Evaluation of B-lines with 2 point-of-care lung ultrasound protocols in cats with radiographically normal lungs

OBJECTIVE

To compare 2 point-of-care lung ultrasound (LUS) protocols for quantification of B-lines in cats without evidence of respiratory disease based on history, physical examination, and thoracic radiography.

DESIGN

Prospective observational study.

SETTING

Single center, veterinary teaching hospital.

ANIMALS

Fifty-seven cats without respiratory disease based on history, physical examination, and thoracic radiographs.

INTERVENTIONS

All cats had 2 point-of-care LUS protocols performed bilaterally: a regional protocol (veterinary bedside lung ultrasound evaluation [VetBLUE]) and a more comprehensive vertical sweeping (VS) protocol. The total number of B-lines per cat, number of sites with B-lines, and maximal number of B-lines at each site were recorded and compared.

MEASUREMENTS AND MAIN RESULTS

Ten cats (18%) had at least 1 B-line identified with VetBLUE, versus 29 (51%) with VS. Comparing protocols, VS had a statistically higher total number of B-lines per cat, higher number of sites with B-lines, and higher maximal number of B-lines per site. B-lines that were too numerous to count were identified at a single location in 1 cat with VetBLUE and 2 cats with VS. A maximum of 3 B-lines were identified at all other positive sites regardless of the protocol used. On average, it took 1.79 times longer to complete VS bilaterally compared to VetBLUE (median [interquartile range]: 140 [33] and 78 [14] s, respectively) (P = 0.001).

CONCLUSIONS

This study demonstrates it is not uncommon to identify a single or even multiple B-lines in 1 or several sites on LUS in cats deemed to be clinically free of respiratory pathology-essential knowledge when using LUS as a screening test and to monitor intrathoracic lesions. In cats asymptomatic for respiratory disease, VS generally identifies more B-lines than VetBLUE, likely because it assesses a larger lung surface area. The sonographic identification of B-lines should be interpreted considering the LUS protocol used, history, and other diagnostics to determine their clinical significance.

Comparison of transrectal and transabdominal transducers for use in fast localized abdominal sonography of horses presenting with colic

Abdominal ultrasonography is valuable in the diagnosis of equine colic. Fast localized abdominal sonography of horses (FLASH) enables practitioners with limited experience to perform ultrasonography in emergency settings. However, many practitioners only possess rectal format linear array transducers (RFLT). The hypotheses are: (a) A low frequency curvilinear transducer (LFCT) and RFLT will detect free abdominal fluid and abnormal small intestinal loops with similar frequency during FLASH, and (b) there will be a difference between the transducers for detection of gastric abnormalities and nephrosplenic entrapment. The objective is to compare transcutaneous abdominal ultrasonographic detection of abnormalities in horses presenting with colic using a LFCT and RFLT. Twenty-four horses requiring FLASH for investigation of colic were enrolled. Horses that were too painful to undergo transcutaneous abdominal ultrasonographic examination were excluded. A single investigator performed FLASH on all horses using a RFLT, while one of three other clinicians simultaneously performed FLASH using a LFCT. Comparison of abnormal findings between the two transducers was performed using Chi square, Fisher's exact or Wilcoxon tests. The incidence of identification of abnormal findings was similar between the two transducers for all comparisons except the visibility of the left kidney and stomach (kidney LFCT 81.25% vs. RFLT 22.92%, stomach LFCT 87.5% vs. RFLT 62.5%). While there are limitations to using a RFLT to identify nephrosplenic entrapment of the colon and detection of the stomach, it reliably detects other common abnormalities, including peritoneal effusion, lesions of the small intestine, and changes to the wall of the large colon and cecum.

Case report: Application of color Doppler sonography for the assessment of pulmonary consolidations in a dog

A 1,5-year-old male Maltipoo was presented to the emergency service for dyspnea, weakness, and cough. An echocardiographic examination showed evidence of pulmonary hypertension with a McConnell sign. Lung ultrasound, including color Doppler, was performed and identified two distinct populations of lung consolidation. Color Doppler analysis of the first type of consolidation showed the absence of blood flow within regions of the consolidation and flow amputation. These findings were consistent with the "vascular sign" reported in human medicine and prompted consideration of pulmonary thromboembolism as a differential diagnosis. In the second type of consolidation, color Doppler identified blood flow within the pulmonary vessels of the consolidated lung, forming a "branching tree-like" pattern that followed the anatomical course of the pulmonary vasculature. These findings suggested that blood flow was preserved within the pulmonary vasculature of the consolidated lung and prompted consideration of inflammatory causes of pulmonary pathology. On recheck 6 days later, recanalization of the first type of consolidation was identified with color Doppler. The case was followed serially once a month for 5 months with LUS, which showed continued improvement. Based on a positive fecal Baermann test, a final diagnosis of Angiostrongylus vasorum was made. New or Unique information Provided-this is the first report of color Doppler LUS being used to characterize and help differentiate the cause of lung consolidation in dogs.

Left atrial measurement in lateral versus sternal recumbency in cats undergoing focused cardiac ultrasound examination

Objective

To compare left atrial measurements carried out by an emergency and critical care (ECC) clinician on cats in lateral and sternal recumbency.

