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PubMed1997

High risk pregnancy outcome following induction of labour.

OBJECTIVE: To evaluate whether induction of labour, performed in a high risk obstetric population, when medically indicated, carries an increased risk for operative delivery and maternal and fetal complications. The secondary goal was to study the effect of the various induction methods used on these outcomes and labour time. STUDY DESIGN: This study was carried out at a level [1] university hospital. A group of 210 women who were induced for various indications, were compared to our general parturient population. Main outcome measures were cesarean section (CS) and instrumental delivery rates, intra-partum and post-partum complications, APGARs 1' and 5' and labour time by induction method. RESULTS: No significant increase in the rates of primary CS (8.6 vs. 7.1%) and instrumental delivery (15.7 vs. 12.7%), were found in the induction high risk group as compared to our general obstetric population. Intra-partum complications and fetal outcome were comparable in both groups. A comparison of methods of induction used (oxytocin, PgE2, Amniotomy) revealed a less favorable outcome with the oxytocin induction method which showed an elevated intra-partum complication rate (P < 0.01) and a tendency toward lower Apgar scores and higher CS rate. CONCLUSIONS: Induction of labour performed in a high-risk obstetric population is safe, carrying no significant increase in CS and neonatal complication rates. Of the three methods of induction used, oxytocin induction showed the least favorable outcome for both mother and her offspring.

Adult↗
PubMed1987

The effect of halothane/nitrous oxide/oxygen mask induction on arterial hemoglobin saturation in cyanotic heart disease.

The effect of a halothane/nitrous oxide/oxygen mask induction on arterial hemoglobin saturation (SaO2) was studied in 25 patients with cyanotic congenital heart disease. During this induction the SaO2 increased from 80% +/- 2 (mean +/- SEM) in awake patients breathing room air to 86% +/- 1 after induction of anesthesia, with an average increase of 6.8% +/- 2 (absolute) (N = 25; P < .005). Patients were retrospectively divided into two groups, A and B. Group A patients had pulmonic infundibular stenosis (PIS) (N = 13) with the potential for variable pulmonary outflow tract obstruction. These patients had awake SaO, values of 76% +/- 3 that increased significantly after induction to 86% +/- 1, with an average increase of 10% +/- 4 (absolute) (P < .01). Group B patients did not have PIS; they had an awake SaO2 of 83% +/- 2, which rose insignificantly after induction to 87% +/- 1, with an average increase of 4% +/- 2 (absolute) (P > .1). Thus, the significant increase in SaO2 during induction for the entire group was primarily due to the large response of patients with PIS. No correlation was found between SaO2 and systolic blood pressure for the entire study population as well as for groups A and B separately. The lack of correlation between systolic blood pressure and SaO2 may indicate that relaxation of pulmonic infundibular stenosis is an important mechanism explaining the observed increase in SaO2 during anesthetic induction in group A (PIS) patients. Six patients had clinically important decreases in SaO2 during the induction of anesthesia, and airway obstruction was usually the cause. Anesthetic induction with halothane/nitrous oxide/oxygen leads to an increase in SaO2 in patients with many forms of cyanotic heart disease, but especially those with the potential for variable pulmonary outflow tract obstruction.

Adult↗
PubMed1998

Prediction of successful induction of labor: comparison of transvaginal ultrasonography and the Bishop score.

OBJECTIVE: To determine whether transvaginal ultrasonography of the cervix before induction of labor is a better predictor of successful induction than the Bishop score. STUDY DESIGN: Eighty-six consecutive patients scheduled for induction of labor underwent digital cervical examination followed by transvaginal ultrasonography to measure cervical length and to determine the presence of wedging. Patients were induced with either oxytocin or intracervical prostaglandin E2 gel followed by oxytocin when required. The agent for induction was selected on the basis of the digital examination. The primary outcome criteria were successful induction and the duration of labor. RESULTS: Successful induction and the duration of labor were significantly associated with the Bishop score and cervical length. Cervical wedging was associated only with successful induction. However, in a logistic regression model that included these parameters as independent variables, only the Bishop score and parity were significantly correlated with successful induction and the duration of labor. CONCLUSIONS: Transvaginal ultrasonographic evaluation of the cervix before induction of labor does not improve the prediction of cervical inducibility obtained by the Bishop score.

