Anesthesia/Emergency

Stabilization for Septic Patients - a Case-Based Presentation

Surviving Sepsis Guidelines

Throughout the lecture I will go over some key points from the guidelines - This is from human medicine, but is still important!!!!

Urgent Care Visit #1 - Day 1

Signalment and history

2 year old, male neutered, Belgian Malinois

Current history:

• Anorexia of 24 hours, but did eat a small amount of chicken when enticed into the car. Is not defecating.
• Is still drinking water, urinating normally
• Vomited 4-6 times one week prior, on and off vomiting since, vomited grass two days prior

Previous medical history

Previous foreign body obstruction with abdominal exploration and surgical intervention - Approximately a year prior

• Ate a whole chuck-it ball

Otherwise unremarkable previous history

Vitals and Exam at Urgent Care visit #1

Temp - Not listed

HR - 120

RR - 40

MM - pink

PE - unremarkable

Radiographs at Urgent Care visit #1

Radiographs at Urgent Care visit #1

Radiographs at Urgent Care visit #1

Hemoclips in abdomen from previous surgery

Normal peritoneal detail

Gastric lumen is moderately filled with gas and volume of soft tissue ingesta that also contains many tiny mineral specks and a region of more uniform mineral opacity.

In the laterals, cranial ventrally just cranial or dorsal to the splenic tail, there is a bowel segment that is mildly dilated with fluid opacity and tiny gas bubbles; this is not defined in the VD. Other small intestines contain variable gas or are soft tissue/fluid opaque. Several of the other gas-filled are upper normal diameter; others are small diameter.

Radiographs at Urgent Care visit #1

CONCLUSIONS:

1. Mineral opacities in the gastric lumen are most consistent with dietary

indiscretion and less likely from normal food or oral medications. Based on the

gas in the intestines, gastric outflow obstruction is unlikely.

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2. No clearly defined small intestinal foreign body or clearly defined obstructed

pattern is evident. The described cranial ventral bowel segment that is mildly

dilated, can be mildly dilated due to either severe enteritis or partial obstruction.

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3. Otherwise normal abdomen.

Treatment & Recommendations visit #1

Sedated for radiographs - dexmedetomidine and butorphanol IM

Received Cerenia 1 mg/kg IV while under

Received 500 mls of LRS SQ

Recommended bland diet

No go home medications at the time

Strict recommendation of return the following day if not eating or is vomiting for abdominal ultrasound

Learning Points

Learning Points from Visit #1

Communication with client about GI cases

• Other possible clinical signs that are concerning
• Interpret the radiographs yourself as well, you may have a different opinion to the radiologist
• With radiographs as concerning as those should set a recheck no matter response to therapy unless completely normal the next day

Bloodwork would have been nice at this visit, but may not have changed the plan

Temperature - an aggressive dog so not getting that awake, but should grab one once sedated

All of this is caveated with the point that the above may have occurred/been discussed with the client in person without being written down

Don’t use butorphanol in your sedation plan for radiographs if potentially will be doing surgery after

Urgent Care Visit #2 - Day 5

History - Urgent Care Visit #2

• Approximately 2 weeks ago, ingested large quantity of grass clippings from yard
• Last vomited Sunday (1 week prior); no vomiting since
• Dietary history: chicken and rice only since last visit
• Stool character: liquid/loose stools early in week, more solid by Friday; no defecation yesterday; explosive, gas filled stool with some liquid ~2-3 hours prior to presentation today
• This morning: eating well, drinking, active, walking without issue
• 30-60 min prior to presentation: acute onset of lethargy, slow movement, hiding behavior, reluctance to move
• Client reports grass/clay-like material visible in stools over the past week
• No known bee sting or bug bite; no further grass clipping access
• No history of chronic GI issues; GI problems occur only with abnormal ingestion per client

Vitals and Exam at Urgent Care visit #2

Temp - 102.9 (post sedation and rads)

HR - 114 pre 90 post sedation

RR - 24

MM - light pink

PE - unremarkable

Bloodwork - Urgent Care Visit #2

CBC - HCT 53.9%, WBC 17.73k, Neut 15.06k (H), Eos 0.01k (L), PLT 280k

Chem - Entirely unremarkable

Resting cortisol - 17.44 (WNL)

Radiographs - Urgent Care Visit #2

Radiographs - Urgent Care Visit #2

Radiographs - Urgent Care Visit #2

Peritoneal contrast and serosal detail are within normal limits.

