Outcome of repeat anaesthesia after investigation for perioperative anaphylaxis.

BACKGROUND: Perioperative anaphylaxis (POA) is infrequent, but remains an important and potentially life-threatening complication of general anaesthesia. The diagnostic uncertainty surrounding the investigation of anaesthetic allergy poses numerous challenges. We aimed to inform practice by auditing the outcomes of repeat anaesthesia, after an investigation for previous POA. METHODS: One-hundred and seventy-four subjects were investigated after suspected POA between December 2002 and August 2015. Outcome data were obtained for a total of 70 patients who underwent repeat anaesthesia after investigation in the drug-allergy clinic. RESULTS: Sixty-seven out of the 70 patients studied underwent repeat anaesthesia without further complications. Three individuals experienced a further episode of anaphylaxis. In two cases, incomplete referral information led to the offending drugs being omitted from initial testing. The third was found to have underlying systemic mastocytosis (SM). CONCLUSIONS: In our cohort, the incidence of repeat anaphylaxis after a comprehensive assessment in the drug-allergy clinic for suspected POA was 4%. Important risk factors include the completeness of referral information provided to the assessor and the role of exacerbating disorders, particularly SM.

Association between environmental factors including second-hand smoke and primary lung cancer in dogs.

OBJECTIVES: To estimate prevalence of exposure to environmental tobacco smoke and other environmental toxins in dogs with primary lung tumours and to analyse association between exposure and lung tumour development. MATERIALS AND METHODS: In this case-control study, an owner survey was developed to collect data on patient characteristics, general health care and environmental exposures. Dogs diagnosed with primary lung carcinomas formed the Case group. Dogs diagnosed with mast cell tumours served as Control Group 1 and dogs diagnosed with neurologic disease served as Control Group 2. Associations between diagnosis of primary lung tumour and patient and environmental exposure variables were analysed using bivariate and multivariate statistical methods. RESULTS: A total of 1178 owner surveys were mailed and 470 surveys were returned and included in statistical analysis, including 135 Cases, 169 dogs in Control Group 1 and 166 dogs in Control Group 2. An association between exposure to second-hand smoke and prevalence of primary lung cancer was not identified in this study. CLINICAL SIGNIFICANCE: Second-hand smoke is associated with primary lung cancer in people but a definitive association has not been found in dogs. The results of this study suggest that tobacco smoke exposure may not be associated with primary lung cancer development in dogs but study limitations may have precluded detection of an association.

Ultrasound and computed tomography of the iliosacral lymphatic centre in dogs with anal sac gland carcinoma.

In this prospective study, we hypothesized that computed tomography (CT) would identify more normal and abnormal iliosacral lymph nodes (LNs) than abdominal ultrasound in dogs with anal sac gland carcinoma (ASGC). Twelve client-owned dogs with ASGC but without distant metastasis were enrolled. Abdominal ultrasound and contrast-enhanced CT scans of the abdomen were obtained. Iliosacral LNs were counted and assessed for location, laterality and size. Significantly (P < 0.00001) more iliosacral LNs were identified with CT (61) than ultrasound (30), including significantly (P = 0.00012) more medial iliac LNs with CT (33) than ultrasound (19). There was no difference in number of internal iliac LNs identified with CT versus ultrasound. Significantly (P = 0.000061) more sacral LNs were identified with CT (15) than ultrasound (0). Ultrasound identified slightly more (7) abnormal iliosacral LNs than CT (5). Contrast CT was able to identify more normal but not more abnormal LNs than ultrasound.

Perfusion and Volume Response of Canine Brain Tumors to Stereotactic Radiosurgery and Radiotherapy.

BACKGROUND: Stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) are highly conformal, high-dose radiation treatment techniques used to treat people and dogs with brain tumors. OBJECTIVES: To evaluate the response to SRS- and SRT-treated tumors using volume and perfusion variables and to measure the survival times of affected dogs. ANIMALS: Prospective study of 34 dogs with evidence of brain tumors undergoing stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT). METHODS: Computed tomography and MRI imaging were used to calculate tumor volume and perfusion at baseline, and at 3 months and 6 months after treatment. Survival analysis was performed to evaluate treatment efficacy. RESULTS: Mean tumor volume significantly declined from baseline to the first recheck by -0.826 cm(3) (95% CI: -1.165, -0.487) (P < .001); this reduction was maintained at the second recheck. Blood flow and blood volume declined significantly in the tumor after treatment. Median survival was 324 days (95% CI: 292.8, 419.4), and 4 dogs survived longer than 650 days. Neither actual tumor volume (hazard ratio = 1.21, P = .19) nor the change in tumor volume from the baseline (hazard ratio = 1.38, P = .12) significantly affected the hazard of death because of the tumor. CONCLUSIONS AND CLINICAL IMPORTANCE: Stereotactic radiosurgery and SRT are effective treatments for reducing tumor volume, blood flow, and blood volume. Treated dogs surviving for more than 1 year are more likely to die from other causes than of their primary brain tumor. SRS and SRT should be considered for noninvasive treatment of intracranial brain tumors.

