Showing papers in "Anesthesiology in 2005"
TL;DR: The most useful bedside test for prediction was found to be a combination of the Mallampati classification and thyromental distance, and currently available screening tests for difficult intubation have only poor to moderate discriminative power when used alone.
Abstract: The objective of this study was to systematically determine the diagnostic accuracy of bedside tests for predicting difficult intubation in patients with no airway pathology. Thirty-five studies (50,760 patients) were selected from electronic databases. The overall incidence of difficult intubation was 5.8% (95% confidence interval, 4.5‐7.5%). Screening tests included the Mallampati oropharyngeal classification, thyromental distance, sternomental distance, mouth opening, and Wilson risk score. Each test yielded poor to moderate sensitivity (20‐62%) and moderate to fair specificity (82‐97%). The most useful bedside test for prediction was found to be a combination of the Mallampati classification and thyromental distance (positive likelihood ratio, 9.9; 95% confidence interval, 3.1‐31.9). Currently available screening tests for difficult intubation have only poor to moderate discriminative power when used alone. Combinations of tests add some incremental diagnostic value in comparison to the value of each test alone. The clinical value of bedside screening tests for predicting difficult intubation remains limited.
856 citations
TL;DR: In patients undergoing elective intraabdominal surgery, intraoperative use of restrictive fluid management may be advantageous because it reduces postoperative morbidity and shortens hospital stay.
Abstract: Background:The debate over the correct perioperative fluid management is unresolved. Methods:The impact of two intraoperative fluid regimes on postoperative outcome was prospectively evaluated in 152 patients with an American Society of Anesthesiologists physical status of I‐III who were undergoing elective intraabdominal surgery. Patients were randomly assigned to receive intraoperatively either liberal (liberal protocol group [LPG], n!75; bolus of 10 ml/kg followed by 12 ml · kg "1 ·h "1 ) or restrictive (restrictive protocol group [RPG], n!77; 4 ml · kg "1 ·h "1 ) amounts of lactated Ringer’s solution. The primary endpoint was the number of patients who died or experienced complications. The secondary endpoints included time to initial passage of flatus and feces, duration of hospital stay, and changes in body weight, hematocrit, and albumin serum concentration in the first 3 postoperative days. Results:The number of patients with complications was lower in the RPG (P!0.046). Patients in the LPG passed flatus and feces significantly later (flatus, median [range]: 4 [3‐7] days in the LPGvs.3 [2‐7] days in the RPG;P<0.001; feces: 6 [4‐9] days in the LPGvs.4 [3‐9] days in the RPG;P<0.001), and their postoperative hospital stay was significantly longer (9 [7‐24] days in the LPGvs.8 [6‐21] days in the RPG;P!0.01). Significantly larger increases in body weight were observed in the LPG compared with the RPG (P<0.01). In the first 3 postoperative days, hematocrit and albumin concentrations were significantly higher in the RPG compared with the LPG. Conclusions:In patients undergoing elective intraabdominal surgery, intraoperative use of restrictive fluid management may be advantageous because it reduces postoperative morbidity and shortens hospital stay.
809 citations
TL;DR: In this paper, the authors identify the patterns of liability associated with malpractice claims arising from management of the difficult airway, using the American Society of Anesthesiologists Closed Claims database.
Abstract: Background:The purpose of this study was to identify the patterns of liability associated with malpractice claims arising from management of the difficult airway.Methods:Using the American Society of Anesthesiologists Closed Claims database, the authors examined 179 claims for difficult airway manag
733 citations
TL;DR: There is evidence that the combination of nonsteroidal antiinflammatory drugs with patient-controlled analgesia morphine offers some advantages over morphine alone, and a decrease in morphine consumption is not a good indicator of the usefulness of a supplemental analgesic.
Abstract: The authors analyzed data from 52 randomized placebo-controlled trials (4,893 adults) testing acetaminophen, nonsteroidal antiinflammatory drugs, or selective cyclooxygenase-2 inhibitors given in conjunction with morphine after surgery. The median of the average 24-h morphine consumption in controls was 49 mg (range, 15-117 mg); it was significantly decreased with all regimens by 15-55%. There was evidence of a reduction in pain intensity at 24 h (1 cm on the 0- to 10-cm visual analog scale) only with nonsteroidal antiinflammatory drugs. Nonsteroidal antiinflammatory drugs also significantly reduced the incidence of nausea/vomiting from 28.8% to 22.0% (number needed to treat, 15) and of sedation from 15.4% to 12.7% (number needed to treat, 37) but increased the risk of severe bleeding from 0% to 1.7% (number needed to harm, 59). Selective cyclooxygenase-2 inhibitors increased the risk of renal failure in cardiac patients from 0% to 1.4% (number needed to harm, 73). A decrease in morphine consumption is not a good indicator of the usefulness of a supplemental analgesic. There is evidence that the combination of nonsteroidal antiinflammatory drugs with patient-controlled analgesia morphine offers some advantages over morphine alone.