Adult↗
PubMed1999

Induction immunotherapy in pediatric heart transplant recipients: a multicenter study.

BACKGROUND: The efficacy and safety of induction immunotherapy with antithymocyte antibody preparations (IND) in pediatric heart transplantation is controversial. Experimentally, recipient age is an important determinant of immune responses. The effects on induction immunotherapy were determined by an analysis of outcomes of 465 pediatric (age <18 years) heart recipients that either did or did not receive IND in the first week post-transplant. METHODS: The outcomes of 2 groups who received either OKT3 (n = 101) or rabbit polyclonal antithymocyte serum (N/R-ATS, n = 105) were compared with 255 recipients who did not receive antithymocyte antibodies. The study population were all heart recipients enrolled in the Pediatric Heart Transplant Study Group (PHTS) between January 1993 and December 1995 and followed up to 36 months. RESULTS: Overall mortality and death due to rejection were lowest with N/R-ATS IND (8/105 and 1/105, respectively) compared with the no-induction group (58/255 and 8/ 255, respectively) or the OKT3 group (22/101 and 7/101, respectively) with significance of p = 0.001 and 0.06 respectively. Late mortality beyond 30 days after transplant was lowest with N/R-ATS IND compared with the OKT3 and no IND (p = 0.01). Induction did not affect cumulative infections, deaths due to infection, or the frequency of malignancies. Patients excluded from N/R-ATS induction had the highest mortality (18/ 43), suggesting that the protocol's exclusion criteria identified a high-risk group. To minimize potential effect(s) of exclusion bias, patients transplanted at centers participating in the N/R-ATS induction trial were reanalyzed with a post hoc intent-to-treat analysis assigning patients by center (IND or no IND) irrespective of actual treatment. With this analysis overall mortality was 18% for N/R-ATS centers, 21% for OKT3 centers, and 26% for centers not using IND (p = 0.3). The mortalities of recipients <6 months old at transplant were lowest at centers using N/R-ATS and OKT3 IND compared to centers not using IND (p = 0.04). Cumulative rejection (0.8 vs 1.2 rejection/pt/year, p = 0.01) and freedom from rejection death (99% vs. 93% at year 1, p = 0.02) of the N/R-ATS centers were lower compared to OKT3 centers but were not different from centers not using IND. CONCLUSION: Following orthotopic transplantation, induction immunotherapy can exert the enduring benefit of reducing late deaths, a possible surrogate for rejection severity, in recipients less than 6 months of age, while not being associated with higher rates of infectious or malignant complications. Since polyclonal anti-T cell antibody preparations appears superior to OKT3 induction in pediatric recipients, the efficacy of ATS induction should be further evaluated in a randomized prospective study in pediatric heart recipients.

Adolescent↗
PubMed2006

Perioperative anxiety and postoperative behavioural disturbances in children: comparison between induction techniques.

BACKGROUND AND OBJECTIVE: This study was designed to determine if subhypnotic propofol reduces postoperative behavioural disturbances in children undergoing sevoflurane induction compared with intravenous propofol induction for elective adenoidectomy and tonsillectomy. METHODS: Following Ethics Committee approval and parental informed consent, ASA I-II, 120 children (2-10 yr) were recruited. Parents were not allowed to accompany their child. Unpremedicated children were randomly allocated to groups receiving inhalation induction with sevoflurane, 2-2.5 mg kg-1 intravenous propofol induction or inhalation induction with sevoflurane followed by subhypnotic dose of propofol (1 mg kg-1). Anaesthesia was maintained with 2-4% sevoflurane, O2 and N2O. Anxiety on arrival to operating theatre, at anaesthesia induction and 30 min after emergence was assessed. Parents completed a state-trait anxiety inventory test preoperatively and a post hospitalization behaviour questionnaire a week later to assess children's postoperative behavioural disturbances. Kruskal-Wallis test, Wilcoxon signed rank sum test, Bonferroni's test, Paired t-test, t-test, Pearson and Spearman's rank correlation test, chi2-test were used for statistical analysis. RESULTS: The anxiety level at induction was high in all groups (P < 0.05). There was no difference between groups in respect to anxiety at other measurement times. A relation between preoperative anxiety level and postoperative behavioural disturbances was determined (P < 0.05). Some behavioural disturbances as nightmare/night fear and desire of sleeping with parents were rarely seen in intravenous propofol induction group (P < 0.05). CONCLUSION: Addition of subhypnotic dose of propofol to sevoflurane induction did not reduce the incidence of postoperative behavioural disturbances.

