a function of recovery time, posture, and exercise.

This study examined the claim made by Niemela et al. (1992) that the decline in heart rate variability after coronary artery bypass graft surgery is irreversible. We tested six women and 16 men six and 12 weeks postoperative in three postures: in the supine position, in the standing position, and during low-intensity steady-state exercise. Beat-by-beat arterial blood pressure and electrocardiographic R-R interval data were collected continuously for 10 min in each condition. R-R interval data were analyzed with spectral analysis; baroreflex data were analyzed using the sequence method. Our results show that the indices of parasympathetic modulation improved over time, as seen by an increased spontaneous baroreflex sensitivity and parasympathetic indicator, that both indices were affected by posture, and that spontaneous baroreflex sensitivity was also affected by low-intensity exercise. The effects of posture are consistent with attenuated responses of healthy older subjects to orthostatic stress. Similarly, the effects of low-intensity exercise are consistent with findings in healthy subjects. We found that spontaneous baroreflex sensitivity declined during exercise, whereas, in healthy subjects, this is maintained during low-intensity steady-state exercise. Our results of significant functional recovery between six and 12 weeks postoperative suggest that at least some of the autonomic dysfunction following surgery is temporary. Previously, no such duration of study has lasted longer than four or six weeks following cardiac surgery, which may not have been long enough to show significant functional restoration in heart rate variability.

Age Factors↗
PubMed1995

[Differentiated thyroid gland carcinomas in "autonomous adenomas" in childhood].

Thyroid surgery is seldomly indicated in childhood and adolescence mainly because of suspicious nodules or proven carcinoma. Indications for operation in Graves disease and focal autonomy are discussed controversially, however. In a retrospective case control study two of our 6 patients up to 18 years demonstrated differentiated thyroid cancer with focal autonomy in the autonomous nodule. Other studies show similar results. Thyroid surgery is therefore warranted in all children and adolescents with focal thyroid autonomy.

Adenocarcinoma, Follicular↗
PubMed2005

Ulcerative and mutilating variant of carpal tunnel syndrome.

Cutaneous involvement in severe carpal tunnel syndrome is secondary to damage to sensory and autonomic fibers of the median nerve. We report the case of a 63 year old man who presented skin and bone lesions, confined to the sensory zones of both median nerves. The lesions consisted of dystrophic modifications of the fingernails, progressive sclerosis, skin thickening and ulcerations on the fingers, acro-osteolysis, and purulent inflammation with subsequent auto-amputation of the distal phalanx of the right index finger. Clinical, neurophysiological and surgical findings are reported. The recovery of the ulcerative lesions suggests the reversibility of autonomic disturbances after surgery.

Acro-Osteolysis↗
PubMed1988

Aortic pulsatile pressure and diameter response to intravenous perfusions of angiotensin, norepinephrine, and epinephrine in conscious dogs.

The aortic elastic behavior has been studied in conscious dogs chronically instrumented with a pressure microtransducer and two ultrasonic crystals. Pressure and diameter measurements were analyzed in terms of their mean values and systolic-diastolic variations, enabling calculation of Peterson elastic modulus, and were displayed in the x-y form to obtain pressure diameter hysteresis loops. After recovery from surgery and under autonomic blockade, intravenous perfusions of angiotensin, norepinephrine, and epinephrine were made at incremental steps of doses until steady-state pressure-diameter changes were achieved. The slopes of the positive pressure-diameter correlations obtained at each dose of the same vasoactive substance were higher for angiotensin than norepinephrine (p less than 0.01) and epinephrine (p less than 0.001) and were higher for norepinephrine than epinephrine (p less than 0.05). Similarly, the slopes of the elastic modulus to mean pressure relation were significantly lower for angiotensin than for norepinephrine (p less than 0.05) and epinephrine (p less than 0.001) and were significantly lower for norepinephrine than epinephrine (p less than 0.001). Thus, at the same transmural pressure, the distension and stiffness of the aorta were lower and higher with epinephrine than with norepinephrine, respectively, and with norepinephrine than with angiotensin suggesting different potencies of these drugs in terms of smooth muscle activation in the aorta.

Angiotensin II↗
PubMed1983

Pro-opiocortin related peptides in human pituitary and ectopic ACTH secreting tumours.

