Q: Which drug is found to be associated with Vasoplegia Syndrome in post cardiac surgery patients?

Answer: ACE inhibitors and ARBs

Though there is a weak evidence, but many reports have suggested that preoperative administration of ACEI/ARBs in patients undergoing cardiac surgery contributes to lowering of SVR (vasoplegia syndrome) postoperatively. It is also suggested, if possible to hold ACEI/ARBs 24 hours before cardiac surgery to avoid postoperative vasodilation.


References:

Lee YK, 

Na SW, 

Kwak YL, 

Nam SB - 

Effect of pre-operative angiotensin-converting enzyme inhibitors on haemodynamic parameters and vasoconstrictor requirements in patients undergoing off-pump coronary artery bypass surgery. J Int Med Res 2005;33:693-702.

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2. Devbhandari MP, 
3. Balasubramanian SK, 
4. Codispoti M, 
5. Nzewi OC, 
6. Prasad SU

.Preoperative angiotensin-converting enzyme inhibition can cause severe post CPB vasodilation – current UK opinion. Asian Cardiovasc Thorac Ann 2004;12:346-349.

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2. Bertrand M, 
3. Godet G, 
4. Meersschaert K, 
5. Brun L, 
6. Salcedo E, 
7. Coriat P

. Should the angiotensin II antagonists be discontinued before surgery? Anesth Analg2001;92:26-30.

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2. Pigott DW, 
3. Nagle C, 
4. Allman K, 
5. Westaby S, 
6. Evans RD

. Effect of omitting regular ACE inhibitor medication before cardiac surgery on haemodynamic variables and vasoactive drug requirements. Br J Anaesth 1999;83:715-720.

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2. Licker M, 
3. Neidhart P, 
4. Lustenberger S, 
5. Valloton MB, 
6. Kalonji T, 
7. Fathi M, 
8. Morel DR

.Long-term angiotensin-converting enzyme inhibitor treatment attenuates adrenergic responsiveness without altering hemodynamic control in patients undergoing cardiac surgery. Anesthesiology 1996;84:789-800.

1. 1. 
      
2. Tuman KJ, 
3. McCarthy RJ, 
4. O'Connor CJ, 
5. Holm WE, 
6. Ivankovich AD

. Angiotensin-converting enzyme inhibitors increase vasoconstrictor requirements after cardiopulmonary bypass. Anesth Analg 1995;80:473-479.

A note on Coronary Perfusion Pressure

Coronary Perfusion Pressure is a very under appreciated concept in ICUs. Coronary perfusion pressure (CPP) refers to the pressure gradient that drives coronary blood pressure. It is the difference between the aortic diastolic pressure and left ventricular end-diastolic pressure.

During cardiac arrest, CPP is one of the most important variables associated with the likelihood of return of spontaneous circulation (ROSC). A CPP of at least 15 mmHg is considered to be necessary for ROSC.

CPP = ADP - LVEDP

It signifies the proper filling pressure and importance of arterial diastolic pressure.

Selected Cephalosporins Can Be Used in Patients with a History of Penicillin Allergy

A widely circulated misconception has been the tale that there is a 10% cross-allergy risk between penicillin and all cephalosporins. Not so, according to a recent literature review. It seems that while some cephalosporins – cephalothin, cephalexin, cefadroxil, and cefazolin – have a significant risk of cross-allergy with penicillin, others do not. The safer drugs to use in a setting of a history of penicillin allergy are: cefprozil, cefuroxime, cefpodoxime, ceftazidime, and ceftriaxone.

Given that there are legions of patients that carry the label “penicillin-allergic,” however valid or erroneous this designation might be, knowing that certain cephalosporins can be used in these patients will be helpful in daily practice.

Reference

1. Pichichero ME. Cephalosporins can be prescribed safely for penicillin-allergic patients. J Fam Pract. 2006; 55(2): 106–107.

