Asymptomatic spinal cord neoplasm detected during induction of spinal anesthesia.

We report a case of an asymptomatic spinal cord neoplasm detected during the placement of a 25-gauge Whitacre spinal needle for spinal anesthesia before elective cesarean delivery. Subarachnoid blood was repeatedly aspirated during otherwise uncomplicated induction of spinal anesthesia. Magnetic resonance imaging revealed a spinal cord ependymoma in the lumbar spine. Asymptomatic spinal cord neoplasms and ependymomas are reviewed. Central nervous system pathology should be considered in the presence of persistent subarachnoid blood.

An observational cohort study of the meniscus test to detect intravascular epidural catheters in pregnant women.

BACKGROUND: The meniscus test is a rapid non-pharmacologic method of confirming epidural catheter placement by observing a normal saline meniscus while physically manipulating the catheter. The aim of this study was to assess whether the meniscus test improves diagnostic accuracy of aspiration to detect intravascular or intrathecal placement of epidural catheters in pregnant women. METHODS: In this prospective observational study, parturients at >or= 36 weeks of gestation were recruited. In the sitting position, participants received a multiorifice epidural catheter for elective cesarean delivery or labor analgesia. After aspiration was confirmed to be negative for blood and cerebrospinal fluid, the meniscus test was performed. Subsequently, a pharmacologic test dose was given with 1.5% lidocaine 3 mL and epinephrine 15 microg. Intravascular placement was diagnosed if the patient experienced an increase in heart rate >or= 20 beats/min within 2 min with or without tinnitus, metallic taste, dizziness, palpitations, headache, or anxiety. RESULTS: The overall intravascular catheter rate was 5.7% (24/419). The rate of intravascular catheter location not detected by aspiration was 0.95% (4/419). Given negative catheter aspiration, the meniscus test demonstrated 25% sensitivity, 87.5% specificity, and 1.9% positive predictive value for intravascular catheter insertion. No intrathecal catheters were observed. CONCLUSIONS: For obstetric patients in the sitting position, the meniscus test does not improve diagnostic accuracy of aspiration for detecting intravascular multiorifice epidural catheter placement.

Are there clinical features of a sensitized cough reflex?

Cough reflex hypersensitization is a key feature in patients with troublesome cough. The clinical consequence of this hypersensitive state is typified by bouts of coughing often triggered by low threshold stimuli encountered by the patient during normal daily activities including exposure to aerosols, scents and odours, a change in air temperature and when talking or laughing. These features are often perceived by cough patients to be the most disruptive aspect of their condition and undoubtedly contribute to impaired quality of life. Patients with troublesome cough may describe a range of additional symptoms and sensations including an 'urge to cough' or the feeling of an 'itch' at the back of the throat, or a choking sensation and occasionally chest pain or breathlessness. It is uncertain if these features arise due to the processes responsible for cough reflex sensitization or as a direct consequence of the underlying cough aetiology. In an attempt to understand the clinical features of a sensitized cough reflex, the spectrum of symptoms typically described by cough patients will be reviewed and possible underlying mechanisms considered. Since an intact cough reflex is crucial to airway protection, anti-tussive treatment that attenuates the hypersensitive cough state rather than abolishing the cough reflex completely would be preferable. Identifying such agents remains a clinical, scientific and pharmacological challenge.

Pathogens of domestic and free-ranging ungulates: global climate change in temperate to boreal latitudes across North America.

In North America broad-based research networks explore the interaction of vertebrates, their characteristic arrays of pathogens and emergent disease. A diversity of programmes address the impact of environmental change on animal health, zoonoses, and human health, but as yet no comprehensive framework or strategy has emerged to develop and implement policy and planning. In a regime of climate change and ecological perturbation, the need to document and understand the health, agricultural, societal and economic impact of pathogens and emerging infectious disease is urgent. An integrated and proactive planning process linking national and international resources can lead to informed predictions aboutthe impact of environmental change and can identify pathways for potential management and mitigation. An effective and comprehensive programme will have components for establishing priorities, developing primary data for faunal structure and biodiversity, a capacity for monitoring and surveillance (including scanning and targeted activities), and linkage to historical and contemporary baselines (against which to assess change) established through archival biological collections. Field and laboratory studies are also necessary to determine developmental thresholds, tolerances and tipping points for many pathogens to establish a context for recognising current constraints and future perturbation, and to explore factors that promote emergence for a variety of pathogens, vectors and pest species. Predictive modelling and risk assessment utilising a range of scenarios for climate change is a final step in this multidisciplinary process.

