Showing papers in "Anesthesiology in 2000"
TL;DR: Five groups of surgeries were selected because the incidence of pain is known to be high, thus improving the probability of detecting predictive factors and the natural history of patients with and without persistent pain after surgery provides an opportunity to improve the understanding of the physiology and psychology of chronic pain.
Abstract: ONE potential adverse outcome from surgery is chronic pain. Analysis of predictive and pathologic factors is important to develop rational strategies to prevent this problem. Additionally, the natural history of patients with and without persistent pain after surgery provides an opportunity to improve the understanding of the physiology and psychology of chronic pain. Ideally, studies of chronic postoperative pain should include (1) sufficient preoperative data (assessment of pain, physiologic and psychologic risk factors for chronic pain); (2) detailed descriptions of the operative approaches used (location and length of incisions, handling of nerves and muscles); (3) the intensity and character of acute postoperative pain and its management; and (4) follow-up at intervals to 1 yr or more. In addition, there would be information about postoperative interventions that may influence pain, such as radiation therapy or chemotherapy. At long-term follow-up visits, patient function, physical signs, and symptoms would be evaluated using a standardized algorithm, including quantitative and descriptive pain assessments. We found no studies that contain all of these data. For this review, we specifically sought population data that reflect the incidence of chronic postoperative pain or predictors (medical, physiologic, and psychologic) of chronic pain. We selected five groups of surgeries (limb amputations, breast surgery, gallbladder surgery, lung surgery, and inguinal hernia surgery). These surgeries were selected because the incidence of pain is known to be high, thus improving the probability of detecting predictive factors. They also represent a range of major surgical procedures.
1,337 citations
TL;DR: In this article, the responses to increasing plasma concentrations of dexmedetomidine in humans were determined, and 10 healthy men (20-27 yr) provided informed consent and were monitored (underwent electrocardiography, measured arterial, central venous [CVP] and pulmonary artery [PAP] pressures,
Abstract: BackgroundThis study determined the responses to increasing plasma concentrations of dexmedetomidine in humans.MethodsTen healthy men (20–27 yr) provided informed consent and were monitored (underwent electrocardiography, measured arterial, central venous [CVP] and pulmonary artery [PAP] pressures,
1,219 citations
TL;DR: Relatively large-dose intraoperative remifentanil increased postoperative pain and morphine consumption is suggested to have caused acute opioid tolerance and hyperalgesia.
Abstract: BackgroundRapid development of acute opioid tolerance is well established in animals and is more likely to occur with large doses of short-acting drugs. The authors therefore tested the hypothesis that intraoperative remifentanil administration results in acute opioid tolerance that is manifested by
855 citations
TL;DR: Being able to more accurately predict DMV may improve the safety of airway management and prevent or reverse signs of inadequate ventilation during positive-pressure mask ventilation under general anesthesia.
Abstract: Background: Maintenance of airway patency and oxygenation are the main objectives of face-mask ventilation. Because the incidence of difficult mask ventilation (DMV) and the factors associated with it are not well known, we undertook this prospective study. Methods: Difficult mask ventilation was defined as the inability of an unassisted anesthesiologist to maintain the measured oxygen saturation as measured by pulse oximetry > 92% or to prevent or reverse signs of inadequate ventilation during positive-pressure mask ventilation under general anesthesia. A univariate analysis was performed to identify potential factors predicting DMV, followed by a multivariate analysis, and odds ratio and 95% confidence interval were calculated. Results: A total of 1,502 patients were prospectively included. DMV was reported in 75 patients (5%; 95% confidence interval, 3.9 ‐ 6.1%), with one case of impossible ventilation. DMV was anticipated by the anesthesiologist in only 13 patients (17% of the DMV cases). Body mass index, age, macroglossia, beard, lack of teeth, history of snoring, increased Mallampati grade, and lower thyromental distance were identified in the univariate analysis as potential DMV risk factors. Using a multivariate analysis, five criteria were recognized as independent factors for a DMV (age older than 55 yr, body mass index > 26 kg/m 2 , beard, lack of teeth, history of snoring), the presence of two indicating high likelihood of DMV (sensitivity, 0.72; specificity, 0.73). Conclusion: In a general adult population, DMV was reported in 5% of the patients. A simple DMV risk score was established.
