Saturday July 31, 2010

Q: Your nerdy ER doc called you to admit a 54 year old male with Mackler's triad. (Hint) Patient has previous history of alcohol abuse and perforated duodenal ulcer. What is Mackler's triad?


Answer: Mackler's triad includes

• lower chest pain,
• vomiting, and
• subcutaneous emphysema
  

It is a classic presentation of esophageal rupture (Boerhaave's syndrome) but present only in few patients (14%).

To note, the triad has been reported without esophageal perforation too.

Tachypnea and abdominal rigidity are usually present along with tachycardia, diaphoresis, fever, and hypotension. Unusual clues include hoarseness caused by involvement of the recurrent laryngeal nerve, tracheal shift, cervical vein distention, and proptosis.

Condition can quickly progress to multi-organ failure.

(continuing our theme from yesterday on adrenal crisis)

Q: Which 2 commonly used medicines in ICU may cause adrenal crisis?

Answer: Phenytoin and Rifampin

Other common causes in ICU include rapid withdrawal of long-term steroid therapy, septic shock, use of etomidate, hypovolumeia, hypothermia and others.

Wednesday July 28, 2010

Involuntary Cough Strength and Extubation Outcomes for Patients in an ICU

Background: Removing the artificial airway is the last step in the mechanical ventilation withdrawal process. In order to assess cough effectiveness, a critical component of this process, we evaluated the involuntary cough peak flow (CPFi) to predict the extubation outcome for patients weaned from mechanical ventilation in ICUs.

Methods: One hundred fifty patients were weaned from ventilators, passed a spontaneous breathing trial (SBT), and were judged by their physician to be ready for extubation in the Tri-Service General Hospital ICUs from February 2003 to July 2003. CPFi was induced by 2 mL of normal saline solution at the end of inspiration and measured using a hand-held respiratory mechanics monitor. All patients were then extubated.

Results: Of 150 enrolled patients for this study, 118 (78.7%) had successful extubation and 32 (21.3%) failed.

In the univariate analysis, in the extubation failures compared with the extubation successes - there were

• higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (16.0 vs 18.5, P = .018),
• less negative maximum inspiratory pressure (−45.0 vs −39.0, P = .010),
• lower cough peak flows (CPFs) (74.0 vs 42.0 L/min, P less than .001),
• longer postextubation hospital stays (15.0 vs 31.5 days, P less than .001), and
• longer postextubation ICU stays (1.0 vs 9.5 days, P less than .001)

In the multivariate analysis, increasing risk of extubation failure were noted in

• a higher APACHE II score and
• a lower CPF

The receiver operator characteristic curve cutoff point for CPF was 58.5 L/min, with a sensitivity of 78.8% and specificity of 78.1%

Conclusions: CPFi as an indication of cough reflex has the potential to predict successful extubation in patients who pass an SBT.

Involuntary Cough Strength and Extubation Outcomes for Patients in an ICU - Chest April 2010 137:777-782

Tuesday July 27, 2010

Q: 32 year old male with sickle cell disease presented to ER with severe episode of priapism. What should be considered?

Answer: For priapism in sickle cell disease, early exchange transfusion is indicated, meanwhile pain can be controlled with epidural analgesia. Exchange transfusions may be required to increase hemoglobin concentration to higher than 10% and decrease hemoglobin S to less than 30%. Before any intervention urology consult should be obtiained for possible use of terbutaline and pseudoephedrine. Some studies suggest that the use of terbutaline orally, at a dose of 5-10 mg, followed by another 5-10 mg 15 minutes later, if required, produces resolution in about one third of patients. Oral pseudoephedrine, 60-120 mg orally has also been suggested as a potential therapy due to its alpha-agonist effect. The exact efficacy of this medication orally is unknown.

Monday July 26, 2010

EPR only vs EPR with chest compressions

Editors' note: EPR is an important concept to know for intensivists.

Read basics of EPR here

Objective: The induction of deep cerebral hypothermia via ice-cold saline aortic flush during prolonged ventricular fibrillation cardiac arrest, followed by hypothermic stasis and delayed resuscitation (emergency preservation and resuscitation), improved neurologic outcome after cardiac arrest in pigs, as compared to conventional resuscitation. We hypothesized that emergency preservation and resuscitation with chest compressions would further improve outcome in the same model.

