REM sleep and drugs

Q: Alcohol ______________ the REM sleep? (select one)

A) increases

B) suppresses

Answer: B

There needs to be more work done on the effect of medications on the sleep pattern of ICU patients, who are simultaneously subject to multiple infusions and high-impact medications. The Rapid Eye movement (REM) phase of sleep and its effect on ventilation remain an area of interest for clinicians. 

Many commonly used drugs in ICU suppress REM sleep, including sedatives-hypnotics, barbiturates, antiepileptics, beta antagonists, monoamine oxidase inhibitors (MOIs), selective serotonin reuptake inhibitors (SSRIs),  tricyclic antidepressants, and other stimulants such as alcohol. Also important to understand that sudden withdrawal of these drugs may increase the REM phase of sleep and can have consequential effects on the patient.

#sleep-in-icu

References;

1. España RA, Scammell TE. Sleep neurobiology from a clinical perspective. Sleep 2011; 34:845.

2. Cooper AB, Thornley KS, Young GB, Slutsky AS, Stewart TE, Hanly PJ. Sleep in critically ill patients requiring mechanical ventilation. Chest. 2000 Mar;117(3):809-18. doi: 10.1378/chest.117.3.809. Erratum in: Chest 2001 Mar;119(3):993. PMID: 10713011.

3. Messineo L, Eckert DJ, Taranto-Montemurro L, Vena D, Azarbarzin A, Hess LB, Calianese N, White DP, Wellman A, Gell L, Sands SA. Ventilatory Drive Withdrawal Rather Than Reduced Genioglossus Compensation as a Mechanism of Obstructive Sleep Apnea in REM Sleep. Am J Respir Crit Care Med. 2022 Jan 15;205(2):219-232. doi: 10.1164/rccm.202101-0237OC. PMID: 34699338; PMCID: PMC8787251.

Liquid ventilation

Q: Which liquid is used in Liquid Ventilation?

Answer: Liquid ventilation is accomplished through perfluorocarbon (PFC) liquid. Perflubron has several unique characteristics that make it very efficient in ventilation and oxygenation.

1. Perflubron is an excellent medium to carry respiratory gases. PFC at one pressure atmosphere can carry 20 times as much oxygen as saline.
2. It can be used as a surfactant product in premature infants or patients with ARDS or lung injury. The lung surface tension in an ARDS patient is 67 to 75 dynes/cm. In a lung with perflubron, the surface tension is only 18 dynes/cm, which helps prevent alveolar collapse and reduces alveolar opening pressures.
3. It will spread uniformly and quickly throughout the lungs to treat ARDS or as a surfactant.
4. PFCs are almost twice as dense as water. It will tend to circulate in dependent areas and those areas where gas exchange is most diminished. This characteristic is useful in the resolution of pulmonary edema.
5. The components of PFCs are not taken up by the body but evaporated by the lungs. Continuous administration may be necessary to maintain an adequate dosage. This is allowable because it does not break down into toxic metabolites like high gaseous oxygen concentrations.

#ventilation

#pulmonary

References;

1. Sarkar S, Paswan A, Prakas S. Liquid ventilation. Anesth Essays Res. 2014 Sep-Dec;8(3):277-82. doi: 10.4103/0259-1162.143109. PMID: 25886321; PMCID: PMC4258983.

2. Quintel M, Waschke KF, Meinhardt J. Flüssigkeitsventilation mit Perfluorcarbonen [Liquid ventilation with perfluorocarbons]. Anasthesiol Intensivmed Notfallmed Schmerzther. 1996 Oct;31(8):461-9. German. doi: 10.1055/s-2007-995960. PMID: 9019174.

Nimbex for intubation

Q: Cisatracurium (Nimbex) at the higher dose provides an advantage during intubation?

A) True

B) False

Answer: A

Although cisatracurium is not usually recommended as a neuro-muscular agent for rapid sequence intubation (RSI) but can be used. The commonly used cisatracurium (Nimbex) dose during intubation is 0.15 mg/kg, but the recommended dose is 0.2 mg/kg. It provides the advantage of about 30 seconds in obtaining good conditions for intubation. 

When administered during the induction of adequate anesthesia, a good to excellent condition for tracheal intubation occurred in 2.0 minutes following 0.15 mg/kg dose of cisatracurium and in 1.5 minutes following 0.2 mg/kg of cisatracurium.

#procedures

References:

1. Lee H, Jeong S, Choi C, Jeong H, Lee S, Jeong S. Anesthesiologist's satisfaction using between cisatracurium and rocuronium for the intubation in the anesthesia induced by remifentanil and propofol. Korean J Anesthesiol. 2013 Jan;64(1):34-9. doi: 10.4097/kjae.2013.64.1.34. Epub 2013 Jan 21. PMID: 23372884; PMCID: PMC3558647.

