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Hypertension in the critically ill patient.

OBJECTIVE: To review the management of persistent hypertension and hypertensive crisis in the critically ill patient. DATA SOURCES: A review of articles reported on hypertension and the critically ill patient. SUMMARY OF REVIEW: Hypertension is defined as a basal systolic blood pressure of greater than 140 mmHg or diastolic blood pressure of greater than 90 mmHg (MAP > 105 mmHg), irrespective of age and is based on the average of two or more readings on two or more occasions over a period of four weeks. While a mean arterial pressure in the critically ill up to a value of 135 mmHg may be tolerated for some hours, in patients with dissecting aortic aneurysm, cardiac failure, angina, acute myocardial infarction, pre-eclampsia and following cardiac, vascular or cerebral surgery a mean arterial blood pressure of > 90 mmHg or greater should be lowered by up to 30% urgently. A hypertensive crisis may be defined as a MAP > 160 mmHg and can be caused by phaeochromocytoma, sympathomimetic overdose, malignant hypertension or autonomic hyper-reactivity secondary to tetanus. Treatment requires direct intra-arterial monitoring and an initial reduction in mean arterial pressure by no greater than 30%. While management of the primary condition (e.g. surgical removal of a phaeochromocytoma, delivery or termination of the pregnancy) may also be necessary, infusions of sodium nitroprusside, phentolamine, hydralazine or esmolol usually require supplementation with oral agents (e.g. angiotensin-converting enzyme inhibitors, beta-adrenergic receptor antagonists and calcium-channel blockers) for long-term management. CONCLUSIONS: A mean arterial pressure in the critically ill is often tolerated up to a value of 135 mmHg for some hours. However in some disorders (e.g. dissecting aortic aneurysm, cardiac failure, angina, acute myocardial infarction, pre-eclampsia or eclampsia and following cardiac, vascular or cerebral surgery) a mean arterial blood pressure of 90 mmHg or greater should be treated urgently.

Journal Article↗

Autonomic auras: left hemispheric predominance of epileptic generators of cold shivers and goose bumps?

PURPOSE: Autonomic seizures in temporal lobe epilepsies associated with "cold shivers and goose bumps" as a principal ictal sign or aura have only rarely been studied. METHODS: Sixteen patients with autonomic auras [cold shivers or cold sweats (n=11), goose bumps (n=4), one patient showed both ictal signs] were analyzed. RESULTS: Lesions were detected in 12 patients. The etiology was heterogeneous [cryptogenic, arteriovenous (AV)-malformation cyst, trauma, hippocampal sclerosis]. Eight patients underwent epilepsy surgery. The localization and lateralization of the focal epileptic activity in the temporal lobes was determined either by magnetic resonance imaging lesions, EEG, ictal signs, or single-photon emission computed tomography imaging. CONCLUSIONS: The patients with temporal lobe epilepsies associated with "cold shivers and/or goose bumps" showed a left hemispheric predominance of the focal abnormality in the temporal lobe.

Adult↗

Complex autonomic dysfunction in cardiovascular, intensive care, and schizophrenic patients assessed by autonomic information flow.

BACKGROUND: The cardiovascular control system is mediated by mechanisms acting at different time scales, such as heart period, vagal, sympathetic, and other slower controllers. Since these elements are interrelated in a complex manner, classical control theory fails and information-based description, based on autonomic information flow (AIF) functions, is appropriate. We investigated the hypothesis that AIF functions of typical time scales specifically characterize autonomic dysfunction and prognosis. MATERIALS AND METHODS: Holter recordings of patients with multiple organ dysfunction syndrome (MODS) (26 survivors, 10 non-survivors), heart failure (13 low risk, 13 high risk of cardiac arrest), idiopathic dilated cardiomyopathy (IDC) (26 low risk, 11 high risk), after abdominal aorta surgery (AAS) [32 with length of stay in hospital (LOS) >7 days; 62 with LOS < or =7 days] or with schizophrenia (n=20) were assessed and compared to 20 control subjects. RESULTS: We found different AIF time scales discriminating risk. AIF measures of heart beat period had predominant prognostic value in heart failure patients, those of vagal communication in MODS and IDC, and those of long-term communication after AAS. Schizophrenic patients were discriminated from controls by vagally mediated communication. CONCLUSION: Different time scales of AIF represent specific pathophysiological aspects of altered complex autonomic control (communication) and consequently have predictive implications.