Common causes and current guidelines.

Chronic cough is a common and disabling symptom. Recent guidelines have attempted to provide direction in the clinical management of cough in both primary and secondary care. They have also provided a critical review of the available literature and identified gaps in current knowledge. Despite this they have been criticized for a reliance on a low quality evidence base. In this review, we summarize the current consensus on the clinical management of chronic cough and attempt to rationalize this based on recent evidence. We have also provided an overview of the likely pathophysiological mechanisms responsible for cough and highlighted areas, where knowledge deficits exist and suggest directions for future research. Such progress will be critical in the search for new and effective treatments for cough.

An observational study of the relationship between lumbar epidural space depth and body mass index in Michigan parturients.

BACKGROUND: Studies of urban parturient populations demonstrate increasing prevalence of obesity, which contributes to difficult epidural catheter placement. The aim of this study was to characterize the relationship between lumbar epidural space depth and body mass index in United States parturients from Michigan. METHODS: We studied the records of 2009 parturients at or beyond 36 weeks' gestation. In addition to lumbar epidural space depth and body mass index, we recorded maternal age, gestational age and vertebral interspace of epidural placement. A multi-linear regression model was created with centimeter depth from skin to lumbar epidural space as the dependent variable and body mass index as the independent variable, adjusted for maternal age, gestational age and vertebral interspace. RESULTS: Lumbar epidural space depth was (mean +/- SD) 5.3 cm+/-1.21, with more than 96% of catheters placed at L2-3 or L3-4. Mean body mass index was 31.5+/-6.2 kg/m(2). Mean maternal age was 29.3+/-5.7 years while mean gestational age was 39.3+/-1.3 weeks. In a multi-linear regression model, body mass index and maternal age were significant predictors of centimeter depth. When adjusted for maternal age, gestational age and vertebral interspace of catheter placement, body mass index was associated with an increase in depth (P<0.0001, R(2)=0.3646). Maternal age, when adjusted for body mass index and vertebral interspace, was associated with a decreased depth (P=0.0014). CONCLUSION: When maternal age, gestational age and vertebral interspace are controlled for, increasing body mass index is associated with increasing depth, while increasing maternal age is associated with decreasing depth.

Survey of obstetric providers' views on the anesthetic risks of maternal obesity.

BACKGROUND: Maternal obesity is increasing in prevalence and associated with numerous complications. Surveys document that obstetricians recognize the obstetric and perinatal health risks of maternal obesity. To determine if they recognize the anesthetic risks and discuss them antenatally with obese patients, we surveyed all obstetric providers at a university-affiliated obstetric unit. METHODS: The survey listed complications of obesity and pregnancy sampled from the literature, including eight anesthetic complications, ten prenatal obstetric complications, ten intrapartum or postpartum obstetric complications, five medical complications and five neonatal complications. Respondents reported if and when they routinely discuss each. Reported routine discussion rates were averaged across respondents and complication categories. We postulated that anesthetic aspects would be discussed less frequently than others. RESULTS: Thirty-six of the 55 obstetric providers responded (65.5%). On average, anesthetic complications were discussed during prenatal care 13.5% of the time, less often than prenatal obstetric complications (48.5%, Wilcoxon signed rank test, P<0.0001), intrapartum or postpartum obstetric complications (40.0%, Wilcoxon signed rank test, P<0.0001) and medical complications (35.0%, Wilcoxon signed rank test, P=0.0001). The survey failed to demonstrate a statistically significant difference in the rate of discussion between anesthetic and neonatal complications (13.5% vs. 22.2%, Wilcoxon signed rank test, P=0.05). Twenty-four respondents reported that they did not routinely discuss any of the listed anesthetic complications with their obese patients in the prenatal period. CONCLUSIONS: This preliminary study suggests that antenatal education about the anesthetic implications of obesity may not be part of routine prenatal care for obese pregnant women.

