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Showing papers in "Anesthesia & Analgesia in 1997"


Journal ArticleDOI
TL;DR: Body mass, duration of anesthesia, and certain types of surgery were significant predictors of pain in the postanesthesia care unit and will allow us to better predict those patients who need intense prophylactic analgesic therapy.
Abstract: Postoperative pain is a common reason for the delayed discharge and unanticipated hospital admission of outpatients.In this study, we examined the pattern of pain in ambulatory surgical patients and determined those factors that predict postoperative pain. Ten thousand eight consecutive ambulatory surgical patients were prospectively studied. Preoperative patient characteristics, intraoperative variables, and pain in the postanesthesia care unit (PACU) and the ambulatory surgical unit (ASU) and 24 h postoperatively were documented. The incidence of severe pain was 5.3% in the PACU, 1.7% in the ASU, and 5.3% 24 h postoperatively. In the PACU, younger male adults (36 +/- 13 vs 47 +/- 22 yr), ASA physical status I patients, and patients with a higher body mass index (26 +/- 5 vs 25 +/- 5 kg) had a higher incidence of severe pain. In the group with severe pain, the duration of anesthesia, the duration of stay in the PACU and the ASU, and the time to discharge was longer than in the group without severe pain. In the PACU, orthopedic patients had the highest incidence of pain (16.1%), followed by urologic (13.4%), general surgery (11.5%), and plastic surgery (10.0%) patients. In patients who had general anesthesia, the intraoperative dose of fentanyl was significantly smaller in the group with severe pain than in the group without severe pain when body mass index and duration of anesthesia were taken into consideration. Body mass index, duration of anesthesia, and certain types of surgery were significant predictors of severe pain in the PACU. This knowledge will allow us to identify those patients at risk of severe postoperative pain and manage them prophylactically. Implications: The pattern of pain was examined in 10,008 consecutive ambulatory surgical patients. The incidence of severe pain was 5.3% in the postanesthesia care unit, 1.7% in the ambulatory surgical unit, and 5.3% 24 h postoperatively. Body mass, duration of anesthesia, and certain types of surgery were significant predictors of pain in the postanesthesia care unit. These data will allow us to better predict those patients who need intense prophylactic analgesic therapy. (Anesth Analg 1997;85:808-16)

483 citations


Journal ArticleDOI
TL;DR: The BIS index appears to be a useful variable for assessing the depth of propofol-induced sedation and amnesia during regional anesthesia as increasing depth of sedation was associated with a significant decrease in intraoperative picture recall.
Abstract: The bispectral (BIS) index and 95% spectral edge frequency (SEF) of the electroencephalograph (EEG) have been used to study the anesthetic and sedative effects of intravenously (i.v.) administered drugs. This prospective study was designed to evaluate the effectiveness of the BIS index and 95% SEF for assessing the level of propofol-induced sedation and amnesia during regional anesthesia. Ten consenting adult patients undergoing surgery with regional anesthesia were administered propofol in increments of 10-20 mg i.v., every 5-10 min until they became unresponsive to tactile stimulation (i.e., mild prodding or shaking). The BIS index and 95% SEF were continuously recorded from a bifrontal montage (Fp1-Cz and Fp2-Cz) using the Aspect B500 monitor. The depth of sedation was assessed clinically at 5- to 10-min intervals using the observer's assessment of alertness/sedation (OAA/S) scale, with 1 = no response to tactile stimulation to 5 = wide awake. Each patient was shown a picture of an animal (cat) prior to administration of an initial dose of propofol, 40 mg i.v.. Subsequently, patients were administered intermittent bolus doses of propofol, 10-20 mg i.v., and shown different pictures upon achieving OAA/S scores of 4, 3, and 2 during the onset of and recovery from propofol-induced sedation. Picture recall was tested upon arrival of the patient in the postanesthesia care unit (PACU). Of the two EEG variables studied, the BIS index exhibited a better correlation with the OAA/S scores during both the onset (Spearman's rho = 0.744) and recovery (Spearman's rho = 0.705) phases of propofol-induced sedation. With the increasing depth of sedation, there was a progressive decrease in the BIS index (OAA/S score of 5, BIS = 94.5 +/- 2.9; 4, 93.3 +/- 3.3; 3, 89 +/- 6.1; 2, 80.1 +/- 8.7; 1, 75.6 +/- 7.5; mean +/- SD). Conversely, there was a progressive increase in the BIS value during recovery from propofol sedation (OAA/S score of 1, BIS = 75.6 +/- 7.5; 2, 82.4 +/- 10.5; 3, 84.9 +/- 5.9; 4, 93.8 +/- 0.8). Although the changes in the 95% SEF values were less consistent during the onset phase, this EEG variable increased from 16.4 +/- 5.0 to 19.3 +/- 5.6 as the OAA/S score increased from 1 to 4 during the recovery phase. Patient recall of the intraoperative pictures decreased with increasing depth of sedation and decreasing BIS values (OAA/S:% BIS:% recall = 5:94.5 +/- 2.9:100%; 4:93.4 +/- 3:63%; 3:87.3 +/- 6.1:40%; 2:80.8 +/- 8.3:0%; 1:75.6 +/- 7.5:0%). The BIS index appears to be a useful variable for assessing the depth of propofol-induced sedation. Increasing depth of sedation was associated with a significant decrease in intraoperative picture recall.

