Emergency GI Surgery - Complications

Management when things go wrong

Outline

• Adhesions
• Ischemia and Reperfusion
• Short bowel syndrome
• Ileus
• Sepsis
• Surviving sepsis
• Hypotension
• Hypoglycemia
• Hypoalbuminemia
• CIRCI
• Prognosis

Adhesions

Adhesions - Pathophysiology

• Surgical manipulation or disease process -> fibrin exudes into peritoneal cavity
• Normally fibrinolysis in 3-4 days
• If vascular damage is present -> fibroblasts infiltrate and produce collagen -> adhesions

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• Normal function
• Bring blood supply to otherwise compromised tissue

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• Influencing factors
• Adhesions to the incision are more likely to occur when peritoneum is sutured
• likelihood of adhesion formation increases with endotoxemia
• intestinal manipulation
• bowel distention
• desiccation of serosal surfaces
• Foreign body contamination
• gauze fragments, lint, cotton fibers, glove powder, and antibiotic powder
• latex, silicone, contrast agents, and vegetable matter have also been associated with adhesion formation

Adhesions - Prevention/Treatment

Meticulous operative technique

• Prevention of tissue desiccation
• Gentle tissue handling
• Meticulous hemostasis
• Precise suture placement
• Complete removal of blood clots and foreign debris
• Thorough lavage

Adhesions - Prevention/Treatment

Numerous physical and chemical manipulations to reduce intraabdominal adhesion formation have been reported,

• In horses
• postoperative peritoneal lavage with LRS
• intraoperative and postoperative administration of heparin
• hyaluronate-carboxymethylcellulose membrane implantation
• In laboratory animals
• intraperitoneal 0.4% hyaluronic acid solution
• subcutaneous administration of TNP-470
• intraabdominal administration of fibrinolytic agents
• Many other agents
• broad-spectrum antibiotics, corticosteroids, nonsteroidal antiinflammatory drugs, dimethyl sulfoxide, dextrans, and interleukin-10 (IL-10), have been advocated to minimize adhesion formation
• Physical techniques
• omentectomy and physical barriers

Ischemia and

Reperfusion Injury

Ischemia and Reperfusion Injury

Pathophysiology: overall is not completely understood

How do you treat Reperfusion injury?

Short Answer

• We don’t know

Longer Answer

• There are lots of things that have been suggested
• Attempting scavenging of reactive oxygen species
• DMSO, N-acetylcysteine, Deferoxamine, Allopurinol
• Other options
• Lidocaine, Ketamine, Steroids?, Colloids?, Platelet Rich Plasma, Therapeutic hypothermia

Short Bowel Syndrome

Short Bowel Syndrome

• Complex disorder that results from removal of a large part of the small intestine
• In summary:
• De­creased absorptive surface area of the small intestine due to extensive resection
• Decreased transit time due to shorter intestine
• Inadequate digestion and absorption of nutrients and water
• Electrolyte imbalance and micro- and macro-­element deficiencies
• Loss of intestinal hormones

Short Bowel Syndrome - Clinical Signs

Acute period

• Severe watery diarrhea
• Electrolyte imbalances
• Metabolic acidosis

First few weeks

• Continued diarrhea
• Malnutrition and continued weight loss
• Hypergastrinemia and steatorrhea
• Polyphagia

Short Bowel Syndrome - Intestinal Adaptation

Aim - to increase absorption of nutrients and increase transit time

Accomplished through:

• Villi elongation
• Deepening of the crypts
• Increased numbers of cells per villus column
• Rate of cell apoptosis is also altered

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This process may take about 2 months in dogs

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Short Bowel Syndrome - Medical Treatment

• Antidiarrheal agents
• Gastroprotectants
• Supplementation of pancreatic enzyme, bile salt binding agents
• Antibacterials for SIBO
• Immediate oral food intake to promote adaptation
• Parenteral nutrition may be required during the initial adaptation phase and weaned
• Complex constantly changing diet plan supplementing micronutrients using highly digestible foods

Ileus

Ileus - Clinical signs/Findings

• Pain
• Regurgitation
• Vomiting
• Abdominal distention from fluid and gas accumulation
• Increased residual volumes on nasogastric tube aspirations
• Decreased gut sounds on abdominal auscultation

Ileus - Pathophysiology

Common complication after surgery, particularly if the gastrointestinal tract is manipulated

• Reduced intestinal motility is believed to be caused by overactivity of the sympathetic nervous system
• is activated with laparotomy
• further stimulated by: manipulation of the intestine, long operative time, and extensive resection

Diffuse intestinal dysmotility during functional or mechanical ileus can result in:

• intestinal dilation, increased intraluminal pressure, and bacterial translocation

Postoperative ileus is often exacerbated by opioid use during and after surgery

• activation of µ-opioid receptors in the gastrointestinal tract inhibits gut motility → mechanism of loperamide (Imodium)

Ileus - Treatment

Management Strategies

• Correction of any underlying disorders that may contribute to the problem
• e.g. sepsis or electrolyte abnormalities
• Early postoperative ambulation and feeding have been suggested in humans
• More frequent walks
• Early enteral nutrition via nasogastric tube
• Maintaining a decompressed stomach for comfort and nausea
• Increase aspiration frequency from nasogastric tube

Ileus - Treatment

Opioids

• Antagonism of peripheral µ-opioid receptors has been shown in humans to significantly accelerate gastrointestinal recovery following surgery
• Would be nice but… available opioid antagonists such as naloxone also act centrally to reverse analgesia → cannot be recommended for treatment of ileus in postoperative patients for ethical reasons
• What else could we do?
• Postoperative use of mixed opioid agonists - butorphanol and buprenorphine?
• Theoretically reduce the severity of opioid-induced ileus, compared with pure µ-agonists
• still provide some analgesia
• No studies demonstrating this effect in dogs and cats…

Ileus - Treatment

Pharmaceutical - Metoclopramide

• prokinetic drug that increases duodenal and jejunal peristalsis and amplitude
• Increases tone of gastric contractions
• Decreases pyloric sphincter tone
• Decreases duration of gastric emptying and intestinal transit
• Dosing
• can be administered as a CRI (1 to 2 mg/kg/d)
• SQ or Orally 1 hour before feeding (0.2 to 0.5 mg/kg q6 to 24h) until motility improves

Ileus - Treatment

Pharmaceutical - Cisapride

• Related to metoclopramide
• Supports motility of the entire gastrointestinal tract but is a little harder to get due to withdrawal from the human market
• Mainly increases lower esophageal peristalsis and sphincter tone, increases gastric emptying

Ileus - Treatment

Pharmaceutical - Mirtazipine

• tricyclic antidepressant that may stimulate gastrointestinal motility and appetite in cats and dogs
• Increases gastric emptying and colon transit times but not intestinal transit in healthy dogs under experimental conditions

Ileus - Treatment

Pharmaceutical - Erythromycin

• Thought to have effects similar to the hormone motilin and stimulates gastric emptying
• Also increases lower esophageal tone and may be useful in treating cats (and maybe dogs) with gastroesophageal reflux
• Stimulates colonic motility in dogs but not cats
• Dosing - note different than when using it as an antibiotic
• low doses (0.5 to 1 mg/kg PO or IV q8h)

Ileus - Treatment

Pharmaceutical - Lidocaine

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Intravenous continuous infusion of lidocaine for treatment of equine ileus Malone et al

• IV lidocaine significantly improved the clinical course in refluxing horses with minimal side effects

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Risk factors for equine postoperative ileus and effectiveness of prophylactic lidocaine Torfs et al

• Prophylactic lidocaine treatment was significantly associated with a reduced incidence of POI

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Intravenous lidocaine and small-intestinal size, abdominal fluid, and outcome after colic surgery in horses Brianceau et al

• Lidocaine improved jejunal distension and peritoneal fluid accumulation and was well tolerated

Ileus - Treatment

Evaluation of gastric emptying time, gastrointestinal transit time, sedation score, and nausea score associated with intravenous constant rate infusion of lidocaine hydrochloride in clinically normal dogs Johnson et al

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6 research Beagles were fed thirty 1.5-mm barium-impregnated spheres (BIPS)

• Saline
• lidocaine bolus (1 mg/kg)and CRI at 25 μg/kg/min
• lidocaine bolus (1 mg/kg) IV followed by a CRI at 50 μg/kg/min

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Results:

• Gastric emptying time did not differ significantly among treatments
• Significantly more BIPS were in the large intestine 4 to 7 hours for the 50-μg/kg/min
• 6 hours after treatment start, significantly more BIPS were in the large intestine for the 25-μg/kg/min than for the saline solution treatment
• Higher sedation and nausea scores with the 50-μg/kg/min CRI

Sepsis

Surviving Sepsis Guidelines

Over the next few slides I will go over some key points from the guidelines - This is from human medicine, but is still important!!!!