Animals and procedures

A prospective observational study was conducted between December 2019 and January 2021 at the university teaching hospital at University of Liège. One hundred and two hospitalized cats were enrolled. Focused cardiac ultrasound (FOCUS) was performed in right lateral and sternal recumbency by a single FOCUS-trained ECC resident. Standard right parasternal long- and short-axis views were recorded. After randomization of the cineloops, the same blinded resident measured maximal left atrial dimension (LAD) and the ratio of left atrial to aortic diameter (LA:Ao). Reproducibility was assessed using the Bland-Altman method.

Results

The LA:Ao and LAD measurements in lateral (LA:Ao median: 1.37, range: 1.02 to 3.22; LAD median: 13.25, range: 7.90 to 32.90) and sternal (LA:Ao median: 1.38, range: 1.06 to 3.22; LAD median: 13.00, range: 8.00 to 32.90) recumbency were not significantly different (bias: -0.003, CI -0.014, 0.007; and bias: -0.101, CI -0.231, 0.029, respectively).

Conclusions and clinical relevance

The FOCUS technique was successfully applied in sternal recumbency in almost all cats. The LAD and LA:Ao measured in sternal and lateral recumbency were not significantly different. Cardiac left atrial measurements obtained using FOCUS can be reliably assessed in sternal recumbency in hospitalized, stable cats.

Markers of tissue perfusion and their relation to mortality in dogs with blunt trauma

OBJECTIVE

To evaluate admission Animal Trauma Triage (ATT) score, shock index (SI), and markers of perfusion, including base excess (BE), plasma lactate, and lactate clearance in dogs with blunt trauma.

DESIGN

Prospective observational clinical study from 2013 to 2015.

SETTING

Private veterinary referral and emergency center.

ANIMALS

Forty-four client-owned dogs hospitalized following blunt trauma.

INTERVENTION

Within 1 hour of presentation and prior to fluid administration an initial hematocrit, total plasma protein, blood glucose, plasma lactate, blood gas, and electrolytes were obtained for analysis. Plasma lactate concentrations were also measured 4 and 8 hours following initial measurement, and a 4-hour lactate clearance was calculated if patients had an increased admission plasma lactate. ATT score and SI were calculated for each patient based on admission data. Outcome was defined as survival to hospital discharge.

MEASUREMENTS AND MAIN RESULTS

Twenty-nine dogs survived, 14 were euthanized, and 1 died. Nonsurviving dogs had a lower mean pH (7.28 ± 0.03 vs 7.36 ± 0.01, P = 0.006), lower median HCO₃ (15.7 vs 18.8 mmol/L, P = 0.004), lower median admission BE (-11.0 vs -7.0 mmol/L, P = 0.004), and higher median admission lactate (3.1 vs 2.4 mmol/L, P = 0.036) than those who survived. Median ATT was significantly higher in nonsurvivors (5 vsF 2, P < 0.001). The SI was not significantly different between survivors and nonsurvivors (P = 0.41). There was no difference in median 4-hour lactate (P = 0.34), median 8-hour lactate (P = 0.19), or 4-hour lactate clearance (P = 0.83) in survivors compared to nonsurvivors. No other statistically significant differences were noted between groups.

CONCLUSION

Dogs hospitalized following blunt trauma with a lower admission pH, HCO₃ , and BE and a higher admission plasma lactate were less likely to survive to hospital discharge. Median ATT score was also significantly higher in nonsurvivors. Although lactate clearance was not predictive of survival, the sample size was small, and additional studies with a larger study population are warranted.

Ultrasonographically derived caudal vena cava parameters acquired in a standing position and lateral recumbency in healthy, lightly sedated cats: a pilot study

OBJECTIVES

The aim of this study was to determine the feasibility of ultrasonographically measuring the caudal vena cava (CVC) at the subxiphoid view of healthy, lightly sedated cats in a standing position and lateral recumbency.

METHODS

This was a prospective, observational, experimental single-centre study. Twenty healthy research-purposed cats were enrolled. Two trained operators scanned each cat in two positions - standing and lateral recumbency - in a randomised order. CVC diameter was measured at the narrowest diameter during inspiration and at the widest diameter during expiration, at two anatomical locations along the CVC - where the CVC crosses the diaphragm (base) and 2 mm caudal to the diaphragm. The CVC collapsibility index (CVC-CI) was calculated for each site. Normalcy was assessed with a Shapiro-Wilk test. A one-way ANOVA with post-hoc Tukey's test was used to compare inspiratory with expiratory values within and between groups. A paired t-test compared the CVC-CI between groups (P ⩽0.05 indicated statistical significance). Spearman's correlation and Bland-Altman analysis assessed inter-operator variability.

RESULTS

All ultrasonographic data passed normalcy and were reported as mean ± SD. When compared with each other, inspiratory and expiratory values were statistically different for position, location and operator (all P <0.0001). There was no statistically significant difference between lateral recumbency or standing position for inspiratory, expiratory and CVC-CI values. Inter-operator variability was substantial, with operator 2 consistently obtaining smaller measurements than operator 1. The mean CVC-CI in lateral recumbency at the base was 24% for operator 1 and 37% for operator 2. For the same site in standing position, CVC-CI was 27% and 41% for operators 1 and 2, respectively.

CONCLUSIONS AND RELEVANCE

This pilot study demonstrates that it is possible to ultrasonographically measure the CVC diameter in both lateral recumbency and a standing position in healthy, lightly sedated cats. However, measurements obtained are operator dependent with variability between individuals. Further studies are needed to determine if ultrasonographic CVC assessment will prove helpful in estimating intravascular volume status in cats.

