Andrew Stephen, MD
General approach
Comorbidities should be determined for all new patients admitted to the TICU and SICU. Cardiopulmonary comorbidities are especially important as they are among the most challenging to manage and most likely to lead to ICU mortality and other organ system complications. Elderly patients with greater than 20% TBSA burns do not die directly from the burn injuries but rather from cardiopulmonary decompensation from lack of reserve or exacerbation of comorbidities. On rounds, comorbidities and associated home medications should be discussed when presenting the CV and pulmonary systems.
Hypertension
According to recent CDC data 75 million American adults have hypertension which is 1/3 of the adult population. The latest guidelines for outpatient management and blood pressure goals can be found at the ACC or AAFP sites. A typical outpatient regimen includes first line agents such as thiazide diuretics, calcium channel blockers, and ACE-I/ARB. None of these agents should be restarted in a bleeding or septic patient. They can only exacerbate hemodynamics and offer no cardiovascular protection in such a short term setting. The goal of antihypertensive regimens is to limit progression of cardiovascular disease(atherosclerosis, CVA, CAD, CKD) over months and years.
A reasonable approach is to add the agents back one at a time as hemodynamics allow and to generally take a permissive approach as it is acceptable for an injured or anxious patient to have an SBP or DBP above the outpatient guidelines for periods of time.
Commonly patients present who have fallen and the home HTN regimen seems overzealous. We should be discussing the regimen with the patient’s PCP and utilizing the geriatric medicine service to make decisions about what the patient’s regimen will be on discharge.
Coronary artery disease/Peripheral vascular disease
We should be aware of the revascularization interventions(stents, bypasses etc) that have been done, what the patient’s level of CV and general function is(i.e. EF if it is known, exercise tolerance), and their home medications. This should be presented on rounds.
Most common medication regimens include a beta blocker, aspirin, and statin. Occasionally patients who have been recently revascularized will be on clopidogrel or prasugrel. Antiplatelet agents should not be restarted without discussion on rounds. Generally noncardiac surgery should be delayed 6 weeks for patients with a bare metal stent and one year for those with a drug eluting stent(DES). However, risk of major adverse cardiac events(MACEs) have been reviewed in large numbers(>20K) of patients with cardiac stents. MACEs were associated with emergency surgery and advanced cardiac disease but not stent type or timing of surgery beyond 6 months after stent implantation.
Risk of major adverse cardiac events following noncardiac surgery in patients with coronary stents. Hawn MT, Graham LA, Richman JS, Itani KM, Henderson WG, Maddox TM. JAMA. 2013 Oct 9;310(14):1462-72.
Patients on beta blockers at home should have these restarted post-injury/postoperatively as hemodynamics allow. Patients not on beta blockers previously but with multiple Revised Cardiac Risk Index(RCRI) factors may benefit from starting beta blocker with goal heart rate around 80 or less.
- RCRI factors:
- CHF
- CAD/PAD
- CKD
- Prior CVA
- DM
The POISE trial from 2008 showed lower MI rates but higher mortality and stroke rates in patients undergoing noncardiac surgery. A 2018 Cochrane database study in non-cardiac surgery, showed an association of beta-blockers with increased all-cause mortality. Data from low risk of bias trials further suggests an increase in stroke rate. More evidence is needed before a definitive conclusion can be drawn. This is the bulk of data that we extrapolate to the SICU setting but it must be stressed that beta blockers are probably more harmful than beneficial if they lead to any hypotension.
-Consider reducing the dose of beta blocker from their home dose by using small but frequent IV dosing initially – 2.5-5 mg q4 hours
2018 Cochrane review: Perioperative beta-blockers for preventing surgery-related mortality and morbidity. Blessberger H, Kammler J, Domanovits H, Schlager O, Wildner B, Azar D, Schillinger M, Wiesbauer F, Steinwender C. Cochrane Database Syst Rev. 2018 Mar 13;3:CD004476.
COPD
COPD patients are at increased risk of developing major complications including respiratory failure, pneumonia, and MI after surgery, with critical illness and likely after injury. Age greater than 70 and COPD are associated with even further increased rates of pulmonary complications. These patients are commonly in our ICU with rib fractures or major abdominal or thoracic surgery. Risk of complications tends to correlate with the severity of the disease and so efforts should be made to find out their pre-ICU COPD severity.
-Moderate risk – FEV1 50-80%
-Severe risk – FEV1 < 50%
-Highest risk – COPD with progression to pulmonary artery hypertension
Key management principles:
-Extubating COPD patients to BiPAP is a well proven technique and is known to reduce risk of extubation failure
-A trial of 4 hours of BiPAP is reasonable to possibly stave off need for intubation. Then the patient’s general appearance, respiratory rate and possibly an ABG should be reassessed.
-Start all home meds-beta agonists, muscarinic antagonists, inhaled corticosteroids
-Mobilize the patient
See the following blog entry for a concise review of how to use BiPAP and high flow nasal cannula. http://emcrit.org/pulmcrit/bipap-hfnc/
Other comorbidities to consider
Aortic stenosis-need to review ECHO, valve area, gradient
OSA Pulmonary HTN-all patients followed by Dr. Klinger, Dr. Ventetuolo, Dr. Mullin should have a pulmonary consult directed to them.