Frank cyanosis and oxygen saturation level

Q: 67 years old male collapsed at the hospital parking lot. "Code blue" is called. On arrival, patient appears to be in frank cyanosis. CPR is started, and the team proceeds to perform intubation. Cyanosis appears to be resolving with CPR and bagging via endotracheal tube (ETT). Frank cyanosis corresponds to an arterial oxygen saturation (SaO2) of around what percentage? - select one

A) 85%

B) 75%

C) 65%

Answer: C

Frank cyanosis usually does not develop until the arterial oxygen saturation (SaO2) level drops to around 65-67 percent. This corresponds to the level of deoxyhemoglobin of about 5 g/dL.

Although pulse oximetry is a great tool for assessing oxygenation, cyanosis often occurs in code situations or in ARDS, and pulse oximetry may not be able to pick up accurate parameters. Clinical exam may play a vital role.

Clinicians should understand that cyanosis is affected by many variables, such as peripheral perfusion, skin pigmentation, and hemoglobin concentration.

#oxygenation

#physical-exam

Reference:

Grace RF. Pulse oximetry. Gold standard or false sense of security? Med J Aust 1994; 160:638.

LBO

Q; 75 years old male is admitted to ICU with severe abdominal pain and is found to have large bowel obstruction due to a tumor formation. Which of the following sites is more prone to have large bowel obstruction? - select one

A) hepatic flexure (Right)

B) splenic flexure (Left)

Answer: B

One-fourth of the bowel obstructions are caused by large bowel obstruction (LBO), and three-fourths by small bowel obstruction (SBO). LBO is more common in elderly people at or above age 70.

One of the most common cause of large bowel obstruction is colon cancer, and in about one-third of the cases, it can be a leading presentation.

Most LBOs occur at or distal to the transverse colon, as the colonic lumen is narrowing there. The most common site of obstructing colorectal cancer is the sigmoid colon. Tumors at the splenic flexure are more likely to obstruct than tumors at the hepatic flexure.

#surgical-critical-care

#oncology

#GI

References:

1. Aslar AK, Ozdemir S, Mahmoudi H, Kuzu MA. Analysis of 230 cases of emergent surgery for obstructing colon cancer--lessons learned. J Gastrointest Surg 2011; 15:110.

2. Biondo S, Parés D, Frago R, et al. Large bowel obstruction: predictive factors for postoperative mortality. Dis Colon Rectum 2004; 47:1889.

3. Frago R, Ramirez E, Millan M, et al. Current management of acute malignant large bowel obstruction: a systematic review. Am J Surg 2014; 207:127.

Analgesic use and the risk of hearing loss

Q: Hearing loss with aspirin is? - select one

A) reversible

B) irreversible

Answer: A

Although high-dose aspirin, about 6 to 8 g/day, can cause hearing loss, it is reversible with discontinuation.

It's not very common, but regular use of standard-dose aspirin, acetaminophen, or nonsteroidal anti-inflammatory drugs can also be associated with an increased risk of hearing loss. Interestingly, this is more common in younger (not older) patients less than 50 years of age. Moreover, similar findings were observed in women with acetaminophen and ibuprofen but not with aspirin.

#pharmacology

#ENT

References:

1. Curhan SG, Eavey R, Shargorodsky J, Curhan GC. Analgesic use and the risk of hearing loss in men. Am J Med 2010; 123:231.

2. Curhan SG, Shargorodsky J, Eavey R, Curhan GC. Analgesic use and the risk of hearing loss in women. Am J Epidemiol 2012; 176:544.

hepatic synthetic function

Q: Which of the following is NOT considered a marker of hepatic synthetic function? - select one

A) Alkaline phosphatase

B) Albumin

C) Bilirubin

D) Prothrombin time (INR)

Answer: A

Liver enzymes measured in the serum lead physician to understand liver injury or it's functional status.