Adenoidectomy↗
PubMed2006

IRF family proteins and type I interferon induction in dendritic cells.

Dendritic cells (DC), although a minor population in hematopoietic cells, produce type I interferons (IFN) and other cytokines and are essential for innate immunity. They are also potent antigen presenters and regulate adaptive immunity. Among DC subtypes plasmacytoid DC (pDC) produce the highest amounts of type I IFN. In addition, pro- and anti-inflammatory cytokines such as IL-12 and IL-10 are induced in DC in response to Toll like receptor (TLR) signaling and upon viral infection. Proteins in the IRF family control many aspects of DC activity. IRF-8 and IRF-4 are essential for DC development. They differentially control the development of four DC subsets. IRF-8-/- mice are largely devoid of pDC and CD8alpha+ DC, while IRF-4-/- mice lack CD4+DC. IRF-8-/-, IRF4-/-, double knock-out mice have only few CD8á-CD4-DC that lack MHC II. IRF proteins also control type I IFN induction in DC. IRF-7, activated upon TLR signaling is required for IFN induction not only in pDC, but also in conventional DC (cDC) and non-DC cell types. IRF-3, although contributes to IFN induction in fibroblasts, is dispensable in IFN induction in DC. Our recent evidence reveals that type I IFN induction in DC is critically dependent on IRF-8, which acts in the feedback phase of IFN gene induction in DC. Type I IFN induction in pDC is mediated by MyD88 dependent signaling pathway, and differs from pathways employed in other cells, which mostly rely on TLR3 and RIG-I family proteins. Other pro-inflammatory cytokines are produced in an IRF-5 dependent manner. However, IRF-5 is not required for IFN induction, suggesting the presence of separate mechanisms for induction of type I IFN and other pro-inflammatory cytokines. IFN and other cytokines produced by activated DC in turn advance DC maturation and change the phenotype and function of DC. These processes are also likely to be governed by IRF family proteins.

Animals↗
PubMed2000

A prospective study of intensive induction therapy with high-dose consolidation in patients with aggressive non-Hodgkin's lymphoma and two or three adverse prognostic factors.

Patients with NHL and two or three factors of the International Prognostic Index (IPI) have a poor prognosis. We performed a prospective trial of intensive induction therapy followed with high-dose consolidation in such patients to determine the feasibility of this approach, as well as the response rate and survival. Untreated patients with aggressive lymphoma under the age of 60 with two or three adverse prognostic factors (disseminated stage, increased serum LDH, ECOG performance status >1) were prospectively included between June 1995 and April 1998 in a trial evaluating intensive induction chemotherapy with the ACE regimen (adriamycin day 1; cyclophosphamide days 1-2; etoposide days 1-3), with G-CSF support. Patients in complete remission after induction received one course of intensification with stem cell support (BEAM regimen), whereas patients in partial response received two intensifications (BEAM, then ICE regimens). Thirty-three patients (median age 38 years) were included. All patients presented WHO grade 4 leukopenia and 84% grade 3-4 thrombocytopenia during induction. There was one toxic death during induction. Twenty-nine patients proceeded to high-dose consolidation, including 12 patients who received a second high-dose treatment. The overall response rate was 88% (95% CI 76-99%), both after induction therapy and treatment completion. Thirty-nine percent of the patients had achieved complete remission after induction, and 73% after treatment completion. With a median follow-up after treatment onset of 29 months, the projected 3-year overall survival was 71% (95% CI 64-78%) and the event-free survival 58% (95% CI 50-66%). Event-free survival was significantly shorter in patients who did not achieve CR after induction therapy or after treatment completion. Early therapeutic intensification after intensive induction chemotherapy is feasible in patients with poor prognosis aggressive NHL and shows promising response and survival rates.

