Large Animal Acute Abdomen: Categorizing and Differentials - PDF

LARGE ANIMAL ACUTE ABDOMEN 1: CATEGORIZING AND DIFFERENTIALS SIGNALMENT AND HISTORY Kira Epstein, DVM, DACVS-LA, DACVECC-LA VETM 5292  COURSE UPDATE General Low stakes deadlines are firm and will not be reopened Each...

LARGE ANIMAL ACUTE ABDOMEN 1: CATEGORIZING AND DIFFERENTIALS SIGNALMENT AND HISTORY Kira Epstein, DVM, DACVS-LA, DACVECC-LA VETM 5292  COURSE UPDATE General Low stakes deadlines are firm and will not be reopened Each activity is worth a small percentage (10% or less) of low-stakes grade (points on eLC not proportionate) You will have access to materials to learn from Exception—excused absences will be allowed to submit later If you are able please submit muddiest point(s) by next Wednesday to be included on the pre-review for midterm 1 Imaging Only material that was discussed during lecture on exams Dr. Giglio will record the 1st lecture again since slides were not recorded (Monday) You will be able to learn about all of the material Dr. Giglio will record the remaining material and make the recording available (Monday) First 30 min of Pulling it Together Lab (2:30-3 on March 12) will be used for Q&A about imaging Would you like to submit questions/muddiest points in advance?  LECTURE LEARNING OBJECTIVES List and compare clinical signs of colic in horses, camelids, cows, and small ruminants Know the common and uncommon groups of causes of colic based on anatomic location and pathophysiologic cause List examples of differential diagnosis in the common groups of causes of colic for large animal species Explain the value of signalment and history in diagnosing colic and list examples of findings that would help you narrow down your differential list Take a complete history for a large animal presenting with colic  CLINIC AL SIGNS OF ABDOMINAL PAIN Colic = abdominal pain Variable Species difference Horses more dramatic Breed and age differences Diagnostic group differences WHAT ARE SOME SIGNS OF COLIC IN LARGE ANIMALS?  COLIC—HORSES Mild Decreased appetite Depression, change in attitude Lying down Stretching out (posturing to urinate) Bruxism Flehman Moderate Pawing Flank watching Kicking at abdomen Getting up and down COLIC—HORSES Severe Hard to keep standing Rolling Self-trauma—scrapes, lacerations, swellings of head, tuber coxae, point of hock Signs of previous severe colic Exhausted Less painful Intestine died Rupture (Resolved?)  COLIC—OTHER LA Small Cows Camelids ruminants Anorexia Anorexia Anorexia Away from herd Refusing to stand Away from herd Kicking at Treading Laying down Stretching out abdomen Kicking at Bruxism Kicking at abdomen abdomen Groaning Bruxism Getting up and Laying down Vocalizing down Kyphosis Splinting abdomen Rolling  IT’S AN EMERGENCY! (USUALLY) GOAL=efficiently get to next step Diagnostics Treatment LOTS of ddxà narrow it down Common vs uncommon Know when things aren’t fitting together and slow down Group vs specific diagnosis Can usually get you to goal Anatomic location Pathophysiologic mechanism  WHAT’S THE PLAN? CONSIDERATIONS OPTIONS Working diagnosis Field Group (or specific) Treat Clinical signs Medical Duration Surgical (ruminants) Owner Refer Veterinarian Euthanize Hospital Medical management Surgical exploration/treatment Euthanasia  C ASE Owner: Ms. Merryweather from Enchanted Woods Farm Horse: Phillip 10 yo Irish Sporthorse Gelding Eventer After working this morning went into stall and lay down, not interested in food, if walk lays down again  ANATOMY, ANATOMY, ANATOMY Forestomach Stomach Stomach Peritoneum Abomasum/C3 Duodenum Reproductive Small Extra-GI Jejunum intestine Hepatobiliary GI Ileum Urinary Cecum Large Colon Spleen Large