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Pediatric Emergencies - VCA Specialty Animal Hospitals
Pediatric Emergencies Robert Murtaugh, DVM Diplomate ACVECC Diplomate ACVIM Pediatric Emergencies Robert J. Murtaugh DVM, MS DACVECC, DACVIM, FCCM Slide credits: Elizabeth Dunphy DVM Diplomate American College of Veterinary Emergency and Critical Care VCA Animal Referral and Emergency Center of Arizona Common Emergencies Allergic reactions Hypoglycemia Hookworm anemia Parvo Pneumonia Portosystemic shunts 1 Allergic Reactions Vaccines – Can happen on the first vaccine Bug bites – Red ants, bees, wasps Medications Allergic Reactions Type I Hypersensitivity Reaction – IgE, Mast cells and basophils – Histamine released • Vasodilation, bronchoconstriction – Prostaglandin and leukotrienes released • Leaky capillaries and smooth muscle constriction student.ccbcmd.edu/.../images/u3fg43c.jpg 2 Allergic Reactions Local reaction Systemic reaction – Anaphylaxis Allergic Reactions Dogs: – 51 % Skin, 40 % GI and 6% respiratory Cats: – 66% GI, 22% respiratory and 12% skin 3 Local Reactions Mild Signs – Swollen face, hives – HR and RR normal, no evidence of hypotension or dyspnea – Benadryl 1 mg/lb IV or IM – +/- Dex SP 0.2-0.5 mg IV Anaphylaxis Cats (and Humans) – Shock organ is the lung • Severe dyspnea due to bronchoconstriction and upper and/or lower airway edema • Hypotensive shock Dogs: – Shock organ is the liver/hepatic vein • Acute splanchnic congestion causing gastrointestinal signs and acute hypotensive shock 4 Anaphylaxis-Treatment Vascular access Fluids – Colloids and Crystalloids Oxygen therapy (especially in cats) Consider bronchodilator in cats – Terbutaline 0.01 mg/kg SC Epinephrine if severe Diphenhydramine Steroids “Important adjunctive therapy for systemic anaphylaxis includes the use of corticosteroids and antihistamines. It should be remembered, however, that these drugs may be helpful in controlling ongoing effects if persistent mediator release is occurring, but these agents are of little benefit in acute, lifethreatening situations. As these agents can have a permissive effect on vasodilation or negative inotropic effect, these drugs should be used only after adequate treatment of circulatory collapse." CVTXII 5 Anaphylaxis Monitoring – – – – – – FREQUENT physical exams Blood pressure Pulse Oximetry PT/PTT PCV/TP BUN, Glucose, Electrolytes Prognosis Feline: 39 cases with nine fatalities Canine: 59 canine cases with 10 fatalities 6 Allergic Reaction vs. Snakebite Snakebite – – – – Very painful +/- puncture, blood Bruising present +/- Echinocytes Questions????? 7 Hypoglycemia Small breed puppies – Chihuahuas common Kittens Usually <10 weeks old Usually not being fed in the night Hypoglycemia Often have other problems – Diarrhea – URI Clinical Signs – – – – – Lethargy/weakness Hypothermia Bradycardia Seizures Comatose 8 Hypoglycemia Stabilization – IV access • 22g or 25g in jugular – Intraosseous catheter – Feeding tube 1 ml/lb of 25 % dextrose IV – Mix 50 % dextrose with saline 1:1 Hypoglycemia Start 5% CRI Recheck Blood glucose q 1-2 hours until stable Give repeat boluses of 25 % dextrose as needed Feed as soon as possible 9 Hypoglycemia Additional Diagnostics – – – – – Fecal float and smear Parvo test Shunt hunt Sepsis Hunt Felv/FIV Prognosis Very good in most uncomplicated cases Client Education ESSENTIAL 10 Questions???? Hookworm Anemia www.mic-d.com/.../ancylostomacaninummale1.html home.student.uu.se 11 Hookworm Anemia Ancylostoma caninum Ancylostoma braziliense Uncinaria stenocephala www.biosci.ohio-state.edu/~parasite/pictures/... Transmission Larvae ingested or penetrate skin Worms attach to intestines and cause bleeding Transmission to offspring transplacental or transmammary www.animalhealth.bayer.ca/content/pictures/An... 12 classroomclipart.com/.../5205_hookworm.jpg Diagnosis Visualize eggs in feces Occasionally see larvae 13 Hookworm Anemia Clinical Signs – – – – Bloody diarrhea Lethargy/Weakness Pale MM Tachycardia www.nematode.net/IMAGES/ancyl.gif Treatment Red Blood Cell Transfusion De-worm – – – – Pyrantel Fenbendazole Ivermectin Milbemycin 14 Zoonotic Risk cpl.yonsei.ac.kr/micro/para/images/p1_9_10.jpg www.indianwalkvet.com/_derived/hookworms.htm www.vaat.org.au/images/hookworm_in_foot.jpg Questions???? www.biosci.ohio-state.edu/~parasite/pictures/... 