Basal and stimulated secretion of N-terminal pro-opiocortin (Pro-gamma-MSH), ACTH and LPH from seven pituitary and three ectopic ACTH secreting tumours have been studied in vitro using a perfused isolated cell system. The peptides were shown to be released concomitantly and in equimolar amounts. The pituitary tumours responded to stimulation with rat stalk median eminence extracts (SME) and synthetic AVP. However, peptide release from the ectopic tumours, although pulsatile, remained autonomous. Prior to surgery, gel-chromatographic profiles of plasma immunoreactive ACTH showed only one peak, which eluted in the position of 1-39 ACTH, in patients with the pituitary tumours, but there was a second peak of large molecular weight ACTH present in the plasma from those with the ectopic ACTH syndrome. This second form of ACTH could not be detected in any of the tumour cell column effluents. An eighth pituitary tumour was atypical, in its unusually large size, clinically aggressive nature and spectrum of peptide release. Although peptide release in response to stimulation with SME was similar to that observed with the other pituitary tumours, the chromatography of the plasma ACTH resembled the ectopic plasma pattern, showing two peaks of immunoreactivity.

ACTH Syndrome, Ectopic↗
PubMed2004

Occurrence of the Bezold-Jarisch reflex during Cesarean section under spinal anesthesia--a case report.

We report a 35-year-old parturient with gestational diabetes mellitus (GDM) history who sustained a nearly fatal Bezold-Jarisch reflex during Cesarean section under spinal anesthesia. A high spinal block combined with acute massive hemorrhage may produce life-threatening Bezold-Jarisch reflex which should be treated prophylactically and aggressively during surgery. Additionally, the autonomic disturbance associated with GDM might exaggerate the reflex in this episode. The patient survived after successful resuscitation and was discharged without any sequela.

Adult↗
PubMedDate not supplied

Intraoperative aspects and complications for the anesthesiologist in the management of patients undergoing thoracic surgery for lung cancer.

Surgery, when feasible, rappresents the treatment of choice for lung cancer. Several problems can come to the attention of the anesthesiologist in relation to the respiratory function with implications in airway control (double-lumen tube for lung collapse required for better surgical exposure of the pulmonary tissue), mechanical and gas-exchange aspects (increase in airway pressure of the dependent lung, increased blood shunt). The effect of these disorders, with no compensatory mechanism (pulmonary hypoxic vasoconstriction) and in the absence of an anesthesiologist (higher FiO2, low tidal volumes, allowing "permissive hypercapnia", CPAP to the non-dependent lung), normal arterial oxygenation (hypoxemia) is impaired. Right heart failure is the major risk particularly in preexisting pulmonary hypertension Supraventricular arrytmias can often occur in case of history of cardiovascular disease, metabolic and mechanical intraoperative alterations (type and duration of surgery, pericardial and autonomic nervous system manipulations). Unusual complications are cardiac herniation and pulmonary re-expansion-edema.

Anesthesia, General↗
PubMed1987

[Study of the visco-elastic response of the aortic wall to angiotensin and noradrenaline in the conscious dog by analysis of the instantaneous pressure-diameter relation in the descending aorta].

The viscoelastic behaviour of the aorta has been studied in 7 adult non-anesthesized mongrel dogs, chronically instrumented with a microtransducer pressure (Konigsberg P7) implanted inside the aortic lumen, and 2 ultrasonic crystals diametrically opposed and fixed in the adventitia of the thoracic aorta. Pressure and diameter were analysed in terms of mean values and of systolic diastolic variations, enabling to calculate the elastic modulus of Peterson. After recovery from surgery, and under autonomic blockade by atropine and propranolol, perfusions of angiotensin and norepinephrine were performed at incremental steps of doses. In individual dogs, instantaneous pressure-diameter relationships were formed by the different pressure diameter hysteris loops obtained at each dose of the same drug; the relationships obtained with the two drugs were curvilinear and were mixed at lower pressure ranges, but at highest levels of pressures it was found, that comparatively to angiotensin curve, that of norepinephrine had shifted toward lower diameter. The percent increase in mean diameter from baseline obtained at each dose of the same drug, was positively correlated to the corresponding per cent increase in mean pressure, with angiotensin (r = 0.83 P less than 0.001), and for norepinephrine (r = 0.82 P less than 0.001), but the slope of the relation was lower with angiotensin (22.3 +/- 3.2) than with norepinephrine (12.8 +/- 1.9) (P less than 0.001); likewise, the elastic modulus, for each dose of a same drug, was positively correlated to the corresponding mean pressure for angiotensin (r = 0.53 P less than 0.01), norepinephrine (r = 0.69 P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1986

Some changes of aging.

Aging is associated with changes in body composition and physiologic function which are important in altering the response to drugs of elderly individuals frequently requiring changes in dosages. Declining abilities to do work can lead to incapacity in the late '70s. Such incapacity can be reduced by reconditioning but is likely to be exacerbated by the deconditioning associated with acute illnesses or surgery. Changes in autonomic function, particularly orthostatic hypotension and bladder atony, are likely causes of disability in the postoperative period. The major increase in mortality in the elderly in the postoperative period is related to co-morbidity rather than physiologic changes. Healthy elderly individuals can be excellent surgical risks with careful management. Those with co-morbid conditions can have their surgical risk substantially reduced by medical management.

Aged↗