Spiral Colon intestine Pancreas Transverse Colon Small Colon  LOOK ALIKE Extra-abdominal body systems Botulism Neuro Signs that could be colic Laminitis Pain Rhabdomyolysis MS Laying down, unable to/unwilling to get up Pleuropneumonia Not eating/decreased appetite Resp Severe arrhythmias CV CHF GROUPING DIFFERENTIALS—ANATOMY Stomach Peritoneum Duodenum Small Stomach Reproductive Jejunum intestine Small intestine Extra-GI Ileum Hepatobiliary GI GI Small intestine Cecum Urinary Large LargeLarge Colon intestine Spleen intestine Large Transverse Colon intestine Small Colon Pancreas  PATHOPHYSIOLOGIC C ATEGORIES FOR GI PAIN Stretch Non-strangulating obstruction Distension Strangulating obstruction Mesentery Inflammation Chemo Other—ex: thrombotic disease Ischemia Inflammation  COMBINING COMMON C ATEGORY AND LOC ATION Stomach(s) Small Intestine Large Intestine Non-Strangulating Stomach NSO SI NSO LI NSO Obstruction Strangulating Stomach SO SI SO LI SO Obstruction Inflammatory Stomach Infl SI Infl LI Infl  LATER—VOMITING NOW—ACUTE ABDOMEN (INTERNAL) Small Large Stomach Intestine Intestine Non- Non- Strangulating SI NSO LI NSO Strangulating Stomach NSO Obstruction Obstruction Strangulating Strangulating SI SO LI SO Stomach SO Obstruction Obstruction Inflammatory SI Infl LI Infl Inflammatory Stomach Infl  NON-STRANGULATING OBSTRUCTIONS—HORSE SMALL INTESTINE LARGE INTESTINE Ileal impaction Spasmodic/unknown? Other Impactions Ascarid Feed, sand, fecalith/bezoar, meconium Ileal hypertrophy Cecum, pelvic flexure, RDC, SC Foreign body Enterolith—RDC and aboral LC Displacements RDDLC LDDLC RIGHT DORSAL DISPLACEMENT LEFT DORSAL DISPLACEMENT  NON-STRANGULATING OBSTRUCTIONS—OTHER LA SMALL INTESTINE LARGE INTESTINE Camelids Camelids Phyto-/Tricho-bezoars Spiral colon fecalith Cattle Cecal impaction Fat necrosis Atresia coli Small ruminants, pigs Cattle Foreign body Cecal dilation/dislocation Atresia coli Pigs Spiral colon fecalith Constipation  STRANGULATING OBSTRUCTIONS— HORSE SMALL INTESTINE LARGE INTESTINE Strangulating lipoma Large colon volvulus Epiploic foramen entrapment SC strangulating lipoma Inguinal hernia Intussusception Segmental volvulus Intussusception Gastrosplenic  STRANGULATING OBSTRUCTIONS— OTHER LA SMALL INTESTINE LARGE INTESTINE Mesenteric volvulus Intussusceptions Intussusception Camelids Camelid Spiral colon torsion Epiploic foramen entrapment Ruminants Cattle Cecal torsion/volvulus Hemorrhagic Bowel Syndrome/Jejunal Pigs Hemmorhage Syndrome (blood clots obstruct lumen; thrombosis of mesentery) Mesenteric volvulus  INFLAMMATORY SMALL INTESTINE LARGE INTESTINE Anterior enteritis Colitis IBD Typhlocolitis IBD  USING GROUPS TO REACH GOAL— HORSE Small Intestine Small Intestine Large Intestine Large Intestine Non- Non-Strangulating Field Refer Treat or refer Strangulating Obstruction SI NSO LI NSO Obstruction Sx Referral Hospital Medical to start Medical to start Strangulating Strangulating ObstructionField SIRefer SO or euthanize LIRefer SO or euthanize Obstruction Sx Referral Hospital Sx or euthanize Sx or euthanize InflammatoryField SI Infl Refer LI Infl Refer Inflammatory Sx Referral Hospital Medical Medical USING GROUPS TO REACH GOAL— DIFFERENCES OTHER LA Surgery more common More stoic If colic à concern for strangulating Severe NSO à rupture reported somewhat frequently Diagnostic High yield answers Cattle standing à relatively low cost and risk Medical management If confident inflammatory Constipation in pigs  NOT FITTING IN? Why? Uncommon GI location Uncommon mechanism Extra-GI location Idiopathic peritonitis Look alike Next? Further diagnostics Field or Hospital  DIAGNOSTIC APPROACH Signalment History Basic Colic Exam (Lecture 2) PE NGT (Horse) Rectal (Horse and Cow) Select Additional Diagnostics Ultrasound Abdominocentesis Bloodwork SIGNALMENT Age, sex, and breed Increased incidenceà increased index of suspicion Response to painà interpretation of clinical signs Not RULES  AGE—HORSE Causes Foal Ascarid impactions Jejunal intussusceptions Older Strangulating lipoma Clinical signs Older more stoic  AGE—C ATTLE Causes Calves Intussusceptions (most calves < 2 mo) Atresia (within 2-3 days) Volvulus (most common 1 wk-6 mo) Adults HBS usually >4 yr Cecal dilation/torsion Clinical signs Older more stoic SEX Causes Peripartum mares GI—LCV, cecal perforation Extra-GI—uterine torsion, uterine artery Stallions—inguinal hernia, testicular torsion Cows—cecal dilation/dislocation/torsion/volvulus (and abomasal dz) Clinical signs Mares more stoic (esp w/ foal)  BREED—HORSE Causes Miniatures—non-strangulating LI like fecoliths STB, SB, TWH—inguinal hernia Arabian, SB, Morgan—enterolith Clinical sings Drafts and gaited often stoic BREED—C ATTLE Causes Brown Swiss HBS Intussusception Dairy breeds Cecal dilation/dislocation/torsion/volvulus Angus and Jersey Mesenteric fat necrosis  MS. MERRYWEATHER DECIDES SHE WOULD LIKE YOU TO COME OUT. WHILE YOU HAVE HER ON THE PHONE YOU FIGURE YOU CAN START GETTING A HISTORY. WHAT QUESTIONS WOULD YOU LIKE TO ASK?  HISTORY—WHAT TO ASK Current Episode Previous Medical Management Signs Previous colic Geographic location Degree How often, when Duration Time of year Dx Surgery Diet Manure Other illness/sx Type/amt hay/grain Change amount/type Pasture? Diarrhea Melena Other medications Change? Preventive care Change in exercise Medications Teeth Type, amount Deworming/vaccination Vices When Response Repro Stallion—collection/breeding Mare—pregnant? due date? Cow—calving/freshened; milk production  DEGREE OF COLIC—GROUPING Small Intestine Large Intestine Non-Strangulating Variable Variable Obstruction Strangulating Severe at some Severe at some Obstruction point point Mild/depressed if Mild/depressed if Inflammatory distension not distension not severe severe  HISTORY—INDEX OF SUSPICION Manure Diarrhea—colitis, SC impaction Cecal impaction—decreased, smaller piles/balls HBS—scant feces, melena Previous colic Recurrence—LDDLC 2.5-21% Adhesions—20% horses following colic sx Medication Colitis—abx useàClostridial? NSAIDs—RD colitis, cecal impaction HISTORY—INDEX OF SUSPICION Preventative care Tapeworms—ileocecal intussusception, ileal impaction Recent 1st dewormer--ascarid Geography Enteroliths—CA Sand—sandy soil (AZ) Time of year HBS—fall/winter Diet Enterolith—alfalfa hay Ileal impaction—Bermuda/coastal hay  HISTORY—INDEX OF SUSPICION Exercise Cecal impaction—stall rest Vices EFE—cribbing Reproductive Inguinal hernia—just after breeding/collection Peripartum mare GI—LCV, cecal perforation Non-GI—uterine torsion, uterine artery bleed Cows Cecal dilation/dislocation/torsion/volvulus— freshening HBS—peak milk production  B ACK TO PHILLIP Signalment—10 yo Irish Sporthorse Gelding History— Mild-moderate colic Owner gave flunixin meglumine orally 10 min ago Regular preventative care Located in GA Coastal hay, pasture at night, 2lb grain BID Cribber No change noted in manure, exercise, diet No hx of colic, illness  BASED ON SIGNALMENT AND HISTORY, YOUR INDEX OF SUSPICION IS INCREASED FOR WHICH DISEASE(S)? LARGE ANIMAL ACUTE ABDOMEN 2: BASIC COLIC EXAM Kira Epstein, DVM, DACVS-LA, DACVECC-LA VETM 5292  LECTURE LEARNING OBJECTIVES Know the components of the basic colic exam in horses and other large animal species. Explain how to safely perform NG intubation and rectal examination in horses. Know normal and common abnormal findings of the basic colic exam in horses and other large animal