479 citations


Journal ArticleDOI
TL;DR: This study demonstrates that dosing anesthetic drugs to lower BIS values achieves a lower probability of movement in response to surgical stimulation.
Abstract: Bispectral analysis (BIS) of the electroencephalogram (EEG) has been shown in retrospective studies to predict whether patients will move in response to skin incision. This prospective multicenter study was designed to evaluate the real-time utility of BIS in predicting movement response to skin incision using a variety of general anesthetic techniques. Three hundred patients from seven study sites received an anesthetic regimen expected to give an approximately 50% movement response at skin incision. EEG was continuously recorded via an Aspect B-500 monitor and BIS was calculated in real time from bilateral frontocentral channels displayed on the monitor. Half of the patients were randomized to a treatment group in which anesthetic drug doses were increased to produce a lower BIS. In the control group, BIS was recorded, but no action taken on the data displayed. A determination of movement in response to skin incision was made in the 2 min succeeding incision. Retrospective pharmacodynamic modeling was performed using STANPUMP to estimate effect-site concentrations of intravenously administered anesthetics. BIS values were significantly higher in the control group (66 +/- 19) versus the BIS-guided group, in which additional anesthesia was administered to produce a lower BIS (51 +/- 19). The movement response rate was significantly higher in the control group at 43% compared with 13% in the BIS-guided group, but response rates were low at sites which used larger doses of opioids. Logistic regression analysis showed that BIS, estimated opioid effect-site concentrations, and heart rate (in that order) were the best predictors of movement at skin incision. This study demonstrates that dosing anesthetic drugs to lower BIS values achieves a lower probability of movement in response to surgical stimulation. BIS is a significant predictor of patient response to incision, but the utility of the BIS depends on the anesthetic technique being used. When drugs such as propofol or isoflurane are used as the primary anesthetic, changes in BIS correlate with the probability of response to skin incision. When opioid analgesics are used, the correlation to patient movement becomes much less significant, so that patients with apparently "light" EEG profiles may not move or otherwise respond to incision. Therefore, the adjunctive use of opioid analgesics confounds the use of BIS as a measure of anesthetic adequacy when movement response to skin incision is used as the primary end point.

469 citations


Journal ArticleDOI
TL;DR: This article developed an instrument (Yale Preoperative Anxiety Scale [YPAS]) that can be used to evaluate the effectiveness of interventions directed toward the treatment of preoperative anxiety in children.
Abstract: Evaluating the effectiveness of interventions directed toward the treatment of preoperative anxiety in children has been hindered by the absence of a statistically valid measurement tool.In a previous investigation, we developed an instrument (Yale Preoperative Anxiety Scale [YPAS]) that can be used

441 citations


Journal ArticleDOI
TL;DR: It is concluded that an US-guided approach for 3-in-1 block reduces the onset time, improves the quality of the sensory block and minimizes the risks associated with this regional anesthetic technique.
Abstract: The use of ultrasound reduces the onset time, improves the quality of sensory block, and minimizes the risks associated with the supraclavicular approach for brachial plexus and stellate ganglion blockade. The present study was designed to evaluate whether ultrasound also facilitates the approach for 3-in-1 blocks. Forty patients (ASA physical status II or III) undergoing hip surgery after trauma were randomly assigned to two groups. In the ultrasound (US) group, 20 mL bupivaCaine 0.5% was administered under US guidance, whereas in the control group, the same amount and concentration of local anesthetic was administered with the assistance of a nerve stimulator (NS). After US- or NS-based identification of the femoral nerve, the local anesthetic solution was administered, and the distribution of the local anesthetic solution was visualized and recorded on videotape in the US group. The quality and the onset of the sensory block was assessed by using the pinprick test in the central sensory region of each of the three nerves and compared with the same stimulation on the contralateral leg every 10 min for 60 min. The rating was performed using a scale from 100% (uncompromised sensibility) to 0% (no sensory sensation). Heart rate, noninvasive blood pressure, and oxygen saturation were measured at short intervals for 60 min. The onset of sensory blockade was significantly shorter in Group US compared with Group NS (US 16 ? 14 min, NS 27 -C 16 min, P < 0.05). The quality of the sensory block after injection of the local anesthetic was also significantly better in Group US compared with Group NS (US 15% -C 10% of initial value, NS 27% + 14% of initial value, P < 0.05). A good analgesic effect was achieved in 95% of the patients in the US group and in 85% of the patients in the NS group. In the US group, visualization of the cannula tip, the femoral nerve, the major vessels, and the local anesthetic spread was possible in 85% of patients. Incidental arterial puncture (n = 3) was observed only in the NS group. We conclude that an USguided approach for 3-in-1 block reduces the onset time, improves the quality of the sensory block and minimizes the risks associated with this regional anesthetic technique. Implications: The onset time and the quality of a regional anesthetic technique for the lower extremity is improved by ultrasonographic nerve identification compared with older techniques. (Anesth Analg 1997;85:854-7) he 3-in-1 block, including the femoral nerve, the obturator nerve, and the lateral cutaneous femoral nerve, is a widely used regional anesthetic technique for many operations and for pain management of the lower extremity. Indications for the 3-in-1 block include operations and wound care of the thigh, muscle biopsy of the thigh, obturator paralysis for transurethral resection of the prostate and urinary bladder, and, in combination with the sciatic nerve block, all operations for one lower limb. For analgesic therapy, the 3-in-1 block can be used for hip fractures, stump pain after amputation of lower limb, and mobilization therapy of the knee and hip joint.

419 citations


Journal ArticleDOI
TL;DR: The purpose of this review is to examine the recent developments in understanding of the pathophysiological mechanisms responsible for this response, the treatment modalities that have been used to ameliorate it, and the possible implications for the conduct of anesthesia for cardiac surgery.
Abstract: C ardiac surgery and cardiopulmonary bypass (CPB) activate a systemic inflammatory response characterized clinically by alterations in cardiovascular and pulmonary function. Significant morbidity is rare (approximately l%-2% of cases), but when severe acute lung injury occurs, mortality is high (50%-70%) (1). H owever, most patients undergoing CPB experience some degree of organ dysfunction as a result of activation of the inflammatory response. The purpose of this review is to examine the recent developments in our understanding of the pathophysiological mechanisms responsible for this response, the treatment modalities that have been used to ameliorate it, and the possible implications of these findings for the conduct of anesthesia for cardiac surgery.