622 citations
TL;DR: The value of this physical sign in answering one of the most common clinical questions, Can the authors use fluid to improve hemodynamics?
Abstract: Mechanical ventilation induces cyclic changes in vena cava blood flow, pulmonary artery blood flow, and aortic blood flow. At the bedside, respiratory changes in aortic blood flow are reflected by "swings" in blood pressure whose magnitude is highly dependent on volume status. During the past few years, many studies have demonstrated that arterial pressure variation is neither an indicator of blood volume nor a marker of cardiac preload but a predictor of fluid responsiveness. That is, these studies have demonstrated the value of this physical sign in answering one of the most common clinical questions, Can we use fluid to improve hemodynamics?, while static indicators of cardiac preload (cardiac filling pressures but also cardiac dimensions) are frequently unable to correctly answer this crucial question. The reliable analysis of respiratory changes in arterial pressure is possible in most patients undergoing surgery and in critically ill patients who are sedated and mechanically ventilated with conventional tidal volumes.
618 citations
TL;DR: The authors discuss the effects and implications of atelectasis in the perioperative period and illustrate how preventive measures may impact outcome and the impact of atElectasis and its prevention in acute lung injury.
Abstract: Atelectasis occurs in the dependent parts of the lungs of most patients who are anesthetized. Development of atelectasis is associated with decreased lung compliance, impairment of oxygenation, increased pulmonary vascular resistance, and development of lung injury. The adverse effects of atelectasis persist into the postoperative period and can impact patient recovery. This review article focuses on the causes, nature, and diagnosis of atelectasis. The authors discuss the effects and implications of atelectasis in the perioperative period and illustrate how preventive measures may impact outcome. In addition, they examine the impact of atelectasis and its prevention in acute lung injury.
585 citations
TL;DR: A regression analysis yielded findings indicating that morphine consumption was positively correlated with the incidence of nausea and vomiting, andPruritus, urinary retention, and respiratory depression were not significantly decreased by NSAIDs.
Abstract: Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly combined with intravenous morphine patient-controlled analgesia to relieve postoperative pain. NSAIDs have a documented 30-50% sparing effect on morphine consumption. However, most of the studies have not demonstrated a decrease in morphine adverse effects. A meta-analysis of randomized controlled trials was performed to evaluate the risk of morphine adverse effects in patients treated with NSAIDs. Twenty-two prospective, randomized, double-blind studies including 2,307 patients were selected. NSAIDs decreased significantly postoperative nausea and vomiting by 30%, nausea alone by 12%, vomiting alone by 32% and sedation by 29%. A regression analysis yielded findings indicating that morphine consumption was positively correlated with the incidence of nausea and vomiting. Pruritus, urinary retention, and respiratory depression were not significantly decreased by NSAIDs.
567 citations
TL;DR: A relatively large dose of intraoperative remifentanil triggers postoperative secondary hyperalgesia and is prevented by small-dose ketamine, implicating an N-methyl-d-aspartate pain-facilitator process.
Abstract: Background: Remifentanil-induced secondary hyperalgesia has been documented experimentally in both animals and healthy human volunteers, but never clinically. This study tested the hypotheses that increased pain sensitivity assessed by periincisional allodynia and hyperalgesia can occur after relatively large-dose intraoperative remifentanil and that smalldose ketamine prevents this hyperalgesia. Methods: Seventy-five patients undergoing major abdominal surgery were randomly assigned to receive (1) intraoperative remifentanil at 0.05 g kg 1 min 1 (small-dose remifentanil); (2) intraoperative remifentanil at 0.40 g kg 1 min 1 (largedose remifentanil); or (3) intraoperative remifentanil at 0.40 g kg 1 min 1 and 0.5 mg/kg ketamine just after the induction, followed by an intraoperative infusion of 5 g kg 1 min 1 until skin closure and then 2 g kg 1 min 1 for 48 h (large-dose remifentanil‐ketamine). Pain scores and morphine consumption were recorded for 48 postoperative hours. Quantitative sensory tests, peak expiratory flow measures, and cognitive tests were performed at 24 and 48 h. Results: Hyperalgesia to von Frey hair stimulation adjacent to the surgical wound and morphine requirements were larger (P < 0.05) and allodynia to von Frey hair stimulation was greater (P < 0.01) in the large-dose remifentanil group compared with the other two groups, which were comparable. There were no significant differences in pain, pressure pain detection threshold with an algometer, peak flow, cognitive tests, or side effects. Conclusion: A relatively large dose of intraoperative remifentanil triggers postoperative secondary hyperalgesia. Remifentanil-induced hyperalgesia was prevented by small-dose ketamine, implicating an N-methyl-D-aspartate pain-facilitator process.
