Efficacy and Safety of Dexmedetomidine Premedication in Balanced Anesthesia: A Systematic Review and Meta-Analysis in Dogs

Dexmedetomidine is commonly used in small animal anesthesia for its potent sedative and analgesic properties; however, concerns regarding its cardiovascular effects prevent its full adoption into veterinary clinical practice. This meta-analysis was to determine the effects of dexmedetomidine on sedation, analgesia, cardiovascular and adverse reactions in dogs compared to other premedications. Following the study protocol based on the Cochrane Review Methods, thirteen studies were included in this meta-analysis ultimately, involving a total of 576 dogs. Dexmedetomidine administration probably improved in sedation and analgesia in comparison to acepromazine, ketamine and lidocaine (MD: 1.96, 95% CI: [−0.08, 4.00], p = 0.06; MD: −0.95, 95% CI: [−1.52, −0.37] p = 0.001; respectively). Hemodynamic outcomes showed that dogs probably experienced lower heart rate and higher systolic arterial blood pressure and mean arterial blood pressure with dexmedetomidine at 30 min after premedication (MD: −13.25, 95% CI: [−19.67, −6.81], p < 0.0001; MD: 7.78, 95% CI: [1.83, 13.74], p = 0.01; MD: 8.32, 95% CI: [3.95, 12.70], p = 0.0002; respectively). The incidence of adverse effects was comparable between dexmedetomidine and other premedications (RR = 0.86, 95% CI [0.58, 1.29], p = 0.47). In summary, dexmedetomidine provides satisfactory sedative and analgesic effects, and its safety is proved despite its significant hemodynamic effects as part of balanced anesthesia of dogs.

Comparison of urinary protein-to-creatinine ration, serum albumin, serum creatinine and systolic arterial blood pressure of glomerular injury cases in dogs with chronic kidney disease

This study aims at assessing the prevalence of glomerular alterations in dogs with chronic kidney disease (CKD) and comparing the clinical and laboratory parameters. The tests conducted include a double-blind histopathological assay conducted by two pathologists, urine tests including inactive sediment, urinary protein-to-creatinine (UPC), serum albumin and serum creatinine, as well as measurement of the systolic arterial blood pressure. The prevalence of glomerular injuries was determined and the predominant injury was compared with a group comprised of the remaining injuries. The study included 24 dogs with CKD. The results revealed a predominance of membranous glomerular alterations 17/24 (70,83%), followed by glomerulosclerosis 3/24 (12,50%), membranoproliferative injuries 2/24, glomerulocystic atrophy 1/24 and glomerular amyloidosis 1/24. Amyloidosis presented the highest UPC while the membranoproliferative injury presented the lowest mean concentration of serum albumin. Higher values in the UPC did not correspond with lower mean serum albumin values. Glomerulosclerosis presented the highest mean systolic blood pressure and glomerular atrophy presented the highest creatinine values. When comparing membranous injuries with a group comprised of the remaining injuries, the UPC did not present significant differences between the groups. Renal amyloidosis was included in the group with the lowest systolic arterial blood pressure values while membranoproliferative injury was included in the group with highest UPC. The group called “others” presented the highest creatinine value. Dogs with CKD may present several types of glomerular injuries with similar clinical and laboratory profiles. This study observed a predominance of membranous glomerular injuries, followed by membranoproliferative injuries, glomerulocystic atrophy and amyloidosis.

Mortality predictors in acute kidney injury patients who underwent continuous venovenous hemodiafiltration: A retrospective, single-center study

Continuous renal replacement therapy (CRRT) is an increasingly preferred treatment that is easier to use in patients with hemodynamic impairment and can be applied in critical care settings. There are various subtypes of CRRT, one of which is continuous venovenous hemodiafiltration (CVVHDF). In this study, we examined the general characteristics of intensive care patients who underwent CVVHDF. Methods. The clinical and biochemical data of 123 patients who underwent CVVHDF in the intensive care units of our center between February 2012 and November 2014 were analyzed retrospectively. Patients who died during the course of therapy were compared with those who survived. Results. The study included 123 patients, 73 males (59.3%) and 50 females (40.7%). The mean age was 64.4 years. Eighty-eight patients (71.5%) died during CVVHDF while 35 patients survived (28.5%). Hemodynamic parameters such as systolic and diastolic arterial blood pressure, mean arterial pressure, and pulse pressure were significantly lower in patients who died compared to survivors (p<0.001). Mean lactic acid level was significantly higher in the deceased group than in the surviving group (8.54 mmol/L vs. 3.68 mmol/L, p<0.001, chi-square test). Conclusions. Low bicarbonate level, low systolic arterial blood pressure, and older age were significant independent predictors of mortality in this study. Mortality rates were significantly higher among patients with lactic acidosis and those over 66 years of age. Lactic acid levels can be used to predict mortality in patients undergoing CVVHDF.