Q: What is the dose of 23.4% Saline bolus in refractory Increased Intra-Cranial Pressure (ICP)

Answer:  30 ml

30 ml of an intravenous bolus administration of 23.4% hypertonic saline reduced ICP and augmented CPP for up to 3 hours in patients with intractable elevations in ICP from diverse origins that were refractory to all conventional therapeutic modalities including hyperventilation, mannitol and barbiturates. 

References:

1. Suarez JI, Qureshi AI, Bhardwaj A, Williams MA, Schnitzer MS, Mirski M, et al: Treatment of refractory intracranial hypertension with 23.4% saline. Crit Care Med 26:1118–1122, 1998

2. Ware ML, Nemani VM, Meeker M, Lee C, Morabito DJ, Man ley GT: Effects of 23.4% sodium chloride solution in reducing intracranial pressure in patients with traumatic brain injury: a preliminary study. Neurosurgery 57:727–736, 2005

Q: What is March Hematuria?

Answer: 

March Hematuria is a form of mechanical hemolytic anemia due to mechanically induced damage to red blood cells, causing hemoglobinuria. The damage is induced through repetitive mechanical motions such as prolonged marching (march hemoglobinuria) or marathon running.

Segmental anatomy in bronchoscopy

How to Setup an Arterial Line Transducer

Q: Consumption of which meat may cause Rhabdomyolysis?

Answer: Quail

Rhabdomyolysis after consumption of Quail meat is known as "coturnism" as the main quail genus is called Coturnix.

Migrating quail usually consume large amounts of hemlock plant, which is a known cause of rhabdomyolysis due to its property of containing neuro-muscular blocker like chemical.

A note on simvastatin and amiodarone interaction

Usage of Simvastatin is generally very high in US population. Amiodarone  is a very frequently use IV medicine in ICUs mostly for  rate control in A.Fib./RVR. If use together, there is a high risk of rhabdomyolysis, leading to life threatening kidney failure. This interaction is dose-dependent with simvastatin doses exceeding 20 mg. 

Q: How long does it take for Xarelto (Rivaroxaban) to have maximum effect after taking a dose?

Answer: 4 hours

Rivaroxaban (Xarelto) is an oral anticoagulant now preferred in A.fib. for stroke prevention as well as for other needs where anticoagulation is needed (like DVT prophylaxis after knee surgery).

Rivaroxaban is very well absorbed from the gut and maximum inhibition of factor Xa occurs four hours after a dose. The effects lasts 8–12 hours, but as factor Xa activity does not return to normal within 24 hours, only daily dosing is enough.

Q: Each milliliter of insulin glargine injection(LANTUS) contains how many units of insulin glargine injection(LANTUS)?

Answer:  100 units.

Over-dosage/error of insulin and other medications are extremely common in ICUs despite all safeguards on place.

Each milliliter of LANTUS (insulin glargine injection) contains 100 Units of insulin glargine.

Q: 52 year old diabetic patient has onset of delirium in ICU. Patient is prescribed quetiapine. What is the concern?

Answer:  Hyperglycemia 

Atypical antipsychotics, commonly used in ICU like quetiapine, olanzapine, clozapine and others may increase blood glucose levels, requiring more close monitoring of blood sugar.

Q: How long the effect of Naloxone lasts?

Answer:  About 45 minutes.

Naloxone is commonly given intravenously in ICU for fastest action to reverse the opiod overdose. Naloxone act within a minute, and last up to 45 minutes.

If no IV access available, It can also be given via intramuscular or subcutaneous  route. Newer nasal forms are available too.

Objective of above question to emhasize the fact that, If patients do show a response they should remain under close monitoring as the effects of naloxone may wear off before those of the opioids and they may require repeat dosing at a later time.

Q: What are the therapeutic target level of Digoxin in Congestive heart failure (CHF) and non-CHF patients?

Answer: 

CHF patients = 0.5–0.9 mcg/L ,

Non CHF patients like for atrial fibrillation rate control, its 0.5–2 mcg/L

References:

Adams KF Jr., Gheorghiade M, Uretsky BF, et al. Clinical benefits of low serum digoxin concentrations in heart failure. J Am Coll Cardiol. 2002;39:946–953.

