Line complications

When do you start pressors?

Old school teaching: volume to fill the tank (3rd space losses, constriction might impair circulation, need line). However, digit necrosis etc.

New school: venodilation and arterial dilation also contribute. Also sometimes cardiomyopathy. Pressors address these components, instead of just hypovol. Additionally, duration of inadequate MAP correlates w risk of renal failure (https://pubmed.ncbi.nlm.nih.gov/22158679/)

Censer trial: blinded RCT of 0.05 mcg/kg/min x 24h through PIV vs placebo & std of care (surviving sepsis) in suspected septic shock. Primary outcome = 65+ MAP & 0.5L/kg/hr UOP or 10% decrease in lactate in 6h: 76.1 NE vs 48.4 Placebo. Nonstatstically significant decrease in mortality. https://pubmed.ncbi.nlm.nih.gov/30704260/

Peripheral Pressors

1st question: do you even need a central line?

RCT: ITT of 135 & 128 pts randomized peripheral vs central. Most frequent PIV complication = couldn't start. Allowed 33.3+ mcg/min NE. http://www.ncbi.nlm.nih.gov/pubmed/23782969

Est extravasation rate: 3.4% rate of extravasation, but no true adverse events in about 1500 patients. (Tian 2019, http://www.ncbi.nlm.nih.gov/pubmed/31698544)

1 Large cohort including 734 ICU patients who received 18g or 20g (mean duration 49+/- 22 hours, max 72h), 2% had extravasation , none had lasting damage, 13% eventually needed central line. (https://emcrit.org/wp-content/uploads/2015/07/Mayo-Peripheral-Pressors.pdf)

Better: 18g or 20g in AC fossa or proximal (less risk, and less risk of damage), protocoled extremity check (e.g. q2h), flushes and draws, ideally wasn't a b**** to place (e.g. deep US guided PIV = harder to monitor extrav). Don't have BP cough on that arm.

If extravasation (Loubani et al 2015 PMID: 25669592 found average time to extravasation = 35h): administer SQ phentolamine (0.1-0.2 mg/kg up to 10, alpha-1 antagonist) and possibly nitroglycerin paste. Also, 1st move if BP drops = check arm.

Agent: epinephrine won't cause tissue necrosis. NE = phentolamine to reverse. Vasopressin = no reversal, so probably avoid.

Midline:

shorter than PICC (terminates before the shoulder)

Great overview: https://emcrit.org/emcrit/midlines-1/

Benefit: long enough they don't dislodge, and that ideally the site of infusion is far enough from the puncture site to avoid extravasation there.

Infusion rate

Cordis 8.5F > Shiley > 16g PIV > 7F CVC > 18g PIV >... > 24g PIV > 18g PICC

Types of Central Lines and their complications

Arterial puncture (4.2 - 9.3%), most common in femoral, least common in Subclavian. Reduced with ultrasound placement. If occurs, non-occlusive pressure for 15 minutes.

Central vein stenosis reported to occur in 20+%, but it's usually asymptomatic so the true frequency is not known. L sided higher risk than R sided.

Fibrin sheath formation (particularly when the catheter remains in place for more than 1 week)

Overall comparison: NEJM 2015 https://www.nejm.org/doi/10.1056/NEJMoa1500964

Subclavian

Pros: best tolerated CVC

Cons: cannot compress the vein (thus coagulopathy is a complication), risk of pneumothorax (~1-2%), higher risk of UE Catheter-DVT

Internal Jugular

0.1 percent pneumothorax. Easiest to supervise.

Femoral

Pro: can be inserted in a patient in extremis.

Con: highest risk of infection of CVCs (recommend to change to UE site), higher rate of thrombosis (https://pubmed.ncbi.nlm.nih.gov/26398070/)

PICC

Pros: 1.1% infection rate (slightly lower than 2.7% from other CVCs. 1.6% for tunneled cath)

Cons: contraindicated in patients at risk for needing dialysis (stenosis, DVT). Probably same risk of infection (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4613416/). Higher risk of UE Catheter-DVT (5-15%, https://pubmed.ncbi.nlm.nih.gov/23697825/ 3x higher when compared with CVC), esp if lumen size approaches vein size.

Malpositioning

Probably not that much of a clinical problem (at least in folks receiving low flow lines) - https://pubmed.ncbi.nlm.nih.gov/18326129/ - 1619 central lines. 9% subclavians and 1.4% R IJ's malpositioned. Non associated with complications.

Intraosseus

Pro: reliable, inserted in code. Con: can cause compartment syndrome if dislodged.