770 citations
TL;DR: Local Anesthetics and the Inflammatory Response: A New Therapeutic Indication?
Abstract: Local Anesthetics and the Inflammatory Response: A New Therapeutic Indication? Markus Hollmann;Marcel Durieux; Anesthesiology
670 citations
620 citations
TL;DR: Development and Clinical Application of Electroencephalographic Bispectrum Monitoring Jay Johansen;Peter Sebel; Anesthesiology.
Abstract: Development and Clinical Application of Electroencephalographic Bispectrum Monitoring Jay Johansen;Peter Sebel; Anesthesiology
614 citations
TL;DR: Fentanyl activates NMDA pain facilitatory processes, which oppose analgesia and lead to long-lasting enhancement in pain sensitivity, and the higher the fentanyl dose used, the more pronounced was the fentanyl-induced hyperalgesia.
Abstract: BackgroundIt has been reported that μ-opioid receptor activation leads to a sustained increase in glutamate synaptic effectiveness at the N-methyl-D-aspartate (NMDA) receptor level, a system associated with central hypersensitivity to pain. One hypothesis is that postoperative pain may result partly
580 citations
TL;DR: A schedule is proposed which minimizes the makespan, the time when the last job is completed, and the constraints are that a job can only be scheduled after its release time, and preemption is not allowed.
Abstract: We study some classical problems in scheduling. In the rst problem a sequence of jobs must be scheduled on m identical parallel machines. As each job arrives, its processing time(pj) is known. We have to assign the job to one of the machines immediately, without knowledge of the jobs that arrive later. Jobs cannot be preempted. The goal is to minimize the makespan, the time when the last job is completed. The second problem deals with scheduling jobs on a single machine/processor. With each job we have an associated weight(wj), release time(rj) and processing time(pj). Now the objective is to minimize the weighted sum of completion times,Pnj=0wjCj . The constraints are that a job can only be scheduled after its release time, and preemption is not allowed. In the third problem again there are m machines. Each job has to visit the machines in the same xed order. The processing time pij of job j on machine i is known. We want a schedule which minimizes the makespan. A job can only be processed on a single machine at a time. Chapter
561 citations
TL;DR: Mechanisms indicate that alterations in the distribution of body heat contribute more to changes in core temperature than to systemic heat imbalance in most patients.
Abstract: Daniel 1. Sessler, M. D. * ANESTHESIA and surgery commonly cause substantial thermal perturbations. Hypothermia, the typical alteration, results from a combination of anesthetic-induced impairment of thermoregulatory control, a cool operating room environment, and factors unique to surgery that promote excessive heat loss. Available data suggest that inhibition of normal thermoregulatory defenses contributes more to hypothermia than does cold exposure per se. Furthermore, much core hypothermia results from altered distribution of body heat rather than from a systemic imbalance between metabolic heat production and heat loss.
492 citations
TL;DR: Anesthesia-related cardiac arrest occurred most often in patients younger than 1 yr of age and in patients with severe underlying disease, as well as patients having emergency surgery, were most likely to have a fatal outcome.