Adolescent↗
PubMed2003

Labor induction rate variation in upstate New York: what is the difference?

BACKGROUND: Labor induction rates in the United States rose from 9.0 percent in 1989 to 20.5 percent in 2001, but reasons for the increase are poorly defined. A birth database from a region of upstate New York, including 31,352 deliveries from 1998 through 1999, was used to determine the degree of variation of labor induction rates among hospitals and practitioners. METHODS: Total and elective labor induction rates were calculated for 16 hospitals and individual staff, and then evaluated using chi-square testing and regression. RESULTS: Using all laboring women as the denominator, the regional labor induction rate was 20.8 percent; of these inductions, 25 percent had no apparent medical indication. Total induction rates and percent of elective inductions that were elective varied significantly among hospitals (10%-39% and 12%-55%, respectively, p<0.0001) and among practitioners within hospitals (7%-48% and 3%-76%, respectively, p<0.0001). Hospitals varied in size, risk status, and cesarean section rates, but these factors did not correlate with induction rates. CONCLUSIONS: Labor induction rates are highly variable among and within hospitals. Delivery volume, population risk status, and differences in cesarean section rates did not explain this variation.

Adult↗
PubMed1999

Cytokines in the induction and circumvention of peripheral tolerance.

Injection of deaggregated (monomeric) human gamma globulin (DHGG) into mice induces a state of immunological tolerance to subsequent challenge with immunogenic forms of HGG. Tolerance was shown to be induced in both the Th1 and Th2 CD4+ subsets. These mice fail to demonstrate antibody production, T cell proliferation, cytokine release, or T cell helper function. On the other hand, simultaneous injection of lipopolysaccharide (LPS) as well as interleukin-1 (IL-1) was capable of interfering with the induction of tolerance to DHGG. The purpose of the present study is to extend these investigations to determination of the cellular mechanisms responsible for the interference of tolerance induction in both CD4+ T cell subsets. It was demonstrated that LPS and IL-1 have differential effects on the induction of tolerance in the CD4+ subsets. As evidenced by immunoglobulin G (IgG) subclass, T helper cell function, and lymphokine secretion, coinjection of LPS with tolerogen interfered with the induction of tolerance in both subsets, whereas IL-1 interfered with the induction of tolerance exclusively in the Th1 subset. LPS and IL-1 had differential effects on the interference of the induction of tolerance in LPS-resistant mice where IL-1, but not LPS, was effective. In contrast to IL-1, IL-12 injected along with DHGG failed to interfere with the induction of tolerance in either Th1 or Th2 cells. Previous studies that demonstrated tolerance in the DHGG models induced in both the Th1 and Th2 subsets was further suggested by the demonstrations in the present study that dose-response curves for the induction of tolerance are identical in both subsets. The above findings taken together are compatible with the suggestion that tolerance induction results from the lack of cytokine production, which then prevents the expansion of Th1 and Th2 subsets following activation of the CD4+ precursor T cell. Furthermore, they support the general opinion that the expansion of these two subsets involve different cytokine pathways and that LPS and IL-1 most likely act through different cell receptors.

Animals↗
PubMed2004

Agitation and changes of Bispectral Index and electroencephalographic-derived variables during sevoflurane induction in children: clonidine premedication reduces agitation compared with midazolam.