380 citations


Journal ArticleDOI
TL;DR: In this paper, meta-analyses of randomized trials evaluating the efficacy and safety of aprotinin, desmopressin, tranexamic acid, and epsilon-aminocaproic a
Abstract: Concern about the side effects of allogeneic red blood cell transfusion has increased interest in methods of minimizing perioperative transfusion.We performed meta-analyses of randomized trials evaluating the efficacy and safety of aprotinin, desmopressin, tranexamic acid, and epsilon-aminocaproic a

333 citations


Journal ArticleDOI
TL;DR: It is concluded that short-term tranexamic acid therapy significantly reduces TKA-associated blood loss and transfusion requirements without increasing thromboembolic complications.
Abstract: The application of a pneumatic tourniquet in orthopedic procedures enhances local fibrinolysis. Consequently, a short-term antifibrinolytic therapy may be indicated in this clinical situation to reduce postoperative blood loss. The purpose of this prospective double-blind study was to investigate the effect of tranexamic acid (TA) on blood loss associated with total knee arthroplasty (TKA). Seventy-five patients scheduled for 77 TKAs were randomized to receive either TA (n = 39) or equal volume of normal saline (NS, n = 38). Before deflation of the tourniquet, 15 mg/kg of TA was given intravenously followed by two 10-mg/kg additional doses. Perioperative blood loss gathered in surgical gauzes, suction reservoirs, and postoperative drainage system was measured. The number of transfusions given during hospitalization was registered. Total blood loss (mean +/- SD) was 689 +/- 289 mL in the TA group and 1509 +/- 643 mL in the NS group (P < 0.0001). The mean number of transfused red cell units in the TA group was 1.0 +/- 1.2 compared to 3.1 +/- 1.6 in the NS group (P < 0.0001). Twenty-two patients in the TA group and four patients in the NS group were treated without transfusion (P < 0.00003). Two patients in the TA group and three in the NS group had a deep venous thrombosis, including a fatal case of pulmonary embolism in the NS group. We conclude that short-term TA therapy significantly reduces TKA-associated blood loss and transfusion requirements without increasing thromboembolic complications.

304 citations


Journal ArticleDOI
TL;DR: A quality assurance study prospectively completed for 1140 children sedated for procedures by nonanesthesiologists highlights the risks associated with the sedation of children and emphasizes the importance of appropriate monitoring by trained personnel.
Abstract: After implementation of hospital-wide monitoring standards, a quality assurance (QA) tool was prospectively completed for 1140 children (aged 2.96 +/- 3.7 yr) sedated for procedures by nonanesthesiologists. The tool captured data regarding demographics, medications used, adequacy of sedation, monito

294 citations


Journal ArticleDOI
TL;DR: It is concluded that infusion of dexmedetomidine by CCIP using published pharmacokinetic parameters overshoots target plasma dexmedetic concentrations during the early postoperative period and heart rate, blood pressure, and plasma catecholamine concentrations decrease during dexmedettomidine infusion.
Abstract: Dexmedetomidine is a selective alpha2-adrenoceptor agonist with centrally mediated sympatholytic, sedative, and analgesic effects. This study evaluated: 1) pharmacokinetics of dexmedetomidine in plasma and cerebrospinal fluid (CSF) in surgical patients; 2) precision of a computer-controlled infusion

279 citations


Journal ArticleDOI
TL;DR: A retrospective review of 4767 consecutive spinal anesthetics performed between June 1987 and June 1990 shows the continued safety of spinal anesthesia.
Abstract: Serious neurologic complications rarely occur after spinal anesthesia. Historically, the reported frequency of persistent sensory or motor deficits has ranged from 0.005% to 0.7%. However, the introduction of small-gauge needles and new local anesthetics and intrathecal adjuvants makes it necessary to reevaluate the frequency of neurologic complications after spinal anesthesia. This study is a retrospective review of 4767 consecutive spinal anesthetics performed between June 1987 and June 1990. Mean patients age was 65 +/- 15 yrs. There were 3560 (74.7%) men and 1207 (25.3%) women. A preexisting neurologic condition was present in 481 (10.1%) cases. The surgical procedures were genitourinary and lower extremity orthopedic in 4348 (91.2%) cases. A paresthesia was elicited during needle placement in 298 (6.3%) cases. Six patients reported pain upon resolution of the spinal anesthetic (persistent paresthesia). Four persistent paresthesias resolved within 1 wk; the remaining two resolved in 18-24 mo. The presence of a paresthesia during needle placement significantly increased the risk of persistent paresthesia (P < 0.001). There, were also two infectious complications. One patient with recent (treated) urosepsis underwent a urologic procedure under spinal anesthesia and subsequently developed a disc space infection. The second patient developed a paraspinal abscess. Both were treated with surgical drainage and antibiotics and remained neurologically intact. There were 62 (1.3%) patients with a postdural puncture headache, including 23 (0.5%) who underwent an epidural blood patch. These results are similar to those of previously published reviews and demonstrate the continued safety of spinal anesthesia.

