Decreased central venous oxygen saturation despite normalization of heart rate and blood pressure post shock resuscitation in sick dogs

OBJECTIVE

To evaluate traditional and global perfusion parameters in clinical canine shock patients, and to evaluate for occult hypoperfusion as evidenced by low central venous oxygen saturation or high plasma lactate concentrations in clinical patients resuscitated to traditional endpoints.

DESIGN

Clinical observational trial designed with a 1-year data entry period and patient follow-up of 28 days posthospital presentation.

SETTING

Large, private urban teaching hospital, and emergency and critical care center.

ANIMALS

Adult canine patients presenting to the emergency department with untreated shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients received fluid resuscitation to normalize perfusion parameters based on physical examination and arterial blood pressure (BP). Monitoring of central venous pressure (CVP) and central venous oxygen saturation (ScvO2 ) was feasible with current standard of care interventions in critically ill, client-owned dogs. Decreased ScvO2 was observed in 37.8% of patients resuscitated to normal traditional perfusion parameters. Hyperlactatemia was commonly recorded.

CONCLUSIONS

Decreased ScvO2 exists in a significant proportion of critically ill dogs following standard fluid resuscitation for shock, providing a relevant target population for implementation of a more standardized early goal-directed therapy bundle in veterinary patients. Normalization of heart rate, blood pressure, mentation, and perfusion parameters directed by physical examination may be attained despite the persistence of significant tissue hypoperfusion and oxygen debt.

Toxic pneumonitis caused by inhalation of hydrocarbon waterproofing spray in two dogs

CASE DESCRIPTION

2 dogs were evaluated because of vomiting and lethargy (a Toy Poodle; dog 1) and acute respiratory distress, vomiting, and anorexia (a Chihuahua; dog 2). Dog 1 had been exposed to a commercial hydrocarbon waterproofing spray 24 hours before the development of clinical signs, and dog 2 was examined 18 hours after exposure to a waterproofing spray containing heptane, a highly flammable liquid hydrocarbon.

CLINICAL FINDINGS

In both dogs, major gastrointestinal tract abnormalities were ruled out but respiratory status worsened. Thoracic radiography revealed a diffuse interstitial pulmonary pattern, and hypoxemia was detected.

TREATMENT AND OUTCOME

Hospitalization for monitoring and care was required for both dogs. The dogs recovered with supportive care, which included administration of oxygen, fluids, and bronchodilators. Additionally, dog 1 received glucocorticoids via inhalation and supplemental enteral nutrition, whereas dog 2 was treated with an antimicrobial.

CLINICAL RELEVANCE

The dogs of this report developed hydrocarbon pneumonitis following exposure to waterproofing sprays. Such sprays contain potentially toxic hydrocarbons. The severity of the adverse effects associated with exposure may have been amplified because the dogs were physically small and were exposed to a relatively large amount of aerosolized spray within small areas. Development of chemical pneumonitis in pet animals is best prevented by application of waterproofing sprays in well-ventilated or outdoor areas from which pets have been excluded. With prolonged hospitalization and considerable monitoring and care, affected dogs can recover from these exposures.

Lactate as a Diagnostic Test for Septic Peritoneal Effusions in Dogs and Cats

Lactate concentration in peritoneal fluid was evaluated and compared to blood lactate concentration in dogs and cats with septic and nonseptic abdominal effusions. All dogs with septic effusions had a peritoneal fluid lactate concentration >2.5 mmol/L and a peritoneal fluid lactate concentration higher than blood lactate, resulting in a negative blood to fluid lactate difference. In dogs, the diagnostic accuracy of the peritoneal fluid lactate concentration and the blood to fluid lactate difference in differentiating septic peritoneal effusion was 95% and 90%, respectively. Peritoneal fluid lactate concentration and blood to fluid lactate difference were not accurate tests for detecting septic peritoneal effusions in cats.

Comparison of peritoneal fluid and peripheral blood pH, bicarbonate, glucose, and lactate concentration as a diagnostic tool for septic peritonitis in dogs and cats

OBJECTIVE

To establish a reliable diagnostic tool for septic peritonitis in dogs and cats using pH, bicarbonate, lactate, and glucose concentrations in peritoneal fluid and venous blood.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Eighteen dogs and 12 cats with peritoneal effusion.