Agreement Among Radiographs, Fluoroscopy and Bronchoscopy in Documentation of Airway Collapse in Dogs.

BACKGROUND: Airway collapse is a common finding in dogs with chronic cough, yet the diagnosis can be difficult to confirm without specialty equipment. HYPOTHESIS: Bronchoscopic documentation of tracheobronchial collapse will show better agreement with fluoroscopic imaging than with standard radiography. ANIMALS: Forty-two dogs prospectively evaluated for chronic cough. METHODS: In this prospective study, three-view thoracic radiographs were obtained followed by fluoroscopy during tidal respiration and fluoroscopy during induction of cough. Digital images were assessed for the presence or absence of collapse at the trachea and each lobar bronchus. Bronchoscopy was performed under general anesthesia for identification of tracheobronchial collapse at each lung segment. Agreement of imaging tests with bronchoscopy was evaluated along with sensitivity and specificity of imaging modalities as compared to bronchoscopy. RESULTS: Airway collapse was identified in 41/42 dogs via 1 or more testing modalities. Percent agreement between pairs of tests varied between 49 and 87% with poor-moderate agreement at most bronchial sites. Sensitivity for the detection of bronchoscopically identified collapse was highest for radiography at the trachea, left lobar bronchi, and the right middle bronchus, although specificity was relatively low. Detection of airway collapse was increased when fluoroscopy was performed after induction of cough compared to during tidal respiration. CONCLUSIONS: Radiography and fluoroscopy are complementary imaging techniques useful in the documentation of bronchial collapse in dogs. Confirming the presence or absence of tracheal or bronchial collapse can require multiple imaging modalities as well as bronchoscopy.

Bacterial urinary tract infections associated with transitional cell carcinoma in dogs.

BACKGROUND: Urinary tract infections (UTI) are believed to be common in dogs with transitional cell carcinoma (TCC), but incidence and contributing factors have not been reported. OBJECTIVES: To determine the frequency and bacterial agents associated with UTI in dogs with TCC and define contributing factors. ANIMALS: Eighty-five dogs with a history of urogenital TCC undergoing treatment with chemotherapy that had at least 1 urine culture performed. METHODS: Medical records and culture results were retrospectively reviewed and ultrasound images were reviewed when available. Clinical factors were evaluated statistically for association with positive culture. RESULTS: Fifty-five percent (47/85) of dogs had at least 1 positive culture during the course of treatment. Female dogs (80%, 40/50) were more likely than male dogs (29%, 10/35) to have at least 1 positive culture. Ultrasound examination determined that female dogs were more likely to have urethral (74%, 31/42) or trigonal tumor involvement (71%, 30/42) compared to male dogs (32%, 9/28 and 43%, 12/28, respectively). The most commonly isolated organisms were Staphylococcus spp. (23.9%, 29/121) and Escherichia coli (19.8%, 24/121). Dogs with urethral involvement of TCC were significantly more likely to have at least 1 positive culture than dogs without urethral involvement (75%, 30/40 versus 30%, 9/30). CONCLUSIONS: Urinary tract infection is common in dogs with TCC highlighting the importance of regular monitoring for bacterial cystitis in dogs with TCC. In addition, clinical factors such as tumor location and sex may be predictive of positive culture and can help clinicians assess the risk of UTI.

Impact of national guidelines on reporting anaphylaxis during anaesthesia -- an outcome audit.