560 citations
TL;DR: CPNB is an effective technique for postoperative analgesia and minor incidents and bacterial colonization of catheters are frequent, with no adverse clinical consequences in the large majority of cases.
Abstract: Background:Continuous peripheral nerve block (CPNB) is the technique of choice for postoperative analgesia after painful orthopedic surgery. However, the incidence of neurologic and infectious adverse events in the postoperative period are not well established. This issue was the aim of the study.Me
483 citations
TL;DR: This meta-analysis demonstrates that mortality, stroke, myocardial infarction, and renal failure were not reduced in off-pump coronary artery bypass surgery surgery; however, selected short-term and mid-term clinical and resource outcomes were improved compared with conventional coronary arteries bypass surgery.
Abstract: The authors undertook a meta-analysis of 37 randomized trials (3369 patients) of off-pump coronary artery bypass surgery versus conventional coronary artery bypass surgery. No significant differences were found for 30-day mortality (odds ratio [OR], 1.02; 95% confidence interval [CI], 0.58-1.80), myocardial infarction (OR, 0.77; 95%CI, 0.48-1.26), stroke (OR, 0.68; 95%CI, 0.33-1.40), renal dysfunction, intraaortic balloon pump, wound infection, rethoracotomy, or reintervention. However, off-pump coronary artery bypass surgery significantly decreased atrial fibrillation (OR, 0.58; 95%CI, 0.44-0.77), transfusion (OR, 0.43; 95%CI, 0.29-0.65), inotrope requirements (OR, 0.48; 95%CI, 0.32-0.73), respiratory infections (OR, 0.41; 95%CI, 0.23-0.74), ventilation time (weighted mean difference, -3.4 h; 95%CI, -5.1 to -1.7 h), intensive care unit stay (weighted mean difference, -0.3 days; 95%CI -0.6 to -0.1 days), and hospital stay (weighted mean difference, -1.0 days; 95%CI -1.5 to -0.5 days). Patency and neurocognitive function results were inconclusive. In-hospital and 1-yr direct costs were generally higher for conventional coronary artery bypass surgery versus off-pump coronary artery bypass surgery. Therefore, this meta-analysis demonstrates that mortality, stroke, myocardial infarction, and renal failure were not reduced in off-pump coronary artery bypass surgery surgery; however, selected short-term and mid-term clinical and resource outcomes were improved compared with conventional coronary artery bypass surgery.
449 citations
TL;DR: It is found that epidural analgesia overall provided superior postoperative analgesia compared with intravenous patient-controlled analgesia, with the exception of hydrophilic opioid–only epidural regimens.
Abstract: The authors performed a meta-analysis and found that epidural analgesia overall provided superior postoperative analgesia compared with intravenous patient-controlled analgesia For all types of surgery and pain assessments, all forms of epidural analgesia (both continuous epidural infusion and patient-controlled epidural analgesia) provided significantly superior postoperative analgesia compared with intravenous patient-controlled analgesia, with the exception of hydrophilic opioid-only epidural regimens Continuous epidural infusion provided statistically significantly superior analgesia versus patient-controlled epidural analgesia for overall pain, pain at rest, and pain with activity; however, patients receiving continuous epidural infusion had a significantly higher incidence of nausea-vomiting and motor block but lower incidence of pruritus In summary, almost without exception, epidural analgesia, regardless of analgesic agent, epidural regimen, and type and time of pain assessment, provided superior postoperative analgesia compared to intravenous patient-controlled analgesia
TL;DR: There are many words in the English language to describe the varieties of pain experience and substantial portions of the words have approximately the same relative positions on a common intensity scale for people who have widely divergent backgrounds.
Abstract: On the language of pain. By Ronald Melzack, Warren S. Torgerson. Anesthesiology 1971; 34:50-9. Reprinted with permission. The purpose of this study was to develop new approaches to the problem of describing and measuring pain in human subjects. Words used to describe pain were brought together and categorized, and an attempt was made to scale them on a common intensity dimension. The data show that: 1) there are many words in the English language to describe the varieties of pain experience; 2) there is a high level of agreement that the words fall into classes and subclasses that represent particular dimensions or properties of pain experience; 3) substantial portions of the words have approximately the same relative positions on a common intensity scale for people who have widely divergent backgrounds. The word lists provide a basis for a questionnaire to study the effects of anesthetic and analgesic agents on the experience of pain.
TL;DR: Intravenous acetaminophen, 1 g, administered over a 24-h period in patients with moderate to severe pain after orthopedic surgery provided rapid and effective analgesia and was well tolerated.
