An 18-µm microaggregate blood filter does not cause hemolysis during in vitro whole blood transfusions in sea turtles

OBJECTIVE

Determine the hemolytic effect of an 18-µm microaggregate blood filter during in vitro sea turtle whole blood transfusions as well as describe the average diameter of leatherback (Dermochelys coriacea) and Kemp's ridley sea turtle (Lepidochelys kempii) RBCs.

ANIMALS

5 green (Chelonia mydas), 5 loggerhead (Caretta caretta), and 5 Kemp's ridley sea turtles (total n = 15).

METHODS

Heparinized sea turtle blood was infused at 60 mL/h through a microbore extension set without and then with a postsyringe, inline 18-µm microaggregate blood filter. Pre- and postfiltration PCV, Hct, total solids, sodium, chloride, potassium, glucose, and free plasma hemoglobin concentrations were measured. With the use of light microscopy and archived blood smears, the maximum and minimum diameter of 20 RBCs from each of the 5 leatherback and 5 Kemp's ridley sea turtles were measured with a calibrated ocular micrometer using 400X magnification.

RESULTS

There were no significant differences between pre- and postfiltration samples for Hct, total solids, sodium, chloride, potassium, glucose, and free plasma hemoglobin concentrations; however, there was a significant median postfiltration decrease in PCV of approximately 4%, representing a 13% decrease of the total RBCs transfused. Average maximum diameters for leatherback and Kemp's ridley sea turtle RBCs were 19.7 and 16.1 µm, respectively.

CLINICAL RELEVANCE

Although the 18-µm microaggregate blood filter does not hemolyze transfused sea turtle RBCs and is likely safe for in vivo blood transfusions, the filter's pores may retain a small proportion of infused RBCs given their diameter.

Intranasal and intravenous apomorphine outperform ropinirole ocular drops for induction of emesis in dogs within ten minutes: a randomized, controlled clinical trial

OBJECTIVE

The primary goal was to compare the efficacy of administration of apomorphine (APO) administered by intranasal (IN), transconjunctival (TC), SC and IV routes with ropinirole eye drops for induction of emesis in dogs with a secondary goal to evaluate the time of emesis as well as difficulty in administration.

ANIMALS

125 client-owned dogs.

METHODS

Dogs were randomly enrolled between October 1, 2021, and March 30, 2022, into groups of 25: IV APO, IN APO, TC APO, SC APO, and ropinirole eye drops. The IV, SC, and TC groups were dosed at 0.03 mg/kg, the IN group was dosed at 0.06 mg/kg, and the ropinirole group was dosed according to manufacturer guidelines. Data collected included success rate of emesis within 600 seconds, time to emesis, time to administer, and difficulty score. Results were compared to IV with P values and CIs being adjusted for multiple comparisons.

RESULTS

Emesis was successful within 600 seconds using IV APO in 22 of 25 dogs. By comparison, IN APO induced emesis in 18 of 25 dogs (P = .63). Ropinirole (14/25), SC APO (6/25), and TC APO (4/25) were significantly less successful (P = .047, P = < .001, and P < 0.001, respectively). When emesis was successful, it occurred most rapidly with TC APO, followed by IN APO and then ropinirole. It was most difficult to administer IV APO and TC APO.

CLINICAL RELEVANCE

Similar to IV APO, IN APO was a rapid, easy, and effective method of inducing emesis in dogs and should be considered when IV administration is not possible. Ropinirole was easy to administer but successfully induced emesis less reliably within a 10-minute timeframe. APO administered TC using the commercially compounded injectable formulation was ineffective.

Pharmacokinetics of a continuous intravenous infusion of hydromorphone in healthy dogs

Introduction

Dosing recommendations for hydromorphone intravenous constant rate infusion (IV CRI) are derived from simulations following IV bolus administration. While this extrapolated dose regimen has been described clinically, pharmacokinetics (PK) of hydromorphone infusions in dogs are not yet described. The study objective was to describe the PK of hydromorphone in healthy dogs receiving an IV bolus followed by an IV CRI for 48 h.

Methods

A prospective, experimental study was performed involving the administration of hydromorphone (0.1 mg/kg IV bolus then IV CRI 0.01 mg/kg/h over a 48 h period) to 6 healthy Beagle dogs. Blood samples were collected at 16 time points between 0 and 58 h relative to the initial bolus. Plasma hydromorphone concentrations were analyzed by high pressure liquid chromatography with tandem mass spectrometry detection. Pharmacokinetic parameter estimates were obtained with compartmental methods using commercially available software.

Results

A two-compartment model with first order elimination was used. At the end of the infusion, median (range) plasma hydromorphone concentrations were 6.8 (5.5-19.6) ng/mL. The median total body clearance was 30.4 (19.8-36.7) mL/min/kg; volume of distribution at steady state was 4.5 (3.2-7.8) L/kg; and terminal elimination half-life was 11.2 (7.6-24.3) h.

Conclusion

Hydromorphone (0.1 mg/kg IV bolus then IV CRI of 0.01 mg/kg/h) maintained steady-state plasma concentrations above the minimum human analgesic target in healthy Beagle dogs with minimal side effects. Further studies are needed to determine the effective plasma concentrations of hydromorphone in painful dogs.

INVESTIGATION OF A POINT-OF-CARE VISCOELASTIC COAGULATION MONITOR AND ITS COMPARISON TO THROMBOELASTOGRAPHY IN CLINICALLY HEALTHY AFRICAN ELEPHANTS (LOXODONTA AFRICANA)

Elephant endotheliotropic herpesvirus (EEHV) can induce fatal hemorrhagic disease (HD) in African elephants (Loxodonta africana). Once clinical signs develop, progression is rapid, even with aggressive treatment. There is a critical need to develop point-of-care diagnostic tests to aid in identification of EEHV-HD prior to the onset of overt clinical signs. Study objectives were to investigate a novel, point-of-care viscoelastic coagulation monitor (VCM Vet), compare the results to thromboelastography (TEG), and report traditional hemostatic analytes in adult African elephants. Whole blood was collected from seven clinically healthy elephants (four females and three males, 18-47 yr) and analyzed in duplicate via VCM Vet and kaolin-activated TEG 1-3 and 30 min following collection, respectively. Separated plasma was frozen for ancillary coagulation testing. Both analyses generated quantifiable clotting reactions with variables (median [range]) describing clot formation rate (VCM Vet, clot time = 682 s [530-987 s], clot formation time = 244 s [186-744 s], Alpha = 40° [14-47°]; TEG, reaction time = 6.2 min [3.7-11.8 min], kinetic time = 1.3 min [0.9-2.6 min], Alpha = 70° [57-77°]), clot strength (VCM Vet, maximum clot formation = 34 units [20-45 units]; TEG, maximum amplitude = 75 mm [69-80 mm], shear elastic modulus strength = 14.7 Kdynes/s [11.3-19.5 Kdynes/s]), and clot lysis (VCM Vet, lysis index at 30 min = 100% [100-99%], lysis index at 45 min = 98% [95-100%]; TEG, lysis index at 30 min = 0% [0-0.4%], lysis index at 60 min = 1.4% [0-2.6%]) recorded. Additional testing (median [range]) included D-dimer concentration (33 ng/ml [28-94 ng/ml]), prothrombin time (12.4 s [12.2-13.2 s]), activated partial thromboplastin time (17.2 s [14.2-18.8 s]), and fibrinogen concentration (297 [282-383] mg/dL). Tracings generated by VCM Vet and TEG were clinically similar, and there was visual agreement and minimal difference between quantitative variables for duplicate tests. VCM Vet is a promising, user-friendly tool for use in identification and management of coagulopathies in African elephants.

Evaluation of thrombin generation in dogs administered clopidogrel

Introduction

The antiplatelet effect of clopidogrel can vary between patients. A modified thromboelastography (TEG) protocol (TEG-Platelet Mapping assay® [TEG-PM]) can be used for clopidogrel monitoring but is not widely available. Thrombin generation (TG) assays could offer a novel alternative. The main objective of this pilot study was to assess TG assay variables (lag time, peak, endogenous thrombin potential [ETP]) in dogs before and after 7 days of clopidogrel administration and compare with TEG-PM variables (maximum amplitude [MA]-ADP and percentage (%) inhibition).

Methods

Six healthy mix-breed dogs were enrolled in this pilot study. Blood samples for platelet count, TG assays, and TEG-PM were obtained at two time points, corresponding to baseline, and after 7 days of clopidogrel administration (mean 2.3 +/- 0.3 mg/kg PO q24 hours). Data were then compared with a Student's t-test.

Results

There was no significant change in TG assay variables performed on platelet poor plasma after 7 days of clopidogrel administration: lag time (Day 1: 1.8 +/- 0.2 min, Day 7: 1.8 +/- 0.2 min, p = 0.42); peak (Day 1: 76 +/- 7 nM, Day 7: 72 +/- 10 nM, p = 0.49); and ETP (Day 1: 399 +/- 27 nM*min, Day 7: 392 +/- 32 nM*min; p = 0.49). There were significant changes in TEG MA-ADP (Day 1: 19 +/- 8 mm, Day 7: 9 +/- 6 mm, p = 0.04) and % inhibition (Day 1: 58 +/- 27, Day 7: 99 +/- 0.3, p = 0.02).

Discussion

Clopidogrel administration did not lead to changes in TG assay variables performed on platelet poor plasma samples, despite concomitant changes in TEG-PM variables consistent with platelet inhibition. Based on this pilot study, thrombin generation performed on platelet poor plasma may not be a useful antiplatelet monitoring tool in dogs.