Journal ArticleDOI
TL;DR: It is demonstrated that a suprascapular nerve block for pain relief in arthroscopic shoulder surgery is an effective and safe modality of postoperative pain relief.
Abstract: Arthroscopic shoulder surgery has a 45% incidence of severe postoperative pain. Opiates and interscalene nerve blocks have a high incidence of side effects, and intraarticular local anesthetic has been shown to be ineffective when used for postoperative pain relief. The suprascapular nerve supplies 70% of the sensory nerve supply to the shoulder joint, and local anesthetic block of this nerve is effective in certain shoulder pain disorders. To determine the efficacy of a suprascapular nerve block, subcutaneous saline was compared with a suprascapular nerve block using 10mL of 0.5% bupivacaine with 1:200,000 epinephrine before general anesthesia was induced. In the immediate postoperative period, a 51% reduction in demand and a 31% reduction in consumption of morphine delivered by a patient-controlled analgesic system was demonstrated. There was more than fivefold reduction in the incidence of nausea, as well as reduced visual analog and verbal pain scores for patients who received a suprascapular nerve block. The duration of hospital stay was reduced by 24% in the suprascapular nerve block group. A 24-h phone call interview revealed a 40% reduction in analgesic consumption and a reduction in verbal pain scores at rest and on abduction. There were no complications from the suprascapular nerve block. This study demonstrates that a suprascapular nerve block for pain relief in arthroscopic shoulder surgery is an effective and safe modality of postoperative pain relief.

Journal ArticleDOI
TL;DR: Production of acylated proteins may be an important mediator of anesthetic-induced hepatotoxicity, as shown in rats exposed to halothane or enflurane, and reported relative rates of metabolism.
Abstract: In susceptible patients, halothane, enflurane, isoflurane, and desflurane can produce severe hepatic injury by an immune response directed against reactive anesthetic metabolites covalently bound to hepatic proteins. The incidence of hepatotoxicity appears to directly correlate with anesthetic metabolism catalyzed by cytochrome P450 2E1 to trifluoroacetylated hepatic proteins. In the present study, we examined whether the extent of acylation of hepatic proteins in rats by halothane, enflurane, isoflurane, and desflurane correlated with reported relative rates of metabolism. After pretreatment with the P450 2E1 inducer isoniazid, five groups of 10 rats breathed 1.25 minimum alveolar anesthetic concentration (MAC) of halothane, enflurane, isoflurane, or desflurane in oxygen, or oxygen alone, each for 8 h. Immunochemical analysis of livers harvested 18 h after anesthetic exposure showed tissue acylation (greatest to least) after exposure to halothane, enflurane, or isoflurane. Reactivity was not different between isoflurane as compared to desflurane or oxygen alone. An enzyme-linked immunosorbent assay showed halothane reactivity was significantly greater than that of enflurane, isoflurane, desflurane, or oxygen, and that enflurane reactivity was significantly greater than desflurane or oxygen. Sera from patients with a clinical diagnosis of halothane hepatitis showed antibody reactivity against hepatic proteins from rats exposed to halothane or enflurane. No reactivity was detected in rats exposed to isoflurane, desflurane, or oxygen alone. These results indicate that production of acylated proteins may be an important mediator of anesthetic-induced hepatotoxicity.

Journal ArticleDOI
TL;DR: In this paper, the authors provided guidelines for minimizing the risk of spinal hematoma in patients undergoing regional anesthesia while receiving perioperative anticoagulant-based prophylaxis.
Abstract: M ultiple randomized clinical trials have established the efficacy of standard heparin (SH) anticoagulation for venous thromboembolism prophylaxis. However, for high-risk populations, such as patients undergoing total hip or knee replacement, SH is relatively ineffective and may be associated with significant bleeding complications (1). Initial animal model studies suggested that low molecular weight fractions of heparin, when administered at equivalent antithrombotic doses, caused less bleeding than SH (2). These early studies raised the exciting possibility of separating the antithrombotic from the bleeding effects of heparin. The efficacy and safety of low molecular weight heparins (LMWH) as postoperative venous thromboembolism prophylaxis subsequently has been demonstrated in more than 60 clinical trials including more than 20,000 patients (3). However, reports of spinal hematoma occurring spontaneously and in association with regional anesthesia (4,5) have generated concern regarding the safety of spinal or epidural anesthesia in patients receiving LMWH. In this review, we focus on the biochemistry and pharmacology of LMWH compared with SH, current LMWH prophylaxis regimens, and the implications of perioperative LMWH prophylaxis for anesthesia, particularly among patients receiving regional anesthesia and analgesia. Guidelines will be provided for minimizing the risk of spinal hematoma in patients undergoing regional anesthesia while receiving perioperative anticoagulant-based prophylaxis.

Journal ArticleDOI
TL;DR: The quality of analgesia obtained with thoracic epidural anesthetic techniques is sufficient to allow cardiac surgery to be performed in awake patients without general endotracheal anesthesia, and increased risk of hematoma formation in this scenario has generated much of lively debate regarding the acceptable risk-benefit ratio.
Abstract: Adequate postoperative analgesia prevents unnecessary patient discomfort. It may also decrease morbidity, postoperative hospital length of stay and, thus, cost. Achieving optimal pain relief after cardiac surgery is often difficult. Many techniques are available, and all have specific advantages and disadvantages. Intrathecal and epidural techniques clearly produce reliable analgesia in patients undergoing cardiac surgery. Additional potential benefits include stress response attenuation and thoracic cardiac sympathectomy. The quality of analgesia obtained with thoracic epidural anesthetic techniques is sufficient to allow cardiac surgery to be performed in awake patients without general endotracheal anesthesia. However, applying regional anesthetic techniques to patients undergoing cardiac surgery is not without risk. Side effects of local anesthetics (hypotension) and opioids (pruritus, nausea/vomiting, urinary retention, and respiratory depression), when used in this manner, may complicate perioperative management. Increased risk of hematoma formation in this scenario has generated much of lively debate regarding the acceptable risk-benefit ratio of applying regional anesthetic techniques to patients undergoing cardiac surgery.