Incidence of superficial abdominal organ identification is similar using high-frequency linear (transrectal) and low-frequency curvilinear (abdominal) transducers in clinically healthy horses: A pilot study

Abdominal organ displacement is a potentially life-threatening condition in horses. Primary care veterinarians commonly make referral decisions based on a combination of clinical and ultrasonographic findings. However, published studies describing the effects of transducer on identifying abdominal organ locations in horses are currently lacking. The objective of this prospective, methods comparison, pilot study was to compare organ identification using a high-frequency linear (transrectal) transducer and a low-frequency curvilinear (abdominal) transducer for transcutaneous abdominal ultrasonography of healthy horses. Twelve clinically normal adult horses owned by the University of Calgary were enrolled in the study. Abdominal ultrasonography was performed by four practitioners, each randomly assigned to an alternating rotation of transrectal or abdominal transducer and left or right side of a horse. Using a Chi square test or Fisher's exact test, the frequency of identification for each organ was compared between both transducers. There was no significant difference in organ identification on the right side of the abdomen. On the left side, the stomach, liver, and kidney were less likely to be detected with the transrectal transducer. Compared with a low-frequency abdominal transducer, a high-frequency linear transrectal transducer delivers images that allow for organ identification in transcutaneous ultrasonography of the equine abdomen except for the left kidney, left liver, and stomach.

Lung Ultrasonography for Pneumothorax in Dogs and Cats

A sonographic diagnosis of pneumothorax (PTX) traditionally relies on excluding the presence of lung sliding, lung pulse, and/or B lines/lung consolidations, and identifying the lung point. However, these criteria can be difficult to identify, particularly in critically ill patients with respiratory disorders, and the lung point is infrequently used. Newer sonographic findings, such as mirrored ribs, reverse lung sliding, and abnormal curtain signs, have been identified to try to increase the accuracy of diagnosing PTX. This article describes and discusses the lung ultrasonography criteria used to diagnose PTX in both human and small animal patients.

Assessment of Volume Status and Fluid Responsiveness in Small Animals

Intravenous fluids are an essential component of shock management in human and veterinary emergency and critical care to increase cardiac output and improve tissue perfusion. Unfortunately, there are very few evidence-based guidelines to help direct fluid therapy in the clinical setting. Giving insufficient fluids and/or administering fluids too slowly to hypotensive patients with hypovolemia can contribute to continued hypoperfusion and increased morbidity and mortality. Similarly, giving excessive fluids to a volume unresponsive patient can contribute to volume overload and can equally increase morbidity and mortality. Therefore, assessing a patient's volume status and fluid responsiveness, and monitoring patient's response to fluid administration is critical in maintaining the balance between meeting a patient's fluid needs vs. contributing to complications of volume overload. This article will focus on the physiology behind fluid responsiveness and the methodologies used to estimate volume status and fluid responsiveness in the clinical setting.

The use of veterinary point-of-care ultrasound by veterinarians: A nationwide Canadian survey

This survey assessed how veterinary point-of-care ultrasound (VPOCUS), including abdominal and thoracic focused assessment with sonography for trauma (AFAST, TFAST), is used across Canada. Seventy-four veterinarians completed an online survey; 88% (65/74) used ultrasound, 94% (61/65) performed AFAST, and 69% (45/65) performed TFAST. Reasons for not performing VPOCUS included no machine/poor quality machine, lack of experience/confidence, and lack of training/education. Abdominal effusion, and pleural and pericardial effusion were the most frequently diagnosed AFAST and TFAST pathologies, respectively. Lung and cardiovascular ultrasound examinations were infrequently performed. Subpleural consolidation was rarely included in VPOCUS. Most respondents performed VPOCUS, with AFAST being more frequently and confidently preformed than TFAST. More training, education, and standardization of techniques appear to be key elements to help build confidence and experience, particularly with regard to TFAST applications and diagnosis.

Intraosseous Catheter Flow Rates and Ease of Placement at Various Sites in Canine Cadavers

Objective: To compare intraosseous catheter placement difficulty, success rates, and flow rates at four different locations in canine cadavers.

Design: Prospective study.

Setting: Private referral center.

Animals: Eleven fresh canine cadavers.

Interventions: With owner consent, animals presenting for euthanasia were recruited. Animals received heparin (1,000 IU/kg IV) at least 5 min prior to euthanasia. After euthanasia, EZIO intraosseous catheters were placed into the ilial wing, proximal medial tibia, proximal lateral humerus, and distal lateral femur on one side of the animal. Time to catheter placement and catheter difficulty were scored for each placement site. Sterile saline was infused into each location simultaneously over 5 min, first via gravity then using 300 mmHg pressure. Animals were repositioned onto the contra-lateral side and the experiment repeated.

Measurements and Main Results: Placement was successful in 16/22 ilial, 18/22 tibial, and 22/22 femoral and humoral attempts. A post-hoc analysis revealed the ileum had a significantly greater difficulty score when compared to the femur and humerus (p ≤ 0.0001). The femur had a statistically significant faster placement time when compared to the ileum (p ≤ 0.05). Gravity infusion rates were statistically lower in the tibia when compared to humerus (p ≤ 0.01) and between the tibia when compared to the femur (p ≤0.001). Additionally, pressurized infusion rates were statistically lower in the tibia compared to the humerus (p ≤ 0.0001), the femur (p ≤ 0.0001), and the ileum (p ≤ 0.01).