Case report: Laryngospasm following ethanol ablation of a parathyroid nodule in a dog with primary hyperparathyroidism

A 12-year-old female spayed dachshund was presented for emergency assessment of respiratory distress, characterized by inspiratory dyspnea with stridor. Percutaneous ultrasound-guided ethanol ablation of a functional parathyroid tumor was performed 72-h earlier for management of primary hyperparathyroidism. The dog was hypocalcemic (ionized calcium 0.7 mmol/L, reference interval: 0.9-1.3 mmol/L) at the time of presentation and had evidence of laryngospasm on a sedated oral exam. The dog was managed conservatively with supplemental oxygen, anxiolysis, and parenteral calcium administration. These interventions were associated with rapid and sustained improvement in clinical signs. The dog did not demonstrate any recurrence of signs afterwards. To the authors' knowledge, this is the first description of laryngospasm following ethanol ablation of a parathyroid nodule in a dog that developed hypocalcemia.

Hemostatic profiles in dogs with sudden acquired retinal degeneration syndrome

BACKGROUND

Sudden acquired retinal degeneration syndrome (SARDS) is a common cause of irreversible blindness in dogs. It bears clinical resemblance to hypercortisolism, which can be associated with hypercoagulability. The role of hypercoagulability in dogs with SARDS is unknown.

OBJECTIVE

Determine hemostatic profiles in dogs with SARDS.

ANIMALS

Prospective pilot study: Dogs with a history of SARDS (n = 12). Prospective case-control study: Dogs with recent onset of SARDS (n = 7) and age-, breed-, and sex-matched controls (n = 7).

METHODS

Prospective pilot study: We performed thromboelastography (TEG). Prospective case-control study: Dogs had CBC, serum biochemistry, urinalysis, TEG, fibrinogen concentration, antithrombin activity, D-dimers, thrombin-antithrombin complexes, and optical platelet aggregometry performed.

RESULTS

Prospective pilot study: 9/12 dogs with a history of SARDS were hypercoagulable with increased TEG G value and 2/3 had hyperfibrinogenemia. Case-control study: All dogs with SARDS and 5/7 controls were hypercoagulable based on TEG G value. Dogs with SARDS had significantly higher G values (median, 12.7 kdynes/s; range, 11.2-25.4; P = .04) and plasma fibrinogen concentration (median, 463 mg/dL; range, 391-680; P < .001) compared to controls.

CONCLUSIONS AND CLINICAL IMPORTANCE

Hypercoagulability was common in both dogs with SARDS and controls, but dogs with SARDS were significantly more hypercoagulable on TEG. The role of hypercoagulability in the pathogenesis of SARDS remains to be determined.

Outcomes of 434 dogs with non-steroidal anti-inflammatory drug toxicosis treated with fluid therapy, lipid emulsion, or therapeutic plasma exchange

BACKGROUND

Traditional management of non-steroidal anti-inflammatory drug (NSAID) intoxication includes gastrointestinal decontamination, intravenous administration of fluids (IVF), and gastroprotection. Intravenous administration of lipid emulsion (ILE) and therapeutic plasma exchange (TPE) are popular novel therapeutic strategies.

HYPOTHESIS

Compare outcomes of dogs treated with IVF, ILE, and TPE for NSAID intoxications and evaluate outcome predictors for drug subgroups.

ANIMALS

Four hundred thirty-four dogs with NSAID intoxications (2015-2020).

METHODS

Multicenter retrospective study of ibuprofen, carprofen, and naproxen intoxication. An ordinal outcome was defined as mild gastrointestinal, moderate kidney, or signs of severe central nervous system disease.

RESULTS

Signs of neurological disease were overrepresented and acute kidney injury underrepresented in the TPE group among dogs exposed to kidney- or CNS-toxic doses (P = .05), though all TPE dogs with signs of neurological disease had evidence of neurotoxicity at presentation. Dogs treated with IVF had a higher maximal creatinine concentration (median, 1.1 mg/dL; range, 0.4-8.44 mg/dL) compared with IVF + ILE (median, 0.9 mg/dL; range, 0.4-6.2 mg/dL; P = .01). Increased maximum time to presentation (P < .001), higher baseline creatinine (P < .001) and PCV (P = .007), and absence of induced emesis (P < .001) were associated with greater clinical severity. Ibuprofen toxicosis was associated with more severe clinical signs compared with carprofen (P = .03). Overall survival rate was 99%.

CONCLUSIONS AND CLINICAL IMPORTANCE

NSAID toxicosis generally carries an excellent prognosis in dogs. Despite similar outcomes of lower incidence of AKI in the TPE group, and slightly lower maximal creatinine concentration in dogs treated with ILE vs IVF alone, ILE and TPE should be considered in the management of severe NSAID toxicosis.

Point-of-care viscoelastic coagulation assessment in healthy dogs during the perianesthetic period

Background

The viscoelastic coagulation monitor (VCM Vet) is a novel, portable device that provides a global assessment of hemostasis. The study aims were to evaluate serial viscoelastic analysis during the perianesthetic period in healthy dogs and to compare the agreement between two VCM Vet devices. Twenty healthy dogs undergoing orthopedic surgery were enrolled. Whole blood samples were collected from an intravenous catheter at four time points: baseline, 15 min after premedication, 60 min after inhalant initiation, and 60 min after inhalant termination. Viscoelastic tests were performed in duplicate on different devices, providing: clot time (CT; seconds), clot formation time (CFT; seconds), alpha angle (α; degrees), amplitude (units) at 10 (A10) and 20 (A20) minutes post clot time, maximum clot firmness (MCF; units), and lysis index (%) at 30 (Li30) and 45 (Li45) minutes post maximum clot formation.

Results

One hundred sixty samples were analyzed. The speed of CT and CFT significantly decreased an average of 25.5 s (95% confidence interval [CI]15.9–35.0) and 6.9 s (95% CI 3.1–10.7) per time point, respectively. There were no significant changes in clot strength or lysis variables. The Bland–Altman style plot shows an acceptable rate of agreement for all variables with intra-class correlation ranging from 0.64–0.94.

Conclusion

The rate of clot formation (CT and CFT) decreased over the perianesthetic period in healthy dogs undergoing surgery. These changes were small and occurred without changes in clot strength or fibrinolysis rate, thus were not clinically relevant. There was clinically acceptable consistency between devices.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03442-x.

Outcomes of nonsteroidal anti-inflammatory drug toxicosis treated with therapeutic plasma exchange in 62 dogs

BACKGROUND

Therapeutic plasma exchange (TPE) is gaining popularity for the management of nonsteroidal anti-inflammatory drug (NSAID) overdose in dogs.

HYPOTHESIS/OBJECTIVES

Describe a population of dogs treated with TPE for NSAID overdose.

ANIMALS

Sixty-two dogs with NSAID overdose treated with TPE.

METHODS

Multicenter retrospective study of dogs treated with TPE for ibuprofen, carprofen, or naproxen overdose.

RESULTS

The median dose of ibuprofen, carprofen or naproxen ingested was 533 mg/kg (range, 36-4857 mg/kg), 217 mg/kg (range, 88-625 mg/kg) and 138 mg/kg (range, 26-3000 mg/kg), respectively. Based on previously established toxic ranges for each NSAID, 2 (3.2%), 14 (22.6%), and 46 (74.2%) dogs ingested a gastrointestinal, renal, and neurological toxic dose, respectively. The median time between ingestion and presentation was 4 hours (range, 1-20 hours). The median number of plasma volumes processed was 1.6 (range, 0.4-2.2). The median TPE session duration was 2 hours (range, 1-4.5 hours). Circuit clotting developed during 8 (12.9%) sessions. Patient adverse events reported during 21 (33.8%) sessions consisted of urticaria (12.9%), asymptomatic hypocalcemia (9.6%), and hypotension (9.6%). The median duration of hospitalization was 2.25 days (range, 1-11 days). Sixty-one (98.4%) dogs survived to discharge, and none were rehospitalized. Thirty-one (91.1%) of the 34 dogs with at least 1 follow-up visit were not azotemic at the time of reevaluation.

CONCLUSIONS AND CLINICAL IMPORTANCE

This population of dogs managed with TPE had excellent outcomes, even in cases of high NSAID dose ingestion. When TPE is available and the time frame is appropriate, this extracorporeal modality should be considered for the management of NSAID overdose.

Pre-operative Hemostatic Status in Dogs Undergoing Splenectomy for Splenic Masses

Portal system thrombosis is a rare but potentially fatal complication of splenectomy in dogs. The mechanism behind development of post-operative portal system thrombosis is unclear but may include alterations of portal blood flow following surgery, acquired hypercoagulability and endothelial dysfunction. The aim of the study was to evaluate hemostatic biomarkers in hemodynamically stable (heart rate <130 beats/min, blood lactate < 2.5 mMol/L) and non-anemic (hematocrit >35%) dogs prior to splenectomy for splenic masses. Our hypothesis was that this population of stable dogs would have pre-existing laboratory evidence of hypercoagulability unrelated to shock, bleeding, anemia, or other pre-operative comorbidities. Pre-operatively, abdominal ultrasonography was performed and blood was collected for platelet enumeration, prothrombin time (PT), activated partial thromboplastin time (aPTT), kaolin-activated thromboelastography (TEG), fibrinogen, von Willebrand factor activity (vWF:Ag), antithrombin and thrombin-antithrombin complex (TAT). Histopathological diagnosis and 30-day survival were recorded. None of the 15 enrolled dogs had pre-operative sonographic evidence of portal system thrombosis. Three of fifteen dogs were thrombocytopenic, three had thrombocytosis, three were hyperfibrinogenemic, one had low vWF:Ag, three had mild prolongations of PT and none had abnormal aPTT. Based on the TEG G value, 13/15 dogs were hypercoagulable (mean ± SD 13.5 ± 5.4 kd/s). Antithrombin deficiency was identified in 9/15 dogs (mean ± SD 68.7 ± 22.7%) with 5/9 having concurrently elevated TAT suggesting active thrombin generation. No dogs developed portal system thrombosis and all achieved 30-day survival. Pre-operative hypercoagulability was recognized commonly but its association with post-operative thrombosis remains undetermined.