15 Parvo Pathophysiology www.vetnetwork.com/.../infect/images/parvo.jpg 16 Pathophysiology Pathophysiology 17 Pathophysiology duke.usask.ca Pathophysiology Intestinal Lining Sloughing – Bloody diarrhea • Fluid lossÆ Hypovolemia • Protein loss • Anemia – Vomiting • Fluid lossÆ Hypovolemia • Electrolyte imbalance – Bacterial Translocation • Sepsis Neutropenia • Sepsis 18 Clinical Signs Bloody diarrhea Nausea/Vomiting Weakness/Depression Marked dehydration Abdominal discomfort Tachycardia Diagnosis Parvo Snap Test – May be negative early on • Repeat q 24 hours – False positive from recent vaccine CBC – Neutropenia • May not be apparent early on – Repeat q 24 hours 19 Minimum Data Base BUN, Glucose, Electrolytes PCV/TP Fecal float and smear Treatment FLUIDS FLUIDS FLUIDS!!!!!!! – Give crystalloid bolus • Norm-R • LRS • 0.9 % Saline – Dehydration – Maintenance – Ongoing losses 20 Total Fluid Rate 1) Maintenance – 1 ml per lb per hr – 30 ml per lb per 24 hours – 60 ml per kg per 24 hours 2) Deficit/Replacement 3) Ongoing losses Fluid Replacement STEP # 1 Determine correct body weight in kg STEP # 2 Estimate % dehydration – – – – Mild = 5-6 % Moderate = 7-8 % Severe = 9-10 % Shrunken Prune = 11-12 % STEP 3 # Calculate deficit volume STEP # 4 Decide how fast to replace – % dehydration (as a decimal) X kg X 1000 21 Fluid Replacement 11 lb puppy, 10% dehydrated 1) 11 lbs ÷ 2.2 = 5 kg 2) 0.10 X 5 kg X 1000 = 500 ml deficit 3) Give 100 ml bolus 4) 500ml – 100ml = 400 ml deficit 5) 400 ml ÷24 hours = 16 ml/hr Fluid Rate Maintenance = 11 ml/hr Deficit = 16 ml/hr Ongoing losses = Estimate – – – – Large volume losses expected 5 vomits X 30 ml=150 ml 3 diarrhea X 60 ml=180 ml Total=330 ml/day = 13ml/hr Fluid rate=11 + 16 + 13= 40 ml/hr 22 Fluid Therapy REASSESS in 4- 6 hours – Hydration improving?? – Ongoing losses?? – Adjust fluid rate as needed Reassess at least twice a day Consider colloids – Shock – Marked ongoing losses Plasma Many benefits – – – – Colloid Proteins Clotting Factors Antibodies Albumin ?? 23 Nausea and Vomiting Visceral Stimuli Dopamine and Serotonin Released Chemoreceptor Trigger Zone Stimuli Dopamine and Serotonin Released Vestibular Input Histamine and Acetylcholine released Medullary Vomiting Center Stimulated Nausea and Vomiting Anti-emetics Metoclopramide – Increases resting pressure in the lower esophageal sphincter – Increases amplitude of peristaltic movements in the esophagus, gastric antrum and small intestine. • Hastened esophageal clearance, accelerated gastric emptying and shortens transit time through the small bowel. – Dopamine antagonist 24 Anti-emetics Metoclopramide – 1-2 mg/kg/day CRI – 0.2-0.4 mg/kg IM/SQ q 6-8 hours – Rarely effective alone in Parvo puppies Anti-emetics Chlorpromazine – – – – – – – Phenothiazine derivative Central acting Dopamine antagonist May decrease gastric acid formation 0.1-0.5 mg/kg IV, IM q 6-8 hours Sedation, hypotension Extrapyramidal signs with overdose 25 Anti-emetics Zofran (ondansteron) – – – – – Central acting Serotonin antagonist Minimal side effects Expensive 0.1-0.17 mg/kg (can go up to 0.5 mg/kg) q 6-12 hours Antacids Prone to esophagitis – Pain, anorexia, nausea Famotidine – 0.5 mg/kg IV or SQ BID 26 Antibiotics Sources of bacteria – Enteric bacteria • Salmonella , C perfringens , E coli , Campylobacter – Any