species. Using basic colic examination findings prioritize a list of differential diagnoses (groups and/or specific diseases) in a colicking large animal  B ASIC EXAM Part of every workup Exceptions Risk to people Risk to patient Physical exam Start w/ triage! Plus Horse—NGT and Rectal Cow—Rectal (+/- ORT—stay tuned for Vomiting section) Camelid—Rectal is possible, but limited and ? value  TRIAGE EXAM—REMEMBER CVRH II? Is the patient in shock? Q=HR×SV Preload E needs > E delivery Afterload êDO2 most common Contractility DO2=Q×CaO2 What type of shock? Stage of shock? Hypovolemic Compensated CaO2=1.34[Hb]SaO2+ 0.003 PaO2 Distributive Early Decompensated Obstructive Late Decompensated Cardiogenic Treat? Metabolic  A BIT MORE ON DISTRIBUTIVE SHOCK Most common pathophysiology Relative hypovolemia d/t vasodilation Systemic Inflammatory Response Infectious Non-infectious In colic Leaky gut à bacteria, other pathogens, toxins enter circulation EX: Endotoxin Ischemia, reperfusion can also à SIRS à inflammatory or strangulating groups most likely  ENDOTOXIN Endotoxin (lipopolysaccharide—LPS) Cell wall gram –’ve bacteria Inner portion = lipid A Toxic Conserved Release w/ rapid death or reproduction http://pathmicro.med.sc.edu/fox/lps.jpg  FINDINGS W/ ENDOTOXEMIA SIRS criteria (at least 2 one must be fever or WBC) Fever Tachycardia Tachypnea WBC changes Leukocytosis or leukopenia Left shift Possible others Colic Injected sclera Toxic mm  TRIAGE EXAM—HOW TO? Respiratory CV Neuro Airflow/ breathing Heart/pulse rate Pulse quality Rate CRT/mm color Mentation Pattern Jug refill Extremity temp +/- Auscultation +/- Ausculation  TRIAGE EXAM—SIGNS OF SHOCK Type Stage ê preload Compensated (normal to éQ) Prolonged jugular refill Rapid CRT MM color—toxic, pale, cyanotic Bounding pulses êQ é HR Prolonged CRT é RR Poor pulse quality Decompensated Cool extremities Progressive êQ ê Mentation Loss of compensatory mechanisms DO YOU THINK MOST HORSES WITH COLIC ARE IN SHOCK?  SHOCK—GROUPING Small Intestine Large Intestine Non-Strangulating H poss w/ time H poss w/ time Shock unlikely O Shock poss w/unlikely time Hypovolemic Obstruction** O poss w/ time Shock less Distributive H variable w/ reflux H++ d/t trapped fluid Strangulating Shock common severe/more D variable w/ amt/degree D++ d/t ischemia/leaky Obstructive Obstruction O poss variable w/ time/lots O++(esp. LCV) d/t distension ** w/ compromise H++ d/t reflux H++ d/t diarrhea to bowel and leakage Inflammatory D++Shock common d/t inflammation/ Shock D++ common d/t inflammation/ add D leaky gut leaky gut  SHOCK—GROUPING Small Intestine Large Intestine Non-Strangulating Shock unlikely Shock unlikely Hypovolemic Obstruction** Shock less Distributive Strangulating Shock common severe/more Obstructive Obstruction (esp. LCV) variable ** w/ compromise to bowel and leakage Inflammatory Shock common Shock common add D  B ACK TO PHILLIP Triage exam RR=20, eupnic, bilaterally symmetric airflow, no adventitial sounds HR=48, mm=moist/pink, crt=2 sec, pulse quality good, jugular refill appropriate, ears warm BAR, aware, interactive  B ASED ON YOUR TRIAGE EXAM, YOU CONCLUDE PHILLIP A. is in late decompensatory shock and likely to have a non- strangulating obstruction B. is in late decompensatory shock and likely to have an inflammatory lesion C. is not in shock and likely to have a non-strangulating obstruction D. is in compensatory shock and likely to have an inflammatory lesion  THE REST OF THE PE Level of pain Other body systems Temperature Complete respiratory, CV, neuro exams GI Add MS, urogenital, integument, LN Borborygmi Evidence of less common causes of colic, look alike dz Distension Evidence of secondary trauma/concurrent