Method: Twenty-four female, large, white breed pigs (27–37 kg). 15 minutes of ventricular fibrillation cardiac arrest were followed by

• 20 mins of resuscitation with chest compressions (control, n = 8),
• deep cerebral hypothermia via 200 mL/kg 4°C saline aortic flush and hypothermic stasis (emergency preservation and resuscitation, n = 8), and
• emergency preservation and resuscitation combined with chest compressions (emergency preservation and resuscitation plus chest compressions, n = 8).
  

At 35 mins after cardiac arrest, cardiopulmonary bypass was initiated, followed by defibrillation. Mild hypothermia was continued for 20 hrs. Pigs were evaluated after 9 days using a neurologic deficit (neurologic deficit score: 100% = brain dead; 0%–10% = normal) and an overall performance category score (overall performance category score: 1 = normal; 2 = slightly handicapped; 3 = severely handicapped; 4 = comatose; 5 = dead/brain dead.

Results: Brain temperature decreased from 38.5°C to 15.3°C ± 3.3°C in the emergency preservation and resuscitation group, and to 11.3°C ± 1.2°C in the emergency preservation and resuscitation plus chest compressions group.

• In the control group, restoration of spontaneous circulation was achieved in four out of eight pigs, and one survived to 9 days.
• In the emergency preservation and resuscitation group, restoration of spontaneous circulation was achieved in seven out of eight pigs and five survived;
• in the emergency preservation and resuscitation plus chest compressions group, all had restoration of spontaneous circulation and seven survived (restoration of spontaneous circulation, p = .08).
• Neurologic outcome for (median and interquartile range) the control group included overall performance category score of 3, neurologic deficit score of 45%;
• For the emergency preservation and resuscitation group, overall performance category score was 3 (2–5) and neurologic deficit score was 45% (36; 50) and
• in the emergency preservation and resuscitation plus chest compressions group, overall performance category score was 2 (1–3) and neurologic deficit score was 13% (5; 21)
  

Conclusions: Emergency preservation and resuscitation by deep cerebral hypothermia combined with chest compressions during prolonged cardiac arrest in pigs are feasible and improve neurologic outcome.

Cold aortic flush and chest compressions enable good neurologic outcome after 15 mins of ventricular fibrillation in cardiac arrest in pigs - Critical Care Medicine: August 2010 - Volume 38 - Issue 8 - pp 1637-1643

Sunday July 25, 2010


Q: Why D-5 is a poor choice of resuscitation at cellular level in septic shock?


Answer: At cellular level, in hypoperfused patients most D-5 get diverted to lactate production making acidosis worse!

Also, as we know - at vascular level - it has no resuscitation effect.

Thursday July 22, 2010
What is DuraHeart?

DuraHeart™ is a Left Ventricular Assist System (LVAS). The DuraHeart is a third-generation rotary blood pump designed for long-term patient support.

Why it is different from other LVADs *: It incorporates a centrifugal flow rotary pump with a magnetically levitated impeller to pump blood from the heart around the body. THE MAGNETICALLY LEVITATED PUMP SETS THE DURAHEART™ APART FROM OTHER SYSTEMS. No clinically significant hemolysis reported with reduced sheer. Also it needs mild anti-coagulation regimen.

* Left Ventricular Assist Systems (LVAS) are mechanical circulatory device to assist ventricles in severe cardimyopathy either as bridge to heart transplant or as destination therapy for those who are ineligible for a heart transplant.

Wednesday July 21, 2010
Combined milrinone and enteral metoprolol therapy in patients with septic myocardial depression


Introduction: The multifactorial etiology of septic cardiomyopathy is not fully elucidated. Recently, high catecholamine levels have been suggested to contribute to impaired myocardial function.

Methods: This retrospective analysis summarizes our preliminary clinical experience with the combined use of milrinone and enteral metoprolol therapy in 40 patients with septic shock and cardiac depression. Patients with other causes of shock or cardiac failure, patients with beta-blocker therapy initiated more than 48 hours after shock onset, and patients with pre-existent decompensated congestive heart failure were excluded. In all study patients, beta blockers were initiated only after stabilization of cardiovascular function (17.7 ± 15.5 hours after shock onset or intensive care unit admission) in order to decrease the heart rate to less than 95 beats per minute (bpm). Hemodynamic data and laboratory parameters were extracted from medical charts and documented before and 6, 12, 24, 48, 72, and 96 hours after the first metoprolol dosage. Adverse cardiovascular events were documented. Descriptive statistical methods and a linear mixed-effects model were used for statistical analysis.