Ahmed A, Rich MW, Love TE, et al. Digoxin and reduction in mortality and hospitalization in heart failure: a comprehensive post hoc analysis of the DIG trial. Eur Heart J. 2006;27:178–186.

Rathore SS, Curtis JP, Wang Y, et al. Association of serum digoxin concentration and outcomes in patients with heart failure. JAMA. 2003;289:871–878.

Q: What are the few clues (pieces of puzzle) to diagnose D-Lactic Acidosis?

Answer: 

This unique form of lactic acidosis can occur in patients with jejunoileal bypasses, small bowel resections, or other forms of short-bowel syndrome. Bacteria are responsible for metabolizing glucose and carbohydrate to D-lactic acid, which is then systemically absorbed. D-lactate is only slowly metabolized by human subjects. Clues to the diagnosis are

• history of a short bowel or any other cause of malabsorption, 
• acidosis with a broad anion gap that cannot be explained,
• neurologic symptoms (Encephalopathy),
• normal lactate level,
• negative Acetest,
• ingestion of large amounts of carbohydrate,
• diminished colonic motility, allowing time for nutrients in the colon to undergo bacterial fermentation

Treatment consists of fluid resuscitation, restriction of simple sugars, NaHCO3 administration as necessary, and the judicious use of antibiotics (such as metronidazole). The latter requires some caution, because antibiotics can precipitate the syndrome by permitting overgrowth of lactobacilli.

Q: One of the measure to correct severe metabolic acidosis during or after cardiac bypass surgery is to use Tris-Hydroxymethyl Aminomethane (THAM). How it is used?

Answer: 

Tham Solution has been found to be very effective in correcting metabolic acidosis which may occur during or immediately following cardiac bypass surgery. If chest is open, 2-6 g of THAM can be injected directly into ventricular cavity, avoiding injection in cardiac muscles. Otherwise, it can be given intravenously with following formula

Tham Solution (mL of 0.3 M) required = Body Weight (kg) x Base Deficit (mEq/L) x 1.1

or simply 9 mL/kg IV

Q: What is the formula for Lactic acid Clearance?

Answer: 

Lactic acid clearance = the initial lactate - subsequent lactate/initial lactate × 100

It is estimated that an 11% decrease in mortality for each 10% decrease in lactate clearance.

References:

1. Arnold RC, Shapiro NI, Jones AE, et al; Emergency Medicine Shock Research Network (EMShockNet) Investigators. Multicenter study of early lactate clearance as a determinant of survival in patients with presumed sepsis. Shock 2009;32(1):35–39

2. Nguyen HB, Rivers EP, Knoblich BP, et al. Early lactate clearance is associated with improved outcome in severe sepsis and septic shock. Crit Care Med 2004;32(8):1637–1642

Q: Why Albumin is the fluid of choice for resuscitation in Fat Embolism?

Answer:  Albumin has been recommended for volume resuscitation in Fat Embolism Syndrome (FES), because it not only restores blood volume but also binds fatty acids, and may help in decreasing the extent of lung injury.

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Q: 32 year old 26 weeks pregnant female brought to ER with  shortness of breath, requiring intubation in field and severe hypotension. According to husband she complains of some coughing and 'unpleasant taste in the mouth', followed by shivering and shortness of breath. What is your concern?

Answer:  Amniotic fluid Emboli

Amniotic fluid emboli is a fatal complication of pregnancy marked by hemodynamic collapse and coagulopathy. Amniotic fluid enters mother circulation along with fetal cells, hair and other debris and trigger an allergic reaction. One diagnostic clue is history of "premonitory symptoms" consists of shivering, coughing, vomiting, and an unpleasant taste in the mouth.

Diagnosis can be made via Pulmonary Artery Catheter insertion and obtaining fetal debris from pulmonary artery. Treatment is supportive.