Abstract: BACKGROUND The Pediatric Perioperative Cardiac Arrest (POCA) Registry was formed in 1994 in an attempt to determine the clinical factors and outcomes associated with cardiac arrest in anesthetized children. METHODS Institutions that provide anesthesia for children are voluntarily enrolled in the POCA Registry. A representative from each institution provides annual institutional demographic information and submits anonymously a standardized data form for each cardiac arrest (defined as the need for chest compressions or as death) in anesthetized children 18 yr of age or younger. Causes and factors associated with cardiac arrest are analyzed. RESULTS In the first 4 yr of the POCA Registry, 63 institutions enrolled and submitted 289 cases of cardiac arrest. Of these, 150 arrests were judged to be related to anesthesia. Cardiac arrest related to anesthesia had an incidence of 1.4 +/- 0.45 (mean +/- SD) per 10,000 instances of anesthesia and a mortality rate of 26%. Medication-related (37%) and cardiovascular (32%) causes of cardiac arrest were most common, together accounting for 69% of all arrests. Cardiovascular depression from halothane, alone or in combination with other drugs, was responsible for two thirds of all medication-related arrests. Thirty-three percent of the patients were American Society of Anesthesiologists physical status 1-2; in this group, 64% of arrests were medication-related, compared with 23% in American Society of Anesthesiologists physical status 3-5 patients (P < 0.01). Infants younger than 1 yr of age accounted for 55% of all anesthesia-related arrests. Multivariate analysis demonstrated two predictors of mortality: American Society of Anesthesiologists physical status 3-5 (odds ratio, 12.99; 95% confidence interval, 2.9-57.7), and emergency status (odds ratio, 3. 88; 95% confidence interval, 1.6-9.6). CONCLUSIONS Anesthesia-related cardiac arrest occurred most often in patients younger than 1 yr of age and in patients with severe underlying disease. Patients in the latter group, as well as patients having emergency surgery, were most likely to have a fatal outcome. The identification of medication-related problems as the most frequent cause of anesthesia-related cardiac arrest has important implications for preventive strategies.
TL;DR: Adjusting pharmacokinetics to the individual patient should improve the precision of target-controlled infusion and may help to broaden the field of application for target- controlled infusion systems.
Abstract: Background:Target-controlled infusion is an increasingly common type of administration for propofol. This method requires accurate knowledge of pharmacokinetics, including the effects of age and weight. The authors performed a multicenter population analysis to quantitate the effects of covariates.M
TL;DR: In this article, the authors used frequency domain near-infrared spectroscopy to determine the ratio of arterial and venous blood monitored by cerebral oximetry during normoxia, hypoxia and hypocapnia.
Abstract: BACKGROUND Cerebral oximetry is a noninvasive bedside technology using near-infrared light to monitor cerebral oxygen saturation (Sco2) in an uncertain mixture of arteries, capillaries, and veins. The present study used frequency domain near-infrared spectroscopy to determine the ratio of arterial and venous blood monitored by cerebral oximetry during normoxia, hypoxia, and hypocapnia. METHODS Twenty anesthetized children aged < 8 yr with congenital heart disease of varying arterial oxygen saturation (Sao2) were studied during cardiac catheterization. Sco2, Sao2, and jugular bulb oxygen saturation (Sjo2) were measured by frequency domain near-infrared spectroscopy and blood oximetry at normocapnia room air, normocapnia 100% inspired O2, and hypocapnia room air. RESULTS Among subject conditions, Sao2 ranged from 68% to 100%, Sjo2 from 27% to 96%, and Sco2 from 29% to 92%. Sco2 was significantly related to Sao2 (y = 0. 85 x -17, r = 0.47), Sjo2 (y = 0.77 x +13, r = 0.70), and the combination (Sco2 = 0.46 Sao2 + 0.56 Sjo2 - 17, R = 0.71). The arterial and venous contribution to cerebral oximetry was 16 +/- 21% and 84 +/- 21%, respectively (where Sco2 = alpha Sao2 + beta Sjo2 with alpha and beta being arterial and venous contributions). The contribution was similar among conditions but differed significantly among subjects (range, approximately 40:60 to approximately 0:100, arterial:venous). CONCLUSIONS Cerebral oximetry monitors an arterial/venous ratio of 16:84, similar in normoxia, hypoxia, and hypocapnia. Because of biologic variation in cerebral arterial/venous ratios, use of a fixed ratio is not a good method to validate the technology.
TL;DR: These data show sex differences in morphine analgesia, with greater morphine potency but slower speed of onset and offset in women, which may explain higher postoperative opioid consumption in men relative to women.
Abstract: BackgroundAnimal and human studies indicate the existence of important sex-related differences in opioid-mediated behavior. In this study the authors examined the influence of morphine on experimentally induced pain in healthy male and female volunteers.MethodsYoung healthy men and women (10 of each
TL;DR: The results suggest that NMDA receptors and nACh receptors composed of &bgr;2 subunits are likely targets for nitrous oxide and xenon, which are distinct from that of isoflurane or ethanol.