Protostrongylid parasites and pneumonia in captive and wild thinhorn sheep (Ovis dalli).

We describe health significance of protostrongylid parasites (Parelaphostrongylus odocoilei and Protostrongylus stilesi) and other respiratory pathogens in more than 50 naturally infected Dall's sheep (Ovis dalli dalli) from the Mackenzie Mountains, Northwest Territories (1998-2002) as well as in three Stone's sheep (O. d. stonei) experimentally infected with P. odocoilei (2000-2002). Histological lesions in the brain and distribution of P. odocoilei in the muscles of experimentally and naturally infected sheep were consistent with a previously hypothesized "central nervous system to muscle" pattern of migration for P. odocoilei. Dimensions of granulomas associated with eggs of P. odocoilei and density of protostrongylid eggs and larvae in the cranial lung correlated with intensity of larvae in feces, and all varied with season of collection. Prevalence of P. stilesi based on the presence of larvae in feces underestimated true prevalence (based on examination of lungs) in wild Dall's sheep collected in summer and fall. Similarly, counts of both types of protostrongylid larvae in feces were unreliable indicators of parasitic infection in wild Dall's sheep with concomitant bacterial pneumonia associated with Arcanobacterium pyogenes, Pasteurella sp., and Mannheimia sp. Diffuse, interstitial pneumonia due to P. odocoilei led to fatal pulmonary hemorrhage and edema after exertion in one experimentally infected Stone's sheep and one naturally infected Dall's sheep. Bacterial and verminous pneumonia associated with pathogens endemic in wild Dall's sheep in the Mackenzie Mountains caused sporadic mortalities. There was no evidence of respiratory viruses or bacterial strains associated with domestic ruminants, from which this population of wild sheep has been historically isolated.

Bionomics of larvae of Parelaphostrongylus odocoilei (Nematoda: Protostrongylidae) in experimentally infected gastropod intermediate hosts.

Parelaphostrongylus odocoilei is a protostrongylid parasite that has recently been recognized at several locations in sub-Arctic, but not Arctic, North America. We investigated factors that may determine the distribution of P. odocoilei, including suitable gastropod intermediate hosts, temperature requirements for larval development in gastropods, and larval emergence facilitating overwinter transmission. We collected and experimentally infected gastropods from a site in the sub-Arctic where P. odocoilei is at the northern limit of its distribution. Deroceras laeve, Catinella sp., and Euconulus cf fulvus, but not members of the Pupillidae, were suitable intermediate hosts. We describe bionomics of larvae of P. odocoilei in D. laeve and Catinella sp. Infective larvae emerged from all slugs (D. laeve) and 60% of Catinella sp. snails, and emergence from D. laeve was intensity dependent. Emerged infective larvae survived up to 6 mo under conditions approximating that of the subnivean environment. In D. laeve, there was a direct relationship between temperature and development rate of larvae of P. odocoilei. Larvae of P. odocoilei did not develop to infective stage below the theoretical threshold (8.5 C), and required a minimum of 163 degree days to complete development. These developmental parameters can be incorporated into a model to predict larval development in the field. Knowledge of the factors influencing larval bionomics provides the foundation for predicting temporal and spatial patterns of parasite distribution, abundance, and transmission.

Climate change and the epidemiology of protostrongylid nematodes in northern ecosystems: Parelaphostrongylus odocoilei and Protostrongylus stilesi in Dall's sheep ( Ovis d. dalli ).

We describe the epidemiology of the protostrongylid parasites Parelaphostrongylus odocoilei and Protostrongylus stilesi in Dall's sheep (Ovis dalli dalli) from the Mackenzie Mountains, Northwest Territories, Canada (65 degrees N; 128 degrees W). Peak numbers of 1st-stage larvae of both parasites were shed by Dall's sheep on their winter range from March until May. In larval development experiments in the Mackenzie Mountains, peak numbers of infective 3rd-stage larvae of P. odocoilei were available in gastropod intermediate hosts in August-September. For both protostrongylids, the majority of transmission likely occurs on the winter range, with infection of gastropods when they emerge from hibernation in spring, and infection of Dall's sheep upon their return in fall. We validated a degree-day model for temperature-dependent development of larval P. odocoilei in gastropods, and applied degree-day models to describe and predict spatial and temporal patterns in development of P. odocoilei and P. stilesi in northern North America. Temperature-dependent larval development may currently limit northward range expansion of P. odocoilei into naïve populations of Dall's sheep in the Arctic, but climate warming may soon eliminate such constraints. In Subarctic regions where both P. odocoilei and P. stilesi are endemic, the length of the parasite 'growing season' (when temperatures were above the threshold for larval development) and amount of warming available for parasite development has increased over the last 50 years. Further climate warming and extension of the seasonal window for transmission may lead to amplification of parasite populations and disease outbreaks in host populations.

