Effect of PEEP on lungs
Sunday, January 25, 2009
Saturday, January 24, 2009
Friday, January 16, 2009
Q: Which electrolytes you need to watch closely while patient receives proton pump inhibitor?
Answer: Magnesium (and potassium secondary to low magnesium)
Mechanism is not very clear. Absorption of dietary magnesium occurs in the ileum and colon via carrier mediated transport and simple diffusion. Low gastric pH is thought to be important for the absorption of minerals. Waves of acidity entering the small intestine from the stomach may help to keep mineral salts in solution until they can be absorbed. Omeprazole induced hypochlorhydria could therefore theoretically cause mineral deficiency, although there is no clear evidence proven yet.
Reference: Click to get abstract
1. Omeprazole and refractory hypomagnesaemia - BMJ 2008;337:a425
2. Epstein M, McGrath S, Law F. Proton-pump inhibitors and hypomagnesemic hypoparathyroidism. N Engl J Med2006;355:1834-6.
Thursday, January 15, 2009
Thursday January 15, 2009
Case: A 62 year old male with past medical history of diabetes mellitus, hyperlipidemia, atrial fibrillation, hypertension, and mild renal insufficiency - presented to ER with severe weakness, anuria and renal failure. Patient report extremely dark urine for few days prior to presentation. Patient was discharged 5 weeks ago from hospital with Aspirin, Coumadin, Lopressor, Amiodarone and simvastatin . Laboratory workup in ED showed creatine kinase (CK) in 80,000 U/L range. BUN 65 mg/dL, creatinine 4.6 mg/dL. Liver function test (LFT) are also moderately elevated. What could be the reason of of this life threatening Rhabdomyolysis?
Answer: Simvastatin-Amiodarone Interaction
Simvastatin is metabolized primarily by CYP3A4, and amiodarone is a recognized inhibitor of this enzyme. This drug interaction may cause severe life threatening Rhabdomyolysis. The risk is higher in patients, particularly with simvastatin doses greater than 20 mg daily.
Reference: Click to get abstract
fda alert - fda.gov
Wednesday, January 14, 2009
IABP in severe septic shock - Bench to bedside?
Background: Fluid refractory septic shock can develop into a hypodynamic cardiovascular state in both children and adults. Despite management of these patients with empirical inotropic therapy (with or without a vasodilator), mortality remains high. The effect of cardiovascular support using intra-aortic balloon counterpulsation was investigated in a hypodynamic, mechanically ventilated canine sepsis model in which cardiovascular and pulmonary support were titrated based on treatment protocols.
Methods: Each week, three animals (n = 33, 10-12 kg) were administered intrabronchial Staphylococcus aureus challenge and then randomized to receive
- intra-aortic balloon counterpulsation for 68 hrs or
- no intra-aortic balloon counterpulsation (control)
- Compared with lower bacterial doses (4-7 x 109 colony-forming units/kg), control animals challenged with the highest dose (8 x 109 colony-forming units/kg) had a greater risk of death (mortality rate 86% vs. 17%), with worse lung injury ([A - a]o2), and renal dysfunction (creatinine). These sicker animals required higher norepinephrine infusion rates to maintain blood pressure (and higher Fio2) and positive end-expiratory pressure levels to maintain oxygenation.
- In animals receiving the highest bacterial dose, intra-aortic balloon counterpulsation improved survival time (23.4 +/- 10 hrs longer) and lowered norepinephrine requirements (0.43 +/- 0.17 [mu]g/kg/min) and systemic vascular resistance index (1.44 +/- 0.57 dynes/s/cm5/kg) compared with controls.
- Despite these beneficial effects, intra-aortic balloon counterpulsation was associated with an increase in blood urea nitrogen and creatinine
- In animals receiving lower doses of bacteria, intra-aortic balloon counterpulsation had no significant effects on survival or renal function
Conclusions: In a canine model of severe septic shock with a low cardiac index, intra-aortic balloon counterpulsation prolongs survival time and lowers vasopressor requirements.
Reference: Click to get abstract
Effects of intra-aortic balloon counterpulsation in a model of septic shock - Critical Care Medicine. 37(1):7-18, January 2009.
Tuesday, January 13, 2009
Tuesday January 13, 2009
Baseline Cortisol in Severe Community-Acquired Pneumonia
The aim of the study was to investigate the predictive value of adrenal response in patients with severe CAP admitted to the ICU.
