Specific ICU Population

Andrew Stephen, MD

The importance of communication with the primary team and surgeon is critical

These subspecialty patients often have management strategies that are unfamiliar to general surgery residents.  Also, the SICU attending may not be versed in each of the particulars of the primary surgeon’s management plan.  The primary surgeon or primary team would rather be asked a seemingly simple question rather than be surprised by a change in management when they come to the SICU.  Some examples:

            -removing a chest tube in an esophagectomy patient

-advancing diet on a HIPEC patient to promote enhanced recovery of bowel function

-extubating and sending a spine patient out of the SICU who was due to return to the OR the next day for the second portion of the operative course 

It is important to notify the primary surgeon or team of the following:

  •             -plans to send a patient out of the SICU
  •             -a change in code status
  •             -a planned family meeting about goals of care
  •             -a declining patient, i.e. new vasopressor requirement, intubation, CVA, MI
  •             -concern that a patient needs to be taken back to the OR

Aortic dissection/aortic syndromes

Aortic syndromes is the accepted term to describe the range of pathologies that relate to weakening or damage to the aortic wall and include the following entities:

            -ulcer

            -dissection

            -intramural hematoma

Dissections can be classified by the Stanford, Debakey or Svensson systems.  Most commonly we use the Stanford system-A= starts proximal to the left subclavian artery and can extend distally B= starts distal to the left subclavian artery. Most commonly we will be managing Type B dissections in the SICU.  Care involves first adequate pain control as untreated dissection related pain can lead to worsening hypertension and in turn extension of the dissection.  Untreated pain essentially creates a cycle.  Then hypertension and wall stress should be treated with a combination of beta blockers, ACE-inhibitors, and possibly nicardipine or nitroprusside infusions. 

While mostly are concerned with MAP for resuscitation goals with septic shock and hemorrhage, SBP matters with aortic syndromes as it is a marker of the wall stress on the aorta.  As is heart rate.  Set goals with the primary team but generally SBP should be less than 120 mm and heart rate less than 80. 

-Wall stress is most related to the force(dP/dt), frequency of LV contraction and blood pressure

Click here to go to the European Society of Cardiology, Japanese, ACC/AHA guidelines for medication management.

AAA Postoperative care

The three most common major complications of a AAA that are more likely to occur with an emergent, leaking or ruptured presentation:

  •             -MI
  •             -AKI leading to need for RRT
  •             -colonic ischemia

All can occur after elective repair too though, endovascular or open. 

Each of these major complications is more likely to occur with an emergency AAA repair as patients are usually more aged and are undergoing significantly greater physiologic stress.  The common pathway with each is hemorrhagic shock or hypotension relative to the patient’s baseline leading to inadequate organ perfusion and oxygen delivery(coronaries, renals, left sided and distal colonic circulation). 

MI- These can occur from the moment the patient presents and generally the risk does not subside for at least 72 hours postop.  Previous teaching was that MI risk was highest at 72 hours postop and was due to fluid shifts.  Some series have debunked this however.  Risk starts the moment the stress starts.  Most of these MIs will be demand Type 2’s so refer to that section of this handbook to review management. 

AKI- This is very much related to hemodynamics and blood loss.  Even a few minutes of hypotension in the ER, OR or postoperatively can lead to AKI, especially in the elderly that have baseline CV disease.  It is important to review the ER course and anesthesia record to determine if there were hypotensive episodes.  A SICU patient that appears euvolemic and well resuscitated may not make much urine if there was already a hypotensive insult earlier leading to ATN.  Along those lines creatinine is not a marker of current volume status. 

Colonic ischemia- Patients that have an emergency AAA repair should have a sigmoidoscopy done within 24 hours.  This is usually done by one of the colorectal surgeons.  If the patient is hemodynamically stable, without signs of significant fluid sequestration, and has pale mucosa it may be possible to continue ICU management and repeat the sigmoidoscopy at an interval.  Others may need return to the OR for resection.  Some papers grade colonic ischemia I-III.  Predictors:

  • -SBP at admission < 90 mm Hg*
  • -hypotension of more than 30 minutes’ duration*
  • -temperature less than 35C*
  • -pH < 7.3*
  • -Postop boluses of > 5 L or more*
  • -PRBCs 6 units or more*
  • -a bloody BM
  • -an early loose nonbloody BM

*From a classic paper from Journal of Vascular Surgery 1999: https://www.ncbi.nlm.nih.gov/pubmed/9882788

HIPEC

Generally the risks of hyperthermic intraperitoneal chemotherapy(HIPEC) and cytoreductive surgery are similar to that of other major abdominal operations.  Operative time, number of anastomoses, and degree of peritonectomy are key factors associated with morbidity.  HIPEC does though cause an additional level of cytokine release and  fluid sequestration due to capillary leak from inflammation related to the heated chemotherapy.  Peritoneal debulking also causes raw surface fluid losses.  

A 5 year review of 51 HIPEC patients admitted to the ICU at Mount Sinai found the following:

            -median fluid required in first 48 h was 6 L (range 1-14 L)

-25% developed postoperative hypotension with seven requiring vasopressor support

-5(10%) developed anastomotic leaks

-mechanical ventilation > 48 h in 18 patients(33%) – possibly acute lung injury or noncardiogenic pulmonary edema

-TPN in 9(18%)

Additional complications:

  •             -AKI
  •             -coagulopathy from dilution – 55% with INR > 1.5 postoperatively
  •             -VTE – 5-10% in the literature
  •             -arrhythmias
  •             -ileus

2017 Mount Sinai review: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5415851/

Major spine surgery

These are often long operations with large volumes of blood loss.  There is a tendency to underestimate how invasive and stressful these operations are for patients.  The patients are often older and have significant baseline comorbidities.  It is again important to review the anesthesia record for the following:

  •             -operative duration
  • -episodes of hypotension
  •             -pressor requirement during the operation
  •             -fluids and blood products intraop
  •             -estimated blood loss
  •             -urine output

In 2008 a group from the University of Washington created a spine surgery invasiveness index(SSII).  Their index was based on the number of vertebrae decompressed, fused, or instrumented and was associated with blood loss and surgery duration.

SSII is also one of the strongest risk factors for surgical site infection, even after adjusting for medical comorbidities, age, and other known risk factors in another review. 

AKI in one series occurred in 4% but this is an issue that needs to be studied more as likely the incidence is higher in the elderly.  Baseline HTN was found to be a risk factor. 

A 5 year review of AKI after spine surgery: https://www.ncbi.nlm.nih.gov/pubmed/24654744