Conclusions: The femur and humerus had high success rate for IO catheter placement and low placement time and difficulty scores. Pressurized intraosseous flow rates were highest in the humerus and femur. Contrary to human literature, success rates for catheter placement in the humerus and femur were higher than at other sites, suggesting the humerus and femur may be preferred sites for intraosseous catheter placement in the dog. Further investigation through a larger sample size is required to confirm these findings.

A pilot study comparing bone marrow aspirates and venous blood for emergency point-of-care blood parameters in healthy dogs

OBJECTIVE

To compare intravenous and intraosseous blood aspirates using point-of-care diagnostic equipment available in veterinary hospitals.

DESIGN

Prospective study.

SETTING

Private referral hospital.

ANIMALS

Dogs undergoing a tibial plateau leveling osteotomy or extracapsular anterior cruciate ligament stabilization procedure were enrolled.

METHODS

Under general anesthesia, simultaneous 0.5 mL intravenous and intraosseous blood samples were collected from the jugular vein and proximal tibia, respectively. Samples were evaluated in duplicate within 10 minutes of collection and averaged for each of the following parameters: blood urea nitrogen (BUN), glucose, packed cell volume, total plasma protein (TPP), plasma lactate, sodium, potassium, chloride, urea, glucose, pH, anion gap, pO_2, and pCO₂ . Normalcy was tested with Kolmogorov-Smirnov test. A Student's t-test and Bland-Altman plot were used to compare intravenous and intraosseous samples.

RESULTS

Twelve dogs were recruited into the study. There were statistically significant differences between intravenous and intraosseous samples for sodium (P = 0.0216), chloride (P = 0.0225), BUN (P = 0.014), and potassium (P < 0.0001), respectively. No significant differences were detected for the other parameters evaluated.

DISCUSSION

The intraosseous space provides an easily accessible, noncollapsible alternative for assessing blood parameters. Omitting potassium, the statistically significant differences noted between sites was not felt to be clinically significant. Although statistically insignificant, the large difference in hematocrit values indicates that the samples should not be used interchangeably.

CONCLUSION

Intraosseous aspirates, excluding potassium and hematocrit, appear to be a reliable alternative for assessing most point-of-care analytes in healthy dogs, although a larger sample size should be investigated. The application of these data in shock patients is unknown.

Retrospective characterization of coma and stupor in dogs and cats presenting to a multicenter out-of-hours service (2012-2015): 386 animals

OBJECTIVE

To describe the signalment, etiology, and short-term outcome of dogs and cats presenting in a coma or stupor.

DESIGN

Retrospective study conducted between May 2012 and February 2015.

SETTING

Multicenter out-of-hours emergency service provider.

ANIMALS

Three hundred eighty-six patients presenting in a coma or stupor to a multicenter out-of-hours emergency care provider.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Records were reviewed to determine the most likely etiology of coma or stupor. Short-term outcomes were defined as deceased (died or euthanized) or transferred (case handed over to a daytime clinic or discharged). There were 168 dogs (coma n = 112, stupor n = 56) and 218 cats (coma n = 148, stupor n = 70) identified. Coma and stupor were more prevalent in cats compared to dogs, and Chihuahuas were over represented. Blood glucose concentrations were frequently outside established reference intervals. Excluding undetermined causes, the most common causes in dogs included traumatic brain injury (TBI) 16.0% (n = 27, deceased n = 22), hypoglycemia 10.7% (n = 18, deceased n = 8), shock 10.1% (n = 17, deceased n = 16), seizure 9.5% (n = 16, deceased n = 13), and renal or hepatic dysfunction 5.3% (n = 9, deceased n = 7). For cats, the most common causes included TBI 21.6% (n = 47, deceased n = 38), renal or hepatic dysfunction 13.3% (n = 29, deceased n = 25), intoxication 10.1% (n = 22, deceased n = 18), hypoglycemia 6.0% (n = 13, deceased n = 4), and shock 5.0% (n = 11, deceased n = 8). When treatment was attempted, 46.0% of dogs (n = 44/96) and 41.2% of cats (n = 35/85) survived to be transferred. Compared to all other etiologies, death was less likely when coma or stupor was attributed to hypoglycemia.

CONCLUSION

In cases where a cause was determined, TBI was the predominant etiology of coma and stupor for both species. With the exception of coma and stupor attributed to hypoglycemia, the overall short-term prognosis was poor.

Cardiopulmonary Effects of a Partial Intravenous Anesthesia Technique for Laboratory Swine

Various anesthetic protocols are used in laboratory swine, each with specific advantages and disadvantages. Partial intravenous anesthetic techniques (PIVA) help minimize dose-dependent cardiopulmonary effects of inhalant drugs. The aim of this study was to determine the cardiopulmonary effects of a PIVA in laboratory swine. In a prospective, nonrandomized clinical study, 8 healthy juvenile Landrace-White pigs were premedicated with azaperone (0.20 ± 0.20 mg/kg IM), dexmedetomidine (0.02 ± 0.002 mg/kg IM), and alfaxalone (2.0 ± 0.20 mg/kg IM), and anesthesia was induced with intravenous alfaxalone. Anesthesia was maintained by using constant-rate infusion of dexmedetomidine (2 μg/kg/h) and alfaxalone (25 μg/kg/min) in combination with isoflurane. After the fraction of expired isoflurane was adjusted to 1.1% to 1.5%, respiratory rate, heart rate, systemic and pulmonary arterial pressure, central venous pressure, cardiac output, bispectral index, systemic vascular resistance, and arterial and mixed venous blood gases were recorded every 10 min for 60 min. Statistical analysis consisted of repeated-measures one-way ANOVA. Significant decreases occurred in heart rate, pulmonary mean arterial pressure, pulmonary diastolic pressure, partial pressure of arterial oxygen, partial pressure of venous oxygen; significant increases occurred in respiratory rate, minute volume index, diastolic arterial blood pressure, systemic vascular resistance, and arterial pH over time. We consider that the observed statistically significant cardiopulmonary changes were clinically important and that the PIVA protocol provided hemodynamic and respiratory stability for short-term anesthesia of laboratory swine.