METHODS

pH, bicarbonate, electrolyte, lactate, and glucose concentrations were measured on 1- to 2-mL samples of venous blood and peritoneal fluid collected at admission. The concentration difference between blood and peritoneal fluid for pH, bicarbonate, glucose, and lactate concentrations were calculated by subtracting the peritoneal fluid concentration from the blood concentration. Peritoneal fluid was submitted for cytologic examination and bacterial culture. Peritonitis was classified as septic or nonseptic based on cytology and bacterial culture results.

RESULTS

In dogs, with septic effusion, peritoneal fluid glucose concentration was always lower than the blood glucose concentration. A blood-to-fluid glucose (BFG) difference > 20 mg/dL was 100% sensitive and 100% specific for the diagnosis of septic peritoneal effusion in dogs. In 7 dogs in which it was evaluated, a blood-to-fluid lactate (BFL) difference < -2.0 mmol/L was also 100% sensitive and specific for a diagnosis of septic peritoneal effusion. In cats, the BFG difference was 86% sensitive and 100% specific for a diagnosis of septic peritonitis. In dogs and cats, the BFG difference was more accurate for a diagnosis of septic peritonitis than peritoneal fluid glucose concentration alone.

CONCLUSIONS

A concentration difference > 20 mg/dL between blood and peritoneal fluid glucose concentration provides a rapid and reliable means to differentiate a septic peritoneal effusion from a nonseptic peritoneal effusion in dogs and cats.

CLINICAL RELEVANCE

The difference between blood and peritoneal fluid glucose concentrations should be used as a more reliable diagnostic indicator of septic peritoneal effusion than peritoneal fluid glucose concentration alone.

Pituitary ACTH and adrenocortical secretion in critically ill dogs

OBJECTIVE

To evaluate pituitary-adrenal function in a population of critically ill dogs by measuring serial plasma concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH.

DESIGN

Prospective study.

ANIMALS

20 critically ill dogs admitted to an intensive care unit (ICU).

PROCEDURE

Basal plasma cortisol, ACTH-stimulated cortisol, and endogenous ACTH concentrations were measured for each dog within 24 hours of admission and daily until death, euthanasia, or discharge from the ICU. Established reference ranges for healthy dogs were used for comparison. Survival prediction index (SPI) scores were calculated for each dog within 24 hours of admission.

RESULTS

No significant difference was found between initial concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH in 13 dogs that survived and those in 7 dogs that died. High initial basal endogenous ACTH concentrations were correlated with subsequent high values. Low basal ACTH-stimulated cortisol concentrations were predictive of higher subsequent values. All basal and ACTH-stimulated cortisol concentrations were within or above the reference range in the 52 plasma samples collected from the 20 dogs during hospitalization. The SPI scores correlated with outcome (ie, alive or dead), but none of the plasma hormone concentrations correlated with SPI score or outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicate that none of the critically ill dogs in our study population developed adrenal insufficiency during hospitalization in the ICU.

Use of closed-suction drains to treat generalized peritonitis in dogs and cats: 40 cases (1997-1999)

OBJECTIVE

To determine outcome of dogs and cats with generalized peritonitis treated by means of closed-suction drainage.

DESIGN

Retrospective study.

ANIMALS

30 dogs and 10 cats with generalized peritonitis.

PROCEDURE

Medical records were reviewed, and information on signalment, clinicopathologic abnormalities, contamination source, results of microbial culture, surgical procedure performed, postoperative management, complications, and outcome was obtained.

RESULTS

The gastrointestinal tract was the most common source of contamination. Abdominal fluid collected from 34 patients at the time of surgery was submitted for bacterial culture; results were positive for 28 (82%). The most commonly isolated organism was Escherichia coli. Postoperative complications included anemia (n = 21), hypoproteinemia (21), vomiting (9), edema (7), and diarrhea (5). Total solids concentration did not decrease during the first 48 hours after surgery, and all drains remained functional until removal. Twenty-eight patients survived to the time of discharge; 8 of the 12 animals that died did so within 18 hours after surgery. The only factor significantly different between patients that survived and patients that died was postoperative systolic blood pressure. Factors that were not significantly associated with outcome included detection of bacteria in the abdominal fluid, number of organisms cultured from the abdominal fluid, selection of antimicrobials for empiric treatment, and source of contamination.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that closed-suction drainage may be a useful method for treating generalized peritonitis in dogs and cats. No clinically important complications were associated with their use.