Surviving Sepsis Guidelines

Key points to remember - initial assessment

• Sepsis and septic shock are medical emergencies - need to act ASAP!!!
• Resuscitation is a must - fluids and otherwise
• Must measure values outside of physical exam - but exam is still important, especially CRT!
• Blood pressure - follow-up as treating and adjust accordingly
• Measure lactate values - follow-up over time and use this to adjust fluid resuscitation over time
• When in septic shock aim for MAP of 65

Surviving Sepsis Guidelines

Key points to remember - control of sepsis

• When there is suspicion of septic shock or a high likelihood of sepsis, antibiotics should be administered WITHIN 1 HOUR
• Must rapidly identify specific anatomical diagnoses of infection that may require emergent source control and intervening AS SOON AS MEDICALLY AND LOGISTICALLY PRACTICAL

Surviving Sepsis Guidelines

Key points to remember - hemodynamic management

• First line therapy - crystalloids
• Albumin is recommended in patients that have received large volumes of crystalloids
• Starches and gelatin are not recommended for resuscitation
• First line vasopressor is norepinephrine
• Backed by general consensus: Murphy et al JVECC 2022
• Recommended next step if not responsive to norepinephrine is vasopressin
• Recommend epinephrine as next step after norepinephrine and vasopressin

Surviving Sepsis Guidelines

Key points to remember - hemodynamic management

• For patients with septic shock and cardiac dysfunction that are hypoperfusing despite adequate volume and blood pressure it is recommended to add dobutamine to norepinephrine or to use epinephrine alone
• Recommended blood pressure monitoring is arterial blood pressure when possible
• Is vasopressor therapy is continuing to be required, it is recommended to give IV corticosteroids

Surviving Sepsis Guidelines

A best practice statement from them for us all to think about - antibiotic de-escalation

• “For adults with suspected sepsis or septic shock but unconfirmed infection, we recommend continuously re-evaluating and searching for alternative diagnoses and discontinuing empiric antimicrobials if an alternative cause of illness is demonstrated or strongly suspected.”
• “For adults with sepsis or septic shock, we suggest daily assessment for de-escalation of antimicrobials over using fixed durations of therapy without daily reassessment for de-escalation.”
• “For adults with an initial diagnosis of sepsis or septic shock and adequate source control, we suggest using shorter over longer duration of antimicrobial therapy.”

Surviving Sepsis Guidelines

Additional key recommendations:

• Any patients that can be fed enterally, it is recommended to institute early enteral nutrition if possible - remember to place a feeding tube!!

�KEY POINT ON ENTERAL NUTRITION - NOT IF THEY ARE ON PRESSORS

Surviving Sepsis Guidelines

Some considerations from the human side that haven’t completely made their way over:

• In humans they will use prolonged infusions (CRIs) of beta-lactams rather than bolus infusions
• In humans it is recommended to use prophylaxis for venous thromboembolism (i.e. anticoagulants such as low molecular weight heparins)
• In humans they monitor closely for hyperglycemia and may actually institute insulin therapy

Hypotension

How do I treat hypotension:

• Annoying short answer - it depends
• Confusing long winded answer - it depends with more words attached

What follows is a general guideline of what I do for hypotension to help with some decision making when you are faced with a hypotensive septic patient but this should not be treated as a protocol that fits all cases

Hypotension

If BP <90 → give 1/4 shock bolus (20 ml/kg) over 15 minutes

• repeat up to four times if improvement in pressure

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If not responding to fluid bolus, or if 4 boluses have been given → add norepinephrine

• start at 1 mcg/kg/min; increase by 0.5 mcg/kg/min as needed for hypotension to a max of 2 mcg/kg/min
• if pressors are initiated, blood pressure should be monitored hourly and ideally a continuous non-invasive blood pressure monitoring system should be hooked up
• In a perfect world, would be monitored with arterial blood pressure

Hypotension

Weaning norepinephrine

• IF BP above 90 mmHg; decrease NOREPINEPHRINE by 0.5 mcg/kg/min
• After changing CRI rate, check BP 5-10 minutes post-change to ensure BP is not dropping significantly.
• Important to wean norepinephrine if hypERtension is noted

Hypotension

Tips with norepinephrine/epinephrine

• Expensive - pull up small volumes at a time
• consider using epinephrine in giant animals → will blow through hospital stock
• Best when mixed with D5W
• can be mixed with other things just theoretically less effective
• Ideally not mixed with other injectable medications
• nicest to go through a separate catheter/central line
• VERY short acting
• Needs to be a CRI, cannot have them disconnected for really any length of time, need to have the next CRI made so there is not a lag when changing syringe over
• Blood pressure changes can be quick - should be checking BPs frequently, particularly when changing dosages up or down

Hypoglycemia

VERY important to check blood glucose in all of your septic patients

• Check it preop, check it immediately post-op, check it routinely after surgery (frequency will vary by patient, but should be minimum q12h - probably more frequently than that)
• Check it anytime you have a change in patient demeanor, blood pressure, etc
• Sometimes that is all that has changed and you will make a massive improvement with minimal intervention

Hyperglycemia

This is a frequent finding in critically ill patients

• May be associated with increased morbidity and mortality
• Studies have shown correction improves outcomes
• But… aggressive insulin therapy may predispose to complications such as hypoglycemia
• Recentish large randomized control in people changed recommendations due to increased mortality

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Summary: Watch for hyperglycemia - likely not going to treat it, but don’t want to over supplement and compound the problem

Hypoalbuminemia

What does it do?