Autonomic Nervous System↗

Diabetes mellitus-associated diffuse autonomic dysfunction causing debilitating hypotension manifested after rapid weight loss in a morbidly obese patient: case report and review of the literature.

The association between weight and blood pressure is well established, especially the paradigm of obesity-related hypertension. The relationship between diffuse autonomic dysfunction and orthostatic hypotension in patients with long-term diabetes mellitus is also well known. We report on a 57-year-old morbidly obese male with a long medical history of hypertension, myocardial infarction, type 2 diabetes mellitus, and hypothyroidism. After a loss of 147 pounds (representing a percent excess weight loss of 76%) within 6 months after gastric bypass surgery, the patient developed worsening orthostatic hypotension and near-syncopal episodes requiring medication. The subsequent diagnosis and treatment, as well as a literature review, are presented.

Anastomosis, Roux-en-Y↗

The incidence and outcome of ventricular arrhythmias after noncardiac thoracic surgery.

UNLABELLED: Atrial arrhythmias are common after thoracic surgery, but the incidence and significance of ventricular arrhythmias early after such surgery are not well established. Our goal was to determine the incidence and outcome of this complication from a continuing prospective database in 412 patients who had lobectomy (n = 243) or pneumonectomy (n = 169) and were continuously monitored with Holter recorders for 72-96 h postoperatively. The primary end point of the study was the occurrence of ventricular tachycardia (VT) defined as three or more consecutive wide complexes. Sixty-one of 412 patients (15%) developed 1 or more episode of VT. There were no episodes of sustained (>30 s) VT and no patient required treatment for hemodynamic compromise associated with any VT episode. Patients with VT had a more frequent incidence of a preoperative left bundle branch block (P = 0.01) but did not differ in other clinical characteristics, operative data, or core temperature on arrival to the postanesthesia care unit, when compared with those without VT. Patients who developed VT had significantly more atrial premature contractions (P < 0.001), ventricular premature contractions (P < 0.001), ventricular couplets (P < 0.001), and postoperative atrial fibrillation, 21 of 61 (34%) versus 58 of 351 (17%), P = 0.001, than those without VT, respectively. Multivariate logistic regression analysis revealed that only postoperative atrial fibrillation occurrence was independently associated with VT (relative risk 2.6, 95% confidence intervals 1.4 to 4.8, P = 0.002). We conclude that nonsustained VT after noncardiac thoracic surgery occurs frequently but is not associated with poor outcome. The strong association of atrial and ventricular arrhythmogenesis with VT suggests that vagal withdrawal and/or adrenergic hyperactivity may have a role in precipitating these events in the early postoperative period. IMPLICATIONS: In 412 patients, we determined that the incidence of nonsustained ventricular tachycardia after major thoracic surgery is 15% and is not associated with poor outcome.

Aged↗

[11C]Methionine positron emission tomography for patients with persistent or recurrent hyperparathyroidism after surgery.

OBJECTIVE: Reoperation in patients with recurrent hyperparathyroidism usually requires localisation of abnormal glands. Current imaging techniques are not always successful in this group of patients. An evaluation of [11C]methionine positron emission tomography (PET) has been made to assess the ability of the technique to localise abnormal glands in patients with hyperparathyroidism after previous surgery. SUBJECTS AND METHODS: Eight patients (five with primary, and three with tertiary hyperparathyroidism) who had undergone one to three previous surgical explorations were studied. [11C]methionine PET scans of the neck and mediastinum were performed in all patients. All had recent technetium-99m (99mTc)-labelled sestamibi (n = 7) or thallium-201 (201Tl)/99mTc subtraction (n = 1) parathyroid scans available for comparison. Subsequent surgical correlation was available in all cases. RESULTS: [11C]methionine PET correctly located an abnormal site of uptake in all five patients with primary hyperparathyroidism compared with only one when conventional nuclear medicine methods were used. In the patients with tertiary hyperparathyroidism, [11C]methionine PET correctly located one, confirmed the absence of cervical or mediastinal abnormality in a patient with an autotransplanted forearm autonomous gland, and failed to demonstrate an abnormality in a third. 99mTc-labelled sestamibi scans were negative in all three patients. CONCLUSION: [11C]methionine PET correctly locates abnormal parathyroid glands in the majority of patients with persistent or recurrent hyperparathyroidism after surgery in whom conventional non-invasive nuclear medicine imaging has failed.

Adenoma↗

Development of overt Cushing's syndrome in patients with adrenal incidentaloma.