Erratum to: Does Adding Transdermal Nitroglycerine to Other Therapies Used for Management of Left-sided Congestive Heart Failure in Dogs Speed the Resolution of Clinical Signs?

<p>Unfortunately the original version of the article had the following two errors.</p>

Does Adding Transdermal Nitroglycerine to Other Therapies Used for Management of Left-sided Congestive Heart Failure in Dogs Speed the Resolution of Clinical Signs?

<p><strong><strong>There is an erratum to this paper published in <em>Veterinary Evidence</em> Vol 3, Issue 1 (2018): <a id="pub-id::doi" href="/index.php/ve/article/view/168/220" target="_blank">http://dx.doi.org/10.18849/ve.v3i1.168</a></strong></strong></p><p><strong>Clinical bottom line</strong></p><p>There is very weak veterinary clinical and experimental evidence based upon a limited number of studies to indicate that adding transdermal nitroglycerine to other therapies used for management of left-sided congestive heart failure in dogs speeds the resolution of clinical signs.</p><p> </p><br /> <img src="https://www.veterinaryevidence.org/rcvskmod/icons/oa-icon.jpg" alt="Open Access" /> <img src="https://www.veterinaryevidence.org/rcvskmod/icons/pr-icon.jpg" alt="Peer Reviewed" />

Influence of the Respiratory Cycle on Caudal Vena Cava Diameter Measured by Sonography in Healthy Foals: A Pilot Study

Background

Intravascular volume assessment in foals is challenging. In humans, intravascular volume status is estimated by the caudal vena cava (CVC) collapsibility index (CVC‐CI) defined as (CVC diameter at maximum expiration [CVC_max] – CVC diameter at minimal inspiration [CVC_min])/CVC_max × 100%.

Hypothesis/Objectives

To determine whether the CVC could be sonographically measured in healthy foals, determine differences in CVC_max and CVC_min, and calculate inter‐ and intrarater variability between 2 examiners. We hypothesized that the CVC could be measured sonographically at the subxiphoid view and that there would be a difference between CVC_max and CVC_min values.

Animals

Sixty privately owned foals <1‐month‐old.

Methods

Prospective study. A longitudinal subxiphoid sonographic window in standing foals was used. The CVC_max and CVC_min were analyzed by a linear mixed effect model. Inter‐rater agreement and intrarater variability were expressed by Bland‐Altman and intraclass correlation coefficients, respectively.

Results

Measurements were attained from 58 of 60 foals with mean age of 15 ± 7.9 days and mean weight of 75.7 ± 17.7 kg. The CVC_max was significantly different from CVC_min (D = 0.515, SE = 0.031, P < 0.001). Inter‐rater agreement of the CVC‐CI differed by an average of −0.9% (95% limits of agreement, −12.5 to +10.7%). Intrarater variability of CVC_max was 0.540 and 0.545, of CVC_min was 0.550 and 0.594, and of CVC‐CI was 0.894 and 0.853 for observers 1 and 2, respectively.

Conclusions and Clinical Importance

These results indicate it is possible to reliably measure the CVC sonographically in healthy foals, and the CVC‐CI may prove useful in assessing the intravascular volume status in hypovolemic foals.

Effects of Yunnan Baiyao on blood coagulation parameters in beagles measured using kaolin activated thromboelastography and more traditional methods

Yunnan Baiyao is anecdotally widely used in veterinary medicine for its pro-coagulation properties. There are no studies determining its effect on clotting tests. The purpose of this study was to determine the effect of oral Yunnan Baiyao (YB) on hemostasis by measuring coagulation via kaolin activated citrated whole blood thromboelastography (TEG), prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and d-dimers. The study was a prospective, randomized controlled crossover trial. Eight healthy University of Calgary owned beagles were treated orally with either Yunnan Baiyao or placebo every 12 h for 5 treatments. Blood was collected immediately before treatment, 2 h after the last treatment, and 24 h after the last treatment. TEG analysis was run 30 ± 5 min after blood collection. All other coagulation analyses were sent to a reference laboratory for further analysis. No treatment adverse effects were observed. Oral YB increased R-time significantly within the YB group, but the increase was still within canine reference ranges. No other changes were observed. Oral YB at the dosage and frequency administered in this study did not produce any significant improvement in hemostatic parameters. There is a need for further research and scientific evidence for YB use and dosage.

Effect of Dexamethasone on Resting Blood Lactate Concentrations in Horses

Background

Blood lactate concentration is a marker of tissue perfusion and helps guide therapeutic interventions in critically ill horses. In both humans and dogs, administration of corticosteroids can increase blood lactate concentration, leading to type B hyperlactatemia. This effect could be a consequence of the impact of corticosteroids on glucose metabolism.