Clinical features and posttreatment monitoring of dogs administered rivaroxaban (2018-2020): 19 cases

OBJECTIVE

To describe a population of sick dogs administered rivaroxaban monitored with a rivaroxaban-calibrated anti-Xa activity assay (aXa).

DESIGN

Descriptive retrospective study.

SETTING

Two veterinary teaching hospitals.

ANIMALS

Client-owned dogs administered rivaroxaban and monitored with aXa from January 2018 to January 2020 were eligible for study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records were reviewed and 19 dogs with a variety of underlying disease processes were identified. Rivaroxaban was administered to 12 of 19 dogs (63%) with confirmed thrombosis, 4 of 19 dogs (21%) with a strong clinical suspicion of thrombosis, and in 3 of 19 dogs (16%) with no current evidence of thrombosis. The median rivaroxaban dose administered was 0.96 mg/kg/day (0.62-1.58 mg/kg/day), with 15 of 19 dogs (79%) receiving rivaroxaban once daily. Clopidogrel was concurrently administered to 11 of 19 dogs (58%). Complete or partial thrombus resolution was identified in 5 of 12 (42%) and 3 of 12 (25%) dogs, respectively. Rivaroxaban appeared safe, with only 1 of 19 dogs (5%), concurrently administered clopidogrel, developing evidence of mild hematuria. Posttreatment monitoring revealed that 8 of 19 dogs (42%) had aXa below the target (aXa range of 150-250 ng/ml associated with effective treatment and prevention of venous thrombosis in people). The remaining 3 to 19 dogs (16%) achieved this range, and 8 of 19 dogs (42%) exceeded the range. No significant relationship between the initial rivaroxaban dose administered and the corresponding aXa result was identified. There were also no significant differences in baseline clinicopathological variables in dogs in which aXa fell within or outside this range.

CONCLUSIONS

aXa was most commonly measured in dogs receiving rivaroxaban with confirmed or suspected thrombosis. Dogs in this study received a range of rivaroxaban dosages and attained variable aXa values that were not directly correlated with dosage.

Clinical features, outcome, and illness severity scoring in 32 dogs with urosepsis (2017-2018)

OBJECTIVE

To describe the clinical features, outcome, and utility of illness severity scoring in dogs diagnosed with urosepsis.

DESIGN

Retrospective study (2017-2018).

SETTING

University teaching hospital.

ANIMALS

Thirty-two dogs diagnosed with urosepsis secondary to pyometra, prostatitis, or pyelonephritis.

INTERVENTIONS

 None.

MEASUREMENTS AND MAIN RESULTS

Urosepsis was identified in 32 dogs, consisting of 9 of 32 (28.1%) with pyometra, 7 of 32 (21.8%) with prostatitis, and 16 of 32 (50%) with pyelonephritis. In total, 28 (87.5%) dogs survived to discharge, with the following group-specific survival rates: pyometra, 9 of 9 (100%); prostatitis, 5 of 7 (71.4%); and pyelonephritis, 14 of 16 (87.5%). Positive bacterial cultures were obtained in 27 of 32 (84.1%) dogs. The most commonly implicated pathogens were Escherichia coli (14/37 [37.8%]), Klebsiella pneumoniae (8/37 [21.6%]), and Staphylococcus pseudintermedius (6/37 [16.2%]). Multiple organ dysfunction syndrome (MODS) was identified in 21 of 32 dogs (65.6%). Although the presence of MODS was not different between survivors and nonsurvivors (P = 0.6), nonsurvivors had more dysfunctional organs (P = 0.04). Nonsurvivors also had higher Acute Patient Physiology and Laboratory Evaluation (APPLE_FAST ) scores compared to survivors (P = 0.01).

CONCLUSIONS

Survival of dogs with urosepsis was good and may be higher than for other sources of sepsis. Compared to survivors, nonsurvivors had more dysfunctional organs and higher illness severity scores, which may be helpful in the assessment and management of dogs with urosepsis.

Influence of long-stay jugular catheters on hemostatic variables in healthy dogs

OBJECTIVE

To compare hemostatic variables performed on blood samples obtained from indwelling jugular catheters or direct venipuncture over a 72-hour period.

DESIGN

Prospective experimental study.

SETTING

University research laboratory.

ANIMALS

Five healthy neutered male purpose-bred Beagle dogs.

INTERVENTIONS

Each dog was sedated to facilitate placement of a long-stay 20-Ga polyurethane IV catheter into the jugular vein. Blood samples were obtained from the preplaced catheters at 4 time points corresponding to 0, 24, 48, and 72 hours relative to placement. Blood samples were also obtained by direct venipuncture of a peripheral vein using a 21-Ga butterfly catheter and evacuated blood tubes at the same time points. Platelet count, platelet closure time, prothrombin time, activated partial thromboplastin time, fibrinogen, and kaolin-activated thromboelastography were performed on these paired samples at each time point. The patency of the indwelling catheters was maintained by flushing every 6 hours with heparinized saline.

MEASUREMENTS AND MAIN RESULTS

No significant differences were identified in any of the hemostatic variables obtained by either blood collection technique at any time point during the study (P > 0.05). There was also no significant day-to-day variation in any catheter-derived hemostatic variable obtained from individual dogs identified over the course of the study.

CONCLUSIONS

These data suggest that accurate hemostatic variables may be obtained using blood collected from indwelling jugular catheters, maintained with heparinized saline for at least 72 hours, in healthy dogs.

Evaluation of point-of-care coagulation tests as alternatives to anti-Xa activity for monitoring the anticoagulant effects of rivaroxaban in healthy dogs

OBJECTIVE

To evaluate a panel of coagulation assays for their potential utility in rivaroxaban monitoring as alternatives to the rivaroxaban-specific anti-Xa activity (RIVA).

DESIGN

Prospective experimental study.

SETTING

University research laboratory.

ANIMALS

Five healthy neutered male Beagles.

INTERVENTIONS

Dogs were administered a median dose of 1.8 mg/kg rivaroxaban (range, 1.6-1.8 mg/kg) orally once daily for 2 consecutive days as part of a pharmacodynamic study. Blood was collected from a preplaced jugular catheter at time points relative to their rivaroxaban administration (0, 2, 4, 8, 24, 36, and 48 h) for measurement of RIVA, prothrombin time (PT), activated partial thromboplastin time, RapidTEG, and thrombin generation variables.

MEASUREMENTS AND MAIN RESULTS

One hundred forty data points were available for analysis. There was poor correlation between RIVA and RapidTEG variables: R time (R) (min) (r = 0.554, P < 0.0001), K time (K) (min) (r = -0.204, P = 0.016), alpha angle (degrees) (r = 0.152, P = 0.073), Maximum amplitude (MA) (mm) (r = 0.106, P = 0.215), and G value (G) (dynes/s) (r = 0.108, P = 0.205). A good correlation was noted between thrombin generation variables and RIVA: lag time (min) (r = 0.827, P < 0.0001), peak (nM) (r = -0.752, P < 0.0001), and endogenous thrombin potential (nM·min) (r = -0.762, P < 0.0001). There was an excellent correlation between PT and RIVA (r = 0.915, P < 0.0001) and a good correlation between activated partial thromboplastin time and RIVA (r = 0.772, P < 0 .0001).

CONCLUSIONS

Of all the coagulation tests investigated, the PT correlated best with RIVA. There is potential for PT being a convenient second-line monitoring option in dogs receiving rivaroxaban, but further work is necessary to validate other PT assays. Thromboelastography performed with strong activators correlated poorly with anti-Xa activity.

The influence of feeding and gastroprotectant medications on the Factor Xa inhibitory activity of orally administered rivaroxaban in normal dogs

OBJECTIVE

Rivaroxaban is a new anticoagulant option for dogs, yet its reported oral bioavailability is as low as 60%. The objective of this study was to examine the influence of feeding and gastroprotectant medications on the bioactivity (anti-Xa activity) of rivaroxaban in healthy dogs.

DESIGN

Prospective experimental study.

SETTING

University research laboratory.

ANIMALS

Five healthy neutered male purpose-bred Beagles.

INTERVENTIONS

Dogs were administered a median dose of 1.8 mg/kg rivaroxaban (range, 1.6-1.8 mg/kg) orally once daily for 2 consecutive days with either (1) no food, (2) food, (3) sucralfate 30 minutes before rivaroxaban, or (4) omeprazole at the same time as rivaroxaban. Blood was collected from preplaced jugular catheters immediately before and at 6 time points after rivaroxaban administration (2, 4, 8, 24, 36, and 48 hours). A rivaroxaban calibrated anti-Xa activity assay (RIVA) was used to monitor anticoagulant effect.