AIMS: Anaphylaxis during anaesthesia is a rare and potentially fatal event. Adequate reporting and investigation of anaphylaxis associated with anaesthesia results in improved patient safety and outcomes. Guidelines from the Association of Anaesthetists of Great Britain and Ireland (AAGBI) designed to improve this process were first issued in 1990 and updated in 1995, 2003 and 2008. In a setting where no formal guideline was previously in place, we compared the reporting and investigation of anaphylaxis in a large hospital before and after the introduction of the 2008 guideline. METHODS: A retrospective outcome audit was conducted to compare data from 12 patients referred from April 2006 to May 2008 prior to release of the 2008 AAGBI guidance, with 53 patients referred from 2008 until April 2011. Data were collected using the AAGBI Anaphylaxis Referral Form. RESULTS: There was an increase in the number of referrals for suspected anaphylaxis following implementation of the AAGBI guidance. The clinical features observed in patients were consistent with previous studies. There was improved documentation of referral to local and national databases. Most cases resulted in cancellation of surgery, and there were no patient deaths. A substantial increase in the number of patients with amoxicillin allergy was noted in the second time period, which was linked to a change in the local perioperative antibiotic policy. CONCLUSIONS: Implementation of the AAGBI guidelines locally in a large hospital in 2008 resulted in an improved awareness of the importance of reporting and investigation of suspected anaphylaxis under anaesthesia. This tool was implemented coincidentally with the change in hospital antibiotic prophylaxis and enabled the cases detected to be accurately recorded and investigated. This led to a change in the hospital antibiotic policy for surgical prophylaxis. Implementation of structured guidance from a national anaesthesia organisation enhances recognition of the clinical features of anaphylaxis, increases number and completeness of referrals and more thorough immunological investigation, leading to improved patient safety during anaesthesia.

Bronchomalacia in dogs with myxomatous mitral valve degeneration.

BACKGROUND: Cough in the geriatric small breed dog with myxomatous mitral valve degeneration (MMVD), a large left atrium, and absence of heart failure often is attributed to compression of the left mainstem bronchus by the left atrium. Studies investigating this syndrome are lacking in dogs. HYPOTHESIS: Airway collapse is independent of left atrial enlargement. ANIMALS: A total of 16 dogs presenting with chronic cough in the absence of congestive heart failure. Group 1 dogs (n = 10) had moderate-to-severe left atrial enlargement based on an echocardiographically calculated left atrial:aortic surface area [LA:Ao(a)] > 6. Group 2 dogs (n = 6) had no to mild left atrial enlargement [LA:Ao(a) ≤ 6]. METHODS: Dogs were prospectively evaluated. CBC, biochemistry, urinalysis, cervical and thoracic radiographs, fluoroscopy, echocardiography, and bronchoscopy were performed. Bronchoscopic abnormalities were compared between groups using Fisher's Exact Test. P < .05 was considered significant. RESULTS: Fluoroscopy identified airway collapse in both groups. Bronchoscopic evidence of airway collapse >50% was observed in multiple bronchi with no difference between groups. All dogs had inflammation on airway cytology with respiratory infection in 1 dog in group 2. Left atrial size was interpreted radiographically as enlarged in 9 of 10 group 1 dog and in 2 of 6 group 2 dogs. VHS was above normal in both groups of dogs regardless of echocardiographic evidence of cardiomegaly. CONCLUSIONS: Results failed to identify an association between left atrial enlargement and airway collapse in dogs with MMVD, but did suggest that airway inflammation is common in dogs with airway collapse.

Tracheal collapse and bronchomalacia in dogs: 58 cases (7 /2001-1 /2008).

BACKGROUND: Tracheobronchomalacia is diagnosed in people by documentation of a reduction in airway diameter during bronchoscopy. While tracheal collapse in the dog has been well described in the literature, little information is available on bronchomalacia in the dog. HYPOTHESES: Bronchomalacia is common in dogs with tracheal collapse, is associated with inflammatory airway disease, and is poorly documented radiographically. ANIMALS: One hundred and fifteen dogs admitted for evaluation for respiratory disease and examined by bronchoscopy. METHODS: Case-controlled, observational study. Dogs examined and having a bronchoscopic procedure performed by a single operator were separated into groups with and without visually identified airway collapse. Clinical parameters and bronchoalveolar lavage findings were compared between groups. Radiographs were reviewed in masked fashion to assess the sensitivity and specificity for detection of bronchomalacia. RESULTS: Tracheobronchomalacia was documented in 50% of dogs examined, with tracheal collapse in 21% and bronchomalacia in 47%. In dogs with bronchomalacia, collapse of the right middle (59%) and left cranial (52%) lung lobes was identified most commonly. Dogs with bronchomalacia were significantly more likely to display normal airway cytology and to have mitral regurgitation and cardiomegaly than dogs without airway collapse (P < .05). Radiographs were insensitive for detection of airway collapse. CONCLUSIONS AND CLINICAL IMPORTANCE: Bronchomalacia was identified more commonly than tracheal collapse in this population of dogs, and documentation required bronchoscopy. This study could not confirm a role for airway inflammation in bronchomalacia, and further studies are required to determine the role of cardiomegaly in the disorder.

Canine intraspinal meningiomas: imaging features, histopathologic classification, and long-term outcome in 34 dogs.

