Ice giant system exploration in the 2020s: an introduction.

The international planetary science community met in London in January 2020, united in the goal of realizing the first dedicated robotic mission to the distant ice giants, Uranus and Neptune, as the only major class of solar system planet yet to be comprehensively explored. Ice-giant-sized worlds appear to be a common outcome of the planet formation process, and pose unique and extreme tests to our understanding of exotic water-rich planetary interiors, dynamic and frigid atmospheres, complex magnetospheric configurations, geologically-rich icy satellites (both natural and captured), and delicate planetary rings. This article introduces a special issue on ice giant system exploration at the start of the 2020s. We review the scientific potential and existing mission design concepts for an ambitious international partnership for exploring Uranus and/or Neptune in the coming decades. This article is part of a discussion meeting issue 'Future exploration of ice giant systems'.

A review of the in situ probe designs from recent Ice Giant mission concept studies.

For the Ice Giants, atmospheric entry probes provide critical measurements not attainable via remote observations. Including the 2013-2022 NASA Planetary Decadal Survey, there have been at least five comprehensive atmospheric probe engineering design studies performed in recent years by NASA and ESA. International science definition teams have assessed the science requirements, and each recommended similar measurements and payloads to meet science goals with current instrument technology. The probe system concept has matured and converged on general design parameters that indicate the probe would include a 1-meter class aeroshell and have a mass around 350 to 400-kg. Probe battery sizes vary, depending on the duration of a post-release coast phase, and assumptions about heaters and instrument power needs. The various mission concepts demonstrate the need for advanced power and thermal protection system development. The many completed studies show an Ice Giant mission with an in situ probe is feasible and would be welcomed by the international science community.

An alternative method to alleviate postoperative nausea and vomiting in children.

STUDY OBJECTIVE: To evaluate whether isopropyl alcohol vapor is an effective treatment for postoperative nausea and vomiting. DESIGN: Double-blind, randomized, controlled study. SETTING: Pediatric surgery center. PATIENTS: 91 ASA physical status I and II children age 6-16 years, scheduled to undergo general anesthesia and elective outpatient surgery. INTERVENTIONS: Subjects were randomized to inhale isopropyl alcohol or saline. The intervention was repeated up to three times. If postoperative nausea or vomiting persisted after three sequences, intravenous ondansetron was administered as rescue therapy. MEASUREMENTS AND MAIN RESULTS: Improvement in nausea was assessed using a visual analog scale, and improvement in vomiting was assessed using categorical analysis. After three treatment sequences, 65% of the children in the treatment group and 26% of the children in the control group had a significant reduction in the severity of either nausea or vomiting (p = 0.03). However, 54% of subjects in the treatment group and 80% of subjects in the control group had recurrent nausea or vomiting within 20 to 60 minutes. CONCLUSIONS: Under the conditions of this study, repetitive inhaled isopropyl alcohol only achieved a transient antiemetic effect in children with established postoperative nausea or vomiting following general anesthesia and surgery.

Social adaptability, cognitive abilities, and other predictors for children's reactions to surgery.

STUDY OBJECTIVE: To examine the relationship between social adaptability, cognitive abilities, and other personality characteristics to perioperative anxiety. STUDY DESIGN: Prospective cohort investigation. PATIENTS: 60 children ASA physical status I and II, age 3 to 10 years. SETTING: Tertiary care children's hospital. MEASUREMENTS: Temperament (EASI), cognitive abilities (KABC), and adaptive behavior (Vineland) were evaluated in a group of children undergoing surgery. Parental coping style (MBBS) and parental state (STAI-S) and trait (STAI-T) anxiety were assessed as well. On the day of surgery, anxiety of the child was measured at the preoperative holding area and during induction of anesthesia (m-YPAS). MAIN RESULTS: Univariate correlational analysis demonstrated that young age (r = -0.27), poor social adaptability (Vineland) (r = -0.38), shy and inhibited personality (EASI; temperament) (r = -0.33), higher intelligence (KABC) (r = 0.29), increased parental anxiety (r = 0.44), and parental high-monitoring coping style (r = -0.25) are all associated with higher levels of perioperative anxiety. Stepwise multivariate regression analysis has demonstrated that controlling for the variables above, parental anxiety (p = 0.004), child's social adaptive capabilities (p = 0.04), and child's temperament (sociability) (p = 0.04) are independent predictors for increased perioperative anxiety (R(2) = 0.38, F = 5.5, p = 0.003). CONCLUSIONS: Anesthesiologists need to pay close attention to the families of pediatric surgical children who are socially maladjusted, shy and inhibited, and have anxious parents.