Abstract: BackgroundLigand-gated ion channels are considered to be potential general anesthetic targets. Although most general anesthetics potentiate the function of γ-aminobutyric acid receptor type A (GABAA), the gaseous anesthetics nitrous oxide and xenon are reported to have little effect on GABAA recepto
TL;DR: The amount of regularity in the EEG increases with increasing desflurane concentrations, suggesting that the approximate entropy could be a useful EEG measure of anesthetic drug effect.
Abstract: Background:The authors hypothesized that the electroencephalogram (EEG) during higher anesthetic concentrations would show more “order” and less “randomness” than at lower anesthetic concentrations. “Approximate entropy” is a new statistical parameter derived from the Kolmogorov-Sinai entropy formul
TL;DR: The review leads to the conclusion that, although several techniques allow one to identify statistically significant differences in depth of anesthesia among defined anesthetic conditions for populations of patients, none has the sensitivity and specificity to allow the clinician to draw certain conclusions aboutdepth of anesthesia in the individual patients for whom he or she treats.
Abstract: AMONG the earliest systematic observations of the physiologic effects of anesthetic agents was John Snow’s description, in 1847, of the various stages of ether anesthesia. Although the focus has evolved somewhat, our interest in measures of the depth of anesthesia has persisted. Although the concern was initially largely one of avoiding the hazards of overdose, we have added a greater interest in the prevention of “underdosage.” There is considerable interest in preventing potentially hazardous hemodynamic and movement responses and in preventing recall. The latter concern applies most particularly to the patient who has received neuromuscular blocking agents. The contemporary literature also indicates an interest in using depth of anesthesia monitors as a means of controlling cost. The hope is that precise titration of anesthetic agents, as guided by a monitor of anesthetic depth, can serve to avoid wastage of expensive anesthetics and expedite postanesthesia care unit or hospital discharge, or both. There have been several thoughtful discussions of the monitoring of depth of anesthesia and of the problem of awareness. Table 1 lists many of the techniques or devices that have been proposed or tested as methods for determining depth of anesthesia. A thorough discussion by Heier and Steen published in 1996 reviews the status of all but the most recent of those techniques. Briefly, the review leads to the conclusion that, although several techniques allow one to identify statistically significant differences in depth of anesthesia among defined anesthetic conditions for populations of patients, none has the sensitivity and specificity to allow the clinician to draw certain conclusions about depth of anesthesia in the individual patients for whom he or she treats. The then-available (1996) devices served as trend monitors of varying reliability but did not permit conclusive statements about depth of anesthesia in individual patients. The purpose of this review is to summarize the developments that postdate the articles cited previously. That progress has involved principally two depth-ofanesthesia monitoring methods: the Bispectral Index, known by the trademarked acronym BIS (Aspect Medical Systems Inc., Newton, MA); and the middle latency auditory evoked response (MLAER). The BIS is an empirically derived index that is dependent on a measure of the “coherence” among components of electroencephalography. The MLAER uses measurements of the amplitude and latency of the early cortical components of the auditory evoked response. This discussion will focus on developments related to those two methods. In addition, because of the interest on the part of the media, patients, practitioners, and investigators regarding the topic of awareness during anesthesia, the issue to which this review gives greatest attention is: Can the available monitors be used to prevent the occurrence of awareness during anesthesia? Professor and Chair, Department of Anesthesiology, University of California; Staff Anesthesiologist, Anesthesia Service, VA Medical Center, San Diego, California.
TL;DR: This commentary examines why postoperative pulmonary complications occur and how the anesthesiologist can help prevent them.
Abstract: THE Confederate General “Stonewall” Jackson was one of the earliest known victims of a respiratory complication after surgery, dying of pneumonia 10 days after an otherwise successful ether anesthetic in 1863. Despite subsequent advances in anesthesia and surgical care, postoperative pulmonary complications (PPCs) still are a significant problem in modern practice. This commentary examines why PPCs occur and how the anesthesiologist can help prevent them.
TL;DR: Application of response-surface methodology permits characterization of the full concentration–response relation between combinations of anesthetic drugs and therefore can be used to develop practical guidelines for optimal drug dosing.
