Plasma nitrate/nitrite concentrations in dogs with naturally developing sepsis and non-infectious forms of the systemic inflammatory response syndrome

Diagnosis of Septic Body Cavity Effusion in Dogs and Cats: Cytology vs. Bacterial Culture

The elective test for the determination of the effusions etiopathogenesis is represented by physico-chemical analysis and cytology. Nevertheless, the bacterial culture and antibiotic sensitivity tests are crucial for setting therapy and for the outcome. This study compared cytology with microbiology in the etiologic diagnosis of exudative body cavity effusions in dogs and cats collected from October 2018 to October 2022. All samples underwent aerobic and anaerobic culture and cytology examination. Bacterial identifications were confirmed using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, whereas cytological samples were blindly evaluated either in May Grunwald-Giemsa (MGG) or Gram-stained samples by two board-certified clinical pathologists. A moderate agreement (κ = 0.454) between cytology and bacterial culture was revealed. The sensitivity of the cytological evaluation in our study ranged from 38.5% to 67.9%, and the specificity ranged from 88.9% to 100%, depending on the type of the effusion, so cytology may not be representative of the etiopathogenesis, whereas bacterial culture can misidentify or fail to isolate the correct pathogen for difficult in vitro growing due to the presence of inhibitory substances or contamination. Cytology and bacterial culture results for exudative body cavity effusions in dogs and cats can be misleading if conducted separately, so these two tests should be performed together to increase diagnostic accuracy.

The role of nutritional-immunological indices in estimating serum LPS and antioxidant enzyme activity and sepsis status in female dogs with pyometra caused by E. coli

The aim of this study was to diagnose pyometra and related sepsis status using cost-effective nutritional-immunological indices, antioxidants, and toxin levels in dogs and to investigate the utility of the indices in predicting toxin and antioxidant status. A total of 29 dogs were enrolled into the present study. Among these, 9 female dogs in their diestrus stages, were allocated for elective ovariohysterectomy. The pyometra group was also separated into two subgroups as Sepsis (+) and Sepsis (-). Blood samples were collected into two tubes containing EDTA for hematological analysis; without anticoagulant for serum progesterone, LPS concentration, and antioxidant levels at the time of diagnosis. Bacteriological and tissue samples of the uterus were collected after the ovariohysterectomy. Antioxidant activity, progesterone, and toxin concentration were determined by using commercial ELISA kits. Statistical analyses were performed using Stata version 16.1 and MedCalc 16 statistical software. Receiver operating characteristics curves were used for the threshold for evaluating pyometra and sepsis status. Pairwise comparisons were carried out of the area under the curve (AUC) for thresholds of nutritional immunologic indices (hemoglobin, albumin, lymphocyte, platelet (HALP) score; prognostic nutritional index (PNI); Albumin hemoglobin index (AHI)), serum LPS and antioxidant activity. Linear regression model was used for the estimation of serum LPS and antioxidant activity by using indices. Mean serum progesterone, LPS concentrations, and Nitric Oxide (NO) production were greater, while serum superoxide dismutase (SOD), tissue SOD, and glutathione peroxidase (GPx) activities were lower in dogs with pyometra. All nutritional-immunologic indices were lower in pyometra cases. Nutritional-immunologic indices (AUC of HALP:0.759; PNI:0.981; AHI 0.994), NO (AUC: 0.787) and SOD (AUC: 0.784) levels were useful for pyometra diagnosis. AHI and LPS were useful for the determination of sepsis status with the AUC values of 0.850 and 0.740, respectively. While AHI was useful for the estimation of serum LPS and NO concentration (p < 0.001), PNI was useful for serum SOD concentration (p = 0.003). In conclusion, PNI, HALP and AHI can be used in the diagnosis of pyometra, however, only AHI and LPS levels can be used in the diagnosis of sepsis. SOD and NO can be used to determine pyometra but have no effect on determining sepsis status. Additionally, the estimation of the levels of serum LPS, NO, and SOD activities can be done using the AHI and PNI values.

A feasibility study investigating the utility of a point-of-care rapid immunoassay for detecting septic peritoneal effusion in dogs

OBJECTIVE

To determine the sensitivity (SN), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), and accuracy of a point-of-care urine bacterial rapid immunoassay (RIA) for a diagnosis of septic peritonitis, compared to more traditional diagnostic tools, such as cytology and bacterial culture.

DESIGN

Prospective, cross-sectional feasibility study conducted from October 2016 to June 2017.

SETTING

Four locations within a private practice referral hospital.

ANIMALS

Sixty-four dogs with peritoneal effusion of any etiology were enrolled. Four dogs were excluded due to absent RIA or bacterial culture results. Two additional dogs were excluded because of an inability to definitively classify them as having septic peritonitis.

INTERVENTIONS

Abdominocentesis was performed to obtain peritoneal effusion samples for aerobic and anaerobic bacterial culture, cytology, and RIA. Cytological slides were evaluated by a clinical pathologist following enrollment.

MEASUREMENTS AND MAIN RESULTS

Fifty-eight dogs were included in the study, 8 of which were classified as having septic peritonitis. Compared to final diagnosis of septic peritonitis, RIA had a low PPV (36.8%) but good NPV (97.4%) and was 77.5% accurate. SN of RIA (87.5%) to diagnose septic peritonitis was similar to cytology (85.7%) and bacterial culture (87.5%); however, SP was lower (76%, 100%, and 98%, respectively). Cytology had the best overall predictive values and accuracy for diagnosing septic peritonitis (PPV 100%, NPV 97.9%, and accuracy 98%) compared to RIA and bacterial culture.