BACKGROUND: This double-blind randomized study was undertaken to assess agitation, Bispectral Index (BIS) and EEG changes during induction of anaesthesia with sevoflurane in children premedicated with midazolam or clonidine. METHODS: Children were allocated randomly to receive rectal midazolam 0.4 mg kg(-1) (n=20) or oral clonidine 4 microg kg(-1) (n=20) as premedication. Rapid induction of anaesthesia was achieved with inhalation of sevoflurane 8% in nitrous oxide 50%-oxygen 50%. After tracheal intubation, the children's lungs were mechanically ventilated and the inspired sevoflurane concentration was adjusted to achieve an end-tidal fraction of 2.5%. The EEG and BIS were recorded during induction until 10 min after tracheal intubation. The EEG was analysed using spectral analysis at five points: baseline, loss of eyelash reflex, 15 s before the nadir of the BIS (BIS(nadir)), when both pupils returned to the central position (immediately before intubation), and 10 min after intubation. RESULTS: Agitation was observed in 12 midazolam-treated and five clonidine-treated patients (P=0.05). At baseline, EEG rhythms were slower in the clonidine group. Induction of anaesthesia was associated with similar EEG changes in the two groups, with an increase in total spectral power and a shift towards low frequencies; these changes were maximal around the end of the second minute of induction (BIS(nadir)). When the pupils had returned to the central position, fast EEG rhythms increased and BIS was higher than BIS(nadir) (P<0.05). In both groups, agitation was associated with an increase in slow EEG rhythms at BIS(nadir). CONCLUSIONS: Compared with midazolam, clonidine premedication reduced agitation during sevoflurane induction. During induction with sevoflurane 8% (oxygen 50%-nitrous oxide 50%), the nadir of the BIS occurred at the end of the second minute of inhalation. Agitation was associated with a more pronounced slowing of the EEG rhythms at BIS(nadir) compared with inductions in which no agitation was observed. The BIS may not follow the depth of anaesthesia during sevoflurane induction in children.

Adjuvants, Anesthesia↗
PubMed2005

Randomized comparison of three methods of induction of anaesthesia with sevoflurane.

BACKGROUND: Rebreathing will occur if a low gas flow and a Mapleson D circuit are used to induce anaesthesia with a volatile anaesthetic agent. This has the advantage that it allows ventilation to be sustained when consciousness is lost, and specific manoeuvres such as breath-holding or vital capacity breaths are not needed to facilitate induction of anaesthesia. However, if the fresh gas flow were too small, this would slow induction by limiting the rate of delivery of the anaesthetic agent. To assess the impact of fresh gas flow and rebreathing, we compared induction using sevoflurane 8% given by three different methods. METHODS: We randomly allocated 65 patients to receive induction of anaesthesia from either a Mapleson A breathing system with a fresh gas flow of 9 litre min(-1) (group A9), a Mapleson D system with a fresh flow of 6 litre min(-1) (group D6) or a Mapleson D system with a fresh flow of 3 litre min(-1) (group D3). We measured times for induction, end-tidal sevoflurane and end-tidal carbon dioxide. RESULTS: The median (quartiles) induction times were 58 (45, 72), 50 (42, 65) and 64 (52, 92) s in the groups A9, D6 and D3 respectively. Induction of anaesthesia took longer (P<0.01) and was more variable in group D3. In this group, end-tidal sevoflurane concentration at the time of induction of anaesthesia was lower (P<0.05). In group A9, end-tidal carbon dioxide was less (P<0.05). CONCLUSIONS: In adult patients allowed to breathe normally, prompt and consistent inhalation induction of anaesthesia with sevoflurane is obtained when fresh gas flow is limited to 6 litre min(-1) from a Mapleson D circuit, but smaller flows are impractical.

Adolescent↗
PubMed2001

ras oncogene expression determines sensitivity for intercellular induction of apoptosis.