Abstract: Background: Intravenous acetaminophen injection (paracetamol) is marketed in Europe for the management of acute pain. A repeated-dose, randomized, double-blind, placebo-controlled, three–parallel group study was performed to evaluate the analgesic efficacy and safety of intravenous acetaminophen as compared with its prodrug (propacetamol) and placebo. Propacetamol has been available in many European countries for more than 20 yr. Methods: After orthopedic surgery, patients reporting moderate to severe pain received either 1 g intravenous acetaminophen, 2 g propacetamol, or placebo at 6-h intervals over 24 h. Patients were allowed “rescue” intravenous patient-controlled analgesia morphine. Pain intensity, pain relief, and morphine use were measured at selected intervals. Safety was monitored through adverse event reporting, clinical examination, and laboratory testing. Results: One hundred fifty-one patients (intravenous acetaminophen: 49; propacetamol: 50; placebo: 52) received at least one dose of study medication. The intravenous acetaminophen and propacetamol groups differed significantly from the placebo group regarding pain relief from 15 min t o6h( P < 0.05) and median time to morphine rescue (intravenous acetaminophen: 3 h; propacetamol: 2.6 h; placebo: 0.8 h). Intravenous acetaminophen and propacetamol significantly reduced morphine consumption over the 24-h period: The total morphine doses received over 24 h were 38.3 35.1 mg for intravenous acetaminophen, 40.8 30.2 mg for propacetamol, and 57. 4 52.3 mg for placebo, corresponding to decreases of 33% (19 mg) and 29% (17 mg) for intravenous acetaminophen and propacetamol, respectively. Drug-related adverse events were reported in 8.2%, 50% (most of them local), and 17.3% of patients treated with intravenous acetaminophen, propacetamol, and placebo, respectively. Conclusion: Intravenous acetaminophen, 1 g, administered over a 24-h period in patients with moderate to severe pain after orthopedic surgery provided rapid and effective analgesia and was well tolerated.
TL;DR: In patients undergoing coronary artery surgery with cardiopulmonary bypass, the cardioprotective effects of sevoflurane were clinically most apparent when it was administered throughout the operation.
Abstract: Background: Experimental studies have related the cardioprotective effects of sevoflurane both to preconditioning properties and to beneficial effects during reperfusion. In clinical studies, the cardioprotective effects of volatile agents seem more important when administered throughout the procedure than when used only in the preconditioning period. The authors hypothesized that the cardioprotective effects of sevoflurane observed in patients undergoing coronary surgery with cardiopulmonary bypass are related to timing and duration of its administration. Methods: Elective coronary surgery patients were randomly assigned to four different anesthetic protocols (n = 50 each). In a first group, patients received a propofol based intravenous regimen (propofol group). In a second group, propofol was replaced by sevoflurane from sternotomy until the start of cardiopulmonary bypass (SEVO pre group). In a third group, propofol was replaced by sevoflurane after completion of the coronary anastomoses (SEVO post group). In a fourth group, propofol was administered until sternotomy and then replaced by sevoflurane for the remaining of the operation (SEVO all group). Postoperative concentrations of cardiac troponin I were followed during 48 h. Cardiac function was assessed perioperatively and during 24 h postoperatively. Results: Postoperative troponin I concentrations in the SEVO all group were lower than in the propofol group. Stroke volume decreased transiently after cardiopulmonary bypass in the propofol group but remained unchanged throughout in the SEVO all group. In the SEVO pre and SEVO post groups, stroke volume also decreased after cardiopulmonary bypass but returned earlier to baseline values than in the propofol group. Duration of stay in the intensive care unit was lower in the SEVO all group than in the propofol group. Conclusion: In patients undergoing coronary artery surgery with cardiopulmonary bypass, the cardioprotective effects of sevoflurane were clinically most apparent when it was administered throughout the operation.
TL;DR: Preoxygenation in the 25° head-up position achieves 23% higher oxygen tensions, allowing a clinically significant increase in the desaturation safety period—greater time for intubation and airway control.
Abstract: Background: Class III obese patients have altered respiratory mechanics, which are further impaired in the supine position. The authors explored the hypothesis that preoxygenation in the 25° head-up position allows a greater safety margin for induction of anesthesia than the supine position. Methods: A randomized controlled trial measured oxygen saturation and the desaturation safety period after 3 min of preoxygenation in 42 consecutive (male:female 13:29) severely obese (body mass index > 40 kg/m 2 ) patients who were undergoing laparoscopic adjustable gastric band surgery and were randomly assigned to the supine position or the 25° head-up position. Serial arterial blood gases were taken before and after preoxygenation and 90 s after induction. After induction, ventilation was delayed until blood oxygen saturation reached 92%, and this desaturation safety period was recorded. Results: The mean body mass indexes for the supine and 25° head-up groups were 47.3 and 44.9 kg/m 2 , respectively (P 0.18). The group randomly assigned to the 25° head-up position achieved higher preinduction oxygen tensions (442 104 vs. 360 99 mmHg; P 0.012) and took longer to reach an oxygen saturation of 92% (201 55 vs. 155 69 s; P 0.023). There was a strong positive correlation between the induction oxygen tension achieved and the time to reach an oxygen saturation of 92% (r 0.51, P 0.001). There were no adverse events associated with the study. Conclusion: Preoxygenation in the 25° head-up position achieves 23% higher oxygen tensions, allowing a clinically significant increase in the desaturation safety period— greater time for intubation and airway control. Induction in the 25° head-up position may provide a greater safety margin for airway control.