MEASUREMENTS AND MAIN RESULTS

Rivaroxaban administration resulted in significant increases in RIVA (P = 0.02), with peak activities occurring 2 to 4 hours after dosingduring each study arm. No feeding was associated with significantly higher RIVA at the 36-hour time point compared to all other treatment arms (P < 0.0001), and feeding resulted in high RIVA at the 48-hour time point compared with sucralfate administration (P = 0.003). No significant changes in RIVA were otherwise identified with respect to feeding or gastroprotectant administration (P = 0.2).

CONCLUSIONS AND CLINICAL IMPORTANCE

Although administration without food demonstrated an apparent increase in RIVA 36 hours after drug administration, clinically relevant differences among treatment groups were not identified in combined analyses of time points. Based on these results, dogs treated with rivaroxaban do not require special modification of feeding practices or gastroprotectant drug administration.

Outcome and treatments of dogs with aortic thrombosis: 100 cases (1997-2014)

Background

Aortic thrombosis (ATh) is an uncommon condition in dogs, with limited understanding of risks factors, outcomes, and treatments.

Objectives/Hypothesis

To describe potential risk factors, outcome, and treatments in dogs with ATh.

Animals

Client‐owned dogs with a diagnosis of ATh based on ultrasonographic or gross necropsy examination.

Method

Multicentric retrospective study from 2 academic institutions.

Results

One hundred dogs were identified. Anti‐thrombin diagnosis, 35/100 dogs were nonambulatory. The dogs were classified as acute (n = 27), chronic (n = 72), or unknown (n = 1). Fifty‐four dogs had at least one comorbidity thought to predispose to ATh, and 23 others had multiple comorbidities. The remaining 23 dogs with no obvious comorbidities were classified as cryptogenic. Concurrent illnesses potentially related to the development of ATh included protein‐losing nephropathy (PLN) (n = 32), neoplasia (n = 22), exogenous corticosteroid administration (n = 16), endocrine disease (n = 13), and infection (n = 9). Dogs with PLN had lower antithrombin activity than those without PLN (64% and 82%, respectively) (P = .04). Sixty‐five dogs were hospitalized with 41 subsequently discharged. Sixteen were treated as outpatient and 19 euthanized at admission. In‐hospital treatments varied, but included thrombolytics (n = 12), alone or in combination with thrombectomy (n = 9). Fifty‐seven dogs survived to discharge. Sixteen were alive at 180 days. Using regression analysis, ambulation status at the time of presentation was significantly correlated with survival‐to‐discharge (P < .001).

Conclusions/Clinical Importance

Dogs with ATh have a poor prognosis, with nonambulatory dogs at the time of presentation having worse outcome. Although the presence of comorbid conditions associated with hypercoagulability is common, an underlying cause for ATh was not always identified.

The influence of packed cell volume versus plasma proteins on thromboelastographic variables in canine blood

OBJECTIVE

Determine the correlation between kaolin-activated thromboelastography (TEG) variables (R, K, angle, and maximum amplitude [MA]) and PCV, fibrinogen concentration (FC), and total fibrinogen (TF) in an ex vivo model.

ANIMALS

Two healthy adult mixed-breed dogs.

PROCEDURES

Citrated whole blood was obtained and separated into packed red cells, platelet rich plasma, and platelet poor plasma (PPP). An aliquot of PPP was heated to denature heat labile proteins (fibrinogen, factor V, factor VIII). Blood components were recombined for analyses of 6 physiological scenarios: anemia with low fibrinogen; anemia with moderate fibrinogen; anemia with normal fibrinogen; anemia with normal saline; normal PCV and normal fibrinogen; and normal PCV and low fibrinogen. A Kruskal-Wallis test, along with linear regressions on pairwise combinations of TEG variables, was used to determine the correlation between TEG variables and PCV, FC, and TF.

RESULTS

Maximum amplitude correlated with FC (R² 0.60, P < 0.001) and TF (R² 0.57, P < 0.001) but not PCV (R² 0.003, P = 0.7). Angle and K time were moderately correlated with FC ([angle: R² 0.53, P < 0.001]; [K: R² 0.55, P < 0.001]) and TF ([alpha angle: R² 0.52, P < 0.001]; [K: R² 0.51, P < 0.001]) but not PCV. The R time was weakly correlated with PCV (R² 0.15, P < 0.009) but not FC or TF.

CONCLUSIONS AND CLINICAL RELEVANCE

In an ex vivo model, plasma proteins but not PCV impacted TEG variables. This suggests that TEG changes noted with anemia are imparted by changes in available fibrinogen in a fixed microenvironment rather than artifact of anemia.

Intervertebral disc disease and aortic thromboembolism are the most common causes of acute paralysis in dogs and cats presenting to an emergency clinic

BACKGROUND

Acute paralysis is a common presentation in small animal emergency clinics, but the aetiological prevalence has not been reported. Knowledge of diagnosis frequency aids prioritisation of differential diagnoses, facilitates resource planning and clinical trial design.

METHODS

Medical records from NC State Veterinary Hospital Emergency Room were searched over a five-year period to identify cases presenting with acute non-ambulatory paraparesis or paralysis. Signalment and diagnosis category were extracted.

RESULTS

Acute paralysis was the presenting problem in 845 of 21,535 (3.9 per cent) dogs and 66 of 4589 (1.4 per cent) cats admitted over this period. Intervertebral disc disease (IVDD) was the most common cause (608 of 845; 72 per cent) in dogs, followed by vascular disease (34 of 845; 4.0 per cent). Other diagnostic categories accounted for the remaining 20 per cent. Dachshunds were the most common breed (263 of 845; 31.1 per cent), then Labrador retrievers (57 of 845; 6.7 per cent). In cats, aortic thromboembolism (ATE) was the most common diagnosis, occurring in 40 of 66 (60.6 per cent), followed by IVDD (7 of 66; 10.6 per cent). Other diagnostic categories accounted for 30.3 per cent. Six of 845 (0.7 per cent) dogs and two of 66 (3 per cent) cats were categorised as pseudoparalysis with a non-neurological diagnosis.

CONCLUSIONS

IVDD and ATE are the overwhelming causes of acute paralysis in dogs and cats, respectively, with approximately 28 per cent of dogs and 40 per cent of cats having a different diagnosis.

Acute chlorfenapyr toxicity in 3 dogs from a single household

OBJECTIVE

To describe the clinical characteristics of acute chlorfenapyr toxicity in 3 dogs from a single household.

CASE SUMMARY

A 4-year-old neutered female Labrador Retriever was presented with severe hyperthermia (42.6°C [108.6°F]). Emergency management consisting of fluid resuscitation, active cooling, general anesthesia, gastric lavage, activated charcoal administration, and intravenous lipid emulsion was started immediately on the suspicion of toxin exposure. The dog developed symptoms following peracute death in 2 other small breed dog housemates. All dogs had a rapid onset of gastrointestinal signs, neurologic signs, and panting. The dog made a rapid and complete recovery and was discharged 48 hours later. Examination of gastric contents collected from the deceased dogs identified the presence of chlorfenapyr.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first reported case of chlorfenapyr toxicity in dogs. Previous case reports in human medicine have reported a variable mortality rate, although 1 of 3 dogs described here made a complete recovery. Chlorfenapyr should be considered in cases of suspected toxicity with similar presenting signs.

Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE): Domain 4-Refining and monitoring antithrombotic therapies

OBJECTIVES

To systematically review the evidence for therapeutic monitoring of antithrombotic drugs in small animals, develop guidelines regarding antithrombotic monitoring, and identify knowledge gaps in the field.

DESIGN

First, a standardized, systematic literature review was conducted to address predefined PICO (Population/Patient, Intervention, Control, Outcome) questions, with categorization of relevant articles according to level of evidence and quality. Preliminary guidelines were developed by PICO worksheet authors and the domain chair. Thereafter, a Delphi-style survey was used to develop consensus on guidelines regarding therapeutic monitoring of antithrombotics in dogs and cats.

SETTING

Academic and referral veterinary medical centers.

RESULTS

PICO questions regarding the utility of therapeutic monitoring were developed for 6 different antithrombotic drugs or drug classes, including aspirin, clopidogrel, warfarin, unfractionated heparin, the low molecular weight heparins, and rivaroxaban, The majority of the literature pertaining to therapeutic monitoring of antithrombotic drugs was either performed in experimental animal models of disease or involved studies of drug pharmacokinetics and pharmacodynamics in healthy laboratory animals. There was a paucity of high level of evidence studies directly addressing the PICO questions, which limited the strength of recommendations that could be provided. The final guidelines recommend that therapeutic monitoring should be performed when using warfarin or unfractionated heparin in dogs and cats at risk of thrombosis. There is insufficient evidence to make strong recommendations for therapeutic monitoring of aspirin or low molecular weight heparin in dogs and cats at this time.

CONCLUSIONS

As in other CURATIVE domains, significant knowledge gaps were highlighted, indicating the need for substantial additional research in this field. Ongoing investigation of the role of therapeutic monitoring of antithrombotic therapies will undoubtedly facilitate improved outcomes for dogs and cats at risk of thrombosis.

Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE): Domain 3-Defining antithrombotic protocols

OBJECTIVES

To systematically examine the evidence for use of a specific protocol (dose, frequency, route) of selected antithrombotic drugs, in comparisons to no therapy or to other antithrombotic therapies, to reduce the risk of complications or improve outcomes in dogs and cats at risk for thrombosis.