Fat Embolism ...

Fat embolism syndrome may cause respiratory failure in trauma and orthopedic patients. It is clinically indistinguishable from ARDS.

This syndrome is most commonly associated with long bone and pelvic fractures, where fat from the bone marrow enters the circulation, causing inflammatory injury to the lung and a non cardiogenic pulmonary edema picture. The reaction may be triggered by thromboplastin with complement and coagulation system activation, and activation of leukocytes. The embolization is microscopic and difficult to diagnose; essentially a diagnosis of exclusion.

Clinical manifestations include neurologic changes, hypoxemia and, rarely, right heart failure. Skin manifestations include petechiae, found in 50% to 60% of patients.

Treatment includes routine care of patients with ARDS, with the caveat that the long bone fractures must be stabilized surgically. Steroids after the onset of the syndrome are controversial, with at least one study showing efficacy of methylprednisolone 7.5 mg/kg/6 hrs for 12 doses for prevention, but not treatment.

How is intraabdominal pressure monitored?

Intraabdominal pressure can be measured by transducing the pressure in the urinary bladder via a Foley catheter.

Twenty to 50 mL saline solution is instilled into the urinary bladder to ensure a continuous column of fluid. A needle (connected to a pressure transducer) is aseptically placed into the sampling port of the drainage tubing, which is clamped downstream from the port. The pubic symphysis is used as a zero reference. Alternatively, the drainage tubing itself can be used as a manometer.

Because urinary specific gravity is approximately 1, the height of the fluid column in centimeters needs to be multiplied by 0.74 to convert to millimeters of mercury.

Respiratory variation should be observed in the measured pressure to confirm that pressure is being transduced in the abdomen.

A sustained Intraabdominal pressure above 20 mm Hg with end-organ dysfunction (renal dysfunction, ventilator failure, or intestinal ischemia) is defined as 'Abdominal Compartment Syndrome.'

What is a Curling Ulcer? 

A Curling ulcer is an acute peptic ulcer resulting as a complication from severe burns, when reduced plasma volume leads to sloughing off of the gastric mucosa. They appear to be more prevalent in pediatric patients with burns compared with adults.

Clostridium difficile infection

Clostridium difficile infection (CDI) has become more refractory to standard therapy. Recent data showed severe refractory CDI successfully treated with tigecycline. Oral vancomycin is now advocated as the therapy of choice for severe CDI. Vancomycin administered intravenously does not reach therapeutic levels in the colonic lumen. Metronidazole, administered either orally or intravenously, only reaches low therapeutic levels in the colon. Therefore, even a slightly elevated minimal inhibitory concentration (MIC) of C. difficile for metronidazole may lead to therapy failure. Recently, C. difficile was reported to have low MIC values for tigecycline.

Because C. difficile colitis is a toxin-mediated disease, it has been assumed that immune globulin acts by binding and neutralizing toxin. Off-label use of pooled IVIG from healthy donors has been used in cases of severe refractory C. difficile infection and in patients with recurrent disease.

Neurologic Outcomes After Cardiac Arrest

Patients in a coma less than 12 hours after resuscitation usually make a favorable recovery. Comas lasting more than 12 hours often have neurologic deficits due to focal or multifocal infarcts of the cerebral cortex.

Somatosensory evoked potentials (SEPs) have the highest prognostic reliability and are the most frequently applied method in clinical and experimental studies evaluating outcome after CPR. Bilateral absence of median nerve-stimulated SEPs is associated with a <1% chance of awakening from coma since it implies that widespread cortical necrosis has occurred. Importantly, the presence of cortical responses is not a guarantee for awakening from coma.

Absence of pupillary responses on the first day or absence of corneal reflexes after the first day following CPR predicts poor outcome. If there are no purposeful motor responses after 3 days, there is a high risk of persistent vegetative state or severe disability.