TL;DR: Poor intraoperative control of blood glucose concentrations in diabetic patients undergoing cardiac surgery is associated with a worsened hospital outcome after surgery, and is significantly more frequent in patients with severe postoperative morbidity.
Abstract: Background:Tight perioperative control of blood glucose improves the outcome of diabetic patients undergoing cardiac surgery. Because stress response and cardiopulmonary bypass can induce profound hyperglycemia, intraoperative glycemic control may become difficult. The authors undertook a prospectiv
TL;DR: Ketamine has a chiralcenter at the carbon-2 atom of the cyclohexanone ring, and therefore exists as the optical stereoisomers S( )and R(-) ketamine.
Abstract: Ketamine thereforerepresents a promising modality in several perioperativestrategies to prevent pathologic pain.Another reason for the renewed interest in ketamine isthe availability of S( ) ketamine. Ketamine has a chiralcenter at the carbon-2 atom of the cyclohexanone ring,and therefore exists as the optical stereoisomers S( )and R(-) ketamine.
TL;DR: Mortality after surgery is substantial and an association was established between perioperative coma and death and anesthesia management factors like intraoperative presence of anesthesia personnel, administration of drugs intraoperatively and postoperatively, and characteristics of delivered intraoperative and postoperative anesthetic care.
Abstract: Background: Quantitative estimates of how anesthesia management impacts perioperative morbidity and mortality are limited. The authors performed a study to identify risk factors related to anesthesia management for 24-h postoperative severe morbidity and mortality. Methods: A case-control study was performed of all patients undergoing anesthesia (1995-1997). Cases were patients who either remained comatose or died during or within 24 h of undergoing anesthesia. Controls were patients who neither remained comatose nor died during or within 24 hours of undergoing anesthesia. Data were collected by means of a questionnaire, the anesthesia and recovery form. Odds ratios were calculated for risk factors, adjusted for confounders. Results: The cohort comprised 869,483 patients; 807 cases and 883 controls were analyzed. The incidence of 24-h postoperative death was 8.8 (95% confidence interval, 8.2-9.5) per 10,000 anesthetics. The incidence of coma was 0.5 (95% confidence interval, 0.3-0.6). Anesthesia management factors that were statistically significantly associated with a decreased risk were: equipment check with protocol and checklist (odds ratio, 0.64), documentation of the equipment check (odds ratio, 0.61), a directly available anesthesiologist (odds ratio, 0.46), no change of anesthesiologist during anesthesia (odds ratio, 0.44), presence of a full-time working anesthetic nurse (odds ratio, 0.41), two persons present at emergence (odds ratio, 0.69), reversal of anesthesia (for muscle relaxants and the combination of muscle relaxants and opiates; odds ratios, 0.10 and 0.29, respectively), and postoperative pain medication as opposed to no pain medication, particularly if administered epidurally or intramuscularly as opposed to intravenously. Conclusions: Mortality after surgery is substantial and an association was established between perioperative coma and death and anesthesia management factors like intraoperative presence of anesthesia personnel, administration of drugs intraoperatively and postoperatively, and characteristics of delivered intraoperative and postoperative anesthetic care.
TL;DR: Combined with an antihyperalgesic dose of ketamine, intraoperative epidural analgesia provides effective preventive analgesia after major digestive surgery.
Abstract: BACKGROUND: As a broader definition of preemptive analgesia, preventive analgesia aims to prevent the sensitization of central nervous system, hence the development of pathologic pain after tissular injury. To demonstrate benefits from preventive treatment, objective measurement of postoperative pain such as wound hyperalgesia and persistent pain should be evaluated. The current study assessed the role and timing of epidural analgesia in this context. METHODS: In a randomized, double-blinded trial, 85 patients scheduled to undergo neoplastic colonic resection were included. All the patients received a thoracic epidural catheter, systemic ketamine at a antihyperalgesic dose, and general anesthesia. Continuous infusion of analgesics belonging to the same class was administered by either intravenous or epidural route before incision until 72 h after surgery. Patients were allocated to four groups to receive intraoperative intravenous lidocaine-sufentanil-clonidine or epidural bupivacaine-sufentanil-clonidine followed postoperatively by either intravenous (lidocaine-morphine-clonidine) or epidural (bupivacaine-sufentanil-clonidine) patient-controlled analgesia. Postoperative pain scores (visual analog scale), analgesic consumption, wound area of punctuate hyperalgesia, residual pain, and analgesics needed from 2 weeks until 12 months were recorded. RESULTS: Analgesic requirements, visual analog scale scores, and area of hyperalgesia were significantly higher in the intravenous treatment group (intravenous-intravenous), and more patients reported residual pain from 2 weeks until 1 yr (28%). Although postoperative pain measurements did not differ, postoperative epidural treatment (intravenous-epidural) was less effective to prevent residual pain at 1 yr (11%; P = 0.2 with intravenous-intravenous group) than intraoperative one (epidural-epidural and epidural-intravenous groups) (0%; P = 0.01 with intravenous-intravenous group). CONCLUSION: Combined with an antihyperalgesic dose of ketamine, intraoperative epidural analgesia provides effective preventive analgesia after major digestive surgery.