Results

• Heart rate control (65 to 95 bpm) was achieved in 97.5% of patients (n = 39) within 12.2 ± 12.4 hours.
• Heart rate, central venous pressure, and norepinephrine, arginine vasopressin, and milrinone dosages decreased
• Cardiac index and cardiac power index remained unchanged whereas stroke volume index increased (P = 0.002).
• In two patients (5%), metoprolol was discontinued because of asymptomatic bradycardia. Norepinephrine and milrinone dosages were increased in nine (22.5%) and six (15%) patients, respectively. pH increased whereas arterial lactate, serum C-reactive protein, and creatinine levels decreased during the observation period.
• Twenty-eight-day mortality was 33%.

Conclusion: Low doses of enteral metoprolol in combination with phosphodiesterase inhibitors are feasible in patients with septic shock and cardiac depression but no overt heart failure. Future prospective controlled trials on the use of beta blockers for septic cardiomyopathy and their influence on proinflammatory cytokines are warranted.


Combined milrinone and enteral metoprolol therapy in patients with septic myocardial depression - Critical Care 2008, 12:R99

Tuesday July 20, 2010

Q: What is the dose of Glucagon in severe life threatening Beta-blocker toxicity?

Answer: The doses of glucagon required to reverse severe beta-blockade are 50 micrograms/kg IV loading dose, followed by a continuous infusion of 1-15 mg/h, titrated to patient response.

Glucagon increases heart rate and myocardial contractility, and improves atrioventricular conduction. These effects are unchanged by the presence of beta-receptor blocking drugs.

Monday July 19, 2010
Drug interaction

Scenario: 58 years old male is admitted to ICU with atrial fibrillation with rapid ventricular rate (RVR). Patient's past medical history is significant only with BPH (prostate hypertrophy) and patient uses Tamsulosin (Flomax) for it. Patient's BP is on lower side so you decide to use Amiodarone instead of cardizem or esmolol. With Amiodarone bolus patient 's blood pressure dropped drastically and patient coded.

Answer: IV Amiodarone bolus is know to cause transient hypotension but it may cause dramatic hypotension with concurrent alpha or beta blockade use. Amiodarone (with its active metabolite, desethylamiodarone) blocks sodium, potassium, and calcium channels. Amiodarone itself is a relatively potent noncompetitive alpha and beta-blocker and with cocomitant use of alpha, beta blockers or calcium channel blockers may cause life threatening situation.

Moreover, Amiodarone itself has direct potent coronary as well as veno vasodilatory property. Amiodarone acts as a direct venodilator through the cyclooxygenase pathway, activation of nitric oxide synthase, and cyclooxygenase-dependent relaxing endothelial factors.

On side note - Hypotension from IV amiodarone (particularly bolus) is also contributed due to its solubilized vehicle called polysorbate 80 which may have histamine releasing effect.

Sunday July 18, 2010

Q: What is the basic difference between PET (Positron emission tomography) scan and other radiological workup such as CT scan or MRI?

Answer: Imaging scans such as CT and MRI displays anatomic changes in the body, PET is capable of detecting areas of molecular biology detail even prior to anatomic change. PET scanning does this using radiolabelled molecular probes that have different rates of uptake depending on the type and function of tissue involved. Changing of regional blood flow in various anatomic structures (as a measure of the injected positron emitter) can be visualized and relatively quantified with a PET scan.

See below an example of PET scan. Non-small cell lung cancer of the right lung showing spread to the mediastinum and right neck.

Saturday July 17, 2010

Q: What factor should be taken into consideration in terms of calorie intake in patients with peritoneal dialysis?

Answer: The peritoneal dialysis fluid typically contains a high percentage of glucose to ensure hyperosmolarity which can add as many as 1000 calories to the diet per day.

