Major incidents and complications in otherwise healthy patients undergoing elective procedures: results based on 1.37 million anaesthetic procedures.

BACKGROUND: Improved anaesthesia safety has made severe anaesthesia-related incidents, complications, and deaths rare events, but concern about morbidity and mortality in anaesthesia continues. This study examines possible severe adverse outcomes or death recorded in a large national surveillance system based on a core data set (CDS). METHODS: Cases from 1999 to 2010 were filtered from the CDS database. Cases were defined as elective patients classified as ASA physical status grades I and II (without relevant risk factors) resulting in death or serious complication. Four experts reviewed the cases to determine anaesthetic involvement. RESULTS: Of 1 374 678 otherwise healthy, ASA I and II patients in the CDS database, 36 met the study inclusion criteria resulting in a death or serious complication rate of 26.2 per million [95% confidence interval (CI), 19.4-34.6] procedures, and for those with possible direct anaesthetic involvement, 7.3 per million cases (95% CI, 3.9-12.3). CONCLUSIONS: This is the first study assessing severe incidents and complications from a national outcome-tracking database. Annual identification and review of cases, perhaps with standardized database queries in the respective departments, might provide more detailed information about the cascades that lead to unfortunate outcomes.

SBAR 'flattens the hierarchy' among caregivers.

As a young ensign in the US Navy on a nuclear submarine, Doug Bonacum had to brief the captain of the ship following his night-time shift, reporting about potentially dangerous situations that might emerge. He described the "situation, background, assessment, and recommendation". This nascent SBAR communication tool served temporarily to flatten the hierarchy between the ensign and the ship's captain. Years later at KP, Bonacum developed SBAR for facilitating effective conversations between obstetricians and nurses. SBAR has been implemented in "real-world" environments with excellent results. We are implementing SBAR to facilitate communication in CliniSpace among caregivers in this 3D immersive, virtual learning environment.

CliniSpace: a multiperson 3D online immersive training environment accessible through a browser.

Immersive online medical environments, with dynamic virtual patients, have been shown to be effective for scenario-based learning (1). However, ease of use and ease of access have been barriers to their use. We used feedback from prior evaluation of these projects to design and develop CliniSpace. To improve usability, we retained the richness of prior virtual environments but modified the user interface. To improve access, we used a Software-as-a-Service (SaaS) approach to present a richly immersive 3D environment within a web browser.

DDT Administered to Neonatal Rats Induces Persistent Estrus Syndrome.

In the report "DDT administered to neonatal rats induces persistent estrus syndrome" by W. L. Heinrichs et al. (13 Aug., p. 642), line 4 in the last paragraph of column 1, page 643, should read " secretion of luteinizing hormone(LH)."

DDT administered to neonatal rats induces persistent estrus syndrome.

The o,p'-isomer of the insecticide DDT when injected into neonatal female rats significantly advanced puberty, induced persistent vaginal estrus after a period of normal estrous cycles, and caused the ovaries to develop follicular cysts and a reduced number of corpora lutea. The uterotropic response to administered estradiol was reduced, and the female pattern of mating behavior was slightly disturbed. Residues of DDT in ovarian, brain, and adipose tissues of the adult animals were the same in both treated and control groups.

Three different types of surgeon-specific stress reactions identified by laparoscopic simulation in a virtual scenario.

BACKGROUND: Minimally invasive surgery causes higher mental strain for surgeons than conventional surgery and is significantly more stressful in consecutive cases. This study aimed to investigate whether individual stress responses are associated with intraoperative alterations of manual surgical skills and technical errors of the laparoscopic surgeon. METHODS: The LapSim virtual reality simulator was used. Stress measurement was carried out for 18 surgeons performing a virtual cholecystectomy using the LapSim simulator in the context of the patient simulator provided by the METI Corporation. In the course of the study, the surgeons were exposed to different external stressors (S1-S4) in defined intervals. The activity of the sympathetic nervous system was evaluated by skin resistance with the help of a sympathicograph. RESULTS: Three different surgeon-specific stress reactions (SSR) could be identified. The first, SSR-1, with significant stress reactions during the study without recovery, showed larger laparoscopic extensions of movement but fewer intraoperative complications than SSR-2 (recovery after the stress reactions) or SSR-3 (without significant stress reactions). CONCLUSIONS: The mental load of the laparoscopic surgeon might be highly optimized by continuous activity of the sympathetic nervous system. The question of what extent or quality of stress produces adverse effects remains unclear.

