Defining reasonable patient standard and preference for shared decision making among patients undergoing anaesthesia in Singapore.

BACKGROUND: A cross-sectional study to ascertain what the Singapore population would regard as material risk in the anaesthesia consent-taking process and identify demographic factors that predict patient preferences in medical decision-making to tailor a more patient-centered informed consent. METHODS: A survey was performed involving patients 21 years old and above who attended the pre-operative evaluation clinic over a 1-month period in Singapore General Hospital. Questionnaires were administered to assess patients' perception of material risks, by trained interviewers. Patients' demographics were obtained. Mann-Whitney U test and Kruskal-Wallis one-way analysis of variance was used. Statistical significance was taken at p < 0.05. RESULTS: Four hundred fourteen patients were eligible of which 26 refused to participate and 24 were excluded due to language barrier. 364 patients were recruited. A higher level of education (p < 0.007), being employed (p < 0.046) and younger age group (p < 0.003) are factors identified in patients who wanted greater participation in medical decisions. Gender, marital status, type of surgery, and previous surgical history did not affect their level of participation. The complications most patients knew about were Nausea (64.8%), Drowsiness (62.4%) and Surgical Wound Pain (58.8%). Patients ranked Heart Attack (59.3%), Death (53.8%) and Stroke (52.7%) as the most significant risks that they wanted to be informed about in greater detail. Most patients wanted to make a joint decision with the anaesthetist (52.2%), instead of letting the doctor decide (37.1%) or deciding for themselves (10.7%). Discussion with the anaesthetist (61.3%) is the preferred medium of communication compared to reading a pamphlet (23.4%) or watching a video (15.4%). CONCLUSION: Age and educational level can influence medical decision-making. Despite the digital age, most patients still prefer a clinic consult instead of audio-visual multimedia for pre-operative anaesthetic counselling. The local population appears to place greater importance on rare but serious complications compared to common complications. This illustrates the need to contextualize information provided during informed consent to strengthen the doctor-patient relationship.

Burial effects of organic coatings on the heterogeneous reactivity of particle-borne benzo[a]pyrene (BaP) toward ozone.

With an aerosol flow tube coupled to an Aerodyne aerosol mass spectrometer (AMS), room temperature (296 ± 3 K) kinetics studies have been performed on the reaction of gas-phase ozone with benzo[a]pyrene (BaP) adsorbed in submonolayer amounts to dry ammonium sulfate (AS) particles. Three organic substances, i.e., bis(2-ethylhexyl)sebacate (BES, liquid), phenylsiloxane oil (PSO, liquid), and eicosane (EC, solid), were used to coat BaP-AS particles to investigate the effects of such organic coatings on the heterogeneous reactivity of PAHs toward ozone. All the reactions of particle-borne BaP with excess ozone exhibit pseudo-first-order kinetics in terms of BaP loss, and reactions with a liquid organic coating proceed by the Langmuir-Hinshelwood (L-H) mechanism. Liquid organic coatings did not significantly affect the kinetics, consistent with the ability of reactants to rapidly diffuse through the organic coating. In contrast, the heterogeneous reactivity of BaP was reduced substantially by a thin (4-8 nm), solid EC coating and entirely suppressed by thick (10-80 nm) coatings, presumably because of slow diffusion through the organic layer. Although the heterogeneous reactivity of surface-bound PAHs is extremely rapid in the atmosphere, this work is the first to experimentally demonstrate a mechanism by which the lifetime of PAHs may be significantly prolonged, permitting them to undergo long-range transport to remote locations.

Quantifying trace gas uptake to tropospheric aerosol: recent advances and remaining challenges.

The interactions of trace gases with tropospheric aerosol can have significant effects on both gas phase and aerosol composition. In turn, this may affect the atmospheric oxidizing capacity, aerosol hygroscopicity and optical properties, and the lifetimes of trace aerosol species. Through the detailed description of specific reaction systems, this review article illustrates how detailed experimental studies of gas-particle interactions lead to both a comprehensive understanding of the underlying physical chemistry as well as accurate parameterizations for atmospheric modeling. The reaction systems studied illustrate the complexity in the field: (i) N(2)O(5) uptake, presented as a benchmark multiphase system, can lead to both NO(x) loss and halogen activation, (ii) loss of HO(2) on aqueous particles is surprisingly poorly studied given its potential importance for HO(x) loss, (iii) uptake of HNO(3) by marine aerosol and heterogeneous oxidation of organic-bearing particles are examples of how gas-particle interactions can lead to substantial alteration of aerosol composition, and (iv) the uptake of glyoxal to ammonium sulfate aerosol leads to highly complex particle-phase chemistry. In addition, for the first time, this article presents the challenges that must be addressed in the design and interpretation of atmospheric gas-to-particle uptake experiments.