Journal ArticleDOI
TL;DR: It is concluded that high-TAES produced a significant decrease in the PCA opioid requirement and opioid-related side effects after low intraabdominal surgery.
Abstract: Given the inherent side effects associated with both opioid and nonopioid analgesic drugs, a nonpharmacologic therapy that could decrease the need for analgesic medication would be valuable. We designed a sham-controlled study to assess the effect of the intensity of transcutaneous acupoint electrical stimulation (TAES) on postoperative patient-controlled analgesia (PCA) requirement for hydromorphone (HM), the incidence of opioid-related side effects, and the recovery profile after lower abdominal surgery. One hundred one healthy consenting women undergoing lower abdominal procedures with a standardized general anesthetic technique were randomly assigned to one of four postoperative analgesic treatment regimens: Group I (n = 26) PCA only; Group II (n = 25), PCA + sham-TAES (no electrical stimulation); Group III (n = 25), PCA + low-TAES (4-5 mA of electrical stimulation); Group IV (n = 25), PCA + high-TAES (9-12 mA of electrical stimulation). The PCA device was programmed to deliver HM, 0.2-0.4 mg intravenously boluses "on demand," with a minimum lockout interval of 10 min. The TAES skin electrodes were placed at the Hegu acupoint on the nondominant hand and on both sides of the surgical incision. The TAES frequency was set in the dense-and-disperse mode, alternating at 2 Hz and 100 Hz every 3 s, with stimulation of the hand and incision alternated every 6 s. The patients in Groups II-IV were instructed to use TAES every 2 h for 30 min while awake. After discontinuation of PCA, oral pain medications were administered on demand. The postoperative PCA-HM requirement, pain scores, opioid-related side effects, and requirements for antiemetic and antipruritic medication were recorded. High-TAES decreased the HM requirement by 65% and reduced the duration of PCA therapy, as well as the incidence of nausea, dizziness, and pruritus. Low-TAES produced a 34% decrease in the HM requirement compared with only 23% in the "sham" TAES group. We conclude that high-TAES produced a significant decrease in the PCA opioid requirement and opioid-related side effects after low intraabdominal surgery.

Journal ArticleDOI
TL;DR: Sevoflurane was associated with transient injury to: 1) the glomerulus, as revealed by postanesthetic albuminuria; 2) the proximal tubule, as shown by post-anesthetic glucosuria and increased urinary alpha-GST; and 3) the distal tubules, as Revealed by post anesthetic increased urinary pi-G ST.
Abstract: Present package labeling for sevoflurane recommends the use of fresh gas flow rates of 2 L/min or more when delivering anesthesia with sevoflurane. This recommendation resulted from a concern about the potential nephrotoxicity of a degradation product of sevoflurane, "Compound A," produced by the action of carbon dioxide absorbents on sevoflurane. To assess the adequacy of this recommendation, we compared the nephrotoxicity of 8 h of 1.25 minimum alveolar anesthetic concentration (MAC) sevoflurane (n = 10) versus desflurane (n = 9) in fluid-restricted (i.e., nothing by mouth overnight) volunteers when the anesthetic was given in a standard circle absorber anesthetic system at 2 L/min. Subjects were tested for markers of renal injury (urinary albumin, glucose, alpha-glutathione-S-transferase [GST], and pi-GST; and serum creatinine and blood urea nitrogen [BUN]) before and 1, 2, 3, and/or 5-7 days after anesthesia. Desflurane did not produce renal injury. Rebreathing of sevoflurane produced average inspired concentrations of Compound A of 41 +/- 3 ppm (mean +/- SD). Sevoflurane was associated with transient injury to: 1) the glomerulus, as revealed by postanesthetic albuminuria; 2) the proximal tubule, as revealed by postanesthetic glucosuria and increased urinary alpha-GST; and 3) the distal tubule, as revealed by postanesthetic increased urinary pi-GST. These effects varied greatly (e.g., on postanesthesia Day 3, the 24-h albumin excretion was < 0.03 g (normal) for one volunteer; 0.03-1 g for five others; 1-2 g for two others; 2.1 g for one volunteer; and 4.4 g for another volunteer). Neither anesthetic affected serum creatinine or BUN, nor changed the ability of the kidney to concentrate urine in response to vasopressin, 5 U/70 kg subcutaneously (i.e., these measures failed to reveal the injury produced). In addition, sevoflurane, but not desflurane, caused small postanesthetic increases in serum alanine aminotransferase (ALT), suggesting mild, transient hepatic injury.

Journal ArticleDOI
TL;DR: Multivariable analysis revealed that HMO penetration is an independent predictor for the use of premedicants among adults and children, and under-scores the lack of consensus among anesthesiologists about the need for premedication.
Abstract: We undertook a mailing survey study to assess the current practice of sedative premedication in anesthesia. A total of 5396 questionnaires were mailed to randomly selected physician members of the American Society of Anesthesiologists. Forty-six percent (n = 2421) of those sampled returned the questionnaire after two mailings. The reported rate of sedative premedication in the United States varied widely among age groups and geographical locations. Premedicant sedative drugs were least often used with children younger than age 3 years and most often used with adults less than 65 years of age (25% vs 75%, P = 0.001). Midazolam was the most frequently used premedicant both in adults and children (> 75%). When analyzed based on geographical locations, use of sedative premedicants among adults was least frequent in the Northeast region and most frequent in the Southeast region (50% vs 90%, P = 0.001). When the frequency of premedication was examined against health maintenance organization (HMO) penetration (i.e., HMO enrollment by total population) in the various geographical regions, correlation coefficients (r) ranged from -0.96 to -0.54. Multivariable analysis revealed that HMO penetration is an independent predictor for the use of premedication in adults and children. The marked variation among geographical areas in premedicant usage patterns underscores the lack of consensus among anesthesiologists about the need for premedication. The data suggest that HMO participation may affect delivery of this component of anesthetic care.