Fibroblasts carrying an inducible ras oncogene acquire the transformed phenotype after oncogene induction. As a consequence, the transformed cells become sensitive to intercellular induction of apoptosis, a novel regulatory process directed by non-transformed fibroblasts against their transformed descendants. The causal relationship between oncogene expression and sensitivity to intercellular induction of apoptosis is based on extracellular superoxide anion production by oncogene-expressing cells. Superoxide anions (after dismutation to hydrogen peroxide) thereby foster HOCl synthesis and at the same time direct the selectivity of apoptosis induction through hydroxyl generation from HOCl. In parallel, ras expression enhances the sensitivity of fibroblasts for apoptosis-inducing stimuli like cycloheximide, ceramide and mitomycin C. This sensitization seems to be based on a decreased concentration of short lived endogenous apoptosis inhibitors. TGF-beta, like ras induction, decreases the concentration of endogenous apoptosis inhibitors, but does not induce the transformed phenotype. Therefore, TGF-beta treatment alone is not sufficient to render fibroblasts sensitive for intercellular induction of apoptosis, but TGF-beta treatment in parallel with ras activation enhances intercellular induction of apoptosis. Our findings demonstrate that Ras-mediated superoxide anion production determines sensitivity to intercellular induction of apoptosis, whereas the parallel decrease in endogenous apoptosis inhibitors modulates the kinetics of apoptosis induction.

Animals↗
PubMed2004

Interactions between sulforaphane and apigenin in the induction of UGT1A1 and GSTA1 in CaCo-2 cells.

The isothiocyanate, sulforaphane and the flavonoid, apigenin modulate gene expression including phase II detoxifying enzymes, such as glutathione S-transferases (GST) and UDP-glucuronosyltransferases (UGT). Using undifferentiated CaCo-2 cells, we have examined the interactions between sulforaphane and apigenin in the regulation of UGT and GST expression. We show that apigenin induces UGT1A1 transcription (4-fold) but not GSTA1, and that sulforaphane induces both UGT1A1 (3.7-fold) and GSTA1 (2.8-fold) transcription in both dose- and time-dependent manners. The combination of sulforaphane and apigenin resulted in a synergistic induction of UGT1A1 mRNA up to 12-fold, although this interaction was not seen for GSTA1. Nuclear factor kappa B (NF-kappaB) mRNA was induced by apigenin and sulforaphane (2.5- and 2-fold, respectively). NF-kappaB translocation inhibitor SN50 and phosphatidylinositol 3-kinase (PI3) inhibitor LY294002 decreased the induction of GSTA1 by sulforaphane almost to baseline level. However, the MEK inhibitor PD98059 enhanced significantly the induction of GSTA1 by sulforaphane. This suggests that NF-kappaB and PI3-kinase signaling pathways play a role in GSTA1 gene expression. Conversely, the induction of UGT1A1 transcription by sulforaphane was totally abolished by PD98059, although PD98059 slightly enhanced (20%) the induction of UGT1A1 by apigenin implying that the induction of UGT1A1 by sulforaphane is mediated by MAPK/extracellular signal-regulated kinase kinase, whereas UGT1A1 induction by apigenin may be associated with NF-kappaB translocation since the NF-kappaB translocation inhibitor, SN50 enhanced the induction of UGT by apigenin. The results show that UGT1A1 and GSTA1 are regulated by sulforaphane through different signal transduction pathways and the differences in the mechanisms of modulation of UGT1A1 transcription by sulforaphane and apigenin resulted in a synergistic effect between these two compounds in the induction of UGT1A1.

Adenocarcinoma↗
PubMed2000

Comparison of the incidence of complications at induction and emergence in infants receiving oral atropine vs no premedication.

We studied 120 patients less than 1 yr of age, allocated randomly to receive atropine 40 micrograms kg-1 orally 1 h before operation (group A) or no premedication (group B). All patients underwent a standardized anaesthetic, including inhalation induction with halothane followed by atracurium 0.5 mg kg-1, tracheal intubation and positive pressure ventilation. Monitoring during anaesthesia included heart rate, arterial oxygen saturation, temperature and airway conditions at induction and emergence. The incidence of a decrease in arterial oxygen saturation to 94% or less at induction and recovery was similar in both groups (30.5% at induction, 39% at extubation in group A; 31% at induction, 41% at extubation in group B). There were significantly more airway complications in group B both at induction and emergence (25% and 49%, respectively, compared with 9% and 25% in group A; P < 0.015). Mean heart rate at induction and in the peroperative period was significantly higher in the group receiving atropine (P < or = 0.001). There was an increased incidence of bradycardia (decrease in heart rate of > or = 20%) at induction in the non-premedicated group (23% in group B compared with 10% in group A), but this was not statistically significant. We conclude that the incidence of airway complications at induction and emergence was reduced by orally administered atropine premedication.

