Ancillary testing (the idea of “confirmatory” testing is not optimal) is not a replacement for the clinical exam, and any confounding factors to the exam that can be corrected (for example, by waiting longer for temperature or drugs to normalize) must be—this cannot be bypassed by skipping to an ancillary test.
Drug levels that may confound the exam should be measured whenever possible, and when there is doubt or question, the monitoring period should be increased, even if this delays the time until declaration of death.
Drug use that results in clear anoxic brain injury can be compatible with declaring brain death based on the later, even if the exact nature of the former is not established.
Temperature must be above 36c during the exam, and above 35.5c for the last 24 hours.
Brain death testing in the setting of anoxia after cardiac arrest should be delayed for at least 24 hours after arrest.
A minimum of one clinical exam should be performed in adults, but one or more additional exams may be useful. A minimum of two are recommended in pediatrics. Local protocol should be followed. No specific interval of waiting between exams is recommended in adults (the important “waiting” should occur prior to performing the first exam), although a 12-hour minimum interval in pediatrics is recommended, mainly for historical reasons.
Advanced practice providers may perform the exam if appropriately trained and credentialed.
EEG is not recommended as an ancillary test, mainly because it primarily gives information on cortical electrical activity, which adds relatively little to a confounded clinical examination. Bloodflow tests like nuclear scintigraphy say something about perfusion to the brain (particularly when a lateral view is used), which is useful.
Brain death testing must be done 100% right, 100% of the time. All providers should follow hospital policy and state law, not just guidelines when there is conflict. Ideally the two will match, but this can take time to catch up when new guidelines are released.
We learn about liver transplant with Dr. Meera Gupta, transplant surgeon at the University of Kentucky Healthcare Transplant Center, and surgical director of the Kidney and Pancreas Transplant Program. We discuss eligibility, triage, the peri-operative course, and important post-op complications.
Liver transplant eligibility is based on need, not time on the list. The MELD score (MELD 3 now, including albumin) is used for this, with MELD >9 (historically >15) considered the cutoff for transplant potentially exceeding the risk of not transplanting.
Livers can now be placed on warm perfusion pumps, allowing continued viability for much longer. This is mainly used in donors who died from cardiac death, those with high BMI or similar risks for primary non-function (i.e. the transplanted liver never starts working), and longer transport distances or expected operative times.
Incision is a large right subcostal incision, extended as needed. The liver hilum is dissected, preserving the feeding vessels. Caval clamping may be tested, then the liver is removed. This anhepatic phase in minimized to <60 minutes, preferably <45 minutes. The new liver is then anastomosed to the portal veins, vena cava, hepatic artery, and the bile duct. Some instability can occur during reperfusion, such as right heart strain, electrolyte abnormalities, or volume shifts.
Patients will usually remain intubated post-op, lines in place. Sedation ideally is limited so the patient can rouse and confirm the absence of encephalopathy. Systolic BP is closely watched (goal >90), as diastolic BP tends to be low in most liver failure patients. Hepatopulmonary patients can rest on the vent a little longer and are expected to remain on oxygen for the time being. Patients can be fed once extubated and stable.
High-dose steroids are loaded up front and then tapered, and oral immunosuppression initiated soon after.
Some AKI is common. Colloid like albumin is favored early.
Chronic thrombocytopenia is common and is monitored to determine when DVT prophylaxis can be started. Platelets >20k are targeted.
If INR >2, vitamin K is given empirically. FFP is usually not given prophylactically. Bleeding is usually considered a little preferable to clotting, in terms of ease of treatment.
A liver duplex is performed in the first 24 hours to ensure the new vascular supply is patent.
We learn about pancreaticoduodenectomy (the Whipple) with Michael Cavnar (@DrMikeCavnar), surgical oncologist at University of Kentucky, with a fellowship in Complex General Surgical Oncology from Sloan Kettering. He specializes in GI surgical oncology (liver, pancreas, stomach, etc), with ongoing research in GI stromal tumors and hepatic artery infusion pump chemotherapy.
The Whipple involves an aggressive resection and reconstruction of pancreatic head tumors. Along with the head of the pancreas, the entire duodenum, the bile duct (up to near the entry of the cystic duct), the gallbladder, and usually the distal third of the stomach, along with the nearby lymph nodes, are all removed. There are then anastomoses at the small intestine, the bile duct, and the stomach.
The pylorus of the stomach is generally removed, but can be left in a pylorus-sparing Whipple. The benefit of this is not well-established.
It is almost always done for malignancy (or occasionally for other conditions like pre-malignant changes or pancreatitis with stricture). Mortality in high-volume centers is a few percent, and usually involves deaths in the first 90 days due to various complications more than death in the OR.
Hypotension in the first 24 hours is a poor sign, as it may lead to bowel ischemia, portal vein thrombosis, anastomotic ischemia, or other injuries to vulnerable areas. If getting behind on hemodynamics, consider holding an epidural if present.
NG tubes are often placed to around 55 cm. They should not be advanced or replaced by the ICU staff, as the stomach has been shortened, and advancing the tube may traumatize the anastomosis. Bilious gastric drainage is normal in anyone with post-Whipple anatomy. Patients will generally remain NPO for several days.
Patients will emerge with 1-2 surgical drains. Output should be serosanguinous (sparsely bloody at most), less than 200ml/hr or so. It may occasionally be lymphatic (clear to lightly serosanguinous), which can be somewhat higher volume. Output should not be bilious or feculent.
Early bleeding requiring surgical take-back is uncommon and usually obvious in the drains, unless they clot, which can occur. A pancreatic leak can also dribble onto the stump of the gastroduodenal artery, causing erosion, and subsequent bleeding usually tracks back up into the bowel lumen and hence GI bleeding.
Respiratory distress can be treated with oxygen or high-flow nasal cannula, but positive pressure (eg. BiPAP) should be used with caution and consultation with the surgical team, particularly within the first two weeks post-op, as aerophagy can apply pressure to the bowel anastomosis.
A leaking pancreatic anastomosis causing fistula will tend to marinate the gastroduodenal artery’s anastomosis in pancreatic juices, creating a pseudoaneurysm; this can be managed early before it turns into massive hemorrhage. Any streak of fresh blood in the drainage should be considered a sentinel marker of this and immediately evaluated, usually involving CTA or pancreas-protocol CT. The treatment of choice is IR embolization and stent, not open repair.
Glucose control in diabetics will usually be worse post-operatively, both due to stress and due to removing a portion of the pancreas. SGLT inhibitors can cause strange metabolic effects as well if not fully washed out.
Exocrine pancreatic insufficiency can be discovered once feeding begins, usually manifesting as diarrhea (steatorrhea), and can be treated with pancreatic enzyme supplements.
A proton pump inhibitor should generally be used post-operatively.
We chat with Janelle Bludorn (@JanelleRBlu), former emergency medicine PA, Assistant Professor and Academic Coordinator at the Duke PA program, about transitioning from clinical work into teaching and academia.