Methods: 72 patients with severe CAP admitted to the ICU were evaluated. Following were measured in first 24 hours
- Baseline and postcorticotropin cortisol levels
- C-reactive protein (CRP),
- clinical variables,
- sequential organ failure assessment (SOFA) score
- APACHE (acute physiology and chronic health evaluation) II, and
- CURB-65 (confusion, urea nitrogen, respiratory rate, BP, age ≥ 65 years) score
The major outcome measure was hospital mortality.
- Baseline cortisol levels were 18.1 μg/dL and the difference between baseline and postcorticotropin cortisol after 250 μg of corticotropin was 19 μg/dL
- Baseline cortisol levels presented positive correlations with scores of disease severity, including CURB-65, APACHE II, and SOFA
- Cortisol levels in nonsurvivors were higher than in survivors.
- CIRCI (critical illness-related corticosteroid insufficiency) was diagnosed in 29 patients (40.8%)
- In univariate analysis, baseline cortisol, CURB-65, and APACHE II were predictors of death.
- The discriminative ability of baseline cortisol for in-hospital mortality was better than APACHE II, CURB-65, SOFA, d-dimer, or CRP.
Conclusion: Baseline cortisol levels are better predictors of severity and outcome in severe CAP than postcorticotropin cortisol or routinely measured laboratory parameters or scores as APACHE II, SOFA, and CURB-65.
Reference: Click to get abstract
Adrenal Response in Severe Community-Acquired Pneumonia - Chest 134:947-954; November 2008
Monday, January 12, 2009
Central venous-to-arterial carbon dioxide difference
Very interesting !!!
Objective: To test the hypothesis that, in resuscitated septic shock patients, central venous-to-arterial carbon dioxide difference
may serve as a global index of tissue perfusion when the central venous oxygen saturation (ScvO2) goal value has already been reached.
It was a prospective observational study.
Patients: After early resuscitation in the emergency unit, 50 consecutive septic shock patients with ScvO2 > 70% were included immediately after their admission into the ICU (T0). Patients were separated according to a threshold of 6 mmHg at T0.
- Low P(cv-a)CO2 group (Low gap) - 26 patients and
- High P(cv-a)CO2 group (High gap) - 24 patients
Measurements were performed every 6 h over 12 h (T0, T6, T12)
Conclusion: In ICU-resuscitated patients, targeting only ScvO2 may not be sufficient to guide therapy. When the 70% ScvO2 goal-value is reached, the presence of a P(cv-a)CO2 larger than 6 mmHg might be a useful tool to identify patients who still remain inadequately resuscitated.
Reference: Click to get abstract
Central venous-to-arterial carbon dioxide difference: an additional target for goal-directed therapy in septic shock? - Intensive Care Medicine, Volume 34, Issue 12 / December , 2008- Pages 2218 - 2225
Sunday, January 11, 2009
Sunday January 11, 2009
Case: 53 year old male is going for urgent thoracic aortic aneurysm repair. On which side should you place the radial arterial line?
Answer: On right radial artery
If the aortic aneurysm begins at or around the left subclavian artery, this vessel might be included in the aortic clamp and reconnected separately into the new aortic graft. Therefore, the left radial artery pressure might not be measurable for a while. Also, both right and left radial arteries can be cannulated to visualize circulation in both arms.
Saturday, January 10, 2009
On fospropofol disodium (LUSEDRA)
FDA has recently approved Fospropofol for monitored anesthesia care sedation in adult patients undergoing diagnostic or therapeutic procedures 1.
Fospropofol is a water-soluble prodrug of the propofol. Fospropofol is metabolized into propofol by the liver. Because of this extra metabolism, blood levels of propofol after the administration of a bolus of fospropofol reach lower peak levels than for an equipotent dose of propofol and also lesser sedative effect. This lower sedative effect make it more desirable to use for procedures such as upper GI endoscopy, colonoscopy, bronchoscopy, cardioversion as well as other bedside surgical procedures.
Another advantage of fospropofol is that, being water-soluble, the problems associated with lipid formulated propofol e.g., pain at the IV catheter site, potential for hyperlipidemia with long-term administration, and an increased chance for bacteremia are expected to be less frequent.
It takes about 4-5 minutes to achieve desire sedative level so its important to have patience before administrating second dose. The recommended maximum dose is 12.5 mg/kg. In this month of chest 2, optimum dose of 6.5 mg/kg is described for patients undergoing flexible bronchoscopy.