TL;DR: Across all strata in 2001, an anesthesiologist was slightly more often directly involved in the care of patients receiving regional analgesia for labor compared with 1981 and 1992 survey data.
Abstract: A dvances and changes in any medical specialty are often defined and detected by surveys. This is particularly true in obstetric anesthesia, especially given the complications arising from medicolegal, financial, maternal, and fetal considerations. Economic pressures, payment variations, decreased numbers of anesthesia providers, patient expectations, and technical aspects have challenged obstetric anesthesia practice. This 2001 obstetric anesthesia workforce survey was performed in conjunction with the Society from Obstetric Anesthesia and Perinatology to estimate and assess current trends and identify potential areas for improvement. A stratified random sample frame of 1300 hospitals was selected. The institutions were stratified based on geographic region and number of births for that year (stratum I, >1500 births; II, 500–1499 births; and III, 100–500 births). Three key labor and delivery personnel were identified at each institution that responded to the initial query. These personnel included from each hospital the chief of anesthesiology, the chief of obstetrics, and the labor and delivery manager. The number of hospitals providing obstetric care decreased from 4163 in 1981 to 3545 in 1992, to 3160 in 2001. A substantial decrease in stratum III facilities occurred between 1992 and 2001 (1603 down to 1081). A total of 378 of the 1300 initially sampled hospitals responded to the request for contact information (29% overall response). In the anesthesiology survey, the response rate was 57% and that for the obstetrics survey was 45%. In the labor and delivery manager survey, the rate of response was 75%. An overall increase in the percent of maternity cases using regional analgesia for labor was noted across all strata. The use of epidural analgesia for labor increased compared with previous surveys; spinal analgesia was used in <10% of cases. Patient-controlled epidural analgesia was used in about 33% of stratum I and II hospitals but in only 18% of stratum III hospitals. For cesarean delivery, use of spinal anesthesia increased and use of epidural anesthesia decreased across all strata. Combined spinal-epidural anesthesia was used in <10% of cesarean deliveries in all strata. Availability of in-house regional analgesia during labor was reported by only 3% of the smallest hospitals. In-house coverage was available in 77% of stratum II hospitals, and only 3% of stratum III hospitals reported that regional analgesia for labor was unavailable. Across all strata in 2001, an anesthesiologist was slightly more often directly involved in the care of patients receiving regional analgesia for labor compared with 1981 and 1992 survey data. In stratum III hospitals, 34% of regional analgesics for labor were administered by independently practicing certified nurse anesthetists, with 14% administered by these personnel under the medical direction of nonanesthesiologist physicians. Pediatricians performed an average of 42% and 48% of neonatal resuscitations during cesarean deliveries in stratum I and II hospitals, respectively. Vaginal birth after cesarean delivery (VBAC) was allowed in 98% and 92% of stratum I and II hospitals, but only 68% of stratum III institutions. Only 25% to 30% of all patients attempted it across all strata. Based on the American College of Obstetricians and Gynecologists practice bulletin on VBAC, 40% of stratum III hospitals no longer perform VBAC, and stratum I and II hospitals reported a reduction in VBAC attempts. Across all strata, at least 60% of VBACs were successful. Most institutions in all strata required anesthesia providers to be in-house during epidural infusion. Between 63% and 94% of hospitals required providers to be in-house when women were attempting VBAC with regional analgesia. Although almost all hospitals allowed ambulation during labor, only about 50% allowed ambulation during epidural or combined spinal-epidural analgesia. Interestingly, only a very small percentage of patients actually ambulated. Across all strata, <10% of hospitals allowed labor floor nurses (LFNs) to reinstitute epidural infusions. LFNs could adjust infusion rates in 28% and 7% of stratum II and I hospitals, respectively. LFNs were allowed to administer epidural boluses in 13% and 3% of stratum II and I hospitals, respectively. Collection rates for professional fees for anesthesia for labor, vaginal and cesarean deliveries, and other surgical procedures steadily decreased from 1981 to 2001. Collection rates for cesarean delivery declined from 76% in 1981 to 70% in 1992 to 66% in 2001. Respective anesthesia collection rates for labor and vaginal delivery were 67%, 68%, and 60%, and for other surgical procedures, 85%, 74%, and 68%. Stratum I hospitals had the largest percentage of health maintenance organization payers, and stratum II and III institutions the largest percentage of Medicaid payers. Percentage payment of actual charges was similar among all groups of payers across all sizes of hospitals. The 2001 survey results indicate that, despite staffing and payment challenges in obstetric anesthesia care, availability of services and anesthesia personnel have improved.