Desire for perioperative information in adult patients: a cross-sectional study.

STUDY OBJECTIVE: To identify which perioperative information outpatients want from their anesthesiologist. DESIGN: Cross-sectional study. SETTING: Outpatient center. PATIENTS: 197 ASA physical status I and II patients undergoing outpatient surgery. INTERVENTIONS: A questionnaire examining for "desire for information". MEASUREMENTS AND MAIN RESULTS: Demographic data including age, ethnicity, gender, socioeconomic status, and history of previous surgery were obtained. Trait, situational anxiety, and coping strategy were assessed using a validated behavioral instrument and a questionnaire adopted from previous studies conducted in Australia, Scotland, and Canada. Each questionnaire contained 14 statements regarding specific perioperative details. An index of the overall patient desire for information (PDI) was calculated for each subject. More than 85% of subjects gave a high priority to being informed for all the 14 items. Scores on the overall index were found to be higher for females than for males (32 +/- 6 vs. 30 +/- 6; p = 0.03), and this finding persisted in a multivariable model that also included coping strategies and anxiety (DF = 1,175, F = 4.6, p = 0.01). Subjects also had higher PDI scores if a first degree relative had a history of previous surgery (33 +/- 5 vs. 31 +/- 6; p = 0.007). On analysis of individual questionnaire items, Latino Americans were significantly less likely than European Americans or African Americans to desire perioperative information (p < 0.05). Similarly, females had a significantly higher desire for information than males. Subjects who were divorced demonstrated a higher desire for information than did single or married subjects. CONCLUSIONS: Ethnicity, gender, coping mechanism, marital status, and a history of previous surgery in a relative have been identified as predictors for the desire for information.

Response modality affects human infant delayed-response performance.

Delayed response performance was assessed in 120 7-, 9-, and 11-month-old infants with correct response defined as either retrieval of a hidden object or gaze toward the location where the object was hidden. Performance improved with age, was above chance for each age group in each condition, and was more often correct with the gaze response. When direction of gaze and reach differed, direction of gaze was more likely to be correct. Infants in the reach condition were more likely to fail to reverse a previously correct response (i.e., to make the A-not-B error). Perseverative responding occurred frequently and was more likely in the reach than the gaze condition. This effect emerged primarily in the context of an incorrect response, which suggests modality-specific sensitivity to the effect of priming rather than reinforcement. Many infants showed strong side biases, and there was a tendency for more reaches to the left but gazes to the right. In a second experiment, 12 5-month-olds gazed toward the correct location more frequently than would be expected by chance but failed to reverse a previously correct response more often than older infants. These findings indicate that response modality has a significant effect on delayed-response performance.

Parental desire for perioperative information and informed consent: a two-phase study.

The purpose of this investigation was to identify the perioperative anesthetic information parents want from the anesthesiologist, and to determine whether the provision of detailed anesthetic risk information is associated with increased parental anxiety. The investigation consisted of a cross-sectional study followed by a randomized controlled trial. In Phase 1, baseline and situational anxiety, coping strategy, and temperament were obtained from parents of children undergoing surgery (n = 334). A questionnaire examining the desire for perioperative information was administered to all parents. In Phase 2, 47 parents were randomly assigned to receive either routine anesthetic risk information (control) or detailed anesthetic risk information (intervention). The effect of the intervention on parental anxiety was assessed over four time points: prior to the intervention, immediately after the intervention, day of surgery in the holding area, and at separation to the operating room. For Phase 1, the majority of parents (> 95%) preferred to have comprehensive information concerning their child's perioperative period, including information about all possible complications. For selected items, increased parental educational level was associated with increased desire for information (P < 0.05). For Phase 2, when the intervention group was compared with the control group, there were no significant differences in parental anxiety over the four time points [F(1,45) = 0.6, P = 0.4]. Also, the interaction between time and group assignment was not significant [F(3,135) = 1.66, P = 0.18]. We conclude that parents of children undergoing surgery desire comprehensive perioperative information. Moreover, when provided with highly detailed anesthetic risk information, the parental anxiety level did not increase.