Anesthesia Recovery Period↗
PubMed1999

Photosynthetic induction responses to variable light under field conditions in three species grown in the gap and understory of a Fagus crenata forest.

Photosynthetic induction responses to abrupt increases in photon flux density (PFD) to 800 and 1500 &mgr;mol m(-2) s(-1) from either darkness or 100 &mgr;mol m(-2) s(-1) were examined in situ in leaves of Fagus crenata Blume, Daphniphyllum humile Maxim., and Acer rufinerve Siebold & Zucc. growing in a gap and the understory of an F. crenata forest. Among the species studied, F. crenata exhibited the highest assimilation rate (A(100)), stomatal conductance (g(s100)) at the background PFD of 100 &mgr;mol m(-2) s(-1), and A(100)/A(max) (A(max) = maximum assimilation rate), in both the gap and the understory. Time required for full induction depended on both background PFD and maximum PFD. The induction period was 2-4-fold shorter at a background PFD of 100 &mgr;mol m(-2) s(-1) than in darkness. For the three understory species, time required to full induction was 2-3-fold longer when irradiance was increased from darkness to 800 &mgr;mol m(-2) s(-1) than when irradiance was increased from darkness to 1500 &mgr;mol m(-2) s(-1). Acer rufinerve showed higher initial stomatal conductance (g(s0)) and a shorter induction period in the understory than in the gap. Fagus crenata exhibited a similar g(s0) and induction period in both habitats. Daphniphyllum humile demonstrated lower g(s0) and a longer induction period in the understory than in the gap. These findings indicate that initial stomatal conductance is closely correlated with the photosynthetic induction response. We conclude that the photosynthetic induction response is affected by the light conditions experienced by plants before the sudden increase in irradiance and by the extent of the increase in irradiance.

Journal Article↗
PubMed1999

Exposure to sevoflurane and nitrous oxide during four different methods of anesthetic induction.

UNLABELLED: The National Institute for Occupational Safety and Health-recommended exposure levels for nitrous oxide exposure are 25 ppm as a time-weighted average over the time of exposure. The exposure limit for halogenated anesthetics (without concomitant nitrous oxide exposure) is 2 ppm. Inhaled sevoflurane provides an alternative to i.v. induction of anesthesia. However, the inadvertent release of anesthetic gases into the room is likely to be greater than that with induction involving i.v. anesthetics. We therefore evaluated anesthesiologist exposure during four different induction techniques. Eighty patients were assigned to one of the induction groups to receive: 1) sevoflurane and nitrous oxide from a rebreathing bag, 2) sevoflurane and nitrous oxide from a circle circuit, 3) propofol 3 mg/kg, and 4) thiopental sodium 5 mg/kg. Anesthesia was maintained with sevoflurane and nitrous oxide via a laryngeal mask. Trace concentrations were measured directly from the breathing zone of the anesthesiologist. During induction, peak concentrations of sevoflurane and nitrous oxide with the two i.v. methods rarely exceeded 2 ppm sevoflurane and 50 ppm nitrous oxide. Concentrations during the two inhalation methods were generally <20 ppm sevoflurane and 100 ppm nitrous oxide. During maintenance, median values were near 2 ppm sevoflurane and 50 ppm nitrous oxide in all groups. Sevoflurane concentrations during inhaled induction frequently exceeded the National Institute for Occupational Safety and Health-recommended exposure ceiling of 2 ppm but mostly remained <20 ppm. Exposure during the maintenance phase of anesthesia also frequently exceeded the 2-ppm ceiling. We conclude that operating room anesthetic vapor concentrations are increased during inhaled inductions and remain increased with laryngeal mask ventilation. IMPLICATIONS: We compared waste gas concentrations to sevoflurane and nitrous oxide during four different induction methods. During inhaled induction with a rebreathing bag or a circle circuit system, waste gas concentrations frequently exceed National Institute for Occupational Safety and Health limits of 2 ppm sevoflurane and 50 ppm nitrous oxide. Therefore, we recommend that people at risk (e.g., women of child-bearing age) should pay great attention when using this technique.