TL;DR: An evaluation in the Anesthesiologist-directed preoperative medicine clinic can significantly impact case cancellations and delays on the day of surgery.
Abstract: Background:Anesthesiologist-directed preoperative medicine clinics are used to prepare patients for the administration of anesthesia and surgery. Studies have shown that such a clinic reduces preoperative testing and consults, but few studies have examined the impact of the clinic on the day of surg
TL;DR: A single exposure to anesthesia crises using a high-fidelity patient simulator can improve the nontechnical skills of anesthesia residents, however, an additional simulation session may confer little or no additional benefit.
Abstract: BACKGROUND: Critical incident reporting and observational studies have identified nontechnical skills that are vital to successful anesthesia crisis management. Examples of such skills include task management, team working, situation awareness, and decision making. These skills are not necessarily acquired through clinical experience and may need to be specifically taught. This study uses a high-fidelity patient simulator to assess the effect of repeated exposure to simulated anesthesia crises on the nontechnical skills of anesthesia residents. METHODS: After institutional research board approval and informed consent, 20 anesthesia residents were recruited. Each resident was randomized to participate as the primary anesthesiologist in the management of three different simulated anesthesia crises using a high-fidelity patient simulator. After each session, videotaped footage was used to facilitate debriefing of their nontechnical skills. The videotapes were later reviewed by two expert blinded independent assessors who rated each resident's nontechnical skills by using a previously validated and reliable marking system. RESULTS: : A significant improvement in the nontechnical skills of residents was demonstrated from their first to second session and from their first to third session (both P < 0.005). However from their second to third session, no significant improvement was observed. Interrater reliability between assessors was modest (single rater intraclass correlation = 0.53). CONCLUSION: A single exposure to anesthesia crises using a high-fidelity patient simulator can improve the nontechnical skills of anesthesia residents. However, an additional simulation session may confer little or no additional benefit.
TL;DR: Increasing depth of propofol anesthesia is associated with increased collapsibility of the upper airway, associated with profound inhibition of genioglossus muscle activity, which seems to be the combined result of depression of central respiratory output toupper airway dilator muscles and of upperAirway reflexes.
Abstract: Background:This study investigated the effect of varying concentrations of propofol on upper airway collapsibility and the mechanisms responsible for it.Methods:Upper airway collapsibility was determined from pressure–flow relations at three concentrations of propofol anesthesia (effect site concent
TL;DR: In this article, the authors reviewed the charts of all pregnant women with severe pulmonary hypertension who were followed up at their institution during the past 10 years, to asses the risk of death.
Abstract: Background:Available literature on pregnant women with severe pulmonary hypertension (PH) relies mainly on anecdotal case reports and two series only.Methods:The authors reviewed the charts of all pregnant women with severe PH who were followed up at their institution during the past 10 yr, to asses
TL;DR: Intraoperative administration of tranexamic acid significantly reduces blood loss during spinal surgery in children with scoliosis, a multivariate predictor of blood loss.
Abstract: Background: Excessive bleeding often occurs during pediatric scoliosis surgery and is attributed to numerous factors, including accelerated fibrinolysis. The authors hypothesized that administration of tranexamic acid would reduce bleeding and transfusion requirements during scoliosis surgery. Methods: Forty-four patients scheduled to undergo elective spinal fusion were randomly assigned to receive either 100 mg/kg tranexamic acid before incision followed by an infusion of 10 mg · kg 1 ·h 1 during surgery (tranexamic acid group) or 0.9% saline (placebo group). General anesthesia was administered according to a standard protocol. Blood loss, transfusion requirements, coagulation parameters, and complications were assessed. Results: In the tranexamic acid group, blood loss was reduced by 41% compared with placebo (1,230 535 vs. 2,085 1,188 ml; P < 0.01). The amount of blood transfused did not differ between groups (615 460 vs. 940 718 ml; P 0.08). Administration of tranexamic acid was a multivariate predictor of blood loss, as was American Society of Anesthesiologists physical status and preoperative platelet count. No apparent adverse drug effects occurred in any patient. Conclusion: Intraoperative administration of tranexamic acid significantly reduces blood loss during spinal surgery in children with scoliosis. SURGICAL correction of scoliosis in children can be associated with substantial perioperative bleeding that may require transfusion of multiple units of erythrocytes and other blood components. Intraoperative transfusion requirements are not necessarily predicted by the cause of scoliosis or preoperative laboratory assessment of coagulation. Replacement for massive intraoperative bleeding ( 50% total blood volume) with crystalloid and packed erythrocytes (PEs) during scoliosis correction can dilute the coagulation factors and further increase surgical bleeding. 1 Other factors that may affect
TL;DR: Org 25969 was both well tolerated and effective in reversing neuromuscular block induced by rocuronium in 29 human volunteers.