Abstract: BackgroundAnesthetic drug interactions traditionally have been characterized using isobolographic analysis or multiple logistic regression. Both approaches have significant limitations. The authors propose a model based on response-surface methodology. This model can characterize the entire dose–res
TL;DR: Monitoring rSO2 with INVOS-3100 to detect cerebral ischemia during CEA has a high negative predictive value, but the positive predictive value is low.
Abstract: BackgroundStroke is an important contributor to perioperative morbidity and mortality associated with carotid endarterectomy (CEA). This investigation was designed to compare the performance of the INVOS-3100 cerebral oximeter to neurologic function, as a means of detecting cerebral ischemia induced
TL;DR: After major abdominal surgery in the elderly patient, patient-controlled analgesia, regardless of the route (epidural or parenteral), is effective and the epidural route using local anesthetics and an opioid provides better pain relief and improves mental status and bowel activity.
Abstract: Background Patient-controlled analgesia (PCA) with intravenous morphine and patient-controlled epidural analgesia (PCEA), using an opioid either alone or in combination with a local anesthetic, are two major advances in the management of pain after major surgery. However, these techniques have been evaluated poorly in elderly people. This prospective, randomized study compared the effectiveness on postoperative pain and safety of PCEA and PCA after major abdominal surgery in the elderly patient. Methods Seventy patients older than 70 yr of age and undergoing major abdominal surgery were assigned randomly to receive either combined epidural analgesia and general anesthesia followed by postoperative PCEA, using a mixture of 0.125% bupivacaine and sufentanil (PCEA group), or general anesthesia followed by PCA with intravenous morphine (PCA group). Pain intensity was tested three times daily using a visual analog scale. Postoperative evaluation included mental status, cardiorespiratory and gastrointestinal functions, and patient satisfaction scores. Results Pain relief was better at rest (P = 0.001) and after coughing (P = 0.002) in the PCEA group during the 5 postoperative days. Satisfaction scores were better in the PCEA group. Although incidence of delirium was comparable in the PCA and PCEA groups (24% vs. 26%, respectively), mental status was improved on the fourth and fifth postoperative days in the PCEA group. The PCEA group recovered bowel function more quickly than did the PCA group. Cardiopulmonary complications were similar in the two groups. Conclusion After major abdominal surgery in the elderly patient, patient-controlled analgesia, regardless of the route (epidural or parenteral), is effective. The epidural route using local anesthetics and an opioid provides better pain relief and improves mental status and bowel activity.
TL;DR: The use of prophylactic antiemetic therapy in high-risk ambulatory surgical patients was more effective in preventing PONV and achieved greater patient satisfaction at a lower cost compared with placebo.
Abstract: Background:In an era of growing economic constraints on healthcare delivery, anesthesiologists are increasingly expected to understand cost analysis and evaluate clinical practices. Postoperative nausea and vomiting (PONV) are distressing for patients and may increase costs in an ambulatory surgical
TL;DR: The ProSeal laryngeal mask airway is capable of achieving a more effective seal than the LMA and facilitates gastric tube placement, but it is more difficult to insert unless an introducer tool is used.