Enzymes that mostly tell about liver injury are:

• Alanine aminotransferase (ALT; formerly called SGPT) 
• Aspartate aminotransferase (AST; formerly called SGOT)
• Alkaline phosphatase
• Gamma-glutamyl transpeptidase (GGTP)
• 5'-nucleotidase
• Lactate dehydrogenase (LDH)

Tests of hepatic synthetic function include:

• Serum albumin
• Prothrombin time/international normalized ratio

Bilirubin (choice C) is unique as its abnormality gives clues about both injury and synthetic function, particularly by division into direct and indirect bilirubinemia.

#hepatology

#lab-medicine

References:

1. Kalas MA, Chavez L, Leon M, Taweesedt PT, Surani S. Abnormal liver enzymes: A review for clinicians. World J Hepatol. 2021 Nov 27;13(11):1688-1698. doi: 10.4254/wjh.v13.i11.1688. PMID: 34904038; PMCID: PMC8637680.

2. Lee TH, Kim WR, Poterucha JJ. Evaluation of elevated liver enzymes. Clin Liver Dis. 2012 May;16(2):183-98. doi: 10.1016/j.cld.2012.03.006. PMID: 22541694; PMCID: PMC7110573.

ACS & women

Q: In the management of acute coronary syndrome (ACS), which gender has a higher risk of bleeding? 

A) Men

B) Women

Answer: B

Although in the management of acute coronary syndrome, the approach to women and men is the same, at least five things should be remembered that women:

• have more atypical symptoms
• are older
• have more significant delays to presentation
• have a higher prevalence of hypertension (HTN)
• have a higher risk of bleeding

Often due to gender bias, common diagnoses get missed, such as myocarditis and aortic dissection.

At least there is one study which found that stress-induced cardiomyopathy (takotsubo cardiomyopathy) may occur in up to 6 percent of women who present with ACS (reference # 2).

#cardiology

References:

1. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2014; 130:2354.

2. Sy F, Basraon J, Zheng H, et al. Frequency of Takotsubo cardiomyopathy in postmenopausal women presenting with an acute coronary syndrome. Am J Cardiol 2013; 112:479.

HOPE score

Q: What is HOPE score?

Answer: The Hypothermia Outcome Prediction after ECLS (HOPE) 

HOPE survival probability score is a survival probability score in percentage. It can be calculated online at www.hypothermiascore.org.

It is recommended that patients with a HOPE score of less than 10 percent should not be rewarmed. 

Favorable prognostic factors at hospital admission in these patients are 

• female sex
• mechanism other than asphyxiation (i.e., exposure or immersion rather than submersion or avalanche burial)
• Higher age*
• lower serum potassium concentration
• shorter duration of cardiopulmonary resuscitation (CPR)
• lower core temperature

Witnessed arrest and cardiac activity (ie, pulseless electrical activity or ventricular fibrillation rather than asystole) were associated with improved survival but were not included in the score. 

*In the original HOPE cohort, the median age of survivors was 40 (range 18 to 56), while the median age of nonsurvivors was 29.5 (range 13 to 54).

HOPE score gets criticized due to its data from retrospective observational studies, methodologic limitations, selection bias and substantial overlap between groups for some parameters, such as age, duration of CPR (median 106 minutes for survivors and 120 minutes for nonsurvivors), and core temperature (median 23°C for survivors and 25°C for nonsurvivors).

Another registry is often used with the name HELP registry (reference # 4)

#hypothermia

References:

1. Pasquier M, Hugli O, Paal P, et al. Hypothermia outcome prediction after extracorporeal life support for hypothermic cardiac arrest patients: The HOPE score. Resuscitation 2018; 126:58.

2. Pasquier M, Rousson V, Darocha T, et al. Hypothermia outcome prediction after extracorporeal life support for hypothermic cardiac arrest patients: An external validation of the HOPE score. Resuscitation 2019; 139:321.

3. Rousson V, Hall N, Pasquier M. HOPE survival probability cutoff for ECLS rewarming in hypothermic cardiac arrest. Resusc Plus 2024; 18:100616.