Ruminants/camelids add problems that change prognosis or needs Rumen/C1 contractions to be addressed Ping Succussion Ballotment Scootch or grunt test  FEVER—GROUPING Small Intestine Large Intestine Generally Non-Strangulating uncommon— Uncommon Obstruction exceptions= SC and sand impactions Strangulating Generally Uncommon Obstruction uncommon Inflammatory Common Common ABDOMINAL DISTENSION Horse LI >> SI SI non-strangulating possible depending on duration and location Ruminants/camelids Less likely with severe strangulating obstructions d/t rapid progression Cow SI obstruction à back up fluid abomasum à rumen à bilateral ventral distension Cecal dilation/torsion à right flank distension  BORBORYGMI AND RUMEN/C1 CONTRACTIONS Small Intestine Large Intestine Non-Strangulating Decreased/absent Decreased/absent Obstruction Strangulating Decreased/absent Decreased/absent Obstruction Borborygmi may be Inflammatory Decreased/absent increased PING Right RDA/RTA Cecum Spiral colon Small intestine Bilateral Pneumorectum Pneumoperitoneum Pneumometrium * Some will ping horses  NASOGASTRIC INTUB ATION Diagnostic Normal=60 bpm Severe Colic Reflux from nose àdo immediately Decrease pain Administer fluids/laxative  NORMAL TRANSVERSE OF NASAL PASSAGE/SINUS Dorsal nasal meatus Conchofrontal Sinus Middle nasal meatus Caudal Cd Maxillary Maxillary Common nasal meatus Sinus Sinus Ventral nasal meatus 111 211 411 311 Mandibles  WHAT C AN GO WRONG? VENTRAL VS MIDDLE NASAL MEATUS Tube in middle nasal meatus Tube in ventral nasal meatus  NORMAL LONGITUDINAL NASAL PASSAGE/PHARYNX Dorsal nasal meatus Middle nasal meatus Ventral nasal meatus Ethmoid Upper esophageal Na opening so ph So ft ary Palat nx e La r yn x  WHAT C AN GO WRONG? NASOPHARYNX VS ETHMOID Tube in ventral nasal meatus and nasopharynx Tube in middle nasal meatus hitting ethmoid turbinates  NORMAL TRANSVERSE LARYNX/ESOPHAGEAL SPHINCTER Caudal fossa Guttural pouch Upper esophageal opening Rima glottidis WHAT C AN GO WRONG? ESOPHAGUS VS LARYNX Tube in Tube in Upper esophageal Larynx opening NASOGASTRIC INTUB ATION SUPPLIES Tube—bigger is better Buckets—markers for quantification Water Empty Pump or dosing syringe Lubricant—water Proper restraint Physical Chemical  NASOGASTRIC INTUB ATION STEP-BY-STEP Pass until get to esophageal Other hand sphincter— hold tube 4-6 spongy Lift false inches from resistance nostril—hand tip—use thumb Get ready over bridge of of first hand to nose lift up w/ direct thumb  NASOGASTRIC INTUB ATION STEP-BY-STEP Check for reflux—dose Enter syringe or stomach—gas create siphon Pass down or stomach esophagus— contents Wait for can use air to swallow open as go TIPS AND TRICKS Horses need to breathe Don’t occlude opposite nostril w/fingers Nasal passage is most sensitive part First 8-12 inches (est w/ nostril to medial canthus) 2-3 quick advancements Use thumb to hold tube ventral and central Mark tube with pen—nostril to throat latch Getting a horse to swallow Wait, gently bump back and for the Pass up other nostril Blow?  THINGS TO AVOID Nosebleeds Not life-threatening, but concerning to owners Avoid ethmoid—ventral and central During placement and removal Good restraint Getting stuck before the esophagus Ethmoid—very firm/bony—ventral and central Dorsal pharyngeal recess—not far enough in— rotate tube  BE SURE! YOU’RE IN THE ESOPHAGUS Keep flexed at poll while passing Check Watch pass down left side Check for negative pressure Check doesn’t “rattle” in trachea Get gas/stomach contents Cough? Not reliable Cough when in esophagus Not always when in trachea  NG REFLUX—GROUPING Small Intestine Large Intestine Non-Strangulating Depend on Uncommon Obstruction duration/location (exception: LDDLC) Strangulating