Abstract: Background: The ProSeal laryngeal mask airway (PLMA) is a new laryngeal mask device with a modified cuff to improve seal and a drainage tube to provide a channel for regurgitated fluid and gastric tube placement. In the present randomized, crossover study, the authors tested the hypothesis that ease of insertion, airway sealing pressure, and fiberoptic position differ between the PLMA and the standard laryngeal mask airway (LMA). For the PLMA, we also assess ease of gastric tube placement and the efficacy of an introducer tool. Methods: Sixty paralyzed, anesthetized adult patients were studied. Both devices (only size 4) were inserted into each patient in random order. Airway sealing pressure and fiberoptic position were determined during cuff inflation from 0 to 40 ml in 10-ml increments. Gastric tube insertion was attempted with the PLMA if there was no gas leak from the drainage tube. In 60 additional patients, ease of insertion for the PLMA was compared with and without an introducer. Results: First-time success rates were higher (60 of 60 vs. 52 of 60; P = 0.003) and the effective airway time shorter (9 ± 3 s vs 20 ± 18 s; P < 0.0001) for the LMA. There were no failed uses of either device within three attempts. Airway sealing pressure was 8-11 cm HO higher for the PLMA at all cuff volumes (P < 0.00001) and was higher in females for both devices. Fiberoptic position was better with the LMA at all cuff volumes (P < 0.00001), but vocal cord visibility was similar (LMA, 59 of 60; PLMA, 56 of 60). For the PLMA, gastric tube placement was successful in 58 of 58 patients and took 9 ± 5 s. First-time success rates were higher (59 of 60 vs 53/60; P = 0.03) and the effective airway time shorter (15 ± 13 s vs 23 ± 18 s; P = 0.008) with the introducer. Conclusion: The PLMA is capable of achieving a more effective seal than the LMA and facilitates gastric tube placement, but it is more difficult to insert unless an introducer tool is used. When correctly positioned, the PLMA isolates the glottis from the upper esophagus with possible implications for airway protection.
TL;DR: Both intensity and unpleasantness of the noxious stimuli are reduced during the hypnotic state, and hypnotic modulation of pain is mediated by the anterior cingulate cortex.
Abstract: BACKGROUND: The neural mechanisms underlying the modulation of pain perception by hypnosis remain obscure. In this study, we used positron emission tomography in 11 healthy volunteers to identify the brain areas in which hypnosis modulates cerebral responses to a noxious stimulus. METHODS: The protocol used a factorial design with two factors: state (hypnotic state, resting state, mental imagery) and stimulation (warm non-noxious vs. hot noxious stimuli applied to right thenar eminence). Two cerebral blood flow scans were obtained with the 15O-water technique during each condition. After each scan, the subject was asked to rate pain sensation and unpleasantness. Statistical parametric mapping was used to determine the main effects of noxious stimulation and hypnotic state as well as state-by-stimulation interactions (i.e., brain areas that would be more or less activated in hypnosis than in control conditions, under noxious stimulation). RESULTS: Hypnosis decreased both pain sensation and the unpleasantness of noxious stimuli. Noxious stimulation caused an increase in regional cerebral blood flow in the thalamic nuclei and anterior cingulate and insular cortices. The hypnotic state induced a significant activation of a right-sided extrastriate area and the anterior cingulate cortex. The interaction analysis showed that the activity in the anterior (mid-)cingulate cortex was related to pain perception and unpleasantness differently in the hypnotic state than in control situations. CONCLUSIONS: Both intensity and unpleasantness of the noxious stimuli are reduced during the hypnotic state. In addition, hypnotic modulation of pain is mediated by the anterior cingulate cortex. Language: en
TL;DR: Partial neuromuscular paralysis caused by atracurium is associated with a four- to fivefold increase in the incidence of misdirected swallowing and the mechanism behind the pharyngeal dysfunction is a delayed initiation of the swallowing reflex, impaired pharynGEal muscle function, and impaired coordination.