2. Bluestein LS, Stinson LW Jr, Lennon RL, Quessy SN, Wilson RM. Evaluation of cisatracurium, a new neuromuscular blocking agent, for tracheal intubation. Can J Anaesth. 1996 Sep;43(9):925-31. doi: 10.1007/BF03011806. PMID: 8874910.

Potassium in extreme leukocytosis

Q: Severe leucocytosis may cause? (select one)

A) Pseudo-hyperkalemia

B) Pseudo-hypokalemia

C) Either A or B

Answer: C

Conventional teaching is to associate pseudo-hyperkalemia with extreme leucocytosis due to hemolysis in the sample. The objective of this question is to highlight that either Pseudo-hypo or hyperkalemia can occur in severe leucocytosis. 

The mechanism of pseudo-hypokalemia is the increased uptake of plasma potassium by high leukocytes in the sample. If Pseudo-hypo or hyperkalemia is suspected, true potassium level can be measured by sending a specimen quickly and requesting to run the sample in separated plasma or serum.

#electrolytes

#lab-medicine

Reference:

Colussi G, Cipriani D. Pseudohyperkalemia in extreme leukocytosis. Am J Nephrol. 1995;15(5):450-2. doi: 10.1159/000168883. PMID: 7503149.

Combining acetaminophen with NSAID in acute postoperative pain

Q: Combine administration of acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) is harmful during perioperative pain and should be avoided?

A) True

B) False

Answer: B

There is a high realization among clinicians for the use of a multi-model approach for pain relief particularly postoperatively instead of solely relying on opioids. Studies have shown that the combined use of acetaminophen and NSAIDs is more effective than either drug alone unless there is a contraindication. The chance of harmful effects is unlikely as both have different mechanisms of action.

This combined approach is highly recommended to be used in multimodal pain control and Enhanced Recovery after Surgery (ERAS) protocols.

#surgical-critical-care

Reference:

Ong CK, Seymour RA, Lirk P, Merry AF. Combining paracetamol (acetaminophen) with nonsteroidal antiinflammatory drugs: a qualitative systematic review of analgesic efficacy for acute postoperative pain. Anesth Analg 2010; 110:1170.

on emergency-release RBC transfusion

Q: pRBC for emergency release is usually? (select one)

A) Group O, RhD-negative

B) Group O, RhD-positive

Answer: A

Blood for emergency release is usually group O, RhD-negative. 

In case it is not available, group O, RhD-positive blood can be used if the recipient is male, or female is above childbearing age. It can also be utilized in mass trauma situation where demand is high.

Contrary to popular belief, emergency release blood transfusion is relatively safe, and chances of hemolytic transfusion reaction is very low (see reference).

#hematology

#transfusion-medicine

Reference:

Goodell PP, Uhl L, Mohammed M, Powers AA. Risk of hemolytic transfusion reactions following emergency-release RBC transfusion. Am J Clin Pathol 2010; 134:202.

Sweet syndrome criteria

Q: 42 years old female is admitted to ICU with a high fever and abrupt onset of painful erythematous nodules mostly in upper extremities after COVID-19 vaccine. Diagnosis of sweet syndrome is made. Excellent response to steroids is considered a major criteria for the diagnosis of Sweet syndrome?

A) True

B) False

Answer: B

A revised set of diagnostic criteria based upon original 1986 criteria is the most widely used. Both major and two of four minor criteria are required to establish a diagnosis of classical or malignancy-associated Sweet syndrome:

Major criteria:

• Abrupt onset of painful erythematous plaques or nodules
• Histopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis

Minor criteria:

• Pyrexia >38°C
• Association with underlying hematologic or visceral malignancy, inflammatory disease or pregnancy, or preceded by upper respiratory infection, gastrointestinal infection, or vaccination
• Excellent response to treatment with systemic glucocorticoids or potassium iodide
• Abnormal laboratory values at presentation (three of four of the following: erythrocyte sedimentation rate >20 mm/hour, positive C-reactive protein, >8000 leukocytes, >70 percent neutrophils)

Case reports of sweet syndrome have been reported after COVID-19 vaccine.

#dermatology

#malignancy

References:

1. von den Driesch P. Sweet's syndrome (acute febrile neutrophilic dermatosis). J Am Acad Dermatol 1994; 31:535. 

2. Agharbi FZ, Oqbani K, Allaoui A, Chikhaoui I, Chiheb S. Sweet syndrome in post-COVID-19 infection: A case report. Travel Med Infect Dis. 2021 Nov-Dec;44:102188. doi: 10.1016/j.tmaid.2021.102188. Epub 2021 Oct 22. PMID: 34688892; PMCID: PMC8530785.

sudden cardiac death and pulse steroid therapy

Q: When administrated during high pulse glucocorticoid therapy, which of the following is suspected to cause sudden cardiac death? (select one)

A) Beta blocker

B) Calcium channel blocker

C) Hydralazine

D) Diuretic

Answer: D

Sudden death has been suspected in some patients who received high pulse infusions of glucocorticoids like 1gm/day. It is hard to blame high-dose steroids with certainty as most of these patients have multiple other underlying comorbidities. 