other • Neutropenia Antibiotics Start with Ampicillin or Cefazolin IV Well hydrated— Gentocin or Amikacin Baytril – Safe for short term use in puppies Metronidazole 27 Analgesia Often necessary Pain increases depression and nausea Buprenorphine – Less likely to exacerbate nausea Fentanyl – Less sedative effects DO NOT GIVE BANAMINE!!!! Summary-Minimum Monitoring Daily PCV/TP and Glucose – +/- electrolytes CBC day 1, then depends on individual case Twice daily body weight Twice daily PE – – – – Hydration/Fluid overload Cardiovascular status Abdominal palpation Pain control 28 Summary-Treatment Initial Fluid Bolus Crystalloids – Add in Reglan, KCL, Dextrose, B-vitamins ? Colloids ? Plasma +/- Albumin Ampicillin or Cefazolin Famotidine Buprenex Summary -Treatment Still vomiting?? – Add in Chlorpromazine or Zofran Still febrile, signs of sepsis? – Add in Baytril, (Aminoglycoside if well hydrated) Low albumin? – Give albumin or plasma • 45 ml/kg to raise albumin 1 g/dl 29 Treatment Start feeding as soon as possible – Enterocytes need direct nutrition Increase anti-emetics if needed NG tube and trickle feed >3 days of anorexia: Consider PPN Prognosis >75% Survival with full treatment Death due to: – Sepsis – Hypovolemic shock – Intussusception 30 31 Isolation Policies Only one tech, one doctor exposed Full gown and gloves Different gown for each puppy – Different parvo strains Foot baths THOROUGH CLEANING – Parvosol or bleach 32 Questions?? Puppy Pneumonia 33 Causes Viral Bacterial Fungal Foreign body Aspiration Ciliary Dyskinesis Parasitic – Distemper, Canine influenza – E.coli, B bronchispetica, Mycoplasma, K. penumoniae – Paragonimus spp., Aerulosyrongylus spp., and Capillaria spp Diagnostics Obtain minimum database (CBC/CHEM/UA + fecal) --> Baerman fecal analysis Distemper titer/conjunctival scrapes Obtain BP and blood gas Pulse Oximetry Obtain thoracic radiographs +/- Perform tracheal washing before initiating antimicrobial therapy (if possible) 34 Radiographs Tracheal Wash Transtracheal wash – Larger puppies – Use Abbotcath or Seldinger catheter Endotracheal wash – Smaller puppies – Sterile ET tube and red rubber Instill sterile saline, coupage and aspirate Cytology, culture and sensitivity 35 Transtracheal Wash Transtracheal Wash 36 Transtracheal Wash Transtracheal Wash 37 Treatment Provide Oxygen if Pulse Ox < 92% Oxygen trial if tachypneic and Pulse Ox >92% Options – Nasal, cage, hood Treatment Antibiotics (pending tracheal C & S) – Unasyn (ampicillin/sulbactam) – +/- Metronidazole – +/- Baytril 38 Treatment Nebulization and Coupage – Saline – ? Bronchodilator • 0.5 ml of the 0.5% albuterol solution for nebulization in 4 ml of saline – ? Aminoglycoside • Amikacin or Gentocin • 7 mg/kg in 5ml saline. – Q 4-6 hours Monitoring Respiratory rate and effort Serial Pulse Ox Arterial Blood Gas Daily PCV/TP/Glucose CBC @ 24-48 hours Recheck thoracic rads q 48 hours 39 Treatment Bronchodilator – May exacerbate ventilation-perfusion mismatch – DO NOT USE in suspect cardiac disease – Albuterol, terbutaline, theophylline Persistent Pneumonia Tracheal Wash or BAL if not already done Lung aspirate, cytology and culture Consider underlying conditions – Ciliary Dyskinesis, FB, Cocci, Recurrent aspiration etc. Persistent Lobar pneumoniaÆ May require Lobectomy 40 41 Questions???? Congenital Portosystemic Shunts “Bella” 42 History 10 month old F Schnauzer Mix History of Intermittent ataxia and incoordination Head bobbing and weakness Seems to worsen after eating PSS-History Usually under age 1 years Breed disposition: – Yorkie, Maltese, Pug, Schnauzer, Wolfhound, Cairn, Dandie Dinmont, and Havanese – Himalayans and Persians Single or multiple vascular communications Congenital or Acquired. Small Breed = extrahepatic shunts Large Breed = intrahepatic shunts 43 Clinical Signs Neuro signs – Head