Enzymatic oxidation and reduction of C19-delta5-3beta-hydroxysteroids by hepatic microsomes. V. Testosterone as a neonatal determinant in rats of the 7- and 16alpha-hydroxylation and reduction of 3beta-hydroxyandrost-5-en-17-one (DHA).

The oxido-reductive metabolism of [14C]dehydroepiandrosterone (DHA) by hepatic microsomes from 40- or 70-day-old rats of either sex castrated neonatally has been compared after several treatment regimens with testosterone propionate (TP). The low transformation rate of DHA to 16-oxygenated metabolites produced by neonatal orchiectomy (0.09 +/- 0.04 nmoles min-1 mg-1), was not restored in 70-day-old males by either neonatal or pubertal treatment with TP. The rates were only partially restored (0.74 +/- 0.44) toward nromal adult levels (1.30 +/- 0.16) by the combination of neontal and pubertal treatments, in increments that maintained normal body weight but produced no visible growth of the male accessory glands. The combination of neonatal and pubertal treatments with larger doses of TP enough to produce normal accessory gland growth, stimulated the enzymatic rates of 16alpha-7alpha-, or 7beta-hydroxylases to levels that exceeded those of intact adult males. In 40-day-old males, the 16-oxygenation rate was restored by the latter regimen, but only to the levels characteristic of yound males (0.56 +/- 0.24), and young females responded more (1.03 +/- 0.33) than the males. The 7-oxygenation rate of DHA responded in both age groups to smaller doses of TP than did that of the 16-oxygenation. None of these manipulations altered the reduction of DHA to androst-5-ene-3bets-17beta-diol. We conclude that testosterone activates hepatic DHA hydroxylases in pubertal male rats only if neonatal imprinting by testosterone preceeds the subsequent stimulus. In addition, the DHA 16alpha-hydroxylase of young males is less sensitive than that of young females, but this pattern is reversed by 70 days of age. The hepatic males are both sensitive to testosterone, but the response of the glands is diminished by age.

Enzymatic oxidation and reduction of C19-delta5-3beta-hydroxysteroids by hepatic microsomes. IV. Induction of DHA hydroxylases and aminopyrine N-demethylase in immature male rats by androgens.

The capacities of various C19 steroids for prematurely inducing the normal metabolic patterns of rat liver in adulthood (70 days old) have been studied with hepatic microsomes of 42-day-old males castrated on day 24, 30, 32, or 34 of life. Dehydroepiandrosterone 16alpha-hydroxylase activity was significantly reduced (P less than 0.05) by castration during this 10-day interval but the 7alpha- and 7beta-hydroxylases, the N-demethylation of aminopyrine, and cytochrome P-450 concentration were unaffected. Daily administration of testosterone stimulated the DHA 16-alpha- and 17beta-hydroxylases, aminopyrine N-demethylation, and increased the P-450 content, but suppressed the 7alpha-hydroxylase. These effects only appeared with more than 1 week of the continuous treatment. Testosterone was the most active of the androgens studied; dihydrotestosterone (DHT) increased the DHA 16alpha-hydroxylase to a lesser extent, but this steroid and etiocholanolone stimulated DHA 7alpha-hydroxylation; androsterone was totally ineffective. These data suggest that testosterone rather than DHT from pubertal testes plays a significant role in control of hepatic oxidative enzyme activities during puberty.

Intention tremor, parkinsonism, and generalized brain atrophy in male carriers of fragile X.

The authors report five elderly men with the fragile X premutation who had a progressive action tremor associated with executive function deficits and generalized brain atrophy. These individuals had elevated fragile X mental retardation 1 gene (FMR1) messenger RNA and normal or borderline levels of FMR1 protein. The authors propose that elevations of FMR1 messenger RNA may be causative for a neurodegenerative syndrome in a subgroup of elderly men with the FMR1 premutation.

Successful treatment of a patient with ARDS after pneumonectomy using high-frequency oscillatory ventilation.