Abstract: BACKGROUND: Residual neuromuscular block caused by vecuronium alters pharyngeal function and impairs airway protection. The primary objectives of this investigation were to radiographically evaluate the swallowing act and to record the incidence of and the mechanism behind pharyngeal dysfunction during partial neuromuscular block. The secondary objective was to evaluate the effect of atracurium on pharyngeal function. METHODS: Twenty healthy volunteers were studied while awake during liquid-contrast bolus swallowing. The incidence of pharyngeal dysfunction was studied by fluoroscopy. The initiation of the swallowing process, the pharyngeal coordination, and the bolus transit time were evaluated. Simultaneous manometry was used to document pressure changes at the tongue base, the pharyngeal constrictor muscles, and the upper esophageal sphincter. After control recordings, an intravenous infusion of atracurium was administered to obtain train-of-four ratios (T4/T1) of 0.60, 0.70, and 0.80, followed by recovery to a train-of-four ratio of more than 0.90. RESULTS: The incidence of pharyngeal dysfunction was 6% during the control recordings and increased (P < 0.05) to 28%, 17%, and 20% at train-of-four ratios 0.60, 0.70, and 0.80, respectively. After recovery to a train-of-four ratio of more than 0.90, the incidence was 13%. Pharyngeal dysfunction occurred in 74 of 444 swallows, the majority (80%) resulting in laryngeal penetration. The initiation of the swallowing reflex was impaired during partial paralysis (P = 0.0081). The pharyngeal coordination was impaired at train-of-four ratios of 0.60 and 0.70 (P < 0.01). A marked reduction in the upper esophageal sphincter resting tone was found, as well as a reduced contraction force in the pharyngeal constrictor muscles. The bolus transit time did not change significantly. CONCLUSION: Partial neuromuscular paralysis caused by atracurium is associated with a four- to fivefold increase in the incidence of misdirected swallowing. The mechanism behind the pharyngeal dysfunction is a delayed initiation of the swallowing reflex, impaired pharyngeal muscle function, and impaired coordination. The majority of misdirected swallows resulted in penetration of bolus to the larynx. (Less)
TL;DR: PPIA in addition to 0.5 mg/kg oral midazolam has no additive effects in terms of reducing a child’s anxiety and parents who accompanied their children to the operating room were less anxious and more satisfied.
Abstract: Background:Although some anesthesiologists use oral sedatives or parental presence during induction of anesthesia (PPIA) to treat preoperative anxiety in children, others may use these interventions simultaneously (e.g., sedatives and PPIA). The purpose of this investigation was to determine whether
TL;DR: The aim of the this article is to review efficacy and risks of allogeneic red blood cell transfusions and blood conservation techniques to enable the anesthesiologist to choose the techniques with the lowest risk for his or her patient.
Abstract: ALLOGENEIC blood transfusions are associated with risks.' As a result, a variety of blood conservation techniques have been developed, but these techniques are also not risk free.2 The aim of the this article is to review efficacy and risks of allogeneic red blood cell (RBC) transfusions and blood conservation techniques to enable the anesthesiologist to choose the techniques with the lowest risk for his or her patient.
TL;DR: ICH after craniotomy is associated with severely prolonged hospital stay and mortality, and patients who develop postcraniotomy ICH are more likely to be hypertensive in the intraoperative and early postoperative periods.
Abstract: BackgroundPrevious data suggest that systemic hypertension (HTN) is a risk factor for postcraniotomy intracranial hemorrhage (ICH). The authors examined the relation between perioperative blood pressure elevation and postoperative ICH using a retrospective case control design.MethodsThe hospital’s d
TL;DR: Effect compartment–controlled TCI can be safely applied in clinical practice and accurately predicted the time course of propofol drug effect, as measured by the bispectral index.
Abstract: Background: Target-controlled infusion (TCI) systems can control the concentration in the plasma or at the site of drug effect. A TCI system that targets the effect site should be able to accurately predict the time course of drug effect. The authors tested this by comparing the performance of three control algorithms: plasma-control TCI versus two algorithms for effect-site control TCI, Methods: One-hundred twenty healthy women patients received propofol via TCI for 12-min at a target concentration of 5.4 mu g/ml, In all three groups, the plasma concentrations mere computed using pharmacokinetics previously reported. In group I, the TCI device controlled the plasma concentration. In groups II and III, the TCI device controlled the effect-site concentration. In group II, the effect site was computed using a half-life for plasma effect-site equilibration (t(1/2) k(eo)) of 3.5 min. In group m, plasma effect-site equilibration rate constant (k(eo)) was computed to yield a time to peak effect of 1.6 min after bolus injection, yielding a t(1/2), k(eo) of 34 s, the time course of propofol was measured using the bispectral index, Blood pressure, ventilation, and time of loss of consciousness were measured. Results The time course of propofol drug effect, as measured by the bispectral index, was best predicted in group III. Targeting the effect-site concentration shortened the time to loss of consciousness compared with the targeting plasma concentration without causing hypotension. The incidence of apnea was less in group III than in group II. Conclusion: Effect compartment-controlled TCI can be safely applied in clinical practice. A biophase model combining the Marsh kinetics and a time to peak effect of 1.6 min accurately predicted the time course of propofol drug effect.