Investigation of aqueous-phase photooxidation of glyoxal and methylglyoxal by aerosol chemical ionization mass spectrometry: observation of hydroxyhydroperoxide formation.

Aqueous-phase processing of glyoxal (GLY) and methylglyoxal (MG) produces highly oxygenated, less volatile organic acids that can contribute to SOA formation and aging. In this study, aerosol chemical ionization mass spectrometry (aerosol CIMS) is employed to monitor aqueous-phase photooxidation of GLY and MG. Using iodide (I(-)) as the reagent ion, aerosol CIMS can simultaneously detect important species involved in the reactions: organic acids, peroxides, and aldehydes, so that the reconstructed total organic carbon (TOC) concentrations from aerosol CIMS data agree well with offline TOC analysis. This study also reports the first direct detection of hydroxyhydroperoxide (HHP) formation from the reaction of H(2)O(2) with GLY or MG. The formation of HHPs is observed to be reversible and an estimate of their equilibrium constants is made to be between 40 and 200 M(-1). Results of this study suggest that HHPs can form additional formic acid and acetic acid via photooxidation and regenerate GLY or MG during photooxidation, compensating their loss. HHP formation needs to be further studied for inclusion in aqueous-phase chemical models given that it may affect the aqueous partitioning of carbonyls in the atmosphere.

Medication use is associated with fatigue in a sample of community-living individuals who have a spinal cord injury: a chart review.

OBJECTIVES: To investigate the relationship between medications known to cause fatigue in spinal cord injury (SCI) and fatigue severity and to describe the pattern of prescription of these medications. STUDY DESIGN: Retrospective chart review. SETTING: GF Strong Rehabilitation Centre, Vancouver, British Columbia, Canada. METHODS: Medical charts of 136 individuals admitted to the GF Strong Outpatient SCI Program between December 2004 and May 2007 were reviewed. Data collected included information on medications, clinical and demographic characteristics and Fatigue Severity Scale (FSS) scores. Multiple linear regression techniques were used to analyse the data. RESULTS: Fifty-two percent of the subjects had clinically relevant fatigue. As a group, the subjects were taking 147 different medications; 41/147 medications were identified as causing fatigue. The two most commonly prescribed categories of medications were antispasticity medications (75 subjects) and analgesic medications (61 subjects). Although several variables were found to contribute to the FSS scores including the use of fatigue-causing medications, the presence of pain (7.6% of variance) and the use of fatigue-causing analgesics (4.2% of variance) explained the most variance in the scores. CONCLUSION: Fatigue is prevalent in outpatients with SCI. Fatigue-causing medications contribute to a higher FSS score. Clinicians treating persons with SCI should be aware that fatigue is a common and significant problem. Clinicians should be aware that fatigue may be exacerbated by the use of medication and should enquire about the effects of medication on fatigue when assessing and prescribing new medications.

Comparison of the single-use LMA supreme with the reusable ProSeal LMA for anaesthesia in gynaecological laparoscopic surgery.

The Laryngeal Mask Airway Supreme (LMAS) is a new, single-use laryngeal mask airway with gastric access. We conducted a randomised controlled study comparing the LMAS with the reusable ProSeal Laryngeal Mask Airway (PLMA) in 70 patients undergoing general anaesthesia with paralysis for gynaecological laparoscopic surgery. Our primary outcome measure was the oropharynegal leak pressure. We also compared the two devices for ease of insertion, adequacy of ventilation and incidence of complications. Both devices had similar rates of successful insertion at the first attempt (LMAS 94% vs PLMA 91%). There was no difference in the time to establish an effective airway (LMAS 25 +/- 22 vs PLMA 24 +/- 9 seconds), although gastric tube insertion was faster for the LMAS (5 +/- 1 vs 7 +/- 3 seconds, P < 0.001). The mean oropharyngeal leak pressure in the LMAS was significantly lower than in the PLMA (27.9 +/- 4.7 vs 31.7 +/- 6.3 cmH2O, P = 0.007). This was consistent with a lower maximum tidal volume achieved with the LMAS (481 +/- 76 vs 515 +/- 63 ml, P = 0.044). We found that after 60 minutes the cuff pressure was significantly higher in the PLMA (110 +/- 21 vs 57 +/- 8 cmH2O, P < 0.001). There was no difference in the ability to provide adequate ventilation and oxygenation during anaesthesia. Complication rates were similar We conclude that the oropharyngeal leak pressure and the maximum achievable tidal volume are lower with the LMAS than with the PLMA.