High frequency oscillatory ventilation (HFOV) was used in a patient who developed the acute respiratory distress syndrome 5 days following a right pneumonectomy for bronchogenic carcinoma. When conventional pressure-controlled ventilation failed to maintain adequate oxygenation, HFOV dramatically improved oxygenation within the first few hours of therapy. Pulmonary function and gas exchange recovered during a 10-day period of HFOV. No negative side effects were observed. Early use of HFOV may be a beneficial ventilation strategy for adults with acute pulmonary failure, even in the postoperative period after lung resection.

Simulated medical learning environments on the Internet.

Learning anatomy and surgical procedures requires both a conceptual understanding of three-dimensional anatomy and a hands-on manipulation of tools and tissue. Such virtual resources are not available widely, are expensive, and may be culturally disallowed. Simulation technology, using high-performance computers and graphics, permits realistic real-time display of anatomy. Haptics technology supports the ability to probe and feel this virtual anatomy through the use of virtual tools. The Internet permits world-wide access to resources. We have brought together high-performance servers and high-bandwidth communication using the Next Generation Internet and complex bimanual haptics to simulate a tool-based learning environment for wide use. This article presents the technologic basis of this environment and some evaluation of its use in the gross anatomy course at Stanford University.

Use of nafarelin versus placebo after reductive laparoscopic surgery for endometriosis.

OBJECTIVE: To evaluate the efficacy of the GnRH agonist (GnRH-a) nafarelin compared with placebo administered for 6 months after reductive laparoscopic surgery for symptomatic endometriosis. DESIGN: Randomized, prospective, placebo-controlled, multicenter clinical trial. SETTING: Thirteen clinics including private practice and university centers. PATIENT(S): One hundred nine women aged 18-47 with laparoscopically proven endometriosis and pelvic pain who had undergone reductive laparoscopic surgery for endometriosis. INTERVENTION(S): Patients were randomized to receive either the GnRH-a nafarelin (200 micrograms twice daily) or placebo for 6 months. MAIN OUTCOME MEASURE(S): Time to initiation of alternative treatment (the length of time from beginning study medication to receiving alternative therapy or to deeming that the study drug was ineffective) and patient-reported and physician-assessed pelvic pain scores. RESULT(S): The median time to initiation of alternative treatment was > 24 months in the nafarelin group versus 11.7 months in the placebo group. Fifteen (31%) of 49 nafarelin-treated patients required alternative therapy, compared with 25 (57%) of 44 placebo-treated patients. The patients' pelvic pain scores dropped significantly in the nafarelin and placebo groups after 6 months of treatment. Physician summary ratings showed significant improvement in the nafarelin group and no significant changes in the placebo group after 6 months of treatment. CONCLUSION(S): Compared with placebo, nafarelin administered after reductive laparoscopic surgery for endometriosis significantly delays the return of endometriosis symptoms requiring further treatment.

Interleukin-1 type I receptor messenger ribonucleic acid expression in human endometrium throughout the menstrual cycle.

OBJECTIVE: To investigate the messenger ribonucleic acid (mRNA) expression of interleukin-1 (IL-1) type I receptor in the endometrial tissue of normal patients during the menstrual cycle. DESIGN: Prospective longitudinal study. SETTING: Department of Obstetrics and Gynecology, Stanford University Medical Center, Stanford, California. PATIENTS: Twenty fertile women between 19 and 41 years of age underwent hysterectomy for benign reasons (n = 9) and laparoscopy for tubal ligation (n = 11). In all cases, endometriosis was not visualized. INTERVENTIONS: Endometrial biopsy using the Novak curette was obtained at the time of surgery. MAIN OUTCOME MEASURE: Total RNA extracted from unfractioned endometrial tissue was analyzed on Northern blots by using specific complementary deoxyribonucleic acid probes. RESULTS: We found IL-1 type I receptor mRNA expression in endometrial tissue throughout the entire menstrual cycle. However, IL-1 type I receptor mRNA levels were significantly higher during both early and late luteal phases than follicular and midluteal phases. CONCLUSIONS: Our results demonstrate the presence of the IL-1 system in the human endometrium and that the receptor is regulated throughout the menstrual cycle with a 4.1-fold increased expression of the IL-1 receptor gene in the early luteal phase compared with preovulatory endometrium.

Midgestational exposure of pregnant BALB/c mice to magnetic resonance imaging conditions.