It is suspected that the risk may be higher if patients receive diuretics simultaneously. This may be due to electrolyte disturbances, particularly hypokalemia.

#cardiology

Reference:

1. White KP, Driscoll MS, Rothe MJ, Grant-Kels JM. Severe adverse cardiovascular effects of pulse steroid therapy: is continuous cardiac monitoring necessary? J Am Acad Dermatol 1994; 30:768.

C.Diff relapse

Q: About what percentage of patients with C. difficile infection have a relapse even if they are not exposed to further antibiotic therapy?

Answer: 20%

About 20% of patients with C. difficile infection have a recurrence of the infection even if they are not exposed to further antibiotic therapy - and even if they finish a course of appropriate treatment. The time interval between the first infection and a recurrence is usually in the first 4 weeks after treatment is ended. Recurrent disease is caused by the germination of residual C. difficile spores that are not killed and remain in the colon after treatment. About 16% of hospitalized patients harbor this bacteria within their colon as inactive spores. 

Clinical significance: Very high vigilance is required for C. diff. Colitis in view of its deadly nature.

#ID

Reference:

Song JH, Kim YS. Recurrent Clostridium difficile Infection: Risk Factors, Treatment, and Prevention. Gut Liver. 2019 Jan 15;13(1):16-24. doi: 10.5009/gnl18071. PMID: 30400734; PMCID: PMC6346998.

ACS in SCD

Q: What is the diagnostic criteria of Acute Chest Syndrome (ACS) in Sickle cell disease?

Answer: ACS is defined by a new pulmonary density on chest imaging involving at least one complete lung segment or diagnosis of Pneumonia, and at least one of the following:

• Temperature ≥38.5°C
• >3 percent decrease in SpO2 (oxygen saturation) from a documented steady-state value on room air
• Tachypnea (per age-adjusted normal)
• Intercostal retractions, nasal flaring, or use of accessory muscles of respiration
• Chest pain
• Cough
• Wheezing
• Rales

#hematology

#pulmonary

Reference:

Ballas SK, Lieff S, Benjamin LJ, et al. Definitions of the phenotypic manifestations of sickle cell disease. Am J Hematol 2010; 85:6.

Temperature dysregulation in salicylate overdose

Q:  Patients with salicylate overdose usually present with? (select one)

A) hyperthermia

B) hypothermia

Answer: A

Few clinical vitals are unique to salicylate overdose and can be diagnostic. The most important are hyperpnea (the depth of respiration), and hyperthermia. Hyperpnea is relatively early in the toxicity, and hyperthermia usually lags behind. Hyperpnea is due to the direct stimulation of the medullary respiratory center, while hyperthermia is due to uncoupling of oxidative phosphorylation in the mitochondria. Said that absence of these two signs should not exclude salicylate toxicity.

#toxicology

Reference:

1. Pearlman BL, Gambhir R. Salicylate intoxication: a clinical review. Postgrad Med. 2009 Jul;121(4):162-8. doi: 10.3810/pgm.2009.07.2041. PMID: 19641282.

Dextrose, Thiamine and Wernicke's encephalopathy

Case: 48 years old male with history of alcohol abuse is admitted to ICU with community-acquired pneumonia. Patient is found to be hypoglycemic with 50 mg/dL on admission. Thiamine and dextrose are ordered. Pharmacy informed that it would take about 15 minutes to get thiamine. The next step? (select one)

A) Administer dextrose due to severe hypoglycemia

B) Wait for thiamine to avoid Wernicke's encephalopathy

Answer: A

Although it is true that ideally, thiamine should be administrated before dextrose in patients with alcohol abuse to avoid the risk of Wernicke's encephalopathy, it is highly over-rated. The evidence in this regard is very weak. The neurological risk in this patient from hypoglycemia outweighs any other risk. It would not be wise to wait for thiamine.

This question highlights that conventional practices based only on isolated incidents (weak evidence) should not cloud the clinician's judgment (see reference#2).

#neurology

#alcohol-abuse

References:

1. Schabelman E, Kuo D. Glucose before thiamine for Wernicke encephalopathy: a literature review. J Emerg Med 2012; 42:488.

2. Hack JB, Hoffman RS. Thiamine before glucose to prevent Wernicke encephalopathy: examining the conventional wisdom. JAMA 1998; 279:583.