Air Pollution, Indoor↗
PubMed2000

Bisulfite-containing propofol: is it a cost-effective alternative to Diprivan for induction of anesthesia?

UNLABELLED: Propofol (Diprivan(TM); AstraZeneca, Wilmington, DE) is a commonly used drug for the induction of general anesthesia in the ambulatory setting. With the availability of a new bisulfite-containing generic formulation of propofol, questions have arisen regarding its cost effectiveness and safety compared with Diprivan(TM). Two hundred healthy outpatients were randomly assigned, according to a double-blinded protocol, to receive either Diprivan(TM) or bisulfite-containing propofol 1.5 mg/kg IV as part of a standardized induction sequence. Maintenance of anesthesia consisted of either desflurane (4%-8% end-tidal) or sevoflurane (1%-2% end-tidal) in combination with a remifentanil infusion (0.125 microg x kg(-1) x min(-1) IV). Patient assessments included pain on injection, induction time, hemodynamic and bispectral electroencephalographic changes during induction, emergence time, and incidence of postoperative nausea and vomiting. The two propofol groups were comparable demographically, and the induction times and bispectral index values during the induction were also similar. However, the bisulfite-containing formulation was associated with less severe pain on injection (5% vs 11%), with fewer patients recalling pain on injection after surgery (38% vs. 51%, P<0.05). None of the patients manifested allergic-type reactions after the induction of anesthesia. The acquisition cost (average wholesale price in US dollars) of a 20-mL ampoule of Diprivan(TM) was $15 compared with $13 for the bisulfite-containing propofol formulation. Therefore, we concluded that the bisulfite-containing formulation of propofol is a cost-effective alternative to Diprivan(TM) for the induction of outpatient anesthesia. IMPLICATIONS: Bisulfite-containing propofol and Diprivan(TM) (AstraZeneca, Wilmington, DE) were similar with respect to their induction characteristics; however, the generic formulation was associated with a smaller incidence of injection pain. Assuming that the drug costs are similar, these data suggest that the bisulfite-containing formulation of propofol is a cost-effective alternative to Diprivan(TM).

Ambulatory Care↗
PubMed2006

Natural prostaglandins for induction of labor and preinduction cervical ripening.

Prostaglandin (PG) E2 has superseded all other natural prostaglandins for induction of labor and pre-induction cervical ripening. This evolution and its rationale are briefly described. PGE2 has been administered intravenously, orally, vaginally, endocervically, and extra-amniotically for induction of labor. All of these, except the intravenous route, have also been explored for pre-induction cervical ripening. The distinction between formal induction and pre-induction is not always clearly made with many studies pursuing both goals at once. Nevertheless, the effectiveness of PGE2 to achieve ripening and induction is currently beyond doubt. In women with unfavorable induction prospects PGE2 results in lower rates of failed induction and higher rates of delivery within a reasonable interval than amniotomy and/or oxytocin. This also applies to women with prelabor rupture of the membranes, but the relative advantages of PGE2 over traditional methods are less clear for women with a favorable cervix. Vaginal administration of PGE2 has superseded virtually all other routes of PGE2 administration except the endocervical route, which tends to give variable results depending on spillage from the endocervical canal. Doses and formulations of vaginal PGE2 with various gels, tablets, pessaries and slow release inserts have varied widely and continue to do so. There is currently no evidence for the superiority of one PGE2 preparation over another.

Cervical Ripening↗