The stomach remains distended with fluid and gas and there is radiopaque material in the ventral part of the stomach.

There is a dilated portion of bowel in the central abdomen that extends all the way to the caudal abdomen best appreciated on the lateral views and this segment would be markedly dilated for small intestine but could represent the colon. This dilated segment is filled with soft tissue opaque contents as well as amorphous and granular metallic opacities similar to what is seen in the stomach. There are other segments that would be abnormally dilated for small intestine also and are gas-filled. The colon is not well differentiated from the small intestinal segments however the distal-most portion of the colon at the level of the pelvic canal is gas-filled.

Radiographs - Urgent Care Visit #2

Conclusions:

1. The markedly dilated bowel segment that is filled with soft tissue opaque material and granular metallic opaque material is concerning for an abnormally dilated small intestinal segment associated with a mechanical obstruction however this could represent a portion of the colon. A positive or double contrast colonogram could be performed to help identify the colon and differentiate from the small intestinal segments versus an abdominal ultrasound to rule out a small intestinal mechanical obstruction and if the small intestine is confirmed, emergency surgery would be recommended.

2. There is some granular mineral opaque material within the lumen of the stomach also and if surgery is performed for #1 emptying the stomach should be considered to remove all of the foreign material though the material in the stomach may continue to pass spontaneously on its own based on its granular appearance.

3. Undersized cardiac silhouette and attenuated cardiopulmonary vasculature supports hypovolemia and should be correlated with the patient's PCV and blood pressure.

4. Unchanged metallic hemoclips in the abdomen.

5. Unchanged intervertebral disc space narrowing and spondylosis deformans.

FAST scan + BP - Urgent Care Visit #2

Free fluid noted

In house cytologic examination

• TNTC WBCs, rods noted with some cocci

BP at 730pm - Average of 3 readings (systolic)

• 99/79, 118/89(99), 97/66 (76)
• Size 4 cuff, right rear foot, patient in left lateral

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Treatment & Recommendations visit #2

Sedated for radiographs - dexmedetomidine and butorphanol IM

Received Ondansetron 0.7 mg/kg IV while under

Received 1300 mls of LRS IV

Unasyn 30 mg/kg IV once

Transfer for further therapy - i.e. stabilization and surgery

Learning Points

Learning Points from Visit #2

Repeating FAST scan after rehydration is important - not listed that it occurred in that order but seems to have from the record

Lactate would have been a nice value to have at this point as well

Should have started Baytril as well as the Unasyn

Would increase dose of Unasyn to 50 mg/kg IV for septic abdomens

Should have pain management - septic abdomen is EXTREMELY painful process

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

Abdominal fluid

Abdominal fluid

Abdominal fluid

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

Presentation to GAVC

Vitals and Exam at GAVC

Vitals and Exam at GAVC

Treatments

Treatments

Learning Points

Additional Treatments that should be instituted

Pain meds should have been started right when antibiotics were given

• Septic abdomens are extremely uncomfortable
• Pain management that I would use:
• If need medication to get catheter - IM methadone
• Fentanyl bolus followed by fentanyl CRI 3-4 mcg/kg/hr
• Lidocaine bolus 1 mg/kg followed by 50 mcg/kg/min

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

Initial Diagnostics at GAVC

Initial Diagnostics - 12am

POCUS - abdominal effusion noted

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Initial BP - unable to read

• 1L fluid bolus over 20-30 mins. Still no readable pressure
• Additional 30 ml/kg fluid bolus IV. Still no readable pressure

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CBC - Severe hemoconcentration HCT 64%, Neutropenia 2.7k

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Chemistry - TP 3.4, Albumin 1.4 g/dL, mild azotemia (BUN 28), Creat 1.6, SDMA 41, Hyperphosphatemia 9.6, Hypokalemia 3.3

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Lactate 9.27

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UA unremarkable

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4Dx - Negative

Learning Points

What else should we have done?