DESIGN

Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence (LOE) and quality (Good, Fair, or Poor), and development of consensus on conclusions via a Delphi-style survey for application of the concepts to clinical practice.

SETTINGS

Academic and referral veterinary medical centers.

RESULTS

Databases searched included Medline via PubMed and CAB abstracts. Eight different antithrombotic drugs were investigated using a standardized Patient, Intervention, Comparison, Outcome (PICO) question format both for dogs and cats, including aspirin, clopidogrel, warfarin, unfractionated heparin (UFH), dalteparin, enoxaparin, fondaparinux, and rivaroxaban, generating a total of 16 worksheets. Most studies identified were experimental controlled laboratory studies in companion animals (LOE 3) with only four randomized controlled clinical trials in companion animals (LOE 1).

CONCLUSIONS

Overall, evidence-based recommendations concerning specific protocols could not be formulated for most antithrombotic drugs evaluated, either because of the wide range of dosage reported (eg, aspirin in dogs) or the lack of evidence in the current literature. However, clopidogrel administration in dogs and cats at risk of arterial thrombosis, notably in cats at risk of cardiogenic thromboembolism, is supported by the literature, and specific protocols were recommended. Comparably, aspirin should not be used as a sole antithrombotic in cats with cardiomyopathy. Using the available safety profile information contained in the literature, the panel reached consensus on suggested dosage schemes for most antithrombotics. Significant knowledge gaps were highlighted, which will hopefully drive novel research.

Recent attempted and actual weight change in relation to pregnancy loss: a prospective cohort study

OBJECTIVE

To assess weight change and attempted weight loss during the 12-18 months before spontaneous conception in relation to the risk of pregnancy loss.

DESIGN

Prospective cohort study.

SETTING

United States, 2007-2011.

METHODS

Women (n = 629) who were attempting pregnancy reported at baseline any weight loss attempts over the past 12 months, and their minimum and maximum weights during that time. Follow up lasted one to six menstrual cycles and throughout pregnancy. Using bodyweight measured at 4 weeks' gestation, participants were categorised as having weight loss ≥5%, weight gain ≥5%, both, or neither, over the previous 12-18 months. Log-binomial models adjusted for potential confounders.

MAIN OUTCOME MEASURES

Risk ratio (RR) and 95% confidence interval (CI) of pregnancy loss.

RESULTS

Attempted weight loss was reported by 44% of women and actual weight loss by 11%, but neither was consistently associated with pregnancy loss. The RR for recent weight gain ≥5% was 1.65 (CI 1.09, 2.49).

CONCLUSIONS

Weight gain over the period spanning 12-18 months pre-conception to 4 weeks' gestation may increase the risk of pregnancy loss among fertile women with prior pregnancy losses. Attempted and actual weight loss were not associated with pregnancy loss; however, replication is needed from larger studies with data on particular weight-loss methods.

TWEETABLE ABSTRACT

Recent weight gain before and around the time of conception may increase the risk of pregnancy loss.

Dogfish glucagon analogues counter hyperglycaemia and enhance both insulin secretion and action in diet-induced obese diabetic mice

AIMS

To investigate the antidiabetic actions of three dogfish glucagon peptide analogues [known glucagon-like peptide-1 and glucagon receptor co-agonists] after chronic administration in diet-induced high-fat-diet-fed diabetic mice.

MATERIALS AND METHODS

National Institutes of Health Swiss mice were pre-conditioned to a high-fat diet (45% fat) for 100 days, and control mice were fed a normal diet (10% fat). Normal diet control and high-fat-fed control mice received twice-daily intraperitoneal (i.p.) saline injections, while the high-fat-fed treatment groups (n = 8) received twice-daily injections of exendin-4(1-39), [S2a]dogfish glucagon, [S2a]dogfish glucagon exendin-4(31-39) or [S2a]dogfish glucagon-Lys(30) -γ-glutamyl-PAL (25 nmol/kg body weight) for 51 days.

RESULTS

After dogfish glucagon analogue treatment, there was a rapid and sustained decrease in non-fasting blood glucose and an associated insulinotropic effect (analysis of variance, p < .05 to <.001) compared with saline-treated high-fat-fed controls. All peptide treatments significantly improved i.p. and oral glucose tolerance with concomitant increased insulin secretion compared with saline-treated high-fat-fed controls (p <.05 to <.001). After chronic treatment, no receptor desensitization was observed but insulin sensitivity was enhanced for all peptide-treated groups (p < .01 to <.001) except [S2a]dogfish glucagon. Both exendin-4 and [S2a]dogfish glucagon exendin-4(31-39) significantly reduced plasma triglyceride concentrations compared with those found in lean controls (p = .0105 and p = .0048, respectively). Pancreatic insulin content was not affected by peptide treatments but [S2a]dogfish glucagon and [S2a]dogfish glucagon exendin-4(31-39) decreased pancreatic glucagon by 28%-34% (p = .0221 and p = .0075, respectively). The percentage of β-cell area within islets was increased by exendin-4 and peptide analogue treatment groups compared with high-fat-fed controls and the β-cell area decreased (p < .05 to <.01).

CONCLUSIONS

Overall, dogfish glucagon co-agonist analogues had several beneficial metabolic effects, showing therapeutic potential for type 2 diabetes.

Methyl isobutyl ketone-induced hepatocellular carcinogenesis in B6C3F1 mice: A constitutive androstane receptor (CAR)-mediated mode of action

In a National Toxicology Program (NTP) chronic inhalation study with methyl isobutyl ketone (MIBK), increases in hepatocellular adenomas and hepatocellular adenomas and carcinomas (combined) were observed in male and female B6C3F₁ mice at 1800 ppm. A DNA reactive Mode-of-Action (MOA) for this liver tumor response is not supported by the evidence as MIBK and its major metabolites lack genotoxicity in both in vitro and in vivo studies. Constitutive androstane receptor (CAR) nuclear receptor-mediated activation has been hypothesized as the MOA for MIBK-induced mouse liver tumorigenesis. To further investigate the MOA for MIBK-induced murine liver tumors, male and female B6C3F1, C57BL/6, and CAR/PXR Knockout (KO) mice were exposed to either 0 or 1800 ppm MIBK for 6 h/day, 5 days/week for a total of 10 days. On day 1, mice were implanted with osmotic mini-pumps containing 5-Bromo-2-deoxyuridine (BrdU) 1 h following exposure and humanely euthanized 1-3 h following the final exposure. B6C3F₁ and C57BL/6 mice had statistically significant increases in liver weights compared to controls that corresponded with hepatocellular hypertrophy and increased mitotic figures. Hepatocellular proliferation data indicated induction of S-phase DNA synthesis in B6C3F₁ and C57BL/6 mice exposed to 1800 ppm MIBK compared to control, and no increase was observed in MIBK exposed CAR/PXR KO mice. Liver gene expression changes indicated a maximally-induced Cyp2b10 (CAR-associated) transcript and a slight increase in Cyp3a11(PXR-associated) transcript in B6C3F₁ and C57BL/6 mice exposed to 1800 ppm MIBK compared to controls, but not in Cyp1a1 (AhR-associated) or Cyp4a10 (PPAR-α-associated) transcripts. CAR/PXR KO mice exposed to 1800 ppm MIBK showed no evidence of activation of AhR, CAR, PXR or PPAR-α nuclear receptors via their associated transcripts. MIBK induced hepatic effects are consistent with a phenobarbital-like MOA where the initiating events are activation of the CAR and PXR nuclear receptors and resultant hepatocellular proliferation leading to rodent liver tumors.

Novel dual agonist peptide analogues derived from dogfish glucagon show promising in vitro insulin releasing actions and antihyperglycaemic activity in mice

The antidiabetic potential of thirteen novel dogfish glucagon derived analogues were assessed in vitro and in acute in vivo studies. Stable peptide analogues enhanced insulin secretion from BRIN-BD11 β-cells (p < 0.001) and reduced acute glycaemic responses following intraperitoneal glucose (25 nmol/kg) in healthy NIH Swiss mice (p < 0.05-p<0.001). The in vitro insulinotropic actions of [S2a]dogfish glucagon, [S2a]dogfish glucagon-exendin-4(31-39) and [S2a]dogfish glucagon-Lys(30)-γ-glutamyl-PAL, were blocked (p < 0.05-p<0.001) by the specific GLP-1 and glucagon receptor antagonists, exendin-4(9-39) and (desHis(1)Pro(4)Glu(9))glucagon amide but not by (Pro(3))GIP, indicating lack of GIP receptor involvement. These analogues dose-dependently stimulated cAMP production in GLP-1 and glucagon (p < 0.05-p<0.001) but not GIP-receptor transfected cells. They improved acute glycaemic and insulinotropic responses in high-fat fed diabetic mice and in wild-type C57BL/6J and GIPR-KO mice (p < 0.05-p<0.001), but not GLP-1R-KO mice, confirming action on GLP-1 but not GIP receptors. Overall, dogfish glucagon analogues have potential for diabetes therapy, exerting beneficial metabolic effects via GLP-1 and glucagon receptors.

Assessment of hemostatic changes in a model of acute hemorrhage in dogs

OBJECTIVE

To evaluate hemostatic changes following experimental acute hemorrhage in dogs using traditional coagulation tests (eg, platelet count, prothrombin time [PT], and activated partial thromboplastin time [aPTT]), kaolin-activated thromboelastography (TEG), and whole blood multiple electrode impedance platelet aggregometry.