OBJECTIVE: The natural course of adrenal incidentalomas, especially those with subclinical autonomous glucocorticoid production, i.e. subclinical Cushing's syndrome, and the risk that such conditions will evolve towards overt Cushing's syndrome are unknown. DESIGN: Longitudinal follow-up evaluation of a series of 284 consecutive patients with adrenal incidentaloma. METHODS AND RESULTS: Out of 284 consecutive patients with adrenal incidentaloma studied at our Institution in the last 15 years, 98 patients (23 with subclinical hypercortisolism) underwent surgery. Of 130 non-operated patients with a follow-up of at least 1 year, eight had subclinical hypercortisolism at diagnosis. We describe in detail four patients who developed overt Cushing's syndrome after 1-3 years of follow-up. Only one of these patients had subclinical hypercortisolism at first diagnosis. Estimated cumulative risk for a non-secreting adrenal incidentaloma to develop subclinical hyperfunction was 3.8% after 1 year and 6.6% after 5 years. For patients with masses with subclinical autonomous glucocorticoid overproduction, estimated cumulative risk to develop overt Cushing's syndrome was 12.5% after 1 year. CONCLUSIONS: In patients with adrenal incidentalomas the risk of progression towards overt Cushing's syndrome is not low, at variance with previous reports. A careful biochemical and hormonal follow-up is advisable in all patients who do not need surgery at first presentation.

Adolescent↗

Xenon does not reduce opioid requirement for orthopedic surgery.

PURPOSE: Is to test the hypothesis that 70% xenon has a relevant opioid sparing effect compared to a minimum alveolar concentration (MAC)-equivalent combination of N(2)O and desflurane. METHODS: In this randomized, controlled study of 30 patients undergoing major orthopedic surgery, we determined the plasma alfentanil concentration required to suppress response to skin incision in 50% of patients (Cp(50)) anesthetized with xenon (70%) or a combination of N(2)O (70%) and desflurane (2%). A response was defined as movement, pressor response > 15 mmHg, heart rate > 90 beats x min(-1), autonomic reactions or a combination of these. At skin incision, alfentanil was administered at a randomly selected target plasma concentration thereafter the concentration was increased or decreased according to the patient's response. After skin incision, desflurane was adjusted to maintain the bispectral index below 60 and prevent responsiveness in both groups. RESULTS: The Cp(50) (+/- standard error) of alfentanil was 83 +/- 48ng x mL(-1) with xenon and 49 +/- 26 ng x mL(-1) with N(2)O/desflurane (P =0.451). During surgery five xenon and 15 N(2)O/desflurane patients were given desflurane at 1.0 +/- 0.5 volume % and 2.5 +/- 0.7 volume %. The total age adjusted MAC was 0.97 +/- 0.07 and 0.94 +/- 0.07 respectively (P = 0.217). The intraoperative plasma alfentanil concentrations were 95 +/- 80 and 93 +/- 60 ng x mL(-1) respectively (mean +/- SD; P = 0.451). Patients given xenon were slightly more bradycardic, whereas blood pressure was similar. CONCLUSION: Xenon compared to a MAC-equivalent combination of N(2)O and desflurane does not substantially reduce opioid requirement for orthopedic surgery. A small but clinically irrelevant difference cannot be excluded, however.

Adult↗

Plastic surgeon's life: marvelous for mind, exhausting for body.

Surgery is accepted as one of the most demanding professions that create both physical and mental strain on the performers. Therefore, the authors aimed to elucidate the mental burden of surgeons, which is dedicated to operative stress. They also tested the hypotheses that participating in surgery creates mental stress on surgeons that leads to cardiovascular changes, and that this stress is more pronounced for actual operators than for first assistants. The method chosen for this purpose was an analysis of heart rate variability. Twelve surgeons (five plastic surgery staff and seven plastic surgery residents) were monitored by a digital ambulatory Holter recorder on at least two occasions. Half of the recordings were carried out on operating days and the other half on office days. Heart rate variability indices (low frequency, high frequency, high frequency/low frequency ratio, and heart rate) were analyzed from those recordings using computerized research tool software. The heart rate variability indices of the operators showed statistically significant differences between operating days and office hours in favor of an increased sympathetic and decreased parasympathetic activity for the former. For first assistants, three of the parameters, with the exception of heart rate, changed in favor of a sympathetic predominance over parasympathetic activity; these changes were also statistically significant. These results showed a sympathetic hyperactivity for both operators and first assistants during the operations. When the sympathovagal balance of the actual operators was compared with that of assistants, the former group showed a more pronounced sympathetic arousal. This difference is accepted as a proof for the mental stress of the surgery being the main factor responsible for the sympathetic hyperactivity that we detected during the operations. Surgeons continuously face a unique mental strain that other professions rarely bring forth, and these psychological stressors are associated with alterations in cardiac autonomic control that may contribute to the development of cardiac disease. Prolonged sympathetic hyperactivity could anticipate cardiac discomfort in more experienced surgeons with marginal cardiac reserve. Such cardiac diseases would be reconsidered as occupation-related illnesses, which might be reimbursed to the physician. In addition, the legal responsibility of surgeons concerning their unfavorable results might be assessed with more understanding with a realization of their undue working conditions.