Journal ArticleDOI
TL;DR: Small doses of fentanyl or sufentanil (synthetic opioids) added to bupivacaine (local anesthetic) for spinal anesthesia for cesarean section reduce the need for intraoperative antiemetic medication and increase the duration of analgesia in the early postoperative period compared with placebo.
Abstract: We compared the effects of intrathecal sufentanil 2.5 and 5 micro g, fentanyl 10 micro g, and placebo when administered together with hyperbaric bupivacaine 0.5% 12.5 mg for cesarean section. The study was performed in a randomized, double-blind fashion in 80 (20 per group) healthy, full-term partur

Journal ArticleDOI
TL;DR: Preemptive ketamine decreased postoperative opioid requirements, which was observed long after the normal expected duration of ketamine, according to anesth Analg 1997.
Abstract: The aim of this study was to determine if preemptive administration of systemic ketamine decreases postoperative pain when compared with postwound closure administration of ketamine.Patients undergoing abdominal procedures were randomized into a preemptive or postwound closure ketamine administration group. Before surgical incision, patients in the preemptive group (n = 20) were given 0.5 mg/kg ketamine followed by a ketamine infusion of 10 micro g [centered dot] kg-1 [centered dot] min-1, which was discontinued at abdominal closure. The patients in the postwound closure (n = 20) group were given 0.5 mg/kg of ketamine immediately after abdominal closure. Postoperatively, all patients received intravenous (IV) morphine in the postanesthesia care unit (PACU) and were started on IV morphine patient-controlled analgesia after discharge from the PACU. Postoperative pain was assessed by measuring morphine consumption and visual analog scale (0-100 mm) pain scores at rest. Patients in the preemptive group had significantly lower morphine consumption on postoperative Days 1 and 2. No significant intergroup differences were seen in the pain scores throughout the study period. Preemptive ketamine decreased postoperative opioid requirements, which was observed long after the normal expected duration of ketamine. (Anesth Analg 1997;84:1086-90)

Journal ArticleDOI
TL;DR: In conclusion, CPSB is easy to perform, safe, and a more efficient technique than parenteral opioid for providing postoperative analgesia after foot surgery.
Abstract: Our study describes an original technique of continuous popliteal sciatic nerve block (CPSB) (Group A, 60 patients) and compares its analgesic efficacy after foot surgery with intramuscular (IM) opioids (Group B, 15 patients) and intravenous patient-controlled analgesia (IV PCA) with morphine (Group C, 45 patients). CPSB was performed using Singelyn's landmarks. The sciatic nerve was localized with a short-beveled needle connected to a peripheral nerve stimulator. A 20-gauge catheter was placed at the same depth as the needle with a Seldinger technique. Thirty milliliters of 1% mepivacaine with epinephrine 1/200,000 was injected and followed by a continuous infusion of 0.125% bupivacaine with sufentanil 0.1 microgram/mL and clonidine 1 microgram/mL at 7 mL/h for 48 h. Postoperative analgesia (intravenous [IV] propacetamol [PRO] and/or IM piritramide [DIPI]) was standardized. Postoperative pain score (PPS), supplemental analgesia, and side effects were noted. CPSB was easy to perform in 55 patients (92%). In Group A, highest and mean PPS were significantly lower, and the mean dose of PRO was reduced by 62% and 36% when compared with Group B and C, respectively. Only 8% of patients required postoperative opioid in Group A compared with 91% and 100% in Groups B and C, respectively. No immediate or delayed complications other than postoperative technical problems (kinked or broken catheter 25%) were noted in Group A. In conclusion, CPSB is easy to perform, safe, and a more efficient technique than parenteral opioid for providing postoperative analgesia after foot surgery.

Journal ArticleDOI
TL;DR: It is concluded that thyroid hormones possess direct vasodilatory effects with both endothelium-independent and endothelia-dependent components.
Abstract: The present study examines the hypothesis that the hormones have direct vasodilatory effects and attempts to determine whether the effects are endothelium-dependent. Rat skeletal muscle resistance arteries of approximately 100 micro m were dissected, and vessel diameter changes were monitored using a videodetection system. After equilibration at 37[degree sign]C, each vessel was preconstricted with the thromboxane analog U46619 1 micro M, and the percentage of dilation was measured after exposure to increasing concentrations of triiodothyronine (T3) or levothyroxine (T4) (10-10 to 10-7 M). Dilation in response to T3 was also measured after endothelial denudation and pretreatment with the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine (L-NNA) 10 micro M, the cyclooxygenase inhibitor indomethacin 10 micro M, the adenosine triphosphate-sensitive K+ channel blocker glibenclamide 1 micro M, or the beta-adrenergic antagonist propranolol 1 micro M. Both T3 and T4 demonstrated concentration-dependent dilation of the U46619-preconstricted vessels (P < 0.001 each), with T3 having a greater effect than T4 (P < 0.05) (36% +/- 9% [mean +/- SD] dilation at 10-7 M T3 vs 24% +/- 6% dilation at 10-7 M T4). In comparison, isoproterenol 10-7 M produced 56% +/- 6% dilation. T3-mediated vasodilation was attenuated but not abolished by endothelial denudation (18% +/- 3% dilation at 10-7 M T3) (P < 0.01), L-NNA (15% +/- 7% dilation at 10-7 M T3) (P < 0.01), indomethacin (20% +/- 9% dilation at 10-7 M T3) (P < 0.05), and glibenclamide (22% +/- 7% dilation at 10-7 M T3) (P < 0.01), but it was not affected by propranolol (37% +/- 20% dilation at 10-7 M T3) (P = 0.99). We conclude that thyroid hormones possess direct vasodilatory effects with both endothelium-independent and endothelium-dependent components. Implications: Thyroid hormones may have modest direct vasodilatory effects. This may partially account for the cardiovascular actions of the hormones in hyperthyroidism or when administered pharmacologically in cardiac surgery. (Anesth Analg 1997;85:734-8)