Objectives

To investigate the effects of daily IM dexamethasone administration on blood lactate and glucose concentrations in horses.

Animals

Nine healthy adult horses.

Methods

A randomized, blinded, controlled, cross‐over study design was used. Horses were randomly assigned to 1 of 2 groups, either receiving 0.05 mg/kg of dexamethasone IM or an equivalent volume of saline, daily for 7 days. Blood was collected to determine lactate and glucose concentrations at baseline, 2 hours after the daily injections and 24 hours after the last injection.

Results

Dexamethasone treatment had a statistically significant effect on lactate (P = .006) and glucose (P = .033) concentrations. The least squares mean lactate concentration was 0.93 mmol/L (95% CI: 0.87–0.99) in the dexamethasone group compared to 0.71 mmol/L (95% CI: 0.70–0.73) for the saline group. A positive relationship between blood lactate and glucose concentrations was identified, with a 0.07 mmol/L (95% CI: 0.05–0.09) increase in lactate concentration per unit increase in glucose (P < .0001) concentration.

Conclusions and Clinical Importance

Dexamethasone induces statistically significant increases in blood lactate and glucose concentrations in healthy horses. Awareness of the potential for corticosteroids to induce type B hyperlactatemia might be important in the management of critically ill horses receiving dexamethasone.

Comparison of tranexamic acid plasma concentrations when administered via intraosseous and intravenous routes

INTRODUCTION

There is a lack of information regarding intraosseous (IO) administration of tranexamic acid (TXA). Our hypothesis was that a single bolus IO injection of TXA will have a similar pharmacokinetic profile to TXA administered at the same dose IV.

METHODS

Sixteen male Landrace cross swine (mean body weight 27.6±2.6kg) were divided into an IV group (n=8) and an IO group (n=8). Each animal received 30mg/kg TXA via an IV or IO catheter, respectively. Jugular blood samples were collected for pharmacokinetic analysis over a 3h period. The maximum TXA plasma concentration (C_max) and corresponding time as well as distribution half-life, elimination half-life, area under the curve, plasma clearance and volume of distribution were calculated. One- and two-way analysis of variance for repeated measures (time, group) with Tukey's and Bonferonni post hoc tests were used to compare TXA plasma concentrations within and between groups, respectively.

RESULTS

Plasma concentrations of TXA were significantly higher (p<0.0001) in the IV group during the TXA infusion. C_max occurred at 4min after initiation of the bolus in the IV group (9.36±3.20ng/μl) and at 5min after initiation of the bolus in the IO group (4.46±0.49ng/μl). Plasma concentrations were very similar from the completion of injection onwards. There were no significant differences between the two administration routes for any other pharmacokinetic variables measured.

CONCLUSION

The results of this study support pharmacokinetic bioequivalence of IO and IV administration of TXA.

Evaluation of a portable oxygen concentrator to provide fresh gas flow to dogs undergoing anesthesia

This study evaluated the ability of a portable oxygen concentrator (POC) to provide fresh gas to an anesthetic machine via an Ayre's T-piece or a Bain circuit. Fraction of inspired oxygen (FiO2) was compared at flows of 0.5 to 3.0 L/min. Measured FiO2 was 96% at flow rates ≥ 1 L/min. Mean battery life at 1.0, 2.0, and 3.0 L/min was 4.21 ± 0.45, 2.62 ± 0.37 and 1.5 ± 0.07 hours, respectively. The POC proved to be useful and effective during 2 power outages. The POC was sufficient to prevent rebreathing in 70% of dogs using a T-piece circuit and 20% of dogs with a Bain circuit. A significant negative correlation between inspired CO2 and O2 flow rates was noted. A significant positive correlation between inspired CO2 and ETCO2 was documented. The occurrence of hypercarbia was associated with low O2 flow. Battery back-up was essential during power outages. The POC can be effectively used for delivery of anesthesia.

Evaluation of coagulation via thromboelastography in healthy horses administered dexamethasone

Dexamethasone was administered to healthy horses daily for 7 days. Blood samples were collected at 3 time points from both treatment and non-treatment groups, and analyzed via thromboelastography (TEG). There were no significant differences in TEG parameters between treated and untreated horses, or within treatment groups over time.

Sound Pressure Levels in 2 Veterinary Intensive Care Units

Background

Intensive care units (ICUs) in human hospitals are consistently noisy environments with sound levels sufficient to substantially decrease sleep quality. Sound levels in veterinary ICUs have not been studied previously, but environmental sound has been shown to alter activity in healthy dogs.

Hypothesis

Veterinary ICUs, like those in human medicine, will exceed international guidelines for hospital noise.

Animals

NA.

Methods

Prospective, observational study performed consecutively and simultaneously over 4 weeks in 2 veterinary ICUs. Conventional A‐weighted sound pressure levels (equivalent continuous level [a reflection of average sound], the sound level that is exceeded 90% of the recording period time [reflective of background noise], and maximum sound levels) were continuously recorded and the number of spikes in sound >80 dBA were manually counted.

Results

Noise levels were comparable to ICUs in human hospitals. The equivalent continuous sound level was higher in ICU1 than in ICU2 at every time point compared, with greatest differences observed on week day (ICU1, 60.1 ± 3.7 dBA; ICU2, 55.9 ± 2.5 dBA, P < .001) and weekend nights (ICU1, 59.9 ± 2.4 dBA; ICU2, 53.4 ± 1.7 dBA, P < .0001) reflecting a 50% difference in loudness. Similar patterns were observed for the maximum and background noise levels. The number of sound spikes was up to 4 times higher in ICU1 (162.3 ± 84.9 spikes) than in ICU2 (40.4 ± 12.2 spikes, P = .001).