Friday July 16, 2010
A/C vs SIMV

Background: Few data are available regarding the benefits of one mode over another for ventilatory support. We set out to compare clinical outcomes of patients receiving synchronized intermittent mandatory ventilation with pressure support (SIMV-PS) compared with assist-control (A/C) ventilation as their primary mode of ventilatory support.

Methods: This was a secondary analysis of an observational study conducted in 349 ICUs from 23 countries. A propensity score stratified analysis was used to compare 350 patients ventilated with SIMV-PS with 1,228 patients ventilated with A/C ventilation. The primary outcome was in-hospital mortality.

Results: In a logistic regression model, patients were more likely to receive SIMV-PS if they were from North America, had lower severity of illness, or were ventilated postoperatively or for trauma. SIMV-PS was less likely to be selected if patients were ventilated because of asthma or coma, or if they developed complications such as sepsis or cardiovascular failure during mechanical ventilation.

In the stratified analysis according to propensity score, we did not find significant differences in the in-hospital mortality. After adjustment for propensity score, overall effect of SIMV-PS on in-hospital mortality was not significant (P = .78).

Conclusions: In our cohort of ventilated patients, ventilation with SIMV-PS compared with A/C did not offer any advantage in terms of clinical outcomes, despite treatment-allocation bias that would have favored SIMV-PS.



Outcomes of Patients Ventilated With Synchronized Intermittent Mandatory Ventilation With Pressure Support - A Comparative Propensity Score Study CHEST June 2010 vol. 137 no. 6 1265-1277

Thursday July 15, 2010
Regarding Nicardipine!


Q: Nicardipine is a Calcium Channel Blocker (CCB) but how it is distinct from other CCBs?

A: Nicardipine (Cardene) is a Calcium Channel Blocker with distinction that it has highly vascular selective calcium channel blockade. It has strong cerebral and coronary vasodilatory effect. It has non to minimal effect on left ventricular function and conduction. It is now preferred drug of choice as IV infusion in hypertensive crisis.

For rapid blood pressure control, therapy is initiated at a loading dose of 5 mg/hr and titrated by 2.5 mg/hour every 5 minutes up to 15 mg/hour until the desired results are achieved. For gradual reduction in blood pressure, the infusion rate is increased every 15 minutes until desired blood pressure is reached.

Wednesday July 14, 2010
"MAZE" Procedure - simply explained!


The MAZE procedure consists of creating a number of incisions in the atrium that disrupt the re-entrant circuits. Once the incisions are made, they are sewn together again. The atrium can then hold blood on its way to the ventricle and can squeeze or contract to push the blood in to the ventricle, but the electrical impulse cannot cross the incisions. The result is what looks like a children's maze in which there is only one path that the electrical impulse can take from the SA node to the AV node. The atrium can no longer fibrillate, and sinus rhythm (the normal rhythm of the heart) is restored.

Tuesday July 13, 2010

Q: Why Vitamin K is called Vitamin "K"?


Answer:

Its called Vitamin K from its german origin"Koagulations-Vitamin".

Story of Vitamin K: In 1929, Danish scientist Henrik Dam investigated the role of cholesterol by feeding chickens a cholesterol-depleted diet. After several weeks, the animals developed hemorrhages and started bleeding. These defects could not be restored by adding purified cholesterol to the diet. It appeared that—together with the cholesterol—a second compound had been extracted from the food, and this compound was called the coagulation vitamin. The new vitamin received the letter K because the initial discoveries were reported in a German journal, in which it was designated as Koagulationsvitamin.

Monday July 12, 2010

Q: What is urinothorax?


Answer: Presence of urine in pleural cavity is called Urinothorax. Urinothorax can occur from urinary tract injury or obstruction - and leakage of urine from the peritoneal and retroperitoneal space into the pleural space.

Urinothorax usually causes a rapidly accumulating pleural effusion. Most cases of urinothorax are due to obstruction, secondary to tumor/metastasis, or trauma of the ureter. In other cases, retroperitoneal fibrosis, shock wave lithotripsy, and removal/blockage of nephrostomy tubes may result in the formation of an urioma. Nephropleural fistula may form, allowing urine to enter the pleural cavity. Accidental placement of nephrostomy tubes too cephalically in the thorax may cause urinthorax too.