The potential for producing reproductive toxicity or teratogenesis in mice by exposure to magnetic resonance imaging (MRI) conditions was evaluated by means of reproduction studies and the homeotic shift test. Embryos from pregnant BALB/c mice were exposed in vivo for 16 hours beginning on gestation day 8.75 to MRI conditions of modest field strength (static field, 0.35 tesla (T); pulsed gradients, 2.3 X 10(-4) T/cm for 2.5 to 10 msec; and radio frequency, 15 MHz at an average of 61.2 mW). Unexposed, sham-exposed (both MRI and X-ray) and X-irradiated (0.5 Gy) animals were the control groups. Neither placental resorptions nor stillbirths were increased by MRI. Fetal weight at birth and crown-rump length were proportional; however, crown-rump length was significantly less (p less than 0.001) in the MRI-exposed fetuses (respective mean values for MRI-exposed fetuses were 21.8 +/- 0.2 mm compared to 22.4 +/- 0.1 for sham-exposed fetuses). Both crown-rump length and fetal weight were significantly reduced after X-irradiation. The percentage of homeotic skeletal shifts was scored for each of eight anatomic sites. Only X-radiation produced significant increases in skeletal shifts. Prolonged midgestational exposure of mice to MRI conditions currently used for human clinical imaging, therefore, failed to reveal overt embryotoxicity (resorptions, stillbirths) or teratogenicity (homeotic shifts), consistent with the non-ionizing properties of MR. However, the slight but significant reduction in fetal crown-rump length after prolonged exposure justifies further study of higher MRI energy levels and consideration of other endpoints for establishing with greater confidence the safety of MRI during pregnancy.

An adaptive lung ventilation controller.

Closed loop control of ventilation is traditionally based on end-tidal or mean expired CO2. The controlled variables are the respiratory rate RR and the tidal volume VT. Neither patient size or lung mechanics were considered in previous approaches. Also the modes were not suitable for spontaneously breathing subjects. This report presents a new approach to closed loop controlled ventilation, called Adaptive Lung Ventilation (ALV). ALV is based on a pressure controlled ventilation mode suitable for paralyzed, as well as spontaneously breathing, subjects. The clinician enters a desired gross alveolar ventilation (V'gA in l/min), and the ALV controller tries to achieve this goal by automatic adjustment of mechanical rate and inspiratory pressure level. The adjustments are based on measurements of the patient's lung mechanics and series dead space. The ALV controller was tested on a physical lung model with adjustable mechanical properties. Three different lung pathologies were simulated on the lung model to test the controller for rise time (T90), overshoot (Ym), and steady state performance (delta max). The pathologies corresponded to restrictive lung disease (similar to ARDS), a "normal" lung, and obstructive lung disease (such as asthma). Furthermore, feasibility tests were done in 6 patients undergoing surgical procedures in total intravenous anesthesia. In the model studies, the controller responded to step changes between 48 seconds and 81 seconds. It did exhibit an overshoot between 5.5% and 7.9% of the setpoint after the step change.(ABSTRACT TRUNCATED AT 250 WORDS)

[Multi-rotation CT during continuous ventilation: comparison of different density areas in healthy lungs and in the ARDS lavage model]. / Multirotations-CT während kontinuierlicher Beatmung: Vergleich unterschiedlicher Dichtebereiche bei gesunden Lungen und im Lavage-ARDS Modell.

PURPOSE: In this animal study, density ranges for CT-based quantification of ventilated lung area were determined. Healthy lungs and ARDS lungs were compared during artificial respiration. MATERIAL AND METHODS: CT-scans were performed in 5 anesthetized pigs using a dynamic multiscan CT option on a predefined transverse slice (slice thickness 1 mm; effective temporal resolution, 250 ms). During continuous CT acquisition, airway pressure was increased or decreased in a stepwise manner. In all images, areas of defined HU ranges were determined planimetrically. The lower threshold was set to -910 HE in all images. The upper threshold was varied from -800 HE to -200 HE in steps of 100 HE. RESULTS: During inspiration in healthy lungs the HU-range of -910 to -700 HU showed the largest increase in area. During inspiration in ARDS lungs the HU range from -910 to -300 HU allowed the most sensitive assessment of area changes. These findings can be explained by recruitment of atelectases (HU-range > -300 HU) and their transition to a HU range from -700 to -300 HU. CONCLUSION: Dynamic multiscan CT acquisitions are a useful method to determine changes of ventilated lung area during a respiratory cycle. Different HU-ranges are required to access volume changes in healthy lungs and in ARDS lungs.