Postoperative behavioral outcomes in children: effects of sedative premedication.

BACKGROUND: Although multiple studies document the effect of sedative premedication on preoperative anxiety in children, there is a paucity of data regarding its effect on postoperative behavioral outcomes. METHODS: After screening for recent stressful life events, children undergoing anesthesia and surgery were assigned randomly to receive either 0.5 mg/kg midazolam in 15 mg/kg acetaminophen orally (n = 43) or 15 mg/kg acetaminophen orally (n = 43). Using validated measures of anxiety, children were evaluated before and after administration of the intervention and during induction of anesthesia. On postoperative days 1, 2, 3, 7, and 14, the behavioral recovery of the children was assessed using the Post Hospitalization Behavior Questionnaire. RESULTS: The intervention group demonstrated significantly lower anxiety levels compared with the placebo group on separation to the operating room and during induction of anesthesia (F[1,77] = 3.95, P = 0.041). Using a multivariate logistic regression model, the authors found that the presence or absence of postoperative behavioral changes was dependent on the group assignment (R = 0.18, P = 0.0001) and days after operation (R = -0.20, P = 0.0001). Post hoc analysis demonstrated that during postoperative days 1-7, a significantly smaller number of children in the midazolam group manifested negative behavioral changes. At week 2 postoperatively, however, there were no significant differences between the midazolam and placebo groups. CONCLUSIONS: Children who are premedicated with midazolam before surgery have fewer negative behavioral changes during the first postoperative week.

Premedication in the United States: a status report.

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

The Yale Preoperative Anxiety Scale: how does it compare with a "gold standard"?

UNLABELLED: Evaluating the effectiveness of interventions directed toward the treatment of preoperative anxiety in children has been hindered by the absence of a statistically valid measurement tool. In a previous investigation, we developed an instrument (Yale Preoperative Anxiety Scale [YPAS]) that can be used to assess anxiety in children undergoing induction of anesthesia. The purpose of the present investigation was to modify and expand the applicability of the instrument to the preoperative holding area and to validate the modified instrument (m-YPAS) against a recognized "gold standard" (State-Trait Anxiety Inventory for Childrens [STAIC]). Videotapes of children in a preoperative holding area were analyzed by the investigators. The existing five categories of the YPAS were found to reflect most of the behaviors observed. Several items, however, were modified to describe new behaviors observed. Reliability analysis using weighted kappa statistics revealed that inter-observer agreement ranged from 0.68 to 0.86, whereas intraobserver weighted kappa ranged from 0.63 to 0.90. Concurrent validity between the YPAS and the STAIC was acceptable (P = 0.01, r = 0.79). Construct validity was high as assessed by increased m-YPAS scores from the preoperative holding area (28 +/- 8) to entering the operating room (35 +/- 12), to introduction of the anesthesia mask (43 +/- 15;F [1,36] = 0.6, P = 0.001]. Showing good to excellent observer reliability and high concurrent and construct validity, the m-YPAS proved to be an appropriate tool for assessing children's anxiety during the perioperative period. IMPLICATIONS: The absence of a statistically valid measurement tool that can be applied easily in perioperative settings hinders the evaluation of interventions directed toward treatment of preoperative anxiety in children. The authors describe the development of such a tool, the modified Yale Preoperative Anxiety Scale.

Preoperative preparation programs in children: a comparative examination.