Verbal responses, purposeful eye movements or motor responses, normal ocular reflexes, and response to verbal commands at 1 day following CPR predict at least a 50% chance of regaining independent function. Patient age, gender, or presence of postanoxic seizure failed to correlate with outcome.

Don’t Count on a Normal Chest Radiograph to Rule Out Pneumonia in a Bedridden Patient

In a study of chest radiography to assess 58 bedridden patients for pneumonia, the sensitivity was found to be 65%, the specificity 93% and the positive and negative predictive values were 83 and 65%, respectively. The overall accuracy of pneumonia diagnosis was 69%

The figures above are clearly not as high as one would wish. In the setting of suspected pneumonia in a bedfast patient, the gold standard continues to be non-contrast-enhanced high-resolution computed tomography of the chest

Reference

Esayag Y, Nikitin I, Bar-Ziv J, et al. Diagnostic value of chest radiographs in bedridden patients suspected of having pneumonia. Am J Med. 2010;123(1):88.e1–e5.

Treatment of ITP in Emergency

Urgent increase in platelet count may be required in those patients requiring surgery, at high risk of bleeding, or with active central nervous system, gastrointestinal, or genitourinary bleeding that cannot be controlled.

Consensus guidelines suggest combination therapy with intravenous corticosteroids and IVIg. In patients with extremely low platelets and bleeding, platelet transfusions can produce a transient rise in platelets to help with hemostasis. 

Antiplatelet therapies and other medications affecting platelet counts should be discontinued.

Antifibrinolytic agents such as tranexamic acid and aminocaproic acid may be useful in preventing recurrent bleeding and may be of value in those patients requiring dental or surgical procedures

Cardiac Complications in Subarachnoid Hemorrhage (SAH)

Cardiac complications are not rare in SAH patients. ECG changes can be seen in ¾ of the patients; the varied symptoms include sinus brady-/ tachycardia, QT prolongation, heart blocks, ST elevation and depression, T-wave changes, and pathological Q waves.

Cardiac markers can also be raised. Echocardiogram often show wall dysfunction and histopathological changes in the myocardium. These signs can mimic acute MI. Acute heart failure can lead to arterial hypotension, pulmonary edema, cardiac arrest, and sudden cardiac death. However, coronary angiography shows typically no evidence of coronary artery stenosis. Causes of the cardiac signs are excessive releases of epinephrine and norepinephrine, as well as imbalances in the parasympathetic nervous system.

Q: What is Jervell and Lange-Nielsen syndrome?

Answer: The Jervell and Lange-Nielsen syndrome (JLNS) is an autosomal recessive form of Long QT Syndrome (LQTS) with associated congenital deafness.

Clinical Significance: if undiagnosed or untreated, about 50 percent die by the age of 15 years due to ventricular arrhythmias.

Q: How Prednisone may help in treatment of hypercalcemia secondary to Vitamin D intoxication?

Answer:

In hypercalcemia secondary to Vitamin D over-ingeation or other causes of Vitamin D toxicity, prednisone may help reduce plasma calcium levels by reducing intestinal calcium absorption.

Q: 21 year old male is admitted to ICU after burn. Patient is intubated in ER and  Intra-venous fluid (IVF) started. Nurse inserted foley catheter in ICU and it appears black in color. What should be your next step?

Answer: Increase IVF and start treatment for myoglobinuria

Failure to clear myoglobinuria after 6 hrs indicates ongoing source, and demands compartment release, immediate debridement of necrotic muscle tissue, or even amputation. A burn expert should be consulted.

A note on Transcranial doppler (TCD) in subarachnoid haemorrhage (SAH)

 TCD has a significant application in SAH to differentiate between vasospasm and hyperaemia in patients. The Lindegaard ratio is calculated. The Lindegaard ratio is the flow velocity of the middle cerebral artery divided by the velocity measured in the extracranial internal carotid artery. A high flow velocity (>120 cm s−1) in association with a Lindegaard ratio of <3 implies hyperaemia. A Lindegaard ratio >3 is likely to imply vasospasm.