Characterization of endemic Providencia stuartii isolates from patients with urinary devices

Providencia stuartii has emerged as a significant nosocomial urinary tract pathogen. An increase in the number of Providencia isolates from urine cultures prompted an investigation into the possibility of an outbreak due to this organism. A high proportion of patients studied had urinary devices. Four wards were screened at two time periods to ascertain the prevalence of Providencia stuartii in urine cultures. Biotype, serotype, antibiogram and plasmid content were determined for each Providencia isolate. Of 129 patients initially sampled 22.5% were found to harbor Providencia stuartii. Biotyping, serotyping and antibiograms indicated an epidemic strain was not present. Similar results were obtained when the wards were screened a second time, with 25.4% of urine cultures found to contain Providencia stuartii. By plasmid analysis the isolates could be grouped into one of ten profiles. A correlation could be made between urease activity and the presence of a large plasmid. No association however could be made between a particular plasmid profile and antibiogram. The data indicate that an epidemic strain of Providencia stuartii was not present. The source(s) of the endemic Providencia stuartii strains remain unknown.

Detection of lipopolysaccharides in polyacrylamide gels by transfer to nitrocellulose followed by immunoautoradiography with antibody and 125I-protein A: "LPS blotting"

Lipopolysaccharides (LPS), which constitute the somatic (O) antigen of gram-negative bacteria, were used to demonstrate the procedure of LPS blotting involving the electrophoretic transfer of electrophoretically resolved LPS from sodium dodecyl sulfate-polyacrylamide gels to nitrocellulose filters. Immobilized LPS could then be immunoautoradiographically visualized in situ by reaction with specific anti-LPS antibody and subsequent binding of radioiodinated Staphylococcus protein A. LPS blotting is expected to provide an efficient and specific means of investigating the LPS (O) antigens of gram-negative bacteria.

Serious nosocomial infection caused by Morganella morganii and Proteus mirabilis in a cardiac surgery unit

In July and August 1981, five patients in the cardiac surgery unit of the Bristol Royal Infirmary developed septicemia caused by Morganella morganii, Proteus mirabilis, or both of these species. Three of the patients had serious wound infections, and three of the patients died. Typing of the M. morganii isolates by O-serotyping and of the P. mirabilis isolates by O-serotyping, proticine production and sensitivity, and the Dienes reaction confirmed cross infection by both species. Although M. morganii has been regarded as a relatively unimportant human pathogen in the past, it may prove to be an important cause of nosocomial infection in the future.

Prospective survey of fecal, urinary tract, and environmental colonization by Providencia stuartii in two geriatric wards

A prospective survey of fecal, urinary tract, and environmental colonization by Providencia stuartii in two wards was undertaken over a 5-month period. Eight of 53 male patients and 2 of 89 female patients were colonized with the endemic serotype O:63. Two patterns of colonization were found on the male ward. Two patients had persistent urinary tract colonization with no detectable fecal carriage. The other patients had fecal carriage, in some cases persistent, with intermittent urinary tract colonization. The ward environment was in general not contaminated. This study demonstrates that fecal colonization of patients by P. stuartii may be an important and previously underestimated nosocomial reservoir.

Species differences in susceptibilities of Proteeae spp. to six cephalosporins and three aminoglycosides

Six cephalosporins and three aminoglycosides were examined for activity against 1,693 isolates belonging to six species of Proteeae. The most notable species-specific differences included the marked susceptibility of Providencia alcalifaciens and Proteus mirabilis to cephalothin, the resistance of Proteus vulgaris to cefamandole, and the resistance of Providencia stuartii to gentamicin and tobramycin. The third-generation cephalosporins cefotaxime and moxalactam were substantially more inhibitory than were cefoperazone, cefamandole, and cefoxitin. P. stuartii, generally the most resistant species, was, however, markedly susceptible to moxalactam and cefotaxime.

Social problems of women patients in a private obstetrics and gynecology clinic

Patients present or exhibit problems other than physical ones to their physicians and need access to some type of assistance for them. Over a 1 year period, women patients were referred to and seen by the medical social worker employed by a private obstetrics and gynecology clinic. Their social problems were studied by content analysis of patients' records, patients' social services cards, and monthly social services summaries. Results showed that 163 women exhibited 288 social problems consisting of three major types, financial, marital, and emotional. Various relationships were shown between the type of social problem and the primary reason the patient visited the clinic. It was also shown that if a patient has a financial problem, she is more likely to have a greater number of social problems than are other patients.