Sedation in GAD treatment and insomnia

Q: Which of the following has the most sedative effect? (select one)

A) Hydroxyzine 

B) Benzodiazepines

C) Buspirone

Answer: A

Hydroxyzine has more sedative properties than benzodiazepines and buspirone. Due to this effect, hydroxyzine is widely use in Generalized Anxiety Disorder (GAD). The good sleep effect eventualy helps reduce the overall anxiety.

#psychiatry

#pharmacology

Reference:

1. Burgazli CR, Rana KB, Brown JN, Tillman F 3rd. Efficacy and safety of hydroxyzine for sleep in adults: Systematic review. Hum Psychopharmacol. 2023 Mar;38(2):e2864. doi: 10.1002/hup.2864. Epub 2023 Feb 26. PMID: 36843057.

2. Guaiana G, Barbui C, Cipriani A. Hydroxyzine for generalised anxiety disorder. Cochrane Database Syst Rev 2010; :CD006815.

PTP

Q: What is Posttransfusion purpura (PTP)?

Answer: Post-transfusion purpura (PTP) is an adverse reaction to blood transfusion that occurs when the body produces alloantibodies to introduced platelets' antigens. Posttransfusion purpura typically occurs 5-12 days following a transfusion. This syndrome can be induced by platelet transfusion, a small amount of platelets contaminating red blood cell transfusion, or, occasionally, following fresh frozen plasma (FFP) transfusion. PTP is most common in women with multiple pregnancies and in men who have undergone previous transfusions.

Thrombocytopenia responds to intravenous immunoglobulin (IVIG) and Plasmapheresis.

#hematology

Reference:

1. Hawkins J, Aster RH, Curtis BR. Post-Transfusion Purpura: Current Perspectives. J Blood Med. 2019 Dec 9;10:405-415. doi: 10.2147/JBM.S189176. PMID: 31849555; PMCID: PMC6910090.

murmur: severe aortic stenosis

Q: Aortic stenosis murmur is best heard at upper ____________ sternal border? (select one)

A) Left

B) Right

Answer: Right

The five characteristics of Aortic stenosis(AS) murmur are:

• heard loudest at the upper right sternal border (at the 2nd right intercostal space).
• radiates to the carotid arteries bilaterally.
• increases with squatting
• decreases with standing
• louder during expiration

#cardiology

#physical-examination

References:

Das P, Pocock C, Chambers J. The patient with a systolic murmur: severe aortic stenosis may be missed during cardiovascular examination. QJM. 2000 Oct;93(10):685-8. doi: 10.1093/qjmed/93.10.685. PMID: 11029480.

Docetaxel and liver dysfunction

Q: Docetaxel should be used with high caution in? (select one)

A) Liver insufficiency

B) Kidney insufficiency

Answer: A

Docetaxel is a popular anti-cancer agent, but it should be used with caution in patients whose bilirubin is above the Upper Limit of Normal (ULN), AST, and/or ALT >1.5 times the ULN concomitant with alkaline phosphatase >2.5 times the ULN.

Patients with elevations of bilirubin or abnormalities of transaminase concurrent with alkaline phosphatase are at increased risk for development of severe neutropenia, febrile neutropenia, infections, severe thrombocytopenia, severe stomatitis, severe skin toxicity, and toxic death. Moreover, patients with isolated transaminase elevations>1.5 times the ULN also had a higher rate of febrile neutropenia. 

Bilirubin, AST, ALT, and alkaline phosphatase should be measured prior to each cycle of docetaxel therapy.

#oncology

#pharmacology

References:

1. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012-. Docetaxel. [Updated 2020 Oct 13]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK548899/

2. Koukourakis MI, Kapsoritakis A, Maltezos E, Potamiano S, Mouzas I, Kouroumalis H. Unexpected toxicity after low-dose docetaxel treatment of a cancer patient with clinically latent HCV-positive hepatic cirrhosis. Anticancer Res. 2002 Jul-Aug;22(4):2491-2. PMID: 12174950.

3. Samur M. Docetaxel and liver dysfunction: is it absolutely contraindicated? Am J Clin Oncol. 2001 Jun;24(3):319-20. doi: 10.1097/00000421-200106000-00024. PMID: 11404510.

Septic Arthritis after central line

Case: 78 year old female is brought back from home with fever, chills, hypotension associated with right pelvic pain. Patient is diagnosed having septic shock with right hip septic arthritis, confirmed by MRI. Patient was previously discharged from hospital two weeks ago after getting treated for community acquired pneumonia. Patient CXR on present admission is improved and sputum gram stain is negative. Urine screen is negative. Review of chart shows emergent insertion of femoral line in ER on previous admission which required 'few attempts' by an intern. Central line was removed on discharge.



Answer: Femoral central line induced hip arthritis

Objective of above question is to highlight relatively unknown complications of central lines. Joint infections from central line rarely get mentioned, but they have been described in literature. Similarly, known complication of subclavian central line is sternoclavicular joint arthritis. 