DESIGN

Prospective study.

SETTING

Research laboratory.

ANIMALS

Five Beagles.

INTERVENTIONS

Dogs were anesthetized prior to obtaining blood samples for baseline PCV, total plasma protein (TPP), arterial blood-gas, platelet count, PT, aPTT, TEG, fibrinogen, and aggregometry. Blood was obtained at 4 additional time points, following 20% blood volume loss, 40% blood volume loss, 60 minutes of sustained hypotension, and after autologous blood transfusion. In addition, heart rate and direct arterial blood pressure were measured at each time point.

MEASUREMENTS AND MAIN RESULTS

Significant decreases were noted for PCV (P = 0.048), TPP (P < 0.0001), and arterial blood pressures (P < 0.0001) over time. Platelet count did not change significantly (P = 0.879), but platelet function was decreased following hemorrhage when arachidonic acid (P = 0.004) and ADP (P = 0.008) were used as agonists. The TEG variables R (P = 0.030), MA (P = 0.043), and G (P = 0.037) were significantly, albeit mildly, changed following hemorrhage. Significant prolongations in PT (P < 0.0001) and aPTT (P = 0.041), and decreases in fibrinogen concentration (P = 0.002) were also seen.

CONCLUSION

Platelet dysfunction occurred following hemorrhage in this model, despite a stable platelet count. Additionally, significant changes associated with hemorrhage were documented in aPTT, fibrinogen, and MA. Platelet function testing in dogs with naturally occurring hemorrhage warrants further investigation.

Hospital-acquired Anemia in Critically Ill Dogs and Cats: A Multi-Institutional Study

BACKGROUND

Hospital-acquired anemia is commonly described in people but limited information currently is available regarding its prevalence in animals.

HYPOTHESIS/OBJECTIVES

Assess the prevalence of hospital-acquired anemia in hospitalized critically ill dogs and cats, and examine its relationship with phlebotomy practices, transfusion administration, and survival to discharge.

ANIMALS

Eight hundred and fifty-one client-owned animals (688 dogs and 163 cats).

METHODS

A multicenter, observational study was conducted in which packed cell volume (PCV) was recorded at the time of admission and on subsequent hospitalization days. Signalment, number of blood samples obtained, underlying disease, whether or not blood products were administered, duration of hospitalization, and survival to discharge were recorded.

RESULTS

Admission anemia prevalence was 32%, with overall prevalence during the hospitalization period of 56%. The last recorded PCV was significantly lower than the admission PCV for both dogs (admission PCV, 42% [range, 6-67%]; last recorded PCV, 34% [range, 4-64%], P < .0001) and cats (admission PCV, 31% [range, 6-55%]; last recorded PCV, 26% [range, 10-46%], P < .0001). Patients that developed anemia had significantly more blood samples obtained (nonanemic, 5 blood samples [range, 2-54]; anemic, 7 blood samples [range, 2-49], P < .0001). Hospitalized cats were significantly more likely to develop anemia compared to dogs (P < .0001), but anemic dogs were significantly less likely to survive to discharge (P = .0001). Surgical patients were at higher risk of developing hospital-acquired anemia compared to medical patients (OR, 0.63; 95% CI, 0.4-0.9; P = .01).

CONCLUSIONS AND CLINICAL RELEVANCE

Hospital-acquired anemia occurred frequently, especially in surgical patients. Additional studies focused on the direct effect of phlebotomy practices on the likelihood of anemia development in hospitalized animals are warranted.

Acute tracheal compression in a large breed dog due to a dorsal tracheal membrane abscess

OBJECTIVE

To describe a case of acute tracheal compression due to a dorsal tracheal membrane abscess in a dog.

CASE SUMMARY

A 3-year-old intact male Bluetick Coonhound presented for evaluation of 36 hours of marked inspiratory dyspnea and stridor. A radiographic diagnosis of tracheal collapse was made on thoracic radiographs, which was confirmed to be static compression by tracheoscopy. Dorsal extraluminal tracheal compression from a fluid filled structure adjacent to the trachea was suspected based on ultrasonography. Endoscopic-guided transtracheal fine needle aspiration yielded septic suppurative inflammation. At surgery an abscess in the dorsal tracheal membrane was identified, lanced, and lavaged, which resulted in restoration of normal tracheal diameter. The dog developed bilateral pneumothorax, which was treated medically by thoracostomy tube placement and manual evacuation of the accumulated air. Postoperative radiographs also revealed evidence of pneumomediastinum. Pneumothorax and pneumomediastinum likely occurred secondary to the surgical approach, worsened by positive pressure ventilation. Cultures of the abscess isolated a nonhemolytic Streptococcus species but with no evidence of anaerobic bacteria. The dog made a full functional recovery.

NEW OR UNIQUE INFORMATION PROVIDED

Tracheal compression is a rare diagnosis in dogs. To the authors' knowledge, this represents the first report of an abscess in the dorsal tracheal membrane, diagnosed by endoscopic-guided transtracheal fine needle aspiration, causing clinically relevant acute tracheal obstruction.

Stable oxyntomodulin analogues exert positive effects on hippocampal neurogenesis and gene expression as well as improving glucose homeostasis in high fat fed mice

The weight-lowering and gluco-regulatory actions of oxyntomodulin (Oxm) have been well-documented however potential actions of this peptide in brain regions associated with learning and memory have not yet been evaluated. The present study examined the long-term actions of a stable acylated analogue of Oxm, (dS(2))Oxm(K-γ-glu-Pal), together with parent (dS(2))Oxm peptide, on hippocampal neurogenesis, gene expression and metabolic control in high fat (HF) mice. Groups of HF mice (n = 12) received twice-daily injections of Oxm analogues (both at 25 nmol/kg body weight) or saline vehicle (0.9% wt/vol) over 28 days. Hippocampal gene expression and histology were assessed together with evaluation of energy intake, body weight, non-fasting glucose and insulin, glucose tolerance, insulin sensitivity and lipids. Oxm analogues significantly reduced body weight, improved glucose tolerance, glucose-mediated insulin secretion, insulin sensitivity, islet architecture and lipid profile. Analysis of brain histology revealed significant reduction in hippocampal oxidative damage (8-oxoguanine), enhanced hippocampal neurogenesis (doublecortin) and improved hippocampal and cortical synaptogenesis (synaptophysin) following treatment. Furthermore, Oxm analogues up-regulated hippocampal mRNA expression of MASH1, Synaptophysin, SIRT1, GLUT4 and IRS1, and down-regulated expression of LDL-R and GSK3β. These data demonstrate potential of stable Oxm analogues, and particularly (dS(2))Oxm(K-γ-glu-Pal) to improve metabolic function and enhance neurogenesis, synaptic plasticity, insulin signalling and exert protective effects against oxidative damage in hippocampus and cortex brain regions in HF mice.

Clinical experience of anti-Xa monitoring in critically ill dogs receiving dalteparin

OBJECTIVES

To describe a population of critically ill dogs receiving dalteparin monitored with an anti-Xa assay, to assess the potential utility of serial monitoring, and to investigate the association between pre-treatment thromboelastography (TEG) and the ability to achieve targeted anti-Xa activity.

DESIGN

Descriptive retrospective study.

SETTING

Veterinary teaching hospital.

ANIMALS

Thirty-eight client-owned dogs receiving dalteparin and monitored with an anti-Xa assay.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records were retrospectively reviewed for signalment, underlying disease, clinicopathological data, occurrence of thromboembolic events, complications, and outcome. Thirty-eight dogs receiving dalteparin were monitored with an anti-Xa assay. Diseases included hematological disease, protein-losing disease, neoplastic disease, and septic processes. Pretreatment hypercoagulability was present in 34/35 dogs by assessment of TEG. Five cases of thromboembolism were confirmed prior to starting treatment and 4 cases occurred during hospitalization. Bleeding complications were rare (3/38) and 29/38 dogs survived to discharge. Interpretation of the anti-Xa assay allowed for dose adjustment although reliable achievement of target anti-Xa activity was not demonstrated. Dogs with higher G values on pretreatment TEG were significantly less likely to achieve the target anti-Xa activity (ie, be above or below the target range).

CONCLUSIONS

Dalteparin was well tolerated in a heterogeneous population of dogs. However, dose adjustment in response to anti-Xa activity interpretation inconsistently resulted in subsequent attainment of the target anti-Xa range. Development of guidelines may be warranted to more consistently achieve the target range. Dogs that appear more hypercoagulable on pre-treatment TEG may require closer monitoring and greater dose adjustment to achieve the target anti-Xa range.