Coagulation profile

• Determine need for plasma transfusion prior to surgical intervention

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Telemetry

• Is noted on vetradar but interpretation of telemetry is not noted on treatment sheet

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)

Blood pressure not responding to fluids

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

Repeat Diagnostics After Initial Stabilization Attempt

Repeat Diagnostics - 2am

TP 2.5

ALB 1.0

Glob 1.6

Lactate 9.30

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Learning point:

• Should recheck BG and PCV at this point as well

What we did next after repeat diagnostics

Clinician noted concerns for DIC/ severely worsening condition and relayed gravity of situation to owner including potentially poor prognosis - owner visit (reportedly long) and then elected to continue care

Plasma transfusion given as per:

Plasma Transfusion in the Dog, Western Veterinary Conference 2004

K. Jane Wardrop, DVM, MS, DACVP, College of Veterinary Medicine, Washington State University, Pullman, WA, USA

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- 10-15 ml of plasma/kg are given to produce a mild increase in albumin, and the transfusion is repeated as needed.

- drip rate of 5-10 ml/kg/hour can be used.

Learning Points

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

The Next Morning - Day 6

Update post-transfusion

Patient tolerated plasma transfusion well, BP reading after administration - 70-72 at 6am

Owner came for visit again in the am ~7-8 am

Discussion with owner: Explained we've seen some improvement overnight right after plasma but unfortunately BP back down again

Team is working on setting up albumin transfusion at this time.

Discussed increased finances for these additional steps as this is a lot of intense care for Kaiser at this time. Owner still wish to proceed with intervention.

Repeat Diagnostics - 7am

Peripheral:

• BG - 16
• Lactate - 9.3

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Abdominal:

• 16
• >12

Learning Points

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

Late Morning/Afternoon - Day 6

Repeat Diagnostics - 11am

CBC: HCT 58.9%, Neut 0.08, Lymph 6.57, Mono 5.44, PLT 242

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Spec 3 - Glucose 69, Alb 1.7, Lactate 4.7

Repeated Blood Pressures 12pm-5pm

12:30 - 44-46

2 - 28-30

3 - 38

3:30 - 56-58 (different cuff size)

4 - 58

4:10 - 62-64

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What we did next after repeat diagnostics

12pm Albumin transfusion underway, however blood pressure continues to remain low. Added norepinephrine therapy to help aid in hypotension.

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3:30pm Kaiser's albumin has improved post albumin transfusion (1.7) and his lactate has also improved with fluid resuscitation, however his blood pressure remains quite low. Added dobutamine CRI. After discussion of prognosis owner elects to proceed with continued care and surgery

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Pressure mildly improved to ~50-60mmHg elect to proceed to surgery at this point

Learning Points

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

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Also treat any other reasons for hypotension

• Hypoglycemia
• Anemia
• Low oncotic pressure - i.e. Hypoalbuminemia
• Management of underlying disease process

Hypotension - Norepinephrine/Epinephrine

Weaning norepinephrine

• IF BP above 90 mmHg; decrease NOREPINEPHRINE by 0.25 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 - Norepinephrine/Epinephrine

Tips with norepinephrine/epinephrine

• Expensive - pull up small volumes at a time
• consider using epinephrine in giant animals → will blow through hospital stock
• Dose for epinephrine is 1/10th of norepinephrine
• I.e. going to range from 0.05-0.2 mcg/kg/min

Hypotension - Norepinephrine/Epinephrine

Tips with norepinephrine/epinephrine

• 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

Hypotension - Secondary Pressors

Additional Pressors:

Dopamine

Vasopressin

Dobutamine

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

Late Afternoon/Evening Day 6 - Anesthesia and Surgery

References

References are listed throughout the presentation