(see case reports in references)

 References: 

1. Clin Rheumatol 1994; 13:507. Fromm SE, Toohey JS. Septic arthritis of the hip in an adult following repeated femoral venipuncture. Orthopedics 1996; 19:1047.

2.  Aglas F, Gretler J, Rainer F, Krejs GJ. Sternoclavicular septic arthritis: a rare but serious complication of subclavian venous catheterization. 

Epi of MDS

Q: Myelodysplastic syndromes (MDS) are more common in younger females?

A) True

B) False

Answer: B

MDS is considered a disease of older people. The median age is 70 years, and the risk increases with age. Also, there is a male predominance in most categories of MDS except in del(5q) category which is more common in women.

#oncology

Reference:

Ma X. Epidemiology of myelodysplastic syndromes. Am J Med. 2012 Jul;125(7 Suppl):S2-5. doi: 10.1016/j.amjmed.2012.04.014. PMID: 22735748; PMCID: PMC3394456.

progressive headache

Q: ICU team has been called to ED to evaluate a patient for probable subarachnoid hemorrhage (SAH) due to complain of headache. CT scan is still pending. Patient described his pain not as the worst headache of his life but says that it is progressively worse during the night, and awaken him from the sleep now more often. CT scan is most probably to find? (select one)

 

A) SAH

B) Tumor

Answer; B

SAH is classically described as 'worst headache of the life'. In contrast, tumor-related headaches are usually worse  at night and may awaken the patient from sleep. The pathophysiology is threefold. During sleep, the partial pressure of carbon dioxide (CO2) goes up. CO2 is a very potent vasodilator. Moreover lying supine may increase the intracranial pressure (ICP). Also, there is a decreased cerebral venous return.

Other signs pointing towards brain tumor are progressive symptoms, and nausea and vomiting which is prominent in the morning.

#neurology

#oncology

Reference:

1. Schankin CJ, Ferrari U, Reinisch VM, Birnbaum T, Goldbrunner R, Straube A. Characteristics of brain tumour-associated headache. Cephalalgia. 2007 Aug;27(8):904-11. doi: 10.1111/j.1468-2982.2007.01368.x. Epub 2007 Jul 17. PMID: 17635527.

diagnostic criteria - ABPA

Q; Asthma or cystic fibrosis (CF) should be present for the diagnosis of Allergic bronchopulmonary aspergillosis (ABPA)?

A) True

B) False

Answer: A

The diagnostic criteria proposed by the International Society for Human and Animal Mycology (ISHAM) working group for ABPA that simplify prior diagnostic schema has following three criteria:

Predisposing conditions (one must be present):

• Asthma
• Cystic fibrosis (CF)

Obligatory criteria (both must be present):

• Detectable serum IgE levels against Aspergillus fumigatus or Aspergillus skin test positivity
• Elevated total serum IgE concentration (typically >1000 IU/mL (if the patient meets all other criteria, an IgE value <1000 IU/mL may be acceptable, especially if serum Aspergillus fumigatus-specific IgG levels are >27 mg/L)

Other criteria (at least two must be present):

• Precipitating serum antibodies to A. fumigatus or elevated Aspergillus fumigatus-specific IgG levels (>27 mg/L)
• Radiographic pulmonary opacities consistent with ABPA (see 'Imaging' above)
• Total eosinophil count >500 cells/microL in glucocorticoid-naïve patients (may be historical)

  

  

#pulmonary

  

 

Reference:

  

Agarwal R, Sehgal IS, Dhooria S, Aggarwal AN. Developments in the diagnosis and treatment of allergic bronchopulmonary aspergillosis. Expert Rev Respir Med 2016; 10:1317.

Antidepressants and anticonvulsants - and generalized pruritis

Q: 44 years old male with a history of cirrhosis is now recovering from esophageal variceal bleeding. Patient complains of generalized pruritus. Antidepressants and anticonvulsants can be used as adjuvant treatment for generalized pruritus?

A) True

B) False

Answer: A

Generalized pruritus is an umbrella term for any pruritus not limited to a specific body area and can be due to any underlying pathology such as skin disorders, renal or hepatic dysfunction, malignancy, systemic rheumatic disease, infections, drug reactions, or simple idiopathic. In severe form, it can be life-limiting.

Antidepressants such as mirtazapine and selective serotonin reuptake inhibitors (SSRIs) work well due to their effect on serotonin and histamine levels. Anticonvulsants such as gabapentin and pregabalin may be helpful due to their effect on nerves and can be very beneficial in neuropathic pruritus or where nerves get affected due to inflammation and edema caused by skin injury/itching.

#neurology

#dermatology

References:

1. Kouwenhoven TA, van de Kerkhof PCM, Kamsteeg M. Use of oral antidepressants in patients with chronic pruritus: A systematic review. J Am Acad Dermatol 2017; 77:1068.