pressing, ataxia, wall hugging, circling, pacing, aggression, seizures, intermittent blindness Ptyalism in cats GI signs in 30% of dogs Signs often worsen after protein meal Copper colored iris Diagnosis Hypoproteinemia – Low albumin and or globulins Hypoglycemia Hypocholesterolemia Normal to low BUN Post-challenged Hyperammonemia 2-3x increase in ALKP and ALT Microcytosis May have ammonium biurate crystalluria 44 Bella’s Bloodwork Albumin 2.1 g/dL (2.3-4.0) BUN 5.0 mg/dL (7-27.0) TP 4.9 g/dL (5.2-8.2) ALKP 254 U/L (23-212) ALT 764 U/L (10-100) MCV 58 fL (58-79) Diagnosis Paired Bile Acids – Pre and Postprandial bile acids 45 Bella’s Bile Acids Normal Pre – Less than 7.0 µmol/L – Bella = 203.1 µmol/L Normal Post – Less than 15.0 µmol/L – Bella = 404.4 µmol/L Diagnostic Imaging Abdominal radiographs – Small liver may be noted or may be normal in appearance. • 50% of cats and 60% -100 % of dogs. – +/- uroliths 46 Diagnostic Imaging Ultrasound – – – – – 80-95 % Sensitive for canine shunts Sensitivity increases for intra-hepatic shunts Doppler and color wave enhances visualization Results highly operator dependent Also looking for • Small liver • Paucity of vasculature • Ratio of PV to CVC and Aorta at Porta Hepatus 47 Diagnostic Imaging Splenoportograms – Contrast injected in the spleen, taken up splenic vein then the portal vein – Will miss shunts caudal to splenic vein – Can also use CT • Trace Portal Vein in 3-D Normal 48 Portocaval Shunt 49 Portal V. Vena Cava Shunt Aorta Azygous v. Diagnostic Imaging Colonic Scintigraphy – – – – – – Instill Technetium into colon Tec is taken up by portal circulation Normally almost all goes to liver In PSS some shunts to heart Can estimate fraction of blood shunted Gives no anatomical information 50 Treatment Treat hepatic encephalopathy – Protein restricted diet • Recommended dietary protein intake (dry matter basis) 18 to 22 per cent (dogs) and 30 to 35 percent (cats). – Metronidazole • Alters urease-producing intestinal bacterial population • Changes flora decreasing ammonia production 51 Treatment Lactulose • Acidifies colonic contents Æcausing ammonia trapping • Shortens the intestinal transit time • Alters colonic flora • Promotes incorporation of ammonia into bacterial proteins • Reduces production of potentially toxic shortchain fatty acids (SCFA) • Dose – 0.1 to 0.22 mL/lb by mouth every 8 to 12 hours to achieve two or three soft stools per day Pre-op considerations PT/PTT – May need plasma prior to surgery Hypoglycemia – Often need dextrose Seizure management – Consider preloading with KBr 52 Surgery Many possible techniques – Ligatures – Ameroid constrictors • Hydroscopic casein material in a stainless steel ring – Intravascular • Coils – Partial or complete ligation Surgery Shunt located/dissected out Jejunal vein catheterized Portal pressures checked with temporary ligature Ameroid placed Liver Biopsy 53 54 Post-operative Considerations Monitor for bleeding Adequate analgesia Post-operative seizures – Narcotics often metabolized by liver – ? Pathophysiology Portal Hypertension – Abdominal pain, hypotension, vomiting, ascites, bloody stools Continue HE treatment – 4-8 weeks Other Considerations Microvascular dysplasia – Microscopic shunting of blood through the liver without the presence of a macroscopic portosystemic shunt – Diagnosed with biopsies – Yorkies and Cairn Terriers predisposed Acquired PSS – Form in response to portal hypertension – Typically multiple extrahepatic shunts – Connect portal system and caudal vena cava 55 Prognosis Single shunt – Good to excellent prognosis IF….. • Total to near total occlusion occurs • No portal hypertension Partial occlusion – Signs recur in 40-60% of dogs Cats – Very difficult to completely occlude – Portal hypertension more common – More likely to get acquired shunts Any Questions?? 56