UNLABELLED: We sought to determine whether an extensive behavioral preparation program for children undergoing surgery is more effective than a limited behavioral program. The primary end point was child and parent anxiety during the preoperative period. Secondary end points included behavior of the child during the induction of anesthesia and the postoperative recovery period. Several days before surgery, children (n = 75) aged 2-12 yr randomly received either an information-based program (OR tour), an information + modeling-based program (OR tour + videotape), or an information + modeling + coping-based program (OR tour + videotape + child-life preparation). Using behavioral and physiological measures of anxiety, we found that children who received the extensive program exhibited less anxiety immediately after the intervention, in the holding area on the day of surgery, and on separation to the operating room. These findings, however, achieved statistical significance only in the holding area on the day of surgery (44[10-72] vs 32[8-50] vs 9[6-33]; P = 0.02). Similarly, parents in the extensive program were significantly less anxious on the day of surgery in the preoperative holding area, as assessed by behavioral (P = 0.015) and physiological measures (P = 0.01). In contrast, no differences were found among the groups during the induction of anesthesia, recovery room period, or 2 wk postoperatively. We conclude that children and parents who received the extensive preoperative preparation program exhibited lower levels of anxiety during the preoperative period, but not during the intraoperative or postoperative periods. IMPLICATIONS: The extensive behavioral preoperative program that we undertook had limited anxiolytic effects. These effects were localized to the preoperative period and did not extended to the induction of anesthesia or the postoperative recovery period.

Parental presence during induction of anesthesia versus sedative premedication: which intervention is more effective?

BACKGROUND: Both midazolam and parental presence during induction of anesthesia are routinely used to treat preoperative anxiety in children. The purpose of this investigation was to determine which of these two interventions is more effective. METHODS: Anxiety of the child during the perioperative period was the primary end point. Secondary end points included anxiety of the parent and compliance of the child during induction. Children (n = 88) were randomly assigned to one of three groups: (1) 0.5 mg/kg oral midazolam; (2) parental presence during induction of anesthesia; or (3) control (no parental presence or premedication). Using multiple behavioral measures of anxiety, the effect of the intervention on the children and their parents was assessed. RESULTS: Observed anxiety in the holding area (T1), entrance to the operating room (T2), and introduction of the anesthesia mask (T3) differed significantly among the three groups (P = 0.032). Post hoc analysis indicated that children in the midazolam group exhibited significantly less anxiety compared with the children in the parental-presence group or control group (P = 0.0171). Similarly, parental anxiety scores after separation were significantly less in the midazolam group compared with the parental-presence or control groups (P = 0.048). The percentage of inductions in which compliance of the child was poor was significantly greater in the control group compared with the parental-presence and midazolam groups (25% vs. 17% vs. 0%, P = 0.013). CONCLUSIONS: Under the conditions of this study, oral midazolam is more effective than either parental presence or no intervention for managing a child's and parent's anxiety during the preoperative period.

Parental presence and a sedative premedicant for children undergoing surgery: a hierarchical study.

BACKGROUND: Although some anesthesiologists use oral sedatives or parental presence during induction of anesthesia (PPIA) to treat preoperative anxiety in children, others may use these interventions simultaneously (e.g., sedatives and PPIA). The purpose of this investigation was to determine whether this approach has advantages over treating children with sedatives alone. METHODS: The child's and the parental anxiety throughout the perioperative period was the primary endpoint of the study. Parental satisfaction was the secondary endpoint. Subjects (n = 103) were assigned randomly to one of two groups: a sedative group (0.5 mg/kg oral midazolam) or a sedative and PPIA group. Using standardized measures of anxiety and satisfaction, the effects of the interventions on the children and parents were assessed. Statistical analysis (varimax rotation) of the satisfaction questionnaire items resulted in two factors that described satisfaction of the separation process and satisfaction of the overall care provided. RESULTS: Anxiety in the holding area, at entrance to the operating room, and at introduction of the anesthesia mask did not differ significantly between the two groups (F[2,192] = 1.26, P = 0.28). Parental anxiety after separation, however, was significantly lower in the sedative and PPIA group (F[2,93] = 4.46, P = 0.037). Parental satisfaction with the overall care provided (-0.28 +/- 1.2 vs. 0.43 +/- 0.26, P = 0.046) and with the separation process (-0.30 +/- 1.2 vs. 0.47 +/- 0.20, P = 0.03) was significantly higher among the sedative and PPIA group compared with the sedative group. CONCLUSIONS: PPIA in addition to 0.5 mg/kg oral midazolam has no additive effects in terms of reducing a child's anxiety. Parents who accompanied their children to the operating room, however, were less anxious and more satisfied.