2. Ständer S, Böckenholt B, Schürmeyer-Horst F, et al. Treatment of chronic pruritus with the selective serotonin re-uptake inhibitors paroxetine and fluvoxamine: results of an open-labelled, two-arm proof-of-concept study. Acta Derm Venereol 2009; 89:45.

3. Pour-Reza-Gholi F, Nasrollahi A, Firouzan A, et al. Low-dose doxepin for treatment of pruritus in patients on hemodialysis. Iran J Kidney Dis 2007; 1:34.

4. Matsuda KM, Sharma D, Schonfeld AR, Kwatra SG. Gabapentin and pregabalin for the treatment of chronic pruritus. J Am Acad Dermatol 2016; 75:619.

5. Yesudian PD, Wilson NJ. Efficacy of gabapentin in the management of pruritus of unknown origin. Arch Dermatol 2005; 141:1507.

Otogenic intracranial complications

Q: Which of the following is the most common cause of otitic meningitis? (select one)

A) S. pneumoniae

B) H. influenzae

C) Group A streptococcus

D) Neisseriae meningitidis 

Answer: A

The objective of the above question is to emphasize that otitic meningitis is the most common intracranial complication of chronic otitis and mastoiditis. It can occur in acute otitis media too but is relatively uncommon in acute episodes. History is the most vital aspect, as clinical signs and lumbar puncture (LP) findings are as universal as to any other cause of meningitis.

The most common organism is S. pneumoniae, followed by H. influenzae. These both should always be covered. Local antibiogram should be consulted to avoid resistance as delay in antibiotic may be harmful. Moreover, neurosurgical services should be alerted in case of non-resolving symptoms.

#neurology

#ID

#ENT

References:

1. Kaplan DM, Gluck O, Kraus M, et al. Acute bacterial meningitis caused by acute otitis media in adults: A series of 12 patients. Ear Nose Throat J 2017; 96:20.

2. Migirov L, Duvdevani S, Kronenberg J. Otogenic intracranial complications: a review of 28 cases. Acta Otolaryngol 2005; 125:819.

Ultrapure dialysis fluid

Q: What is ultrapure dialysis fluid?

Answer: This may be shocking to know that standard dialysis fluid is generally not sterile and may contain a wide range of microorganisms and bacterial products. Moreover, some microbial contamination of the dialysis fluid is considered acceptable. 

Historically and conventionally, it was believed that dialyzer membranes can effectively remove bacterial products. Some even argued that low level of contamination stimulates immune system and heightens the inflammatory state of dialysis patients. All these assumptions proved to be either wrong or partially true. Over time manufacturers built dialysis machines that can filter most of the contamination. This also leads to the quest for creation of ultrapure dialysis fluid.

Ultrapure dialysis fluid is created by filtering standard dialysis fluid via bacterial- and endotoxin-retentive ultrafilters in vivo. This is still not ultrapure at 100 percent, as some bacterial DNA segments may stay back.

#nephrology

References:

1. Canaud B, Lertdumrongluk P. Ultrapure dialysis fluid: a new standard for contemporary hemodialysis. Nephrourol Mon. 2012 Summer;4(3):519-23. doi: 10.5812/numonthly.3060. Epub 2012 Jun 20. PMID: 23573478; PMCID: PMC3614300.

2. Ledebo I. Ultrapure dialysis fluid--direct and indirect benefits in dialysis therapy. Blood Purif. 2004;22 Suppl 2:20-5. doi: 10.1159/000081869. PMID: 15655318.

3. Ledebo I. Ultrapure dialysis fluid--how pure is it and do we need it? Nephrol Dial Transplant. 2007 Jan;22(1):20-3. doi: 10.1093/ndt/gfl574. Epub 2006 Oct 11. PMID: 17035373.

intestinal ischemia in young atheletic male

Case: 34 years old athletic male is admitted to ICU with severe abdominal pain with a presumed diagnosis of intestinal ischemia. In a young athletic male, which side is more prone to ischemic colitis? (select one)

A) left

B) right

Answer: B

Athletes with underlying risk factors such as iron deficiency anemia, dehydration, or cardiovascular disease may develop Exercise-induced intestinal ischemia. It mostly involves proximal colon due to an increased susceptibility of end arteries in low-flow states. Said that it can occur in other parts of the intestine as well. During exercise, mesenteric blood flow may decrease up to 50 to 80 percent.

Pathogenesis doesn't only involve a low flow state or hypovolemia but increased intestinal permeability due to mucosal injury. This is correlated with exercise intensity, duration, dehydration, and higher environmental temperature. In severe cases, rectal bleeding and/or blood in diarrhea may occur. Abdominal pain is usually severe, vague, and persistent even after cessation of exercise.

IV hydration is usually sufficient but, in extreme cases, may require surgical intervention.