1. Lusedra - fda.gov
2. A Phase 3, Randomized, Double-Blind Study To Assess the Efficacy and Safety of Fospropofol Disodium Injection for Moderate Sedation in Patients Undergoing Flexible Bronchoscopy - CHEST January 2009 vol. 135 no. 1 41-47
Friday, January 9, 2009
Friday January 9, 2009
Does N-terminal pro-brain natriuretic peptide (N-proBNP) and troponin I (TnI) profile following mitral and/or aortic valve surgery in children correlate with echocardiography measures and outcome criteria?
In a prospective cross-controlled study in twenty children with acquired valvular disease requiring valvular surgery N-proBNP correlated with the Pediatric Heart Failure Index, left ventricle shortening fraction, left atrium to aorta ratio, left ventricle mass index, end-systolic wall stress, and with outcome measures such as inotropic score, duration of inotropic support, and ICU length of stay. Preoperative N-proBNP was significantly more elevated in patients with complicated outcome than in patients with uneventful postoperative course.
Conclusion: In pediatric valvular patients, perioperative N-proBNP is a promising risk stratification predicting factor. It is correlated with evolutive echocardiographic measures, need for inotropic support, and ICU length of stay. BNP could be used as marker of heart failure in conjunction with other measures such as echocardiographic finding and clinical severity of illness while explaining parents about short term outcome after surgery such as length of intensive care, need for inotrope support etc.
Value of brain natriuretic peptide in the perioperative follow-up of children with valvular disease.- Intensive Care Med. 2008 Jun;34(6):1109-13.
Thursday, January 8, 2009
Dr. Richard Savel and colleagues are publishing an important paper (in next month's Critical Care Medicine journal) on the controversial topic of projects that have components of both Quality Improvement (QI) and Human-subjects research (HuSR).
Background of controversy: Dr. Peter Pronovost and his group at Johns Hopkins have been at the forefront in the academic analysis of the use of checklists in the ICU in an attempt to improve outcomes. In an analogous—albeit much larger—study, this same group worked with the Michigan Health and Hospital Association to implement checklists in ICUs throughout that entire state (the Keystone Project). Despite a couple of articles in media espousing the use of checklists in the ICU, the Office for Human Research Protections (OHRP) announced the termination of any further data collection involving the Michigan Keystone Project. OHRP claimed that by not obtaining explicit Informed consent (IC) from each patient and provider involved in the project, the Hopkins researchers had violated fundamental scientific and ethical research regulations.
What is an institution to do when a project has components of both QI and HuRS? Dr. Savel's group has made the following 3 middle-ground recommendations:
1) OHRP must develop new ways to help institutions streamline the approval process of QI/HuSR by designing and developing structured criteria as to what constitutes “impracticability” of protocols without waivers of consent and “minimal risk” to the subjects, as well as providing some guidance for multicenter QI/HuSR projects like Keystone (including an explicit policy for central IRB approval of such projects).
2) More institutions should have formal processes within their IRBs to rapidly and safely evaluate QI/HuSR, with the goal of improving patient safety, making the approval process less onerous and more efficient, while at all times protecting the rights of the individual patient.
3) Hospitals too small to have their own IRBs should be allowed to use IRBs from predetermined designated nearby regional centers of excellence.
Richard H. Savel MD, FCCM is an Asssociate professor of Clinical Medicine, Albert Einstein College of Medicine [in application] and Medical co-director, surgical intensive care unit at Montefiore Medical Center in NYC.
He is also SCCM's associate editor for podcasting and podcast host.
Critical care checklists, the Keystone Project, and the Office for Human Research Protections: A case for streamlining the approval process in quality-improvement research - Crit Care Med 2009 Vol. 37, No. 2, - Feb. 2009
Wednesday, January 7, 2009
Wednesday January 7, 2009
Scenario: 67 year old s/p colectomy patient in ICU, went into acute agitation and psychosis. He pulled all his IVs and not allowing nurses to insert any IV. What could be your option to 'cool him down' before further evaluation, but without any IV access and inability to use enteral route?
Answer: Orally disintegrating olanzapine (Zedis)
Zydis® (olanzapine) is an orally disintegrating tablets of formulation of ZYPREXA - that dissolves in the mouth on contact with saliva. It is available in 5-mg, 10-mg, 15-mg, and 20-mg tablets. Tablets can be taken without water. The mode of action of olanzapine's antipsychotic activity is unknown.
Tuesday, January 6, 2009
Q; Name few major etiologies for delirium?
Answer: Remember WWHHHIMP
W = Withdrawal (ETOH/drug)
W = Wernicke encephalopathy
H = Hypoxemia
H = Hypoglycemia
H = Hypertensive encephalopathy
I = Intracranial bleeding / CVA
M = Meningitis/encephalitis
P = Poisoning
Monday, January 5, 2009
Decontamination of the Digestive Tract and Oropharynx in ICU Patients
Interesting study on this controversial topic published this week in NEJM 1
Background Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) are infection-prevention measures used in the treatment of some patients in intensive care, but reported effects on patient outcome are conflicting.