Genotoxicity screening via the γH2AX by flow assay

The measurement of serine139-phosphorylated histone H2AX (γH2AX) provides a biomarker of DNA double-strand breaks (DSBs) and may identify potential genotoxic activity. In order to evaluate a flow cytometry assay for γH2AX detection (hereafter termed the γH2AX by flow assay), 6 prototypical (3 pro- and 3 proximate) genotoxins, i.e. dimethylbenz[a]anthracene (DMBA), 2-acetylaminofluorene (2-AAF), benzo[a]pyrene (B[a]P), methyl methane sulphonate (MMS), methyl nitrosourea (MNU) and 4-nitroquinoline oxide (4NQO), were selected to define assay evaluation criteria. In addition, 3 non-genotoxic cytotoxins (phthalic anhydride, n-butyl chloride and hexachloroethane) were included to investigate the influence of cytotoxicity on assay performance. At similar cytotoxicity levels (relative cell counts; RCC 75-40%) all prototypical genotoxins induced marked concentration-dependent increases in γH2AX compared with the non-genotoxins. As a result, assay evaluation criteria for a positive effect were defined as >1.5-fold γH2AX @ RCC >25%. Twenty five additional chemicals with diverse structures and genotoxic activity were selected to evaluate the γH2AX by flow assay. Results were compared with Ames bacterial and in vitro mammalian genotoxicity tests (mouse lymphoma assay and/or chromosome aberration assay). γH2AX by flow assay results were highly predictive of Ames (sensitivity 100%; specificity 67%; concordance 82%) and in vitro mammalian genotoxicity tests (sensitivity 91%; specificity 89%; concordance 91%) and provide additional evidence that γH2AX is a biomarker of potential genotoxic activity, underpinned mechanistically by the cellular response to DSBs. Discordant findings were predominately attributed to differences in specificity for some mammalian cell genotoxins that are Ames non-mutagens or for "biologically-irrelevant" positives in the mammalian tests. Simple anilines were classified as genotoxic following rat liver S9-mediated bioactivation, however, effects on γH2AX were atypical and limited to a small sub-population of S-phase nuclei. Nevertheless, the γH2AX by flow assay represents a novel genotoxicity assay with the potential to flag both pro- and proximate genotoxins.

Dysregulated complement activation as a common pathway of injury in preeclampsia and other pregnancy complications

The complement system protects the host against invading organisms, initiates inflammation and dispose of immune complexes and the products of inflammatory injury. The complement system provides an important link between the innate and adaptive immune systems. Experimental observations suggest that increased complement activation causes and/or perpetuates inflammation during pregnancy. Recent studies suggest a link between complement activation and preeclampsia. Excessive activation or insufficient regulation of complement recruits leukocytes and unleashes potent inflammatory and anti-angiogenic mediators associated with placental insufficiency and maternal endothelial dysfunction characteristic of preeclampsia. We review the animal and human studies that link complement activation and pathogenic events in preeclampsia, present evidence that activation of the complement system is associated with the development of preeclampsia and provides new targets to prevent its complications.

The interrelationship of complement-activation fragments and angiogenesis-related factors in early pregnancy and their association with pre-eclampsia

OBJECTIVE

To determine the interrelationships during early pregnancy of complement-activation fragments Bb, C3a and sC5b-9, and angiogenesis-related factors placental growth factor (PiGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), and their associations with pre-eclampsia.

DESIGN

Prospective cohort study.

SETTING

Denver complement study (June 2005-June 2008).

POPULATION

A total of 668 pregnant women with singleton gestations, recruited between 10 and 15 weeks of gestation.

METHODS

Using univariable and multivariable logistic regression analysis, concentrations of complement-activation fragments and angiogenesis-related factors were compared between 10 and 15 weeks of gestation in women who subsequently did or did not develop pre-eclampsia. Interrelationships between these variables were tested using the non-parametric Spearman rank correlation coefficient.

MAIN OUTCOME MEASURE

Pre-eclampsia. The association of complement-activation fragments and angiogenesis-related factors with obesity was also examined.

RESULTS

The mean (+/-SD) levels of complement Bb in early pregnancy among women who did and did not develop pre-eclampsia were 0.84 (+/-0.26) microg/ml and 0.69 (+/-0.2) microg/ml, respectively (P = 0.001). Concentrations of PiGF were significantly (P = 0.01) lower (31 +/- 12 pg/ml) in early pregnancy in the pre-eclamptic group of women, as compared with the normotensive group (39 +/- 32 pg/ml). The adjusted odds ratio (AOR) of Bb and PiGF were 2.1 (CI = 1.4-3.1, P < 0.0003) and 0.2 (CI = 0.07-0.7, P = 0.01), respectively. There was no significant difference in the levels of C3a, sC5b-9, sFlt-1 and sEng in early pregnancy among women who developed pre-eclampsia, compared with women who remained normotensive during pregnancy. Higher levels of Bb (P = 0.0001) and C3a (P = 0.03), and lower levels of sFlt-1 (P = 0.0002) and sEng (P = 0.0001) were found among women with obesity, compared with non-obese controls. No meaningful relationships were found between the complement-activation fragments and the angiogenesis-related factors.

CONCLUSIONS

In this cohort during early pregnancy, increased concentrations of complement-activation factor Bb and lower concentrations of PiGF were associated with the development of pre-eclampsia later in pregnancy.

Effectiveness and safety of a structured swimming program in previously sedentary women during pregnancy

OBJECTIVE

To determine whether undertaking a swimming program in sedentary women during pregnancy would improve maternal fitness without adverse fetal consequences.

METHODS

Prospective observational investigation of healthy sedentary pregnant women participating in a monitored swimming program.

RESULTS

Twenty-three women attended swimming sessions from 16 to 28 weeks of gestation resulting in increasing distances swum and improved aerobic fitness as measured by physical work capacity (PWC170) (p = 0.003). Resting maternal heart rate decreased (p = 0.041) and resting systolic (p = 0.092) and diastolic (p = 0.971) blood pressures remained unchanged over gestation. The mean fetal heart rates decreased with advancing gestational age (p = 0.001), consistent with normal physiology. Non-stress tests and umbilical artery systolic/diastolic ratios were similar before and after swimming sessions, providing evidence that fetal well-being was unchanged.

CONCLUSIONS

A structured swimming program in sedentary pregnant women increases maternal fitness without any alteration in maternal and fetal well-being.

Effectiveness of a teaching programme in pain and symptom management for junior house officers

The objectives of this study were (i) to assess the level of knowledge with respect to pain and symptom management among doctors in their first year after graduation and (ii) to measure the impact of a structured teaching programme on their level of knowledge. All 34 newly qualified junior house officers in one teaching hospital were offered a six-session teaching programme in pain and symptom management. A multiple-choice questionnaire was used to assess their level of knowledge at the beginning and at the end of a 6-month period over which the teaching sessions took place. Attendance at and satisfaction with the programme were high. There was a significant improvement in the level of knowledge at the end of the programme, with the greatest improvement in those who attended most sessions. The low scores recorded for the questionnaire administered before the teaching programme suggest that there is a critical need for improved education in palliative care amongst newly qualified doctors. We have shown that a simple in-service case-based teaching programme can meet this need effectively.

How much does physical appearance say about the psychological adjustment of competent and dysfunctional children?

Presents a study in which three sets of photographs of socially competent, aggressive, and anxious preschoolers were rated by college students (n = 150 raters per set), blind to the children's group membership. This was done to assess the extent to which adults are able to make valid and reliable evaluations of children's psychological adjustment on the basis of physical appearance alone. Sets 1 and 2 were photographs of different children taken under the same conditions and providing both facial and nonfacial cues. Sets 2 and 3 were of the same children taken under conditions that varied as to the amount of nonfacial cues they provided. Results showed that (a) socially competent children were judged to be better adjusted than their dysfunctional peers (i.e., more competent, less aggressive, less anxious, and less likely to have emotional or behavioral problems); (b) within the dysfunctional group, aggressive and anxious children were distinguished in ways that correspond closely to what is known about them from behavioral and clinical research; (c) irrespective of group membership, girls and boys were generally distinguished in ways that reflect normative beliefs about gender differences from social and developmental research; (d) group differences in ratings of psychological adjustment were generally comparable across photograph sets and could not be accounted for by differences in the children's perceived physical attractiveness; and (e) raters reported that they relied mainly on the children's expression, eyes, and posture to make their judgments of adjustment. These results replicate and extend earlier findings based on 1 of the 3 photograph sets (Serketich & Dumas, 1997). They suggest that when first impressions matter, competent children are at an advantage and their dysfunctional peers at a disadvantage even before their actual behavior comes to confirm or to invalidate these impressions. Theoretical and clinical implications of the findings are discussed.

Food-derived heterocyclic amine mutagens: variable metabolism and significance to humans

The cooking of meat has been found to generate compounds that possess extreme mutagenicity when examined in short term tests. This observation led to the isolation and identification of a family of mutagenic chemicals, all of which are heterocyclic amines. These amines are potent bacterial and eukaryotic cell mutagens, and all of those tested have been found to induce tumors in laboratory animals. Metabolic activation of the heterocyclic amines predominantly involves CYP1-mediated N-hydroxylation and then O-esterification by phase II enzymes. In contrast, carbon oxidation, glucuronidation, and sulfation reactions at sites other than the hydroxylamine yield detoxication metabolites. In humans, the activities of these pathways are known to vary between individuals and are likely to influence susceptibility to the genetic toxicity of the heterocyclic amines. Clearly, accurate determination of human exposure to the heterocyclic amines and identification of the key enzyme systems involved and their regulation will be required for rational assessment of the risk and will help devise strategies to reduce such risk.