Depend on Uncommon Obstruction duration/location Inflammatory LOTS of reflux Uncommon  B ACK TO PHILLIP Rest of PE Temperature 100.1F Borborygmi decreased in all quadrants Owner confirms abdominal distension No other abnormalities noted 1-2L net reflux B ASED ON THE FULL PHYSIC AL EXAMINATION AND NASOGASTRIC INTUB ATION FINDINGS YOU BELIEVE PHILLIP IS A. more likely to have a small intestinal lesion B. more likely to have a large intestinal lesion C. more likely to have an inflammatory lesion D. more likely to have a strangulating lesion  RECTAL EXAM—WHAT C AN YOU FEEL? HORSE Caudal ~1/3àInferring Left side GI Small colon Large colon (pelvic flexure) Extra-GI Spleen Left kidney Bladder/lateral ligament of bladder Inguinal rings Uterus/ovaries Aorta  RECTAL EXAM—WHAT C AN YOU FEEL? HORSE Right side GI Cecum (ventral/medial band) Small colon (Large colon [pelvic flexure]) Extra-GI Bladder/lateral ligament of bladder Inguinal rings Uterus/ovaries Aorta RECTAL EXAM—WHAT C AN YOU FEEL? COW Cow Left—rumen Midline—left kidney Caudal Bladder Uterus and ovaries Inguinal rings RECTAL EXAM SUPPLIES Not much! Your arm and hand—pick one and stick with it Rectal sleeve Lubricant—water soluble Proper restraint Physical Chemical—usually not needed except horse Other—horse N-butylscopolammonium bromide Lidocaine—60 cc syringe w/ extension set  RECTAL EXAM STEP-BY-STEP Middle cranial—small Right cranial— colon +/- lg feel cecum colon Advance slowly and evacuate Get ready— feces as you go proper restraint cranial  RECTAL EXAM STEP-BY-STEP Dorsal— aorta Pelvis— inguinal rings Middle caudal— Left caudal— bladder +/- tail of spleen uterus/ Left cranial— ovaries left kidney, NS space, spleen  MINIMIZE COMPLIC ATIONS— MAINLY HORSES Rectal tear Getting kicked Lubricant Stocks Restraint Doorway—stand behind door jam N-butylscopolammonium bromide Close to the side of hindlimb Intrarectal lidocaine No jewelry, short nails, fingers together Evacuate feces Let contractions push out Be efficient RECTAL EXAM—KEY FINDINGS HORSE #1 Normal vs Abnormal #2 Grouping—SI vs LI distension SI Balloons, sausages, bicycle tires No bands (except ileum) LI Cecum/large colon Large, tight bands Content—gas, fluid, ingesta Small colon Wide antimesenteric band Gas backing up into large colon/cecum  RECTAL EXAM—SPECIFIC DISEASES HORSE Small Intestine Large Intestine Ileal impaction—firm LDDLC—colon trapped Non-Strangulating tubular structure next to over NS ligament Obstruction cecum on right Impactions—cecum, PF, SC Inguinal hernia—into ring Strangulating on rectal; externally LCV—distension can be Obstruction severeàpelvic inlet Ischemic—thickened AE—not turgid, Inflammatory thickened Fluidy contents  RECTAL EXAM—PITFALLS Differentiating impaction from deH20 ingesta SI lesions prevent fluid reaching LIàdeH20 ingesta Impactions Distend the colonàno sacculations Obstruct lumenàgas colon and cecum DeH20 Vacuum packed/haustra and little/no gas distension Overinterpretation of horizontal bands across abdomen Will happen with a RDDLCàcan’t feel cecum Can also happen with many other causes of LC distension  RECTAL EXAM—ABNORMAL COW Stomachs Texture of contents of rumen Dry Fluid backing up Sometimes DA (RDA/RTA more) Small intestinal distension Cecal dilation/dislocation/torsion/volvulus Can be difficult to differentiate from RDA/RTA ALWAYS check repro  B ACK TO PHILLIP Rectal examination Moderate gas distension of large viscus Moderately tight bands  YOU THINK PHILLIP HAS A ____________, AND WOULD LIKE TO _____________ NEXT. A. no idea; do all the diagnostics B. small intestinal lesion; refer C. large intestinal lesion; monitoring and medical management at farm D. strangulating lesion; euthanize