Distress during the induction of anesthesia and postoperative behavioral outcomes.

UNLABELLED: We determined whether children who are extremely anxious during the induction of anesthesia are more at risk of developing postoperative negative behavioral changes compared with children who appear calm during the induction process. Children (n = 91) aged 1-7 yr scheduled for general anesthesia and elective outpatient surgery were recruited. Using validated measures of preoperative anxiety and postoperative behaviors, children were evaluated during the induction of general anesthesia and on Postoperative Days 1, 2, 3, 7, and 14. Using a multivariate logistic regression model, in which the dependent variable was the presence or absence of postoperative negative behavioral changes and the independent variables included several potential predictors, we demonstrated that anxiety of the child, time after surgery, and type of surgical procedure were predictors for postoperative maladaptive behavior. The frequency of negative postoperative behavioral changes decreased with time after surgery, and the frequency of negative postoperative behavioral changes increased when the child exhibited increased anxiety during the induction of anesthesia. Finally, we found a significant correlation (r) of 0.42 (P = 0.004) between the anxiety of the child during induction and the excitement score on arrival to the postanesthesia care unit. We conclude that children who are anxious during the induction of anesthesia have an increased likelihood of developing postoperative negative behavioral changes. We recommend that anesthesiologists advise parents of children who are anxious during the induction of anesthesia of the increased likelihood that their children will develop postoperative negative behavioral changes such as nightmares, separation anxiety, and aggression toward authority. IMPLICATIONS: Anesthesiologists who care for children who are anxious during the induction of anesthesia should inform parents that these children have an increased likelihood of developing postoperative negative behavioral changes.

Midazolam: effects on amnesia and anxiety in children.

BACKGROUND: The minimum time interval between administration of oral midazolam and separation of children from their parents that ensures good anterograde amnesia has not been previously determined. This is of particular importance in a busy operating room setting where schedule delays secondary to midazolam administration may not be tolerated. METHODS: Children (n = 113) undergoing general anesthesia and surgery completed preoperative baseline memory testing using a validated series of picture cards and were randomly assigned to one of three midazolam groups or a control group. Exactly, 5, 10, or 20 min after receiving oral midazolam (0.5 mg/kg) or 15 min after receiving placebo, children were administered a second memory test that used pictures. Anxiety of children was assessed during induction of anesthesia with use of a validated anxiety measurement tool. Postoperatively, recall and recognition for picture cards seen during baseline testing and postintervention testing were assessed. RESULTS: Postoperatively, recall and recognition of pictures presented to patients after drug administration (anterograde amnesia) showed significant group differences (P = 0.0001), with recall impaired in the 10- (P = 0.004) and 20-min groups (P = 0.0001). Similarly, recognition memory was impaired in the 5- (P = 0.0008), 10- (P = 0.0001) and 20-min (P = 0.0001) groups. Significant anxiolytic effects of midazolam were observed as early as 15 +/- 4 min after midazolam administration (P = 0.02). CONCLUSIONS: Midazolam administered orally produces significant anterograde amnesia when given as early as 10 min before a surgical procedure.

Ultra-relativistic electrons in Jupiter's radiation belts.

Ground-based observations have shown that Jupiter is a two-component source of microwave radio emission: thermal atmospheric emission and synchrotron emission from energetic electrons spiralling in Jupiter's magnetic field. Later in situ measurements confirmed the existence of Jupiter's high-energy electron-radiation belts, with evidence for electrons at energies up to 20[?]MeV. Although most radiation belt models predict electrons at higher energies, adiabatic diffusion theory can account only for energies up to around 20[?]MeV. Unambiguous evidence for more energetic electrons is lacking. Here we report observations of 13.8[?]GHz synchrotron emission that confirm the presence of electrons with energies up to 50[?]MeV; the data were collected during the Cassini fly-by of Jupiter. These energetic electrons may be repeatedly accelerated through an interaction with plasma waves, which can transfer energy into the electrons. Preliminary comparison of our data with model results suggests that electrons with energies of less than 20[?]MeV are more numerous than previously believed.