Adult↗

[Anesthetic management of a child with congenital sensory neuropathy with anhydrosis].

Congenital sensory neuropathy with anhydrosis is a rare disorder characterized by insensitivity to pain with normal tactile perception, self-mutilation, anhydrosis, recurrent unexplained fever, mental retardation and variable autonomic abnormality. We managed a 14-year-old boy with this syndrome who underwent repair of right femur fracture. Anesthesia was induced with propofol and ketamine. Adequate depth of anesthesia was carefully controlled by processed electroencephalogram, and core body temperature was maintained at 37.0 degrees C during the surgery. The patient was well sedated, and nausea and vomiting were not noted postoperatively. Use of droperidol and propofol may be beneficial for anesthetic management of this syndrome, because droperidol exerts residual hypnotic effect postoperatively, and both drugs have antiemetic property.

Adolescent↗

Clinical utility of a simple physical technique in thyroid scintigraphy.

Fifty two patients with visualization of one lobe or one lobe with faint active thyroid tissue in the region of the other lobe on thyroid scintigraphy, were studied using shielding of the active thyroid tissue in order to visualize the rest of the gland. This technique is useful in the differential diagnosis of autonomous nodules without need for the time consuming, costly, and sometimes hazardous TSH stimulation and T3 suppression tests. Furthermore, this technique could be used to verify total lobectomy in patients following thyroid surgery. Further work to differentiate congenital thyroid hemiagenesis from non toxic sutonomous nodules is suggested.

Adenoma↗

Differential effects of surgical sympathetic block at the T2 and T4 level on vasoconstrictor function.

Endoscopic sympathetic block (ESB) is used as a treatment of excessive palmar sweating. In a prospective study we compared the effect of ESB at the level of the second (T2) and fourth thoracic ganglion (T4) on vasoconstriction and sweating of the hands. Sympathetic vasoconstriction was measured by computerassisted infrared thermography following ice water immersion of the hands in 22 hyperhidrosis patients before, two days and 3 months post op. In addition, palmar sweating before and 3 months post op was assessed by sudometry. After ESB the rewarming was accelerated in both T2 and T4 patients, but was significantly slower in the T4 group. Three months postoperatively rewarming had returned to the preoperative pattern in T4 patients but was still significantly faster in the T2 group. These effects were more pronounced in the fingertips than the hand dorsum. Sudomotor function was blocked in all T2 patients but had relapsed in 2 patients in the T4 group. Two T4 patients had not shown an effect on sudomotor function postoperatively. The normalization of rewarming kinetics may be explained by remaining fibers, denervation hypersensitivity or stimulation of catecholamine receptors, or neuronal reorganization. The effect of ESB T4 on sudomotor function has to be proven.

Adult↗

Anaesthesia defined (gentlemen, this is no humbug).

Our charge was to define anaesthesia as produced by inhaled anaesthetics. A definition may be useful to an understanding of the anaesthetic state, and it may guide studies of the mechanisms by which anaesthesia is produced. All inhaled anaesthetics act on the central nervous system to produce two reversible conditions, immobility and amnesia, that define the anaesthetic state. No other reversible, clinically useful, conditions are essential to the definition. Some conditions are unmeasurable (unconsciousness), not present for all inhaled anaesthetics (relaxation), or are not present at anaesthetizing concentrations (suppression of autonomic reflexes.) One (analgesia) is unmeasurable (the anaesthetized patient cannot tell an investigator that he/she hurts or does not hurt), and surrogate measures (increases in breathing, blood pressure, and heart rate with surgery) suggest that some pain is perceived. These and myriad other changes produced by inhaled anaesthetics are side effects; they do not define anaesthesia; only immobility and amnesia supply such a definition.

Anesthesia, Inhalation↗