Grand Rounds Recap 3.13.19
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CBC with Differential WITH DR. Hassani
See this intro for some background
The CBC can be helpful in identifying sepsis beyond just the presence of leukocytosis, although it is of course not diagnostic. Lymphocytopenia and neutrophil-lymphocyte count ratio can actually be more predictive of bacteremia that leukocytosis alone according to one study.1 Bandemia >10% has a higher odds ratio for infection than leukocytosis alone.2
Acute myeloid leukemia (AML) is a hematologic malignancy that causes increased production of the myeloid cell line. The CBC will show signs of bone marrow failure. Many patients present with significant leukocytosis, but the range can be quite variable with some patients having normal white counts but an abnormal differential. Often, patients present with symptoms of poor tissue perfusion. Many patients will complain of CNS symptoms (altered mental status, somnolence, or stroke mimics). Pulmonary complaints are also common with shortness of breath, pneumonia, hypoxia, and pulmonary emboli are some of the common presenting complaints. There is a 20-40% one-week mortality, but this increases to 90% if patients present with CNS and pulmonary symptoms. The management should include admission for biopsy and emergent chemotherapeutic induction. Patients who present symptomatic from leukostasis may benefit from emergent leukopheresis. Severe presentations can cause DIC.
Acute promyelocytic leukemia (APL) is a sub-type of AML that often presents with significant coagulopathy and bleeding. It is treated with all-trans retinoic acid (ATRA) plus other chemotherapeutic agents. ATRA can and should be started in the ED because early initiation can lead to significantly decreased mortality.
Hemolytic anemia can be found on the CBC and has a variety of underlying etiologies. Thrombotic thrombocytopenic purpura (TTP) is due to decreased activity of ADAMTS13. It presents as a microangiopathic hemolytic anemia with thrombocytopenia. The thrombocytopenia is often severe (<30). Treatment is plasma exchange (PLEX), Rituximab, +/- steroids.
Hemolytic uremic syndrome (HUS) is also a microangiopathic hemolytic anemia with thrombocytopenia. The thrombocytopenia is usually less severe than TTP (<100), and an acute kidney injury is common. It is seen more often in children. Supportive care is the mainstay of treatment for HUS.
References
Jager C., Wijk P., Mathoera R., Jongh-Leuvenink J., et al. Lymphocytopenia and neutrophil-lymphocyte count ratio predict bacteremia better than conventional infection markers in an emergency care unit. Critical Care, 2010; 14:R192.
Cavallazzi R., Bennin C., Hirani A., Gilbert C., et al. Is the band count useful in the diagnosis of infection? An accuracy study in critically ill patients. J Intensive Care Med, 2010; 25(6): 353-357
CPC: myxedema coma WITH DR. Hughes
The case is a middle-aged female with a remote history of laryngeal cancer and a known new sternal abnormality who presented with generalized weakness. She was hypothermic, hypotensive, and tachypneic on presentation. Work-up revealed a neutrophilic predominance, hyponatremia, lactic acidosis, and hypoglycemia. LFTs revealed a transaminitis (AST>>ALT) and an elevated INR. After fluid resuscitation, her lactate continued to rise and she ultimately dropped her pressures requiring pressors. The final diagnosis was myxedema coma.
Myxedema coma is a significant misnomer because edema and coma are not required for the diagnosis. The most common presenting finding is actually hypothermia. Hypotension, respiratory depression, and altered mental status are other common presenting symptoms. Thyroxine, T4, is a pro-hormone broken down by peripheral organs to the active hormone T3. This is responsible for a number of important physiologic functions such as temperature management, cardiac output, glucose availability, and vascular permeability (via increased ADH and impaired water excretion). Severe hypothyroidism then can lead to significant hypothermia, cardiovascular instability, and hypoglycemia.
There is a diagnostic scoring system available, but the data behind is is limited at best.1 It is a retrospective review of 21 patients. Scores > 60 are potentially diagnostic of myxedema coma. The treatment is intravenous levothyroxine, and this should be given with intravenous steroids. Admission is generally required. While this is a very uncommon diagnosis, hyponatremia, hypothermia, and hypoglycemia should prompt consideration for this diagnosis.
References
Popoveniuc G., Chandra T., Sud A., Sharma M., et al. A diagnostic scoring system for myxedema coma. Endocr Pract, 2014; 20(8):808-817.
R4 Capstone: CT USE WITH DR. Whitford
Emergency providers are notorious for CT utilization…or over-utilization. It is important to keep in mind that this is not without risk to the patient. Below are a few examples of presentations we see in the ED in which we may over-scan such patients.
Pancreatitis: Many providers scan these patients to evaluate for tumor, pseudocyst, or abscess. The American College of Gastroenterology recommends otherwise and issued a statement essentially saying there is little utility for CT scan in the first 24-48 hours symptom onset in hemodynamically stable patients. They offer a conditional recommendation to obtain a CT with low quality evidence in patients who are over 40. If foregoing a CT scan, every patient with new pancreatitis should have a right upper quadrant ultrasound to evaluate for gall stone pancreatitis.