Diagnosis: Urinothorax should be suspected if the sample is straw colored or has a urine-like odor. Measurement of pleural creatinine to serum creatinine has been found to be the most reliable laboratory value and should be the definitive evaluation of urinothorax. Pleural fluid/serum creatinine ratio higher than 1 is diagnostic in association with other features. Moreover urinothorax may be both transudative and acidic (lower than 7.30).

Saturday July 10, 2010
Cardio-pulmonary arrest in cocaine overdose


Q: Why vasopressin is preferable over epinephrine in cardio-pulmonary arrest due to cocaine overdose?


Answer: Epinephrine like cocaine has alpha-adrenergic effects. Because of this similarity in the cardiovascular effects, the administration of epinephrine to a patient who arrests in a hyperadrenergic state has been like "pouring gasoline over fire."

Moreover, cocaine prevents the reuptake of exogenously administered epinephrine. Therefore, if epinephrine is used, AHA Guidelines recommends that high-dose epinephrine should be avoided and that the interval for its administration be increased (q 5-10min).

Vsopressin offer considerable advantages over epinephrine in cardiac arrest secondary to cocaine toxicity. The hyperadrenergic state caused by cocaine increases myocardial oxygen demand and vasopressin increases coronary blood flow, and thereby myocardial oxygen availablity.

Also, cocaine toxicity causes acidosis and epinephrine loses much of its effectiveness in an acidotic enviroment, whereas vasopressin demonstrates good efficacy even with severe acidosis.

Friday July 9, 2010


Q; Patient with C. Diff. Colitis is having no improvement with PO Flagyl. You ordered PO Vancomycin. Pharmacy informed you that PO Vancomycin is not available. What would be your trick of trade here?


A; Actually, IV Vancomycin can be given via oral route. It works just as well, and a lot cheaper. The ordered dose may be diluted in water and given to the patient to drink. Common flavoring syrups may be added to the solution to improve taste.

Thursday July 8, 2010

SfVO2? - Nah!

Background: Central venous oxygen saturation (Scvo₂) has been used as a surrogate marker for mixed venous oxygen saturation (Svo₂). Femoral venous oxygen saturation (Sfvo₂) is sometimes used as a substitute for Scvo₂. The purpose of this study is to test the hypothesis that these values can be used interchangeably in a population of patients who are critically ill.

Methods: We conducted a survey to assess the frequency of femoral line insertion during the initial treatment of patients who are critically ill. Patients with femoral and nonfemoral central venous catheters (CVCs) were included in this prospective study. Two sets of paired blood samples were drawn simultaneously from the femoral and nonfemoral CVCs. Blood samples were analyzed for oxygen saturation and lactate.

Results: Thirty-nine patients were enrolled.

• The mean Scvo₂ and Sfvo₂ were 73.1% ± 11.6% and 69.1% ± 12.9%, respectively (P = .002), with a mean bias of 4.0% ± 11.2% (95% limits of agreement: −18.4% to 26.4%).
  
• The mean serum lactate from the nonfemoral and femoral CVCs was 2.84 ± 4.0 and 2.72 ± 3.2, respectively (P = .15).
  

Conclusions: This study revealed a significant difference between paired samples of Scvo₂ and Sfvo₂. More than 50% of Scvo₂ and Sfvo₂ values diverged by more than 5%. Sfvo₂ is not always a reliable substitute for Scvo₂ and should not routinely be used in protocols to help guide resuscitation.

Femoral-Based Central Venous Oxygen Saturation Is Not a Reliable Substitute for Subclavian/Internal Jugular-Based Central Venous Oxygen Saturation in Patients Who Are Critically Ill - Chest July 2010 138:76-83; also published ahead of print April 23, 2010.

Wednesday July 7, 2010


Q: Patient reports allergy to albumin as well as charted as Jehovah's Witnesses but require large volume Paracentesis. What's your other option?


A: Terlipressin (eg, 1 mg every 4 hours for 48 hours) can be use as an alternative to albumin for the prevention of circulatory colapse after large-volume paracentesis. Terlipressin is said to be as effective as albumin for this purpose.