Association of variants m.T16172C and m.T16519C in whole mtDNA sequences with high altitude pulmonary edema in Han Chinese lowlanders

Background: High altitude pulmonary edema (HAPE) is a hypoxia-induced non-cardiogenic pulmonary edema that typically occurred in un-acclimatized lowlanders, which inevitably leads to life-threatening consequences. Apart from multiple factors involved, the genetic factors also play an important role in the pathogenesis of HAPE. So far, researchers put more energy into the nuclear genome and HAPE, and ignored the relationship between the mitochondrion DNA (mtDNA) variants and HAPE susceptibility. Methods: We recruited a total of 366 individuals including 181 HAPE patients and 185 healthy or non-HAPE populations through two times. The first time, 49 HAPE patients and 58 non-HAPE cases were performed through whole mtDNA sequences to search the mutations and haplogroups, which were associated with the HAPE. The second time, 132 HAPE patients and 127 non-HAPE subjects were collected to apply of verifying these variants and haplogroups of mtDNA with routine PCR method. Results: We analyzed and summarized the clinical characteristics and sequence data for 49 HAPE patients and 58 non-HAPE cases. We found that a series of routine blood indexes including systolic arterial blood pressure (SBP), heart rate (HR), white blood cell (WBC) and C-reactive protein (CRP) in HAPE group presented higher and displayed the significant differences compared with those in non-HAPE group. Though the average numbers of variants in different regions and groups samples were not statistically significant (P > 0.05), the mutation densities of different region in the internal group shown the significant differences. Then we found that two mutations (T16172C and T16519C) associated with the HAPE susceptibility, and the T16172C mutation increased the risk of HAPE, and the T16519C mutation decreased the HAPE rating. Furthermore, the two mutations were demonstrated with 132 HAPE cases and 127 non-HAPE individuals. Unfortunately, all the haplogroups were not associated with the HAPE haplogroups.Conclusions: We provided the evidence of differences in mtDNA polymorphism frequencies between HAPE and non-HAPE Han Chinese. Genotypes of mtDNA 16172C and 16519C were correlated with HAPE susceptibility, which indicated that the role in mitochondrial genome in the pathogenesis of HAPE.

An Elusive Prize: Transcutaneous Near InfraRed Spectroscopy (NIRS) Monitoring of the Liver

Introduction: We postulate a relationship between a transcutaneous hepatic NIRS measurement and a directly obtained hepatic vein saturation. If true, hepatic NIRS monitoring (in conjunction with the current dual-site cerebral-renal NIRS paradigm) might increase the sensitivity for detecting shock since regional oxygen delivery changes in the splanchnic circulation before the kidney or brain. We explored a reliable technique for hepatic NIRS monitoring as a prelude to rigorously testing this hypothesis. This proof-of-concept study aimed to validate hepatic NIRS monitoring by comparing hepatic NIRS measurements to direct hepatic vein samples obtained during cardiac catheterization.Method: IRB-approved prospective pilot study of hepatic NIRS monitoring involving 10 patients without liver disease who were already undergoing elective cardiac catheterization. We placed a NIRS monitor on the skin overlying liver during catheterization. Direct measurement of hepatic vein oxygen saturation during the case compared with simultaneous hepatic NIRS measurement.Results: There was no correlation between the Hepatic NIRS values and the directly measured hepatic vein saturation (R = −0.035; P = 0.9238). However, the Hepatic NIRS values correlated with the cardiac output (R = 0.808; P = 0.0047), the systolic arterial blood pressure (R = 0.739; P = 0.0146), and the diastolic arterial blood pressure (R = 0.7548; P = 0.0116).Conclusions: Using the technique described, hepatic NIRS does not correlate well with the hepatic vein saturation. Further optimization of the technique might provide a better measurement. Hepatic NIRS does correlate with cardiac output and thus may still provide a valuable additional piece of hemodynamic information when combined with other non-invasive monitoring.