A practical approach to the patient with dysmenorrhea.

Pelvic pain associated with the menses may be a result of physiologic problems, premenstrual tension syndrome, primary dysmenorrhea or secondary dysmenorrhea. All of these conditions may be caused by both physiologic and psychologic factors. An accurate diagnosis requies a complete history and physical examination and astute assessment of predisposing or aggravating conditions. Diagnosis has been improved through the use of laparoscopy, hysteroscopy, hysterosalpingography and dilatation and curettage. Treatment has been revolutionized with the use of oral contraceptives and prostaglandin synthesis inhibitors. These diagnostic and therapeutic advances now enable the sympathetic physician to effectively evaluate and treat almost all patients with menstrually related pelvic pain. When all of these approaches fail, the physician should consider psychiatric consultation or referral to pain clinic or gynecologist with special interest in this field.

Human issues and medical economics of endometriosis. Three- vs. six-month GnRH-agonist therapy.

OBJECTIVE: To project the efficacy and economic consequence of short-term intranasal gonadotropin-releasing hormone agonist (GnRH-a) for diagnosis of and therapy for endometriosis. STUDY DESIGN: Multicenter, placebo-controlled clinical trials of GnRH-a comparing three vs. six months of treatment, three months of retreatment and three months of postoperative treatment for the symptoms and signs of laparoscopically diagnosed endometriosis. RESULTS: The reduction in symptoms and signs of endometriosis was similar at the end of three months to the relief at six months. Retreatment was as effective as initial treatment, and the return of symptoms after laparoscopic surgery plus postoperative treatment for three months was delayed by approximately 18 months as compared to surgery alone. The projected charges for the surgical approaches (laparoscopy or minilaparoscopy) to diagnosis and therapy were 50-60% greater than those for the medical approach. CONCLUSION: GnRH-a administration for three months could be a cost-effective approach to the presumptive diagnosis and treatment of endometriosis among women with chronic pelvic pain.

Assessment of pulmonary mechanics and gastric inflation pressure during mask ventilation.

INTRODUCTION: Mask ventilation is a procedure routinely used in emergency medicine. Potential hazards are inadequate alveolar ventilation and inflation of the stomach with air, leading to subsequent regurgitation and aspiration. The aim of this study was to measure lung function and gastric inflation pressures during mask ventilation. METHODS: For this purpose, 31 patients scheduled for routine urological procedures were studied during induction of anesthesia. Lung function was assessed by recording respiratory flow and pressure directly at the face mask. Gastric inflation was observed with a microphone taped to the epigastric area. RESULTS: Gastric inflation occurred in 22 of the 31 patients. Mean gastric inflation pressure was 27.5 +/- 6.55 cm H2O, mean compliance was 67 +/- 24.1 ml/cm H2O, mean resistance was 17.4 +/- 6.41 cm H2O/L/sec, and the mean respiratory time constant was 1.1 +/- 0.26 seconds. CONCLUSIONS: These data suggest that inspiratory pressure be limited to 20 cm H2O, and that an inspiratory time of at least four times the respiratory time constant be allowed. Monitoring airway pressure and gastric inflation is a simple technique that may improve the safe-ty of patients during mask ventilation.

The essential human-machine interface for surgery: biological signals transmission.

The concept of a machine-augmented surgeon will become a widespread reality only after the barrier of harnessing the computer as a tool has been successfully accomplished. The prospects of surgical robots for computer-assisted surgery, for telemedicine, and for teleoperation-cybersurgery-will be greatly enhanced when computers are no longer considered a separate component that links a system together, they must lose their identity, becoming transparent. The ideal human-machine interface for surgery is one juxtaposed between surgeon and patient that derives digital biosignals directly from both bodies, transmitting them transparently without perceptible delay, and distributes them bilaterally into afferent (sensory) and efferent (operator or effector) limbs. This ideal human-computer interface will be based upon biosignal processing and will optimize the technology to the physiology, in what has been called biocybernetics. Applications of biosignal interfaces are being developed in entertainment, medicine, commerce, defense, and in sales and distribution (Table 1).