Journal ArticleDOI
TL;DR: It was demonstrated that children <8 kg had more bleeding and required more coagulation products than children >8 kg, and fresh-frozen plasma administration after platelets worsened coagulated parameters and was associated with greater chest tube drainage and more coAGulation product transfusions in the ICU.
Abstract: UNLABELLED Coagulopathies in children after cardiopulmonary bypass (CPB) are complex. There are very limited data correlating coagulation tests with postoperative bleeding. We evaluated coagulation changes after CPB and after the administration of coagulation products to 75 children. Baseline coagulation tests were obtained and repeated after protamine administration, after transfusion of individual coagulation products, and on arrival in the intensive care unit (ICU). Regression analysis demonstrated no baseline coagulation test to predict postoperative chest tube drainage. Weight and duration of CPB were determined to be the only predictors of bleeding. Further analyses demonstrated that children 8 kg. Postprotamine platelet count and fibrinogen level correlated independently with 24-h chest tube drainage in children 8 kg. Platelet administration alone was found to restore effective hemostasis in many patients. With ongoing bleeding, cryoprecipitate improved coagulation parameters and limited blood loss. Fresh-frozen plasma administration after platelets worsened coagulation parameters and was associated with greater chest tube drainage and more coagulation product transfusions in the ICU. Objective data to guide post-CPB component therapy transfusion in children are suggested. IMPLICATIONS Children <8 kg can be expected to have more severe coagulopathies, require more coagulation product transfusions, and bleed more after cardiopulmonary bypass. Correlations between coagulation tests and postoperative chest tube drainage are defined. Platelets and, if necessary, cryoprecipitate optimally restore hemostasis. Fresh-frozen plasma offers no benefits in correcting postcardiopulmonary bypass coagulopathies in children.

Journal ArticleDOI
TL;DR: Although the surgery was successful, the patient developed signs and symptoms of sustained carbon dioxide (CO,) absorption: supraventricular tachycardia, massive subcutaneous emphysema, hypercarbia, and acidosis.
Abstract: Increasingly, laparoscopic surgeries are being performed to treat a number of conditions. The technical aspects of specific laparoscopic procedures can increase the risk of certain complications that, although they are of concern in conventional procedures, may be more likely or may occur with greater severity during laparoscopic procedures. We report the anesthetic course and complications that were encountered during laparoscopic parathyroidectomy, a procedure that to our knowledge, has not previously been performed. Although the surgery was successful, the patient developed signs and symptoms of sustained carbon dioxide (CO,) absorption: supraventricular tachycardia, massive subcutaneous emphysema, hypercarbia, and acidosis.

Journal ArticleDOI
TL;DR: Data indicate that fentanyl analgesia involves augmentation of painevoked cerebral responses in certain areas, as well as both activation and inhibition in other brain regions unresponsive to pain stimulation alone.
Abstract: Recent positron emission tomography (PET) studies have demonstrated areas of pain processing in the human brain. Given the inhibitory effects of opioids on neuronal activity, we predicted that fentanyl's analgesic effects would be associated with suppression of pain-evoked responses in these distinct brain areas. To test this, PET was used to measure cerebral blood flow responses, as reflections of regional neuronal activity, to painful and nonpainful thermal stimuli both in the absence and presence of fentanyl in humans. During each PET scan in nine healthy volunteers a tonic heat source was placed against the subject's left forearm, delivering a preset temperature of either 40 degrees C (nonpainful) or 47-48 degrees C (painful). Subjects underwent eight blood flow studies, each consisting of 50 mCi [15O]water injection and a PET scan. The first four studies were performed during placebo administration in the stimulus sequence: nonpainful, painful, painful, nonpainful. This sequence was then repeated during intravenous (i.v.) administration of fentanyl 1.5 micrograms/kg [corrected]. Significant differences in regional cerebral blood flow (rCBF) between the placebo and the fentanyl conditions during nonpainful and painful stimuli were identified using statistical parametric mapping. It was found that pain increased rCBF in the anterior cingulate, ipsilateral thalamus, prefrontal cortex, and contralateral supplementary motor area. Fentanyl increased rCBF in the anterior cingulate and contralateral motor cortices, and decreased rCBF in the thalamus (bilaterally) and posterior cingulate during both stimuli. During combined pain stimulation and fentanyl administration, fentanyl significantly augmented pain-related rCBF increases in the supplementary motor area and prefrontal cortex. This activation pattern was associated with decreased pain perception, as measured on a visual analog scale. In contrast to our hypothesis, these data indicate that fentanyl analgesia involves augmentation of pain-evoked cerebral responses in certain areas, as well as both activation and inhibition in other brain regions unresponsive to pain stimulation alone.