Tuesday July 6, 2010

Swallowing Dysfunction in "Trach" Patients

Background: The aim of this study was to determine the incidence of swallowing dysfunction in nonneurologic critically ill patients who require percutaneous dilatational tracheostomy (PDT) for prolonged mechanical ventilation (MV) and to compare the duration of the cannulation period and length of stay in the critical care unit (CCU) in patients with and without swallowing dysfunction.

Methods: A total of 40 consecutive patients without neurologic disorders who require PDT for prolonged MV were included. Previous to the tracheostomy decannulation process, an otolaryngologist performed a fiberoptic endoscopic evaluation of swallowing (FEES).

Results: Mean age was 62 ± 15 years. Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were 21 ± 2 and 9 ± 1, respectively. Time of MV previous to PDT was 20 ± 11 days, total MV duration was 38 ± 16 days, and CCU stay was 63 ± 27 days.

• The incidence of swallowing dysfunction in this group of patients was 38% (15/40).
• No difference was found in the age or time period of MV previous to PDT between groups.
• The time period between FEES to tracheostomy decannulation process was 19 ± 11 days in patients with swallowing dysfunction vs 2 ± 4 days in those patients without dysfunction
• Patients who developed swallowing dysfunction stayed longer in the CCU (69 ± 23 vs 47 ± 19 days)

Conclusions: Nearly 40% of nonneurologic critically ill patients requiring PDT for prolonged MV presented swallowing dysfunction and experienced a significant delay in their tracheostomy decannulation process.

Swallowing Dysfunction in Nonneurologic Critically Ill Patients Who Require Percutaneous Dilatational Tracheostomy - Chest June 2010 137:1278-1282; published ahead of print March 18, 2010

Monday July 5, 2010

How Passy-Muir Valve works

Sunday July 4, 2010

Saturday July 3, 2010
Stages of Decub ulcer

Stage I
This stage is characterized by a surface reddening of the skin. The skin is unbroken and the wound is superficial. This decubitus ulcer quickly fades when pressure is gone. Treatment consists of turning or alleviating pressure. Increased nutrition is part of prevention.

Stage II
This stage is characterized by a blister either broken or unbroken. A partial layer of the skin is now injured. Involvement is no longer superficial. The goal of care is to cover, protect, and clean the area.

Stage III
The wound extends through all of the layers of the skin. It is a primary site for a serious infection to occur. The goals and treatments of alleviating pressure and covering and protecting the wound still apply as well as an increased emphasis on nutrition and hydration.

Stage IV
A Stage IV wound extends through the skin and involves underlying muscle, tendons and bone. The diameter of the wound is not as important as the depth. This is very serious and can produce a life threatening infection. All of the goals of protecting, cleaning and alleviation of pressure on the area still apply. Nutrition and hydration is now critical. Without adequate nutrition, this wound will not heal. Anyone with a Stage IV wound requires medical care by someone skilled in wound care. Surgical removal of the necrotic or decayed tissue is often used on wounds of larger diameter.

Friday July 2, 2010

Q: You confirmed propofol infusion syndrome in a patient on prolong high concentration infusion. Once you stop propofol how long does it take to recover from propofol associated lactic acidosis?


Answer: About 6 hours

Propofol infusion syndrome (PRIS) has been observed in patients receiving propofol at high dosages and for prolonged periods though reported with lower doses as well as short infusion time. It is said to be synergestic when given concomitantly with catecholamines or steroids in the setting of acute neurologic or inflammatory diseases.
Propofol infusion syndrome is said to occur in patients with genetic mitochondrial abnormalities.

MCQ on PRIS here (posted here earlier)

Thursday July 1, 2010


Q: 34 year old male with previous history of lung transplant is admitted to ICU with sepsis. Patient is recovering well but continue to have persistent ileus. Junior resident wrote for erythromycin to increase GI motility. What need to be watch in this patient?



Answer: Tacrolimus level

Tacrolimus has clinically major drug interactions with erythromycin, dilantin and rifampin. Erythromycin may increase Tacrolimus to toxic level. It is recommended that concurrent administration of erythromycin and tacrolimus be avoided. However, if concomitant therapy is necessary, tacrolimus concentrations should be monitored.

Other significant interactions Tacrolimus may have is with amphotericin, barbiturates, calcium channel blockers, itraconazole, ketoconazole, fluconazole, cyclosporine, and cimetidine.