BACKGROUND: Meningioma is the most common primary intraspinal nervous system tumor in dogs. Clinical findings, clinicopathologic data, and treatment of these tumors have been reported sporadically, but little information is available regarding cerebrospinal fluid (CSF) analysis, histologic tumor grade, or efficacy of radiation therapy as an adjunct to cytoreductive surgery. ANIMALS: Dogs with histologically confirmed intraspinal meningiomas (n = 34). METHODS: A retrospective study of dogs with intraspinal meningiomas between 1984 and 2006 was carried out. Signalment, historical information, physical examination, clinicopathologic data, radiation therapy protocols, surgery reports, and all available images were reviewed. All tumors were histologically classified and graded as defined by the international World Health Organization classification scheme for central nervous system tumors. RESULTS: Intraspinal mengiomas in dogs are most common in the cervical spinal cord but can be found throughout the neuraxis. Location is correlated with histologic grade, with grade I tumors more likely to be in the cervical region than grade II tumors. Myelography generally shows an intradural extramedullary compressive lesion. On magnetic resonance imaging, the masses are strongly and uniformly contrast enhancing and a dural tail often is present. CSF analysis usually shows increased protein concentration with mild to moderate mixed pleocytosis. Surgical resection is an effective means of improving neurologic status, and adjunctive radiation therapy may lead to an improved outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: Biopsy is necessary for definitive diagnosis, but imaging and CSF analysis can suggest a diagnosis of meningioma. Treatment of meningiomas with surgery and radiation therapy can result in a fair to excellent prognosis.

Management of carpal tunnel syndrome in renal dialysis patients using an extended carpal tunnel release procedure.

BACKGROUND: Chronic dialysis patients are susceptible to median nerve compression. This may be due to oedema or vascular insufficiency related to a dialysis shunt or fistula. Patients with renal failure may also develop amyloid disease. Amyloid infiltration of the synovium within the carpal canal may be a contributing factor to the nerve compression. Traditional carpal tunnel release, although simple to perform, is associated with a much higher recurrence rate in this group than in nonrenal patients. Our aim was to modify the carpal tunnel release procedure and prevent these recurrences. METHODS: A retrospective review of 24 extended carpal tunnel decompressions in 19 dialysis patients was performed, with reference to patient records. The surgical technique is detailed and the clinical results analysed. RESULTS: All patients noted an early and sustained improvement in symptoms; those patients with established sensory or motor signs had poorer results following surgery. There were no instances of recurrence of nerve compression during this follow-up period, range 2-6 years. CONCLUSIONS: Carpal tunnel decompression enhances hand function and quality of life in this group.

Mesoscale iron enrichment experiments 1993-2005: synthesis and future directions.

Since the mid-1980s, our understanding of nutrient limitation of oceanic primary production has radically changed. Mesoscale iron addition experiments (FeAXs) have unequivocally shown that iron supply limits production in one-third of the world ocean, where surface macronutrient concentrations are perennially high. The findings of these 12 FeAXs also reveal that iron supply exerts controls on the dynamics of plankton blooms, which in turn affect the biogeochemical cycles of carbon, nitrogen, silicon, and sulfur and ultimately influence the Earth climate system. However, extrapolation of the key results of FeAXs to regional and seasonal scales in some cases is limited because of differing modes of iron supply in FeAXs and in the modern and paleo-oceans. New research directions include quantification of the coupling of oceanic iron and carbon biogeochemistry.

Lowering the dose of hydroxyurea minimizes toxicity and maximizes anti-HIV potency.

The goal of this study was to optimize the hydroxyurea dosage in HIV-infected patients, and to minimize the toxicity and maximize the antiviral efficacy of the hydroxyurea-didanosine combination. In a randomized, open-label study (RIGHT 702, a multicenter trial performed in private and institutional practices), three daily doses (600 microg, 800-900 microg, and 1200 microg) of hydroxyurea were administered in combination with didanosine and stavudine to 115 chronically HIV-infected patients, one-third antiretroviral drug naive, with viremia between 5000 and 200,000 copies/ml regardless of CD4+ cell count. The primary efficacy end point was the proportion of patients with plasma HIV-1 RNA levels below 400 copies/ml after 24 weeks of therapy. In the RIGHT 702 intent-to-treat population the lowest (600 mg) dose of hydroxyurea was better tolerated, associated with fewer adverse events, and more potent by all efficacy parameters, including the primary end point (76 versus 60% patients with viremia<400 copies/ml at week 24 for the 600-mg and 800- to 900-mg dose groups, respectively; p=0.027), the mean area under the curve (60.3 versus 65.8; p=0.016), and the mean log10 decrease (-1.95 versus -0.77; p=0.001). Patients receiving 600 mg of hydroxyurea daily also had the highest CD4+ cell count, CD4+/CD8+ cell ratio, and lowest CD8+ cell count and percentage (p=0.035). The RIGHT 702 trial provides an explanation for the increased toxicity and decreased efficacy of hydroxyurea when it was used at high dosage (1200 mg daily). At the optimal dosage of 600 mg daily, hydroxyurea, in combination with didanosine, deserves reevaluation for the long-term management of HIV/AIDS worldwide, because of its excellent resistance profile, durability, and affordability.