• In charge of 80% of plasma colloid osmotic pressure (COP)
• Transport of drugs and endogenous substances
• Maintenance of coagulation factor and platelet function
• Free radical scavenging in inflammatory states

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Hypoalbuminemia

Why does it drop in critically ill patients?

• Gastrointestinal loss
• Lack of nutritional intake
• Lack of production
• Hepatic dysfunction
• Kidney disease
• Inflammatory of septic processes (negative acute phase protein)
• Vasculitis

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Hypoalbuminemia

What happens to our patients when it drops?

• Circulating volume depletion leading to shock
• Tissue edema and hypoperfusion
• Organ dysfunction

Overall this combination leads to increased morbidity and mortality in critically ill patients

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Hypoalbuminemia

Has been linked to worse outcomes in multiple studies

• Increased healing times following GI surgery
• Increased rates of perioperative complications including dehiscence following gastrointestinal surgery
• Worse survival rates in septic peritonitis patients
• Linked to development of thrombotic events
• Linked to development of acute respiratory distress syndrome

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Hypoalbuminemia

Risks of human serum albumin:

• 80% homology between human and canine albumin
• 8-10% of canine patients will have naturally occurring alloantibodies to HSA
• Can lead to acute and delayed hypersensitivity reactions - may lead to vasculitis, AKI and death
• Can really only give it one time as they will develop antibodies after administration

Hypoalbuminemia

With the increased availability of canine serum albumin, administration to our patients has increased in frequency

Calculating CSA dose theoretically:

• Formula A: Albumin dose of 0.45 g/kg will increase serum albumin concentration by 5 g/L (0.5 g/dL)
• Formula B: Albumin dose (in g) = 10 × (Albumin desired g/dL –Albumin patient g/dL) × body weight (kg) × 0.3 (or 1.5 g/kg for each 5 g/L[0.5 g/dL] increase])

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Hypoalbuminemia

Reactions to watch for:

• Occurred in 20% of transfusion events
• Febrile nonhemolytic transfusion reaction
• Transfusion associated dyspnea
• Most commonly severe in nature
• Not able to determine that it was from the transfusion definitively
• Regurgitation

Dose: 0.56 g/kg increased albumin a median of 0.3 g/dL

Hypoalbuminemia

Reactions to watch for:

• Febrile nonhemolytic transfusion reaction - responded to diphenhydramine
• Transfusion associated dyspnea
• Death occurred during transfusion in some patients
• These patients were critically ill when they started the albumin (was a hail mary) so suspected not to be related to transfusion

16% albumin transfusions produced the greatest increase in serum albumin

Predicted dose increase from study: 0.23 g/dL per each 1 g/kg albumin administered

CIRCI

Critical illness related corticosteroid insufficiency

• Functional hypothalamic-pituitary-adrenal axis insufficiency
• Clinical syndrome
• Systemic hypotension refractory to fluids and vasopressors
• Associated with increased mortality
• Treatment
• Low-dose (i.e. physiologic) glucocorticoid administration in patients displaying the above features
• Scientifically jury is out → clinically “magic steroids”, also in these cases we are fighting against the worst outcome

Acute Kidney Injury

AKI was diagnosed in 40% of patients with septic peritonitis

• More common for dogs to have it at presentation
• Things that made having AKI at presentation more likely
• Increased baseline respiratory rate
• Decreased systolic blood pressure
• Increased BCS
• Mortality rate of 20%
• Decreased odds of survival for dogs with AKI (OR 0.2)

Other values to remember when in ICU

Electrolytes

Lactate

Organ function - azotemia, liver enzymes, bilirubin

PCV/TS

Hydration status

Auscultation

Ins and Outs

Weights

SpO2

Oxygen therapy

Nutrition

Gastric residual volumes

Gut sounds

Heart rate and rhythm

Pain

JP drain

Nursing Care (flip sides, lube eyes, keep clean, ucath?, central line?, nasal cannula?, IV CATHETER)

Tender Loving Care

Compassion

Prognosis for Sepsis

What we used to always say: “50/50 mortality”

What the literature says now:

• Marshall et al JVECC 2019 “Surgically treated septic peritonitis” - 87% survival
• Stastny et al JVECC 2021 “Surgically treated sepsis” - 70% survival
• Summers et al JVECC 2020 “Septic shock” - 81% mortality rate

Recurrence

• Fink et al JVECC 2020 - 10% recurrence, more likely with lower albumin and higher PCV preoperatively

Prognosis for Sepsis

What about cats?