Comparison of Doppler ultrasonic and oscillometric devices (with or without proprietary optimisations) for non-invasive blood pressure measurement in conscious cats

Objectives This study compared Doppler and oscillometric (PetMAP+) devices (with or without proprietary optimisations) for the non-invasive measurement of blood pressure in conscious cats. Methods Twenty-three cats were enrolled; however, five were excluded as fewer than five measurements were obtained for each assessment. All measurements were obtained according to American College of Veterinary Internal Medicine consensus guidelines. Oscillometric device modes A and B were operated according to the manufacturer’s guidelines. Doppler and oscillometric devices were used alternately as the first device. Results Systolic arterial blood pressure (SAP) measurements were obtained by Doppler (SAPd) and oscillometry; the mean of each set of five values was used for statistical analysis. There was a significant difference between SAPd and SAP measurements in oscillometric modes A ( P <0.001) and B ( P <0.001). While both modes measured SAP higher than SAPd, B had a smaller bias (+15.72 mmHg) and narrower limits of agreement (LOA). There was also a significant difference between SAPd and mean arterial pressure (MAP) on oscillometric modes A ( P = 0.002) and B ( P <0.001). Both modes’ MAP readings were lower than SAPd and oscillometric A MAP was closer to SAPd (–14.94 mmHg), with a smaller bias and narrower LOA. Conclusions and relevance The findings support that Doppler and oscillometric devices cannot be used interchangeably, with or without proprietary optimisations. Methodology should always be taken into account and reference intervals (RIs) need to be defined for the different methodologies. Until methodology-specific RIs are published, definitive diagnosis of hypertension and sub-staging of patients with kidney disease according to the International Renal Interest Society guidelines remains challenging.

Unilateral Spinal Anaesthesia in Calves

In this study, we aimed to evaluate the effects of unilateral anaesthesia by the administration of hyperbaric bupivacaine through the lumbosacral space into the subarachnoid space in calves. A total of 10 calves with unilateral femoral fractures were included in the study. After each calf was placed in a lateral position on the side intended for surgery, 15 mg of hyperbaric bupivacaine was slowly injected into the subarachnoid space. The onset, duration and depth of anaesthesia were determined by the pinprick test (scale 1–4). In addition, heart rate, diastolic arterial blood pressure, systolic arterial blood pressure, mean arterial blood pressure, respiratory rate and body temperature of the calves were monitored and recorded from the onset to 120 min after anaesthesia. The onset of unilateral spinal anaesthesia was within 20 s and the mean duration of anaesthesia was 155.40 min. Although there were statistical differences between hemodynamic values in the study, they were within the reference values. As a result, we believe that unilateral spinal anaesthesia in calves provides adequate anaesthesia for use in orthopaedic procedures; thus, it can be used in practice.

Indirect Doppler flow systolic blood pressure measurements taken with and without headphones in privately-owned, conscious dogs

Objective The purpose of this study was to assess the effect of headphone use and covariates on indirect radial Doppler flow systolic arterial blood pressure (BP) measurements in dogs. Methods Between May and August 2018, 100 privately-owned dogs were enrolled. Blood pressure was measured in lateral recumbency, with and without headphones, using a randomized crossover design. The initial BP, mean of BP 2-6, weight, BCS, MCS, anxiety score, and heart rate were recorded. Mixed effects crossover analyses and Spearman rank correlation coefficients were determined. Results Eighty-four dogs completed the study. Eleven dogs were removed due to excessive anxiety, 10 of which were in the non-headphone first group. The number of dogs diagnosed as hypertensive did not differ between measurement types (19 vs. 18), with seven dogs categorized as hypertensive during both periods. Significant differences in BP were identified (F[1, 80] = 4.3, P = 0.04) due to higher results for measurements taken without headphones for BP 1, but not BP 2-6. Systolic BP was positively correlated with anxiety score, age, and weight. Conclusions and Clinical Relevance Though BP 1 was significantly higher when taken without headphones, this pattern did not persist for BP 2-6. Lack of association between BP 2-6 results and measurement type could reflect exclusion of dogs most sensitive to white coat hypertension, acclimation to technique, or improved sound quality of headphones. Given significantly higher BP 1 results and disproportionate exclusion of dogs due to anxiety when measurements first were taken without headphones, use of headphones is recommended to improve accuracy of results.