Trends in veterinary cancer imaging.

With the recent advances in diagnostic imaging technology, cancer imaging in veterinary medicine has become more specific for disease diagnosis, more accurate for determining tumour margins and more sensitive for detecting metastatic disease. Ultrasound provides highly detailed images of parenchymal masses and infiltrative lesions while providing a means for aspiration or biopsy using real-time image guidance. Computed tomography and magnetic resonance-imaging techniques provide exquisite anatomical resolution that improves diagnostic accuracy, provides an accurate means of radiation or surgical treatment planning and a quantitative means for monitoring response to therapy. In addition to traditional anatomic imaging, new techniques are being developed for estimating functional parameters such as tumour perfusion, cell metabolism and gene expression. While conventional planar scintigraphy has been available for some time, newer nuclear imaging modalities such as positron emission tomography promise to further improve the accuracy of initial tumour diagnosis and staging and determination of response to therapy. Although many of these functional techniques are not yet clinically available, it is highly likely that some will be integrated into routine clinical practice in the near future.

Hydroxyurea in combination with didanosine and stavudine in antiretroviral-experienced HIV-infected subjects with a review of the literature.

The safety and efficacy of hydroxyurea with didanosine in combination with stavudine in nucleoside reverse-transcriptase inhibitor (NRTI)-experienced patients was investigated. Entry criteria included HIV-1 infected, NRTI-experienced adults, with CD4(+) counts 50-550 cells/mm(3) and viral loads >or=12,500 copies/mL. Subjects were treated with didanosine 200 mg twice a day (BID), stavudine 40 mg BID, and hydroxyurea 1000 mg daily for 16 weeks. Thirty-one HIV-1 subjects with mean bDNA viral load 1x10(5) log(10) copies/mL and mean CD4(+) T-cell counts of 231 cells/mm(3) were enrolled. A 1.3 log(10) decrease in mean viral load was seen at 12 weeks of therapy. Prior didanosine use resulted in a more rapid response to therapy compared with prior zidovudine use. Side effects consisting of neutropenia, pancreatitis, and peripheral neuropathy occurred in four subjects and resolved upon withdrawal of therapy. This non-randomized study in subjects with a mean CD4(+) T-cell count of 230 cells/mm(3) demonstrates the antiviral activity of hydroxyurea+didanosine and stavudine. Toxicities related to therapy need to be followed closely. The results support the need for a randomized, prospective study to determine the safety and efficacy of hydroxyurea plus didanosine in antiretroviral-experienced patients with CD4(+) cell counts below 300 cells/mm(3).

Effects of Z-100, a Mycobacterium-tuberculosis-derived arabinomannan, on the LP-BM5 murine leukemia virus infection in mice.

OBJECTIVE: To investigate the effects of Z-100, an arabinomannan extracted from Mycobacterium tuberculosis, on the LP-BM5 murine leukemia virus (LP-BM5 MuLV) infection in mice. METHODS: C57BL/6 mice infected intraperitoneally with 4.5 x 10(2) PFU/mouse of LP-BM5 MuLV (MAIDS mice) were treated intraperitoneally with a 10-mg/kg dose of Z-100 every other day beginning 1 day after the viral infection. MAIDS mice treated with Z-100 were compared with control mice (MAIDS mice treated with saline) for their survival and splenomegaly after LP-BM5 infection. Cytokine-producing profiles of splenic T cells from these two groups of mice were also compared. RESULTS: When MAIDS mice treated with Z-100 were compared with those of control mice, a decrease in splenomegaly and lymphadenopathy was observed. Splenomegaly was markedly enhanced in MAIDS mice treated intraperitoneally with IL-4 or IL-10. When MAIDS mice were treated with Z-100, their survival rates were significantly increased compared to those of controls. Splenic T cells from control mice produced type-2 cytokines (IL-4 and IL-10). However, a decreased production of type-2 cytokines by splenic T cells from MAIDS mice treated with Z-100 was demonstrated. CONCLUSION: Z-100 could decrease the severity of the LP-BM5 MuLV infection through the regulation of MAIDS-associated type-2 T-cell responses.