Conclusions and Clinical Importance

These findings show that sound in veterinary ICUs is loud enough to potentially disrupt sleep in critically ill veterinary patients.

Effects of rapid intravenous 100% L-isomer lactated Ringer's administration on plasma lactate concentrations in healthy dogs

OBJECTIVE

To determine if rapid intravenous administration of lactated Ringer's solution containing 28 mmol/L of l-lactate (L-LRS) can result in an increase in plasma lactate concentration in healthy dogs.

DESIGN

Prospective cross over study with a 4-week washout period.

SETTING

Veterinary teaching hospital.

ANIMALS

Six healthy adult Beagles.

INTERVENTIONS

Dogs received 180 mL/kg/h of L-LRS over 60 minutes, followed by a 4-week washout period, then 180 mL/kg/h of 0.9% sodium chloride (NaCl) over 60 minutes.

MEASUREMENTS AND MAIN RESULTS

Blood samples were drawn at baseline (T0), every 10 minutes during fluid administration (T10 to T60), and 60 minutes after fluid administration (T120). Samples were measured in duplicate at all time points with a handheld meter and at T0, T60, and T120 with a blood gas analyzer. Data were analyzed with 1-way or 2-way ANOVA for repeated measures and post hoc tests with Dunnett's or Bonferroni's correction for within-group and between group analyses, respectively. P values < 0.05 were considered significant. Results are mean ± SD. There was no difference between groups at T0 (L-LRS = 1.1 ± 0.6 mmol/L, NaCl = 1.2 ± 0.9 mmol/L). Within the L-LRS group, T0 was significantly lower than all other time points except T120. At T50 and T60, the L-LRS group was higher than the NaCl group. There was a statistical significance between the 2 groups over time.

CONCLUSIONS

The rapid administration of intravenous L-LRS to healthy dogs significantly increases plasma lactate concentration within 10 minutes and returns to baseline values within 60 minutes after cessation of administration. This could have implications in how plasma lactate concentration is interpreted with respect to prognosis, particularly in patients receiving resuscitative rates of L-LRS. Interpretation of plasma lactate concentrations should be considered in light of the rate, quantity and type of fluid administered, and timing of blood samples.

Retrospective evaluation of potential causes associated with clinically relevant hyperlactatemia in dogs with lymphoma

The aim of this study was to determine whether or not canine lymphoma could be associated with a clinically relevant type B hyperlactatemia (> 2.5 mmol/L). The medical database from the University of Montreal Veterinary Medical Teaching Hospital was searched for confirmed cases of canine lymphoma with a blood lactate measurement. Information retrieved included stage, clinical observations compatible with causes of type A and B hyperlactatemia other than cancer, hepatic involvement, and drugs administered. Twenty (40%) dogs were hyperlactatemic. Five dogs (10%) were classified as having cancer-related hyperlactatemia. Seventy-five percent of hyperlactatemic dogs had clinical evidence of type A hyperlactatemia. In addition to lymphoma, 70% of hyperlactatemic dogs had evidence of an additional cause of type B hyperlactatemia. A significant association (P = 0.01) was identified between corticosteroid administration and hyperlactatemia. Cytological, echographic, and/or biochemical tests revealed hepatic changes in all hyperlactatemic dogs. Lymphoma alone may not be sufficient to explain clinically relevant hyperlactatemia in dogs.

Effects of prednisone on blood lactate concentrations in healthy dogs

BACKGROUND

Glucocorticoids affect carbohydrate and lactate metabolism.

HYPOTHESIS

Administration of prednisone to healthy dogs will result in clinically relevant hyperlactatemia.

ANIMALS

Twelve healthy adult Beagle dogs.

METHODS

Prospective, controlled experimental study. Twelve healthy adult Beagles were divided into 2 groups (3 of each sex per group). One group served as control. The other group received 2 treatments: low, 1 mg/kg prednisone PO q24h for 2 weeks; high, 4 mg/kg prednisone PO q24h for 2 weeks. A washout period of 6 weeks separated the treatments. Blood samples were drawn for whole blood lactate measurement on day (D) 0, D4, and D14 and measured in duplicate.

RESULTS

Compared with the control group, low and high groups had significantly higher blood lactate concentrations at D4 and D14. There was no difference at D0. There was no effect of time within the control group. In the low and high groups, blood lactate concentration was increased at D4 and D14 versus D0. Blood lactate concentration was greater in the high group than the low group at D14 only.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs treated with prednisone experience statistically significant increases in blood lactate concentrations, which can result in type B hyperlactatemia. In such cases, improving tissue perfusion, treatment for the commonest form of hyperlactatemia (type A) would be unnecessary.

Management of acute renal failure in cats using peritoneal dialysis: a retrospective study of six cases (2003-2007)

Information regarding the use and success of peritoneal dialysis (PD) in the management of acute renal failure (ARF) in cats is lacking. The purpose of this retrospective study is to describe the indications, efficacy, complications and outcome of cats undergoing PD for ARF. Six cats that underwent PD for treatment of ARF of various etiologies were included. PD effectively replaced renal function in all cats and allowed renal recovery in 5/6 cats. Five cats were discharged and one cat died. Complications were reported in all cats and included subcutaneous edema (n=5), hyperglycemia (n=4), dialysate retention (n=3), and hypoalbuminemia (n=3). A novel technique consisting of a Blake surgical drain and an intermittent closed suction system was used, which appears to be a viable option for PD in cats. Although complications are common, PD is an effective renal replacement therapy for ARF in cats and carries a reasonable prognosis in selected cases.