CONCLUSIONS

RIA testing was similarly sensitive in identifying septic peritonitis compared to cytology and bacterial culture but was not very specific or accurate. As a stand-alone test, RIA commonly had false-positive test results, making it unreliable in identifying septic peritonitis. Cytology was the most accurate diagnostic test and had no false-positive results. Further investigation with a larger sample size and prevalence of septic peritonitis may prove beneficial.

Circulating Methemoblogin Fraction in Dogs With Sepsis

Large amount of nitric oxide (NO) can be released in patients with sepsis. Methemoglobin is formed from the interaction between NO and hemoglobin. Mild methemoglobinemia reflecting NO overproduction has been reported in septic people, and occasionally associated to septic shock and organ dysfunction. The aim of this retrospective study was to evaluate circulating methemoglobin fraction in dogs with sepsis and to assess its prognostic value. Methemoglobin reference interval (RI) was calculated in 41 healthy dogs and was set at 0–2.2%. A total of 131 dogs with sepsis were included in the study; 24/131 had a circulating methemoglobin ≥2.2%. The median methemoglobin fraction was significantly higher in dogs with sepsis compared to healthy ones (1.7%, 0.4–3.5% vs. 1.0, 0.3–2.2%, P = 0.0005). No significant difference was observed between dogs with uncomplicated sepsis (n = 98) vs. dogs with septic shock (n = 33) (1.8%, 0.4–2.8% vs. 1.5%, 0.4–3.5%, P = 0.74), between dogs with and without multi-organ dysfunction (n = 38 and n = 93, respectively) (1.7%, 0.4–3.5% vs. 1.7%, 0.5–2.8%, P = 0.27), and between survivors (n = 77) vs. non survivors (n = 54) (1.5%, 0.4–2.8% vs. 1.8%, 0.4–3.5%, P = 0.05). Dogs with methemoglobin fraction above or equal to the upper limit of the RI had a significantly higher frequency of death compared to dogs with methemoglobin levels <2.2% (60.0% vs. 36.8%, P = 0.04). In conclusion, mild methemoglobinemia is detected in dogs with sepsis, and methemoglobin values above the RI might be associated with a worse outcome.

Use of 2-dimensional speckle-tracking echocardiography to assess left ventricular systolic function in dogs with systemic inflammatory response syndrome

Background

Early identification of systolic dysfunction in dogs with systemic inflammatory response syndrome (SIRS) potentially could improve the outcome and decrease mortality.

Objective

To compare 2‐dimensional speckle tracking (2D‐STE) with 2‐dimensional (2D) and M‐mode echocardiography in the evaluation of systolic function in SIRS dogs.

Animals

Seventeen SIRS and 17 healthy dogs.

Methods

Prospective observational case‐control study. Each dog underwent physical examination, conventional echocardiography, 2D‐STE, and C‐reactive protein measurement.

Results

Dogs with SIRS had lower 2D‐STE ejection fraction (X4D‐EF; 44 ± 8 versus 53 ± 8; P = .003), endocardial global longitudinal strain (ENDO‐G‐Long‐St; −14.6 ± 3.2 versus −18.5 ± 4.1; P = .003), and normalized left ventricular diameter in diastole (1.38 ± 0.25 versus 1.54 ± 0.17; P = .04) and systole (0.85 ± 0.18 versus 0.97 ± 0.11; P = .03) as compared to healthy dogs. Simpson method of disks (SMOD) right parasternal EF (55 ± 9 versus 60 ± 6; P = .07) and end systolic volume index (ESVI; 23 ± 10 versus 21 ± 6; P = .61), SMOD left apical EF (59 ± 9 versus 59 ± 6; P = .87) and ESVI (20 ± 8 versus 22 ± 6; P = .25), fractional shortening (FS; 34 ± 5 versus 33 ± 4; P = .39), M‐mode EF (64 ± 7 versus 62 ± 5; P = .35), and ESVI (23 ± 11 versus 30 ± 9; P = .06) were not significantly different between SIRS and control group, respectively.

Conclusion and Clinical Importance

Speckle tracking X4D‐EF and ENDO‐G‐Long‐St are more sensitive than 2D and M‐Mode FS, EF, and ESVI in detecting systolic impairment in dogs with SIRS.

Multiple organ dysfunction syndrome in humans and animals

Multiple organ dysfunction syndrome (MODS), defined as the presence of altered organ function in an acutely ill patient such that homeostasis cannot be maintained without intervention, is a cause of high morbidity and mortality in humans and animals. Many advances have been made in understanding the pathophysiology and treatment of this syndrome in human medicine, but much still is unknown. This comparative review will provide information regarding the history and pathophysiology of MODS in humans and discuss how MODS affects each major organ system in animals.

The immunopathology of sepsis: pathogen recognition, systemic inflammation, the compensatory anti-inflammatory response, and regulatory T cells

Sepsis, the systemic inflammatory response to infection, represents the major cause of death in critically ill veterinary patients. Whereas important advances in our understanding of the pathophysiology of this syndrome have been made, much remains to be elucidated. There is general agreement on the key interaction between pathogen-associated molecular patterns and cells of the innate immune system, and the amplification of the host response generated by pro-inflammatory cytokines. More recently, the concept of immunoparalysis in sepsis has also been advanced, together with an increasing recognition of the interplay between regulatory T cells and the innate immune response. However, the heterogeneous nature of this syndrome and the difficulty of modeling it in vitro or in vivo has both frustrated the advancement of new therapies and emphasized the continuing importance of patient-based clinical research in this area of human and veterinary medicine.