Global warming is changing the dynamics of Arctic host-parasite systems.

Global climate change is altering the ecology of infectious agents and driving the emergence of disease in people, domestic animals, and wildlife. We present a novel, empirically based, predictive model for the impact of climate warming on development rates and availability of an important parasitic nematode of muskoxen in the Canadian Arctic, a region that is particularly vulnerable to climate change. Using this model, we show that warming in the Arctic may have already radically altered the transmission dynamics of this parasite, escalating infection pressure for muskoxen, and that this trend is expected to continue. This work establishes a foundation for understanding responses to climate change of other host-parasite systems, in the Arctic and globally.

Development and pathogenesis of Parelaphostrongylus odocoilei (nematoda: protostrongylidae) in experimentally infected thinhorn sheep (Ovis dalli ).

Recently, the protostrongylid nematode Parelaphostrongylus odocoilei has been reported in a new host species, thinhorn sheep (Ovis dalli). For the first time, we completed the life cycle of P. odocoilei in three Stone's sheep (O. dalli stonei) and two thinhorn hybrids (O. dalli stonei x O. dalli dalli), each infected with 200 third-stage larvae from slugs (Deroceras laeve). The prepatent period ranged from 68 days to 74 days, and shedding of first-stage larvae (L1) peaked at >10,000 L1 per gram of feces between 90 and 110 days postinfection. A total of 75, 27, and 14 adult P. odocoilei were recovered from skeletal muscles of three Stone's sheep. Starting in the prepatent period, all infected sheep lost weight and developed peripheral eosinophilia. At 2 wk before patency, two thinhorn hybrids developed neurologic signs (hind end ataxia, loss of conscious proprioception, and hyperesthesia) that resolved at patency. Eosinophilic pleocytosis and antibody to Parelaphostrongylus spp. were detected in the cerebrospinal fluid of the affected sheep, suggesting that the migration route of the "muscleworm" P. odocoilei may involve the central nervous system. Twenty days after treatment with ivermectin, neurologic signs recurred and larval shedding ceased in one infected thinhorn hybrid, whereas multiple treatments transiently suppressed but did not eliminate larval shedding in the other. During patency, two Stone's sheep with numerous eggs and larvae of P. odocoilei in the lungs died of respiratory failure following anesthesia or exertion. Parelaphostrongylus odocoilei has widespread geographic distribution, high prevalence, the possibility of causing neurologic and respiratory disease, resistance to treatment, and may constitute a significant emerging disease risk for thinhorn sheep.

Demographic differences between consenters and non-consenters in an obstetric anesthesiology clinical study.

Willingness to participate in obstetric anesthesiology clinical studies may be influenced by age, parity or ethnicity. This study was designed to determine whether there were demographic differences between consenters and non-consenters in a minimum local analgesic concentration clinical study. Four hundred and fifty-two women were approached for the study and the age, ethnicity and parity of patients who consented or declined to participate were collected. Ethnicity was categorized as Asian or Pacific Islander, black, Hispanic, white, or other. Parametric data were analyzed using t-tests and non-parametric data using chi(2) tests. There were no significant differences in the consent rate based on age or parity. Black Americans were more likely to consent than Asian Americans (P<0.001) and as likely to consent as white Americans. There were no statistically significant differences in the consent rate between Caucasian and Asian Americans. More studies are needed to determine the socioeconomic and demographic factors that affect consent rates of labor patients.

Umingmakstrongylus pallikuukensis (Nematoda: Protostrongylidae) in gastropods: larval morphology, morphometrics, and development rates.