Prognostic implication of ST-segment resolution following primary percutaneous transluminal coronary angioplasty for ST-elevation acute myocardial infarction.

BACKGROUND: ST-segment changes have been shown to correlate with myocardial tissue perfusion. Complete ST-segment resolution after thrombolysis in acute myocardial infarction is associated with lower mortality and better left ventricular function. Primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction restores better epicardial coronary flow to the infarct-related artery than thrombolysis. However, ST changes may persist and flow can remain poor despite a patent vessel. AIM: To examine the prognostic implication of ST-segment resolution immediately following primary and rescue PTCA for ST-elevation acute myocardial infarction (STEMI). METHODS: Records of 201 consecutive primary and rescue PTCA performed at Westmead Hospital for STEMI from January 2000 to December 2001 were reviewed. ST-segment elevation (taken 20 ms after the end of the QRS complex) was measured immediately before and after the procedure. ST-segment resolution of greater than 70% after the procedure was considered as -'complete' ST-segment resolution, whereas ST-segment resolution of less than 70% was considered as 'incomplete' ST-segment resolution. RESULTS: Of the 201 patients, 117 (58%) had complete ST-elevation resolution and 84 (42%) did not. There was a significant difference in survival free of major adverse cardiovascular events; 60% of those with complete ST-segment resolution were event-free at 2 years compared with 35% of those patients without complete ST-segment resolution. CONCLUSION: ST-segment resolution after primary and rescue PTCA for STEMI is associated with significantly higher event-free survival. The goal of primary angio-plasty should be the restoration of normal epicardial flow with normalization of ST-segments.

Auricular anthropometry of Hong Kong Chinese babies.

OBJECTIVES: To provide a database of the auricular measurements of Chinese infants born in Hong Kong. DESIGN: Prospective cross-sectional study. SETTING AND SAMPLE POPULATION: A total of 2384 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from October 1998 to September 2000, were included in the study. The range of gestation was 33-42 weeks. MEASUREMENTS AND RESULTS: Measurements included ear width (EW), ear length (EL) and ear position (EP). The data show generally higher values for males in the parameters measured. When compared with previously published data for Caucasian and Jordanian term babies, Chinese babies have shorter EL. The ears were within normal position in nearly all our infants. CONCLUSION: The human ear appears to grow in a remarkably constant fashion. This study establishes the first set of gestational age-specific standard of the ear parameters for Chinese new-borns, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these ear parameters.

Facial anthropometry of Hong Kong Chinese babies.

OBJECTIVES: To provide a database of the craniofacial measurements of Chinese infants born in Hong Kong. DESIGN: Prospective cross-sectional study. SETTING AND SAMPLE POPULATION: A total of 2371 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from June 1998 to June 2000, were included in the study. The range of gestation was 33-42 weeks. MEASUREMENTS AND RESULTS: Measurements included facial width (FW), facial height (FH), nasal length (NL), nasal width (NW), and length of the philtrum (PhilL). The facial, nasal, nasofacial and nasozygomatic indices were derived. The data show generally higher values for males in the parameters measured. The various indices remained remarkably constant and did not vary significantly between the two genders or with gestation. When compared with previously published data for white people term babies, Chinese babies have similar NW but shorter philtrum length. CONCLUSION: The human face appears to grow in a remarkably constant fashion as defined by the various indices of facial proportions. This study establishes the first set of gestational age-specific standard of such craniofacial parameters for Chinese new-borns, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these craniofacial parameters.

Craniofacial anthropometry of Hong Kong Chinese babies: the eye.

OBJECTIVES: To provide a database of the canthal measurements of Chinese infants born in Hong Kong. DESIGN: Prospective cross-sectional study. SETTING AND SAMPLE POPULATION: A total of 2,371 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from June 1998 to June 2000, were included in the study. The range of gestation was 33-42 weeks. MEASUREMENTS AND RESULTS: Canthal parameters were measured and included the outer canthal distance (OCD), intercanthal distance (ICD) and palpebral fissure length (PFL). The data generally show higher values for males in the parameters measured. The measurements were also compared with data published overseas. PFL and OCD were significantly larger in Hong Kong Chinese newborn babies, whereas ICD was smaller. CONCLUSION: This study establishes the first set of gestational age-specific standard of such craniofacial parameters for Chinese newborn babies, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these canthal parameters.