Methods We evaluated the effectiveness of SDD and SOD in a crossover study using cluster randomization in 13 intensive care units (ICUs), all in the Netherlands. Patients with an expected duration of intubation of more than 48 hours or an expected ICU stay of more than 72 hours were eligible. In each ICU, three regimens (SDD, SOD, and standard care) were applied in random order over the course of 6 months. Mortality at day 28 was the primary end point.
SDD consisted of 4 days of intravenous cefotaxime and topical application of tobramycin, colistin, and amphotericin B in the oropharynx and stomach.
SOD consisted of oropharyngeal application only of the same antibiotics.
Monthly point-prevalence studies were performed to analyze antibiotic resistance.
Results A total of 5939 patients were enrolled in the study, with 1990 assigned to standard care, 1904 to SOD, and 2045 to SDD; crude mortality in the groups at day 28 was 27.5%, 26.6%, and 26.9%, respectively. In a random-effects logistic-regression model with age, sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, intubation status, and medical specialty used as covariates, odds ratios for death at day 28 in the SOD and SDD groups, as compared with the standard-care group, were 0.86 (95% confidence interval [CI], 0.74 to 0.99) and 0.83 (95% CI, 0.72 to 0.97), respectively.
Conclusions In an ICU population in which the mortality rate associated with standard care was 27.5% at day 28, the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD.
Reference: click to get abstract
Decontamination of the Digestive Tract and Oropharynx in ICU Patients - The New England Journal of Medicine, Volume 360:20-31, Number 1, January 1 2009
Sunday, January 4, 2009
Sunday January 4, 2009
Q: Hyponatremia should be corrected slowly and extreme caution should be taken. Rapid correction of Na may lead to central pontine myelinolysis (CPM) characterized by focal demyelination in the pons and extrapontine areas associated with serious neurologic sequelae. Which four subgroups of patients are more prone to develop CPM and at higher risk?
Answer: Patients with
- female gender,
- history of alcoholism and
- liver transplant
Reference: click to get abstract
Murase T, Sugimura Y, Takefuji S, et al. Mechanisms and therapy of osmotic demyelination. Am J Med. Jul 2006;119(7 Suppl 1):S69-73
Saturday, January 3, 2009
Something which we have been doing, here is the data now
Intensivist have been using pig tail drainage catheter under ultrasound guidance for several years. Study by Liang in Intensive Care Medicine confirmed the findings.
On a retrospective review of 133 patients, pigtail drainage catheter yielded largest amount of fluid (5382 +/- 4844 ml) in massive transudative effusion with longest duration of drainage (9 +/- 7 days). It has the highest complication rate of 18%. The success rate was highest when used to treat traumatic hemothorax (100%) and postoperative pleural effusions (85%); drains inserted for empyema were more likely to fail (overall success rate, 42%). No significant insertion complications, such as hollow organ perforation, were caused by this procedure.
Editor’s Comment: This procedure is simple and safe to perform. In addition it helps us to prevent transfer critically ill patients to radiology department.
Laing SJ, Tu CY, Chen HJ, Chen W et al. Application of ultrasound-guided pigtail catheter for drainage of pleural effusions in the ICU. Intensive Care Medicine. Published online Oct 11 2008.
Friday, January 2, 2009
Case: 52 year old male is admitted with frequent runs of ventricular tachycardia and was started on IV Lidocaine with 2mg/min drip. First lidocaine serum level is 8.5 micrograms/ml. To determine the time period to shut off Lidociane drip, do you know the half life of intravenous Lidocaine?
Answer: The elimination half-life of lidocaine is approximately 1.5–2 hours in most patients. But it may be prolonged in patients with liver insufficiency upto 6-8 hours. Also, in patients with congestive heart failure, it may be slightly prolonged upto 3 hours. Though Lidociane is excreted via urine but renal insufficiency doesn't effects its level much as 90% Lidocaine is metabolized in the liver by to the pharmacologically-active metabolites.
Lidocaine alters depolarization in neurons, by blocking sodium (Na+) channels in the cell membrane, leading to its anaesthetic effects. And toxic dosage may lead to nervousness, tingling, tinnitus, tremor, dizziness, blurred vision and seizures.
In above case, it would be appropriate to hold Lidocaine drip for 4-6 hours and drew the level again to determine the rate of infusion.