• Anderson et al JSAP 2021
• Overall survival of 66%
• If survived beyond 1 day post-op survival improved to 87.5%
• Scotti et al JVECC 2019
• Overall survival 70%
• Cats that received appropriate antimicrobial therapy were 4.4 times more likely to survive

References

1. Johnston, Tobias. Veterinary Surgery: Small Animal, 2nd ed. St Louis: Elsevier 2018.
2. Breton. “Ischemia and Reperfusion Injury: When Cells Almost Die.” VetFolio. Veterinary Technician. 2019. https://www.vetfolio.com/learn/article/ischemia-and-reperfusion-injury-when-cells-almost-die
3. Kouti et al. “Short-Bowel Syndrome in Dogs and Cats.” VetFolio. Compendium. 2006 https://www.vetfolio.com/learn/article/short-bowel-syndrome-in-dogs-and-cats
4. Ward BC, Panitch A. Abdominal adhesions: current and novel therapies. J Surg Res. 2011 Jan;165(1):91-111. doi: 10.1016/j.jss.2009.09.015. Epub 2009 Oct 2. PMID: 20036389.
5. Malone E, Ensink J, Turner T, et al. Intravenous continuous infusion of lidocaine for treatment of equine ileus. Vet Surg. 2006;35(1):60-66
6. Torfs S, Delesalle C, Dewulf J, Devisscher L, Deprez P. Risk factors for equine postoperative ileus and effectiveness of prophylactic lidocaine. J Vet Intern Med. 2009;23(3):606-611
7. Brianceau P, Chevalier H, Karas A, et al. Intravenous lidocaine and small-intestinal size, abdominal fluid, and outcome after colic surgery in horses. J Vet Intern Med. 2002;16(6):736-741
8. Johnson RA, Kierski KR, Jones BG. Evaluation of gastric emptying time, gastrointestinal transit time, sedation score, and nausea score associated with intravenous constant rate infusion of lidocaine hydrochloride in clinically normal dogs. Am J Vet Res. 2017;78(5):550-557
9. Evans, Laura1 et al.. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2021. Critical Care Medicine 49(11):p e1063-e1143, November 2021. | DOI: 10.1097/CCM.0000000000005337
10. Murphy KM, Rishniw M, Silverstein DC. Use of vasopressors for treatment of vasodilatory hypotension in dogs and cats by Diplomates of the American College of Veterinary Emergency and Critical Care. J Vet Emerg Crit Care. 2022;32:714-722.
11. Marshall H, Sinnott-Stutzman V, EwingP, Bracker K, Kalis R, Khorzad R. Effect of peritoneal lavage on bacterial isolates in 40 dogs with confirmed septic peritonitis. JVet Emerg Crit Care. 2019;29:635–642
12. Stastny T, Koenigshof AM, Brado GE,Chan EK, Levy NA Retrospective evaluation of the prognostic utility of quick sequential organ failure assessment scores in dogs with surgically treated sepsis (2011-2018): 204 cases. JVet Emerg Crit Care. 2022;32:68–74.
13. Summers AM, Vezzi N, Gravelyn T,Culler C, Guillaumin J. Clinical features and outcome of septic shock in dogs: 37 cases (2008-2015). J Vet Emerg Crit Care.2021;31:360–370.
14. Anderson, T., Beever, L., Hall, J., Moores, A., Llanos, C., Adams, R., Meakin, L., Coppola, M., Bowlt-Blacklock, K., Holmes, M.A. and Barnes, D. (2021), Outcome following surgery to treat septic peritonitis in 95 cats in the United Kingdom. J Small Anim Pract, 62: 744-749.
15. Scotti KM, Koenigshof A, Sri-JayanthaLSH, et al. Prognostic indicators in cats with septic peritonitis (2002–2015): 83 cases. J Vet Emerg Crit Care. 2019;1–6.
16. Fink O, Buysse A, Drobatz K, Bentley A. Identification of risk factors for recurrent secondary septic peritonitis following initial surgical treatment of secondary septic peritonitis in dogs. J Vet Emerg Crit Care. 2020;1–8