Morphological and morphometric aspects of larval development of Umingmakstrongylus pallikuukensis in Deroceras laeve and the effects of temperature on development rates in D. laeve and Deroceras reticulatum were investigated in the laboratory. Larval stages were best differentiated by separation of cuticular sheaths, tail structure, and viability following digestion. Growth in body and esophagus width was observed during the first-stage within the intermediate host, but the major increases in body length and width occurred immediately following the second molt. Larval development in D. laeve and D. reticulatum occurred more rapidly at warmer temperatures. The calculated threshold temperatures were 8.5 and 9.5 C in D. laeve and D. reticulatum, respectively, and 167 degree-days were required for development to third-stage larvae (L3) in both hosts. These thresholds are higher than those calculated from published data for the closely related Muellerius capillaris (4.2 C) but are similar to those for the more distantly related northern protostrongylid, Elaphostrongylus rangiferi (8.3-10.3 C). Conversely, degree-days required for development to infective L3 were more similar among the Muelleriinae than between this group and the Elaphostrongylinae. Developmental parameters for protostrongylid larvae may be influenced both by the environment and by features of the parasites and the intermediate hosts, including phylogeny.

A new lungworm in muskoxen: an exploration in Arctic parasitology.

Ruminants are vital elements of the Holarctic ecosystem. Little is known, however, of the structure or biology of their parasite fauna, particularly in North America. Global warming, coupled with increasing human activity in the Arctic, requires enhanced international interdisciplinary efforts to better understand the many factors, including parasites, that influence the population health of caribou, reindeer, muskoxen and wild sheep. The discovery of an unusual new genus of protostrongylid lung nematode in muskoxen from the central Canadian Arctic is described, and the intricacies of the parasite's relationship with its muskoxen definitive hosts, its gastropod intermediate hosts and the arctic environment are discussed.

New host and geographic records for two protostrongylids in Dall's sheep.

Biodiversity survey and inventory have resulted in new information on the distribution of Protostrongylidae in Dall's sheep (Ovis dalli dalli) from the Northwest Territories (NT, Canada) and from Alaska (AK, USA). In 1998, Parelaphostrongylus odocoilei adults were found for the first time in the skeletal muscles of Dall's sheep in the Mackenzie Mountains (NT). Adult P. odocoilei were associated with petechial and ecchymotic hemorrhages and localized myositis; eggs and larvae in the lungs were associated with diffuse granulomatous pneumonia. Experimental infections of the slugs Deroceras laeve and Deroceras reticulatum with dorsal-spined first-stage larvae assumed to be P. odocoilei, from ground-collected feces from Dall's sheep in the Mackenzie Mountains, yielded third-stage larvae by at least 28 (in D. laeve) and 48 (in D. reticulatum) days post-infection. Third-stage larvae emerged from D. laeve between days 19 and 46 post-infection and emergence occurred both at room temperature and at 10 to 12 C. Protostrongylus stilesi were definitively identified from the lungs of Dall's sheep collected in the Mackenzie Mountains, NT in 1998. Specimens collected from sheep in the Mackenzie Mountains, NT in 1971-72, and the Alaska Range, AK in 1972 were also confirmed as P. stilesi. Lung pathology associated with adults, eggs, and larvae of P. stilesi was similar to that described in bighorn sheep (Ovis canadensis). Concurrent infections with P. odocoilei and P. stilesi in a single host have not been previously reported.

National occurrence reporting of Trichinella and trichinellosis using a computerized database.

Historical and contemporary national data on the occurrence and distribution of Trichinella and trichinellosis in people, domestic animals and wildlife in Canada have been incorporated into a computerized database, the Canada Database of Animal Parasites (CDAP). This database was established in 1998, and contains similar information on several other helminth and protozoan parasites which are of importance in animal health, human health, food safety or trade. The CDAP is a unique assemblage of national information on parasite occurrences, not available from any other single source. This paper describes the CDAP, with emphasis on sources of data, database structure and outputs, logistical issues associated with database development and maintenance, and the application of the CDAP to Trichinella surveillance at a national level. It is suggested that the CDAP, or a similar approach, could be applied in other countries for assembling data on Trichinella and trichinellosis.