Flow cytometric enumeration of micronucleated reticulocytes: high transferability among 14 laboratories

This laboratory previously described a single-laser flow cytometric method, which effectively resolves micronucleated erythrocyte populations in rodent peripheral blood samples. Even so, the rarity and variable size of micronuclei make it difficult to configure instrument settings consistently and define analysis regions rationally to enumerate the cell populations of interest. Murine erythrocytes from animals infected with the malaria parasite Plasmodium berghei contain a high prevalence of erythrocytes with a uniform DNA content. This biological model for micronucleated erythrocytes offers a means by which the micronucleus analysis regions can be rationally defined, and a means for controlling interexperimental variation. The experiments described herein were performed to extend these studies by testing whether malaria-infected erythrocytes could also be used to enhance the transferability of the method, as well as control intra- and interlaboratory variation. For these studies, blood samples from mice infected with malaria, or treated with vehicle or the clastogen methyl methanesulfonate, were fixed and shipped to collaborating laboratories for analysis. After configuring instrumentation parameters and guiding the position of analysis regions with the malaria-infected blood samples, micronucleated reticulocyte frequencies were measured (20,000 reticulocytes per sample). To evaluate both intra- and interlaboratory variation, five replicates were analyzed per day, and these analyses were repeated on up to five separate days. The data of 14 laboratories presented herein indicate that transferability of this flow cytometric technique is high when instrumentation is guided by the biological standard Plasmodium berghei.

Promoting intervention fidelity. Conceptual issues, methods, and preliminary results from the EARLY ALLIANCE prevention trial

Fidelity refers to the demonstration that an experimental manipulation is conducted as planned. In outcome research, an intervention can be said to satisfy fidelity requirements if it can be shown that each of its components is delivered in a comparable manner to all participants and is true to the theory and goals underlying the research. Demonstrating the fidelity of an intervention is a key methodologic requirement of any sound prevention trial. This paper summarizes key conceptual and methodologic issues associated with intervention fidelity, and describes the steps taken to promote fidelity in EARLY ALLIANCE, a large-scale prevention trial currently testing the effectiveness of family, peer, and school interventions to promote competence and reduce risk for conduct disorder, substance abuse, and school failure. The paper presents preliminary results (Trial Year 1) that demonstrate content and process fidelity for two of these interventions, and discusses how the EARLY ALLIANCE methodology may be generalized to address fidelity issues in other prevention studies.

Embryo survival, and fetal and placental growth following elevation of maternal estradiol blood concentrations in the rat

High doses of estrogens cause embryonic mortality, and fetal and placental growth retardation in rats. This study addresses the physiological relevance of such findings. Estradiol benzoate (EB), by s.c. injection, or estradiol-17beta (E2), delivered by a miniosmotic pump, raised maternal E2 concentrations from only slightly above control values to 5-fold. EB (1 microgram/day) over Days 6-13, 8-13, and 11-13, and continuous infusion of E2 (15 ng/h; Days 10-13) reduced fetal survival to 0%, 0%, 22%, and 75%, respectively. Single injections of EB showed that its lethal effect declined rapidly over Days 9 (44% survival) to 13 (90% survival). Embryos died within 48 h, but death was not due to luteal failure since progesterone levels were maintained and progesterone administered with EB did not reduce mortality. Administration of EB at 1 microgram/day (Days 14-21) or E2 at 40 ng/h (Days 13-16) retarded fetal and placental growth but did not affect survival. The rat embryo is highly sensitive to elevated maternal estradiol concentrations over much of gestation. The early lethal effect implies that endogenous E2 production is carefully regulated to maintain pregnancy; the latter growth-retarding effect suggests that E2 may have a role in the normal control of fetal growth.

Analysis of gene mutations and clastogenicity following short-term treatment with azathioprine in MutaMouse

The mutagenicity and clastogenicity of the immunosuppressive drug azathioprine (AZA), a multitissue rodent carcinogen and IARC-classified human carcinogen, was investigated using transgenic lacZ mice (MutaMouse). Male animals (n = 5 per group) were dosed with AZA (10, 50, 100 mg/kg p.o. daily for 5 days), vehicle (n = 10), or the positive control, chlorambucil (15 mg/kg i.p., n = 3), and killed 24 hr or 25 days after the last treatment. Micronucleus assays were performed with bone marrow (24-hr samples) or peripheral blood (24-hr and 25-day samples) and DNA was extracted from bone marrow and liver for gene mutation analysis at the transgenic lacZ locus. AZA induced 5.3-111.3-fold increases in %MNPCE (P < 0.01) in bone marrow compared with vehicle control, accompanied by 4.4-5. 6-fold increases in %MNRETs (P < 0.01) in peripheral blood. Chlorambucil caused a 14.5-fold increase in %MNRET and there was evidence of significant stem cell toxicity in both positive control and AZA treatment groups. By day 25, however, there was evidence of substantial recovery of the bone marrow as determined by the frequency of RET, and the %MNRET in all treatment groups was the same as the vehicle control. Analysis of lacZ MF showed 1.4-1.6-fold increases in AZA 24-hr bone marrow samples, increasing to approximately 2.0-fold above concurrent controls by day 25 (medium dose P < 0.05, high dose P < 0.01). For liver, there was a 2-fold increase in MF (P < 0.05) in the 24-hr sample at the highest dose only, and increases of 1.3-1.5-fold by day 25 in the medium (P < 0. 05) and high (P = 0.055) dose groups, respectively. The positive control, chlorambucil, induced 2-3-fold increases (P < 0.01) in mean MF in both bone marrow (25-day sample) and liver (24-hr and 25-day samples). These data confirm the clastogenicity of AZA in the mouse, and show that this compound induces gene mutations in bone marrow and liver, in vivo, at the highest dose and supports the view that AZA is a genotoxic carcinogen.

Genetic analysis of PHIP intestinal mutations in MutaMouse

The mutagenicity of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated in male MutaMouse mice administered 20 mg/kg per o.s. for 4 days and killed 7 days later. Genomic DNA was extracted from liver, kidney and small and large intestine and the mutation frequency (MF) at the lacZ locus was determined using a positive selection assay. Mutant lacZ clones from the intestine were characterized further by direct PCR amplification and DNA sequencing. A total of 57 lacZ mutants from PhIP-treated (40) and untreated (18) mice were analysed. In mutants from the PhIP group, 33% were G:C-->T:A transversions from a total of 65% base substitutions (cf. 17% in the vehicle control group). In untreated control mice, 39% of mutants were G:C-->A:T transitions from a total of 72 % base substitutions (cf. 25 % in the PhIP group). Interestingly, 20% of the PhIP group mutations were due to G:C base pair (-G) deletions (cf. none in controls). This study confirms that PhIP is mutagenic to the intestine of the MutaMouse and induces a spectrum of mutations which are clearly distinct from those spontaneously generated. Also, the PhIP mutation signature in vivo is very similar to that observed for the HPRT and DHFR loci in hamster and human cells in vitro. This suggests that the mutational characteristics of PhIP are well conserved over different reporter genes and between species and that the mutation signature could be of value in molecular epidemiology studies.

Do hospital palliative care teams improve symptom control? Use of a modified STAS as an evaluation tool

The support team assessment schedule (STAS) has previously been validated as an evaluation tool for community palliative care teams and inpatient units. This study reports on use of an expanded STAS (E-STAS) to determine symptom prevalence and outcome for inpatients and outpatients referred to a multiprofessional hospital palliative care team. E-STAS forms were completed on patients at referral and twice weekly thereafter. Between August 1996 and May 1997, 352 patients had one or more E-STAS forms completed; 122 of this group had three or more assessments. One-hundred-and-eighty-two patients were male and 170 were female, the median age was 68.5 years (range 26-101 years) and all but 27 (8%) had malignant disease. Of the symptoms assessed on referral, the most common were psychological distress 93%, anorexia 73%, pain 59%, mouth discomfort 59%, depression 40%, constipation 36%, breathlessness 32%, nausea 24% and vomiting 13%. In the 122 patients where three or more assessment were completed, statistically significant improvements from first to last assessment were seen in all symptoms except depression. This study suggests that E-STAS may be a useful tool to evaluate interventions by a hospital palliative care team in patients with advanced disease.

Assessing human risk to heterocyclic amines

Heterocyclic amines such as MeIQx and PhIP are potent genotoxic chemicals which are formed at part per billion levels when meat is cooked. Using assays based on gas chromatography/mass spectrometry with stable isotope labelled analogues as internal standards we have demonstrated MeIQx and PhIP, are efficiently absorbed into the systemic circulation after ingestion of fried beef. Using a potent and selective inhibitor of human CYP1A2, furafylline, we have shown that N-hydroxylation catalysed by this enzyme is the major pathway of metabolism of MeIQx and PhIP and is solely responsible for their oxidation to mutagenic species. This is in contrast to the situation in laboratory animals in which both activation by N-hydroxylation and deactivation by C-oxidation occurs. When furafylline was administered to human volunteers before ingestion of fried beef, we showed that > 90% of MeIQx and approximately 70% of PhIP elimination could be inhibited, demonstrating the extent to which activation occurred in man. MeIQx is a very powerful mutagen in bacterial assays whereas PhIP is a more potent mammalian cell mutagen. Using a mammalian cell target gene, hprt, we have shown that PhIP induces a characteristic mutational 'fingerprint' which is identical to that detected in the Apc gene of 5/8 colonic tumours induced by PhIP in rats. These studies support a biological association between HA exposure and diet-related tumours but emphasise that information obtained from animal studies does not always reflect the situation in humans.

Overwhelming postsplenectomy infection

The incidence of overwhelming sepsis in asplenic patients is low. It carries, however, an unacceptably high morbidity rate and mortality rate. The risk of development is related to the age of the patient as well as the duration since and the reason for splenectomy. It may also occur in functionally hyposplenic states. The rapidly lethal clinical course demands intense efforts toward prevention by both physician and patient, rapid recognition within the initial medical setting, and aggressive intervention with broad-spectrum antibiotics and other supportive measures.