Triaging colic patients (Proceedings)

Signalment and history

     • The history can be very brief in order to speed up the examination process

     • The history can be conducted after the initial exam for horses with active signs of colic.

     • The most critical pieces of the history:

          o Treatments already administered

          o Any known reactions to medications

          o Duration of colic

          o Severity of colic

Examination of the horse with colic

     • Physical examination (TPR, peripheral pulse quality, mucous membrane color, capillary refill time, auscultation of the chest and abdomen)

     • Assessment of dehydration

     • Listen for the frequency and quality of gut sounds (Over 1-minute, gut sounds should be present in the upper and lower quadrants of both sides of the abdomen). Specific gut sounds include:

          o Opening of the ileocecal orifice (sounds like emptying of a drain)

          o Sand in the ventral colon (sounds like sand within a paper bag as you slowly turn it over)

          o Short, sharp tinkling sounds such as those you experience with 'GI upset.'

     • Rectal findings. Normal findings include:

          o Bladder

          o Reproductive tract

          o Ventral band of the cecum on the right

          o Aorta dorsally

          o Left kidney

          o Nephrosplenic ligament

          o Spleen

          o Pelvic flexure (or doughy colon on the lower left quadrant)

     • Nasogastric reflux (up to 2L is normal)

     • Abdominocentesis (normal: TNCC < 10,000 cells/μl; TP < 2.5g/dl)

When to refer to a case(see table)

     • Refractory or unrelenting pain

     • Lack of response to therapy

          o Be thinking of referral the second time you go out to see a patient

               o Evidence of endotoxemia (consistently elevated heart rate, congested gums, prolonged capillary refill time)

               o A finding inconsistent with a simple colic, such as excessive reflux (> 2-5L), a distended viscous, tight band, or extensive impaction on rectal examination, a serosanguinous abdominocentesis

Causes of nasogastric reflux:

     • Pyloric obstruction

     • Small intestinal obstruction or strangulation

     • Nephrosplenic entrapment of the large colon

     • Occasionally with large colon volvulus

     • Anterior enteritis

Causes of tight bands:

     • Large colon displacement or volvulus

     • Grossly distended cecum

     • Mesentery under tension

     • Uterine torsion

Causes of abnormal abdominal taps:

     • Small intestinal compromise (strangulation or prolonged simple obstruction)

     • Enteritis

     • Large intestinal compromise (prolonged simple obstruction)

     • Splenic tap

How to prepare a patient for referral

     • Encourage your clients to pre-plan for an emergency:

          o Which horses will they consider referring based on emotional and financial factors?

          o Who will make decisions if the owner is away?

          o Consider insurance on those horses for which colic surgery would be a consideration

          o Is there a truck a trailer available consistently?

     • If the horse is severely dehydrated, consider placing a catheter and bolusing fluids (at least 20L)

          o If reflux was obtained from a nasogastric tube, tape the tube in place. This can prevent a ruptured stomach. Place a rubber glove with a finger cut off over the end of the tube to act as a valve.

          o Provide enough analgesics/sedatives for the duration of the trip.

          o The horse should be confined in the trailer to prevent attempts at recumbency and rolling en route.

          o Call the referral hospital prior to the horse's departure

          o Have the referral veterinarian talk to the owner about the costs

          o Send a copy of the examination findings and drugs administered