Renal Colic: A study of 2759 patients with flank or abdominal pain suspected to be caused by ureterolithiasis looked at ultrasound prior to CT imaging.1 All of the patients underwent abdominal aortic ultrasounds in addition to renal ultrasounds. They found no difference in adverse events, missed diagnoses, return visits, and hospitalizations. 40.7% of patients had additional imaging, however, but the reason for this is not clear in the study. Stone size does not necessarily indicate rate of passage. 60% of 5 mm stones will pass, and 30% of 10 mm stones will pass without surgical intervention. Therefore, many patients warrant conservative management initially. Emergent CT is suggested in cases of infection or refractory pain. In patients without hydronephrosis on ultrasound, it may be more useful to obtain a CT due to diagnostic uncertainty. In addition, all elderly patients warrant imaging of the aorta, but ultrasound is 99% sensitive for detection of AAA and may help to avoid CT imaging.
Cervical Spine Clearance: There are a variety of criteria that may be used for cervical spine clearance including Canadian CT rules or the NEXUS criteria. Interestingly, 16% of clinically significant cervical spine injuries are missed with the NEXUS criteria. This is important to keep in mind when evaluating for spinal injuries.
Pulmonary Embolism: CTPA has a significant number of false positives with nearly 60% of sub-segmental PEs being false positive according to one study.2 Well’s and D-Dimer can help risk stratify patients, and shared decision-making in discussion with the patient may be useful in equivocal cases.
References
Smith-Bindman R., Aubin C., Bailitz J., Benjiamin R., et al. Ultrasonography versus computed tomography for suspected nephrolithiasis. NEJM, 2014; 371:1100-1110.
Hutchinson B., Navin P., Marom E., Truong M. Overdiagnosis of pulmonary embolism by pulmonary CT angiography. American Journal of Roentgenology, 2015; 205(2): 271-277.
Pediatric Sim WITH DR. Bensman
The Crashing Neonate
History is crucial in the crashing neonate and should include a detailed birth history, exposures, and time course of the illness. In addition to the standard evaluation of ABCs, special attention should be paid to assessing pulses in all extremities and assessment for organomegaly. Hepatomegaly may be a subtle suggester of a congenital heart defect (CHD).
Initial evaluation should include four-extremity blood pressures, pre and post-ductal saturations, and obtaining a rectal temperature. IV fluid resuscitation is important, but it should be used very cautiously given the potential for cyanotic congenital heart defects because one can easily push them into florid cardiogenic shock. If concerned for a CHD, prostaglandin should be administered empirically. This will take time to act, so continued resuscitation is warranted. Emergent cardiology consultation is crucial because surgical repair is often the mainstay of treatment.
Critical coarctation: The ductus arteriosis is generally patent for about 24-72 hours in healthy babies. In children with CHD, the ductus may close later (1-2 weeks) due to the patient being “ductal dependent.” Coarctation of the aorta is generally pre-ductal. Symptoms usually become apparent once the ductus starts to close. Many children will have minimal or absent lower extremity pulses which should suggest the diagnosis.
The decision to take a neonate’s airway is multifactorial. In ductal dependent lesions, intubation may be helpful because it increases intrathoracic pressure. Prostaglandins do carry a risk of apnea, so intubation should be considered especially in cases that require transfer. Prior to intubation, fluid resuscitation is crucial. Atropine should be considered before intubating neonates, particularly if they are relatively bradycardic prior to the procedure. Recall that neonates require chronotropy to increase their cardiac output as opposed to increased inotropy, so bradycardia should be avoided at all costs.
Blue Babies (cyanosis): right obstructive lesions such as tricuspid atresia, pulmonary atresia, Ebstein anomaly
-The goal is to change the shunt from left to right, and the treatment is to give oxygen.
Gray Babies (circulatory collapse): left obstructive lesions such as hypoplastic left heart, coarctation, aortic atresia
-The goal is to change the shunt from right to left, and the treatment is often volume. Caution should be used with supplemental oxygen because this drops pulmonary vascular resistance and may worsen the shunt and hasten closure of the ductus.
Pediatrics Case WITH The Peds Fellows
Case 1: The patient is a 9 year old who presented with difficulty breathing and tripoding. The differential includes bacterial tracheitis, epiglottitis, croup, Ludwig’s angina, retropharyngeal abscess, peritonsillar abscess, airway foreign body, etc. Management should include avoiding agitating the patient because this can easily worsen respiratory distress. In a community setting without ENT in house, the decision has to be made about calling in the consultant versus transferring the patient to a tertiary care facility. The concern is obviously impending airway compromise and when this is likely to occur. Temporizing measures that should be considered include steroids, nebulized lidocaine, racemic epinephrine, glycopyrrolate, and atropine. In bacterial tracheitis, early antibiotics are paramount. Empiric regimens should include coverage of strep, staph, H. flu, and moraxella.
Case 2: The patient is a 5 day old male who is jaundiced, slightly lethargic, with poor tone. Workup should include evaluation for infection/sepsis, coagulopathy, meningitis, +/- heart failure. Hypoglycemia commonly presents with acute liver failure, so early fingerstick may be helpful. Fluid resuscitation and empiric antibiotic coverage is warranted in this sick infant. He was found to have a leukocytosis to 24 and a TBili of 14 which is on the border for his age according to the BiliTool. His symptoms should not be just attributed to hyperbilirubinemia, and he should be considered septic until proven otherwise. In reality, altered mental status/kernicterus is unlikely with a TBili less than 25.