#surgical-critical-care

References:

1. Wright H, Collins M, Villiers RD, Schwellnus MP. Are splanchnic hemodynamics related to the development of gastrointestinal symptoms in Ironman triathletes? A prospective cohort study. Clin J Sport Med 2011; 21:337.

2. Beaumont AC, Teare JP. Subtotal colectomy following marathon running in a female patient. J R Soc Med 1991; 84:439.

3. Moses FM. Exercise-associated intestinal ischemia. Curr Sports Med Rep 2005; 4:91.

4. Sanchez LD, Tracy JA, Berkoff D, Pedrosa I. Ischemic colitis in marathon runners: a case-based review. J Emerg Med 2006; 30:321.

Hinchey classification

Q: Hinchey classification system describes stages of? (select one)

A) pelvic contamination

B) peritoneal contamination 

Answer: B

The extent of peritoneal contamination is usually assessed by the Hinchey classification system described more than four decades ago. It has four stages.

Stage I – Pericolic or mesenteric abscess

Stage II – Walled-off pelvic abscess

Stage III – Generalized purulent peritonitis

Stage IV – Generalized feculent peritonitis

Clinically, in general, stages 1 and 2 can be managed conservatively. Stages Hinchey 3 and 4 require surgical intervention.

#surgical-critical-care

Reference:

Hinchey EJ, Schaal PG, Richards GK. Treatment of perforated diverticular disease of the colon. Adv Surg 1978; 12:85.

Ketamine for procedure

Q: Ketamine, when used as a sedative for procedures, doesn't need adjustment in renal or liver insufficiency?

A) True

B) False

Answer: A

Now ketamine is being frequently used for procedures particularly like intubations in ICU. Many of its characteristics which are favorable for procedures are:

• a trance-like state 
• sedation
• analgesia
• amnesia 
• preserve upper airway muscle tone and so airway protective reflexes
• preserve spontaneous breathing
• rapid onset
• short duration of effect (10 to 20 minutes)
• less hemodynamic effect
• No dose adjustments for impaired kidney or liver function

It should be remembered that Ketamine can exacerbate schizophrenia.

The dose for procedures in adults is 1 to 2 mg/kg intravenous over one to two minutes. Dose can be repeated every 5 to 10 minutes.

#procedures

#pharmacology

References:

1. Brown TB, Lovato LM, Parker D. Procedural sedation in the acute care setting. Am Fam Physician 2005; 71:85.

2. Baekgaard JS, Eskesen TG, Moo Lee J, Ikast Ottosen C, Bennett Gyldenkaerne K, Garoussian J, Ejlersgaard Christensen R, Sillesen M, King DR, Velmahos GC, Rasmussen LS, Steinmetz J. Ketamine for rapid sequence intubation in adult trauma patients: A retrospective observational study. Acta Anaesthesiol Scand. 2020 Oct;64(9):1234-1242. doi: 10.1111/aas.13651. Epub 2020 Jul 6. PMID: 32531068.

ABCDE of American Spinal Injury Association impairment scale

Q: What is the ABCDE of the American Spinal Injury Association (ASIA) impairment scale (AIS)?

Answer: 

A = Complete. 

No sensory or motor function is preserved in the sacral segments S4-5.

B = Sensory incomplete. 

Sensory but not motor function is preserved below the neurologic level and includes the sacral segments S4-5 (light touch or pinprick at S4-5 or deep anal pressure), AND no motor function is preserved over three levels below the motor level on either side of the body.

C = Motor incomplete. 

Motor function is preserved at the most caudal sacral segments for voluntary anal contraction (VAC), OR the patient meets the criteria for sensory incomplete status (sensory function preserved at the most caudal sacral segments S4-5 by LT, PP or DAP*), and has some sparing of motor function more than three levels below the ipsilateral motor level on either side of the body. (This includes key or non-key muscle functions to determine motor incomplete status.) For AIS C – less than half of key muscle functions below the single NLI^ have a muscle grade ≥3.

D = Motor incomplete. Motor incomplete status as defined above, with at least half (half or more) of key muscle functions below the single NLI having a muscle grade ≥3.

E = Normal.

#trauma

*LT = Light touch, PP = Pain Prick, DAP = deep anal pressure 

^ NLI = Neurological level of injury

Reference:

American Spinal Injury Association. International Standards for Neurological Classification of Spinal Cord Injury. American Spinal Injury Association, Chicago 2002.

Risk factors for DDS

Q: Describe at least five risk factors for dialysis disequilibrium syndrome (DDS)?