Journal ArticleDOI
TL;DR: Tranexamic acid can reduce perioperative blood loss in children undergoing repeat cardiac surgery and the total transfusion requirements, total donor unit exposure, and financial cost of blood components were less in the tranexamic Acid group.
Abstract: The antifibrinolytic drug, tranexamic acid, decreases blood loss in adult patients undergoing cardiac surgery. However, its efficacy has not been extensively studied in children. Using a prospective, randomized, double-blind study design, we examined 41 children undergoing repeat sternotomy for repair of congenital heart defects. After induction of anesthesia and prior to skin incision, patients received either tranexamic acid (100 mg/kg, followed by 10 mg.kg-1.h-1) or saline placebo. At the onset of cardiopulmonary bypass, a second bolus of tranexamic acid (100 mg/kg) or placebo was administered. Total blood loss and transfusion requirements during the period from protamine administration until 24 h after admission to the intensive care unit were recorded. Children who were treated with tranexamic acid had 24% less total blood loss (26 +/- 7 vs 34 +/- 17 mL/kg) compared with children who received placebo (univariate analysis P = 0.03 and multivariate analysis P < 0.01). Additionally, the total transfusion requirements, total donor unit exposure, and financial cost of blood components were less in the tranexamic acid group. In conclusion, tranexamic acid can reduce perioperative blood loss in children undergoing repeat cardiac surgery.

Journal ArticleDOI
TL;DR: It is believed that SAS patients are at particularly high risk of postoperative respiratory depression from any mode of analgesic therapy, and guidelines for the anesthetic management of such patients are suggested.
Abstract: Current prominent textbooks on anesthesiology mention sleep apnea syndrome (SAS) only briefly. However, three patients in Illinois (two at one hospital) had sudden postoperative arrests associated with epidural opioids and sleep apnea. We therefore reevaluated the literature, which suggests that epidural opioids are the therapy of choice for patients with sleep apnea (1). Of the 15 patients with SAS reported in the literature, 10 had severe respiratory problems due to postoperative analgesia. Only one report was associated with epidural analgesia, to which we now add three. Based on the experiences we now describe (Case Reports l-3) and review of the literature (Case Reports 4-18), we believe that SAS patients are at particularly high risk of postoperative respiratory depression from any mode of analgesic therapy. Our theory is based on a review of a series of cases and not on mathematical estimates of relative risk. Because of our conclusion, we suggest guidelines for the anesthetic management of such patients.

Journal ArticleDOI
TL;DR: It is concluded that regional anesthesia should not necessarily be withheld when the platelet count is <100,000 mm-3, and any neurologic complications in the medical records are found.
Abstract: Regional anesthesia is a popular form of pain relief for the management of labor and delivery. Thrombocytopenia is considered a relative contraindication to the administration of regional anesthesia. Some authorities have recommended that an epidural anesthetic be withheld if the platelet count is 100,000 mm(-3) that subsequently decreased below 100,000 mm(-3), and 28 did not receive a regional anesthetic. We found no documentation of any neurologic complications in the medical records. We conclude that regional anesthesia should not necessarily be withheld when the platelet count is <100,000 mm(-3).

Journal ArticleDOI
TL;DR: It is concluded that the BURP maneuver improved the visualization of the larynx more easily than simple back pressure on the laryngoscopy.
Abstract: The displacement of the larynx in the three specific directions (a) posteriorly against the cervical vertebrae, (b) superiorly as possible, and (c) slightly laterally to the right have been reported and named the “BURP” maneuver. We evaluated the efficacy of the BURP maneuver in improving visualization of the larynx. Six hundred thirty patients without obvious malformation of the head and neck participated in this study. We divided the degree of visualization of the larynx using laryngoscopy into five grades and compared the visualization of the larynx using the BURP maneuver with that of laryngoscopy with and without simple laryngeal pressure (“Back”). The maneuver of Back and BURP significantly improved the laryngoscopic visualization from initial inspection. The BURP maneuver also significantly improved the visualization compared with the Back maneuver. We concluded that the BURP maneuver improved the visualization of the larynx more easily than simple back pressure on the larynx. (Anesth Analg 1997;84:419-21)

Journal ArticleDOI
TL;DR: Ondansetron (4 mg IV) was more effective in reducing the need for rescue antiemetics in the recovery room when administered at the end versus prior to the start of otolaryngologic surgery.
Abstract: A randomized, double-blind, placebo-controlled study was designed to compare the relative efficacy of prophylactic ondansetron, 4 mg intravenously (IV), when administered before induction of anesthesia or at the end of surgery to an outpatient population at high risk of developing postoperative nausea and vomiting (PONV). Patients undergoing otolaryngologic surgery were randomly assigned to one of three different treatment groups: Group 1 (placebo) received saline 5 mL prior to induction of anesthesia and again at the end of surgery; Group II received ondansetron 4 mg in 5 mL prior to induction of anesthesia and saline 5 mL at the end of surgery; and Group III received saline 5 mL prior to induction of anesthesia and ondansetron 4 mg at the end of surgery. All patients received the same general anesthetic technique. A standardized regimen of rescue antiemetics was administered in the recovery room to patients with > or = 2 emetic episodes or at the patients request for persistent nausea. Episodes of nausea and vomiting, as well as the need for rescue antiemetics, were recorded for 24 h after the operation. The incidences of nausea and emesis in the recovery room after prophylactic ondansetron, 4 mg IV, administered either before induction (68% and 20%, respectively) or at the end of surgery (60% and 4%, respectively) were not significantly decreased compared to the placebo control group (80% and 12%, respectively). However, when ondansetron was administered at the end of the operation, it significantly reduced the need for rescue antiemetics in the recovery room (36% vs 64% in the control group). The postanesthesia care unit and hospital discharge times were similar in all three study groups. One patients in Group II and one patient in Group III were hospitalized because of intractable symptoms related to PONV. After discharge from the ambulatory surgery unit, the incidence of nausea, vomiting, and the need for rescue antiemetic drugs were similar in all three treatment groups. In conclusion, ondansetron (4 mg IV) was more effective in reducing the need for rescue antiemetics in the recovery room when administered at the end versus prior to the start of otolaryngologic surgery. Therefore, when ondansetron is used for antiemetic prophylaxis in outpatients undergoing otolaryngologic procedures, it should be administered at the end of the operation rather than prior to induction of anesthesia.