One-step method for catheterising the jugular vein of cats to enable repeated blood sampling

A one-step method for catheterising the jugular vein of cats for taking multiple blood samples was developed, with the aid of radiography, to determine an appropriate internal catheter length for adult cats. The effects of multiple blood sampling and heparin flushes on the cats' haematocrit and blood total solids were also assessed. Seven healthy adult cats were used. A total of 128 of 132 (97 per cent) blood samples were collected successfully through a 19 G, 30.5 cm catheter introduced as a central venous catheter and maintained in place during two periods of 48 hours. The haematocrit and total solids were significantly decreased in all the cats, but no clinically significant blood loss or coagulation disorders were observed.

Evaluation of a focused assessment with sonography for trauma protocol to detect free abdominal fluid in dogs involved in motor vehicle accidents

OBJECTIVE

To establish a focused assessment with sonography for trauma (FAST) protocol in dogs, determine whether FAST can be performed by veterinary clinicians without extensive ultrasonographic experience, and assess the frequency of free fluid (as determined via FAST) in the abdominal cavity of dogs following motor vehicle accidents (MVAs).

DESIGN

Prospective study.

ANIMALS

100 client-owned dogs evaluated within 24 hours of an MVA.

PROCEDURE

Dogs were placed in lateral recumbency for the FAST examination. To detect fluid in the abdomen, 2 ultrasonographic views (transverse and longitudinal) were obtained at each of 4 sites (just caudal to the xiphoid process, on the midline over the urinary bladder, and at the left and right flank regions).

RESULTS

In the 100 dogs evaluated via FAST, free abdominal fluid was detected in 45 dogs. In 40 of those 45 dogs, abdominocentesis was performed; hemoperitoneum and uroperitoneum were diagnosed in 38 and 2 dogs, respectively. Compared with dogs that had no free abdominal fluid detected via FAST, dogs that had free abdominal fluid detected via FAST had significantly higher heart rates and serum lactate concentrations and significantly lower PCVs and total solid concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicate that FAST is a simple and rapid technique that can be performed on dogs in an emergency setting to detect intra-abdominal free fluid and can be performed by veterinary clinicians with minimal previous ultrasonographic experience.

Ultrasonographic findings in dogs and cats with gastrointestinal perforation

A retrospective study was performed to evaluate the sonographic features of gastrointestinal (GI) perforation in dogs and cats. Sonographic findings in 19 animals (14 dogs and 5 cats) included regional bright mesenteric fat (19), peritoneal effusion (16), fluid-filled stomach or intestines (12), GI wall thickening (11), presence of free air (9), loss of GI wall layering (9), regional lymphadenopathy (8), reduced GI motility (7), pancreatic changes (4), corrugated intestines (4), presence of a mass (3), presence of a foreign body (3), and mineralization of the gastric wall (1). In 14 patients, "perforation" was listed as a differential diagnosis by the sonographer. Abdominal radiographs and radiographic reports were available for 14 patients. Radiographic findings were decreased serosal detail (12), free air (8), peritoneal contrast medium (1), and suspected foreign body (1). GI perforation was listed as radiographic diagnosis in eight patients, seven of which had evidence of pneumoperitoneum, and one had leakage of contrast material on an upper GI study. In 9/14 patients with radiography, "GI perforation" was listed as a sonographic diagnosis. In three patients in which free air was diagnosed sonographically, radiographs were either not available (2) or the presence of free air was not detected at presentation (1). Peritoneal fluid analysis was performed in nine patients, five of which were identified as septic inflammation, and the remaining four were classified as neutrophilic inflammation with no etiologic agent identified. The histologic or surgical diagnoses were as follows: three intestinal surgical dehiscence; one percutaneous endoscopic gastrostomy tube site leakage; one duodenal adenocarcinoma; one ileocolic lymphoma; one trichobezoar; one ascarid impaction; and one bobby pin foreign body. In the remaining 10 patients, a focal area of gastric/intestinal ulceration or transmural necrosis with perforation was identified without evidence of an underlying cause.

Tremorgenic mycotoxicosis in four dogs from a single household

Mycotoxins are fungal metabolites that induce undesirable effects. The effects of these mycotoxins vary depending on the chemical structure of the toxin and degree of toxicity. Mycotoxins that induce muscle tremors, ataxia, and convulsions are termed tremorgenic mycotoxins. Our report documents the clinical course of 4 dogs from a single household that were simultaneously affected by tremorgenic mycotoxins. Diagnosis of tremorgenic mycotoxicosis was confirmed by stomach content analysis from 1 of the dogs. The mycotoxins identified were penitrem A and roquefortine, which are both produced by Penicillium spp. Treatment goals following tremorgenic mycotoxin ingestion include minimizing absorption, controlling tremors and seizures with methocarbamol and pentobarbital sodium administration, and providing supportive care. Two of the affected dogs required ventilatory support. With early aggressive treatment, prognosis is good and recovery is complete without sequelae. It is helpful for the clinician to be familiar with the typical clinical signs at the time of admission, treatment, and clinical course of dogs with tremorgenic mycotoxicosis.