Answer: DDS can be fatal. Proper assessment of risk factors associated with DDS can help to mitigate its effect. Some of the risk factors are:

• First hemodialysis(HD) session
• Markedly elevated blood urea nitrogen (BUN) before dialysis session
• Old age
• Pre-existing head trauma
• History of CVA
• History of seizure 
• Concomitant encephelitis/meningitis
• Concomitant hyponatremia
• History of hepatic encephalopathy
• Concomitant hypertensive emergency
• Sepsis
• History of vasculitis
• Thrombotic thrombocytopenic purpura (TTP)

#nephrology

References:

1. Arieff AI. Dialysis disequilibrium syndrome: current concepts on pathogenesis and prevention. Kidney Int 1994; 45:629.

2. Patel N, Dalal P, Panesar M. Dialysis disequilibrium syndrome: a narrative review. Semin Dial 2008; 21:493.

3. Bagshaw SM, Peets AD, Hameed M, et al. Dialysis Disequilibrium Syndrome: brain death following hemodialysis for metabolic acidosis and acute renal failure--a case report. BMC Nephrol 2004; 5:9.

BB and electrolyte imbalance

Q: Beta blockers may cause? (select one)

A) Hyperkalemia

B) Hypernatremia

Answer: A

Rarely discussed on clinical grounds is the possible hyperkalemia from beta-blockers, mostly from the nonselective beta blockers such as propranolol and labetalol. Beta-2-adrenergic activity are involved in driving potassium into the cells. Beta blockers interfere with this beta-2-adrenergic facilitation of potassium uptake by the cells. This is particularly after a patient receives a potassium load. Although clinically this may not be apparent but rise can be up to 0.5 mEq/L, particularly in patients who are on angiotensin-converting enzyme(ACE) inhibitors, and angiotensin receptor blockers (ARBs).

This BB-K connection is important in ICU where labetalol is frequently use after kidney transplants, and may cause life-threatening hyperkalemia. (see reference #1)

#pharmacology

#electrolytes

References:

1. Arthur S, Greenberg A. Hyperkalemia associated with intravenous labetalol therapy for acute hypertension in renal transplant recipients. Clin Nephrol 1990; 33:269.

2. Lim M, Linton RA, Wolff CB, Band DM. Propranolol, exercise, and arterial plasma potassium. Lancet 1981; 2:591.

Liver dysfunction in RCC

Case: 46 years old male is admitted to ICU with flank pain, hematuria, and a palpable abdominal renal mass and diagnosed with Renal Cell Carcinoma (RCC). No distant metastasis was found but found to have an unproportionate elevation of serum alkaline phosphatase. What is the diagnosis?

Answer: Stauffer syndrome

The triad of flank pain, hematuria, and a palpable abdominal renal mass strongly suggests RCC. The triad has been known for more than five decades now. Patients with RCC without hepatic metastasis may develop hepatic dysfunction without liver metastases. The most common finding is an elevation in serum alkaline phosphatase. This is due to the paraneoplastic phenomenon. Hepatic dysfunction usually ameliorates after RCC removal. This is known as Stauffer syndrome and was first described in 1968.

If hepatic dysfunction continues to recur in such patients after cancer removal, local recurrence of RCC or distant metastasis is highly suspected.

#oncology

#hepatology

References:

1. Skinner DG, Colvin RB, Vermillion CD, et al. Diagnosis and management of renal cell carcinoma. A clinical and pathologic study of 309 cases. Cancer 1971; 28:1165.

2. Walsh PN, Kissane JM. Nonmetastatic hypernephroma with reversible hepatic dysfunction. Arch Intern Med 1968; 122:214.

3. Chuang YC, Lin AT, Chen KK, et al. Paraneoplastic elevation of serum alkaline phosphatase in renal cell carcinoma: incidence and implication on prognosis. J Urol 1997; 158:1684

salicylate-induced noncardiogenic pulmonary edema

Q: Salicylate-induced noncardiogenic pulmonary edema is an absolute indication for hemodialysis?

A) True

B) False

Answer: A

Although salicylate-induced noncardiogenic pulmonary edema and acute lung injury (ALI) can occur in acute toxicity, it is more common in older patients, and in cases with chronic ingestion. These patients may present with fever, hyperdynamic shock, and multiple-system organ failure, and popularly called in "pseudo-sepsis."

Hemodialysis is an absolute indication in salicylate-induced noncardiogenic pulmonary edema as volume resuscitation and sodium bicarbonate administration is hard to do, and only way to salvage patient safely from toxicity is hemodialysis. 

#toxicology

References:

1. Niehoff JM, Baltatzis PA. Adult respiratory distress syndrome induced by salicylate toxicity. Postgrad Med 1985; 78:117.

2. Leatherman JW, Schmitz PG. Fever, hyperdynamic shock, and multiple-system organ failure. A pseudo-sepsis syndrome associated with chronic salicylate intoxication. Chest 1991; 100:1391.

3. Glisson JK, Vesa TS, Bowling MR. Current management of salicylate-induced pulmonary edema. South Med J. 2011 Mar;104(3):225-32. doi: 10.1097/SMJ.0b013e318205e548. PMID: 21297545.