Abstract: Background:Acetylcholinesterase inhibitors are widely used for the reversal of neuromuscular blocking agents. However, acetylcholinesterase inhibitors have several side effects and are not effective during profound block. Org 25969 is a modified γ-cyclodextrin that encapsulates the neuromuscular blo
TL;DR: Combination of a high-dose phenylephrine infusion and rapid crystalloid cohydration is the first technique to be described that is effective for preventing hypotension during spinal anesthesia for cesarean delivery.
Abstract: Background:Many methods for preventing hypotension during spinal anesthesia for cesarean delivery have been investigated, but no single technique has proven to be effective and reliable. This randomized study studied the efficacy of combining simultaneous rapid crystalloid infusion (cohydration) wit
TL;DR: Nerve block anesthesia for outpatient rotator cuff surgery provides several same-day recovery advantages over general anesthesia, and patients who received nerve block bypassed the postanesthesia care unit more frequently and were ready for home discharge sooner.
Abstract: Background:Both general and nerve block anesthesia are effective for shoulder surgery. For outpatient surgery, it is important to determine which technique provides more efficient recovery. The authors’ goal was to compare nerve block with general anesthesia with respect to recovery profile and pati
TL;DR: The aim of this Clinical Concepts and Commentary article is to provide clini-cians with a brief overview of the literature on potential side effects of various HES preparations, includinghetastarches, pentastarhes, and the novel tetrastarches on both plasmatic and cellular hemostasis.
Abstract: HYDROXYETHYL starch (HES) solutions are frequentlyused plasma expanders that are indicated to restore andmaintain intravascular volume, to stabilize hemodynamicconditions, and to improve tissue perfusion. Accordingto these clinical indications, HES is used in perioperativesituationswithahighriskofbleeding.SideeffectsofHESon hemostasis pose serious limitations to the clinical useof this artificial colloid. Recent developments have cen-tered around designing new starch molecules by modu-lating their pharmacochemical characteristics to in-crease colloid osmotic pressure and hemodynamicefficacy while minimizing the risk of adverse reactionssuch as antithrombotic effects. The aim of this ClinicalConcepts and Commentary article is to provide clini-cians with a brief overview of the literature on potentialside effects of various HES preparations, includinghetastarches, pentastarches, and the novel tetrastarches,on both plasmatic and cellular hemostasis.
TL;DR: The three tested pulse oximeters overestimated arterial oxygen saturation during hypoxia in dark-skinned individuals, and skin pigment-related differences were significant with Nonin below 70% Sao2, with Novametrix below 90%, and with Nellcor at all ranges.
Abstract: Background: It is uncertain whether skin pigmentation affects pulse oximeter accuracy at low HbO2 saturation. Methods: The accuracy of finger pulse oximeters during stable, plateau levels of arterial oxygen saturation (SaO2) between 60 and 100% were evaluated in 11 subjects with darkly pigmented skin and in 10 with light skin pigmentation. Oximeters tested were the Nellcor N-595 with the OxiMax-A probe (Nellcor Inc., Pleasanton, CA), the Novametrix 513 (Novametrix Inc., Wallingford, CT), and the Nonin Onyx (Nonin Inc., Plymouth, MN). Semisupine subjects breathed air‐nitrogen‐carbon dioxide mixtures through a mouthpiece. A computer used end-tidal oxygen and carbon dioxide concentrations determined by mass spectrometry to estimate breath-by-breath SaO2, from which an operator adjusted inspired gas to rapidly achieve 2- to 3-min stable plateaus of desaturation. Comparisons of oxygen saturation measured by pulse oximetry (SpO2) with SaO2 (by Radiometer OSM3) were used in a multivariate model to determine the interrelation between saturation, skin pigmentation, and oximeter bias (SpO2 SaO2). Results: At 60‐70% SaO2 ,S p O2 (mean of three oximeters) overestimated SaO2 (bias SD) by 3.56 2.45% (n 29) in darkly pigmented subjects, compared with 0.37 3.20% (n 58) in lightly pigmented subjects (P < 0.0001). The SD of bias was not greater with dark than light skin. The dark‐light skin differences at 60‐70% SaO2 were 2.35% (Nonin), 3.38% (Novametrix), and 4.30% (Nellcor). Skin pigment‐related differences were significant with Nonin below 70% SaO2, with Novametrix below 90%, and with Nellcor at all ranges. Pigmentrelated bias increased approximately in proportion to desaturation. Conclusions: The three tested pulse oximeters overestimated arterial oxygen saturation during hypoxia in dark-skinned individuals.