4. Darocha T, Podsiadło P, Polak M, et al. Prognostic Factors for Nonasphyxia-Related Cardiac Arrest Patients Undergoing Extracorporeal Rewarming - HELP Registry Study. J Cardiothorac Vasc Anesth 2020; 34:365.

Risk factors for acute pancreatitis

Q; All of the following are risk factors for developing complications and worse prognosis in acute pancreatitis EXCEPT? - select one

A) Older age 

B) Male gender

C) Alcoholic pancreatitis 

D) Short time interval to symptom onset 

E) Obesity 

Answer: B

Gender doesn't play much role in predicting prognosis in acute pancreatitis.

One study showed that age above 75 years had more than a 15-fold greater chance of dying within two weeks and a more than 22-fold greater chance of dying within 91 days compared with patients aged 35 years or younger (reference # 1).

Alcoholic pancreatitis has higher chances of developing pancreatic necrosis and of buying a ventilator due to the development of ARDS.

Short time interval to symptom onset and hospital admission, particularly of less than 24 hours is associated with poor outcomes.

BMI >30 is also a risk factor.

On clinical exam, if there is rebound tenderness and/or guarding is present, severe pancreatitis and chances of complications should be suspected.

#GI

References:

1. Frey CF, Zhou H, Harvey DJ, White RH. The incidence and case-fatality rates of acute biliary, alcoholic, and idiopathic pancreatitis in California, 1994-2001. Pancreas 2006; 33:336.

2. Banks PA, Freeman ML, Practice Parameters Committee of the American College of Gastroenterology. Practice guidelines in acute pancreatitis. Am J Gastroenterol 2006; 101:2379.

3. Papachristou GI, Papachristou DJ, Morinville VD, et al. Chronic alcohol consumption is a major risk factor for pancreatic necrosis in acute pancreatitis. Am J Gastroenterol 2006; 101:2605.

4. Martínez J, Johnson CD, Sánchez-Payá J, et al. Obesity is a definitive risk factor of severity and mortality in acute pancreatitis: an updated meta-analysis. Pancreatology 2006; 6:206.

PCS

Q: Which of the following is more common in postconcussion syndrome (PCS)? - select one

A) noise sensitivity

B) visual sensitivity

Answer: A

Experts are divided into accepting the wide range of complaints after mild traumatic brain injury - as symptoms are vague, subjective, and common in the general population syndrome. Still, postconcussion syndrome (PCS) is the most commonly used term as there are no alternative explanations. Other suggested terms are "persisting symptoms after concussion" and "post-TBI syndrome.," 

The most common symptoms of PCS - in descending order, though not necessary - are 

• fatigue
• headache
• forgetfulness
• sleep disturbances
• anxiety
• irritability
• headaches
• dizziness
• noise sensitivity
• psychological complaints

Visual sensitivity is unlikely and, if present, needs thorough investigation to rule out other pathology or higher levels of TBI.

#neurology

#neurosurgery

References:

1. Bazarian JJ, Wong T, Harris M, et al. Epidemiology and predictors of post-concussive syndrome after minor head injury in an emergency population. Brain Inj 1999; 13:173.

2. Broshek DK, Pardini JE, Herring SA. Persisting symptoms after concussion: Time for a paradigm shift. PM R 2022; 14:1509.

3. Evans RW. Persistent post-traumatic headache, postconcussion syndrome, and whiplash injuries: the evidence for a non-traumatic basis with an historical review. Headache 2010; 50:716.

4. Paniak C, Reynolds S, Phillips K, et al. Patient complaints within 1 month of mild traumatic brain injury: a controlled study. Arch Clin Neuropsychol 2002; 17:319.

Tramadol's potential side effect

Q: 54-year-old male with past medical history (PMH) of depression is recovering in ICU after his cardiac bypass surgery. As part of multi-model pain regimen, he received tramadol. The patient progressively developed agitation, tachycardia, hallucinations, increased body temperature, and abnormal eye movements. What is your concern?

Answer: Serotonin syndrome

Tramadol has been inducted in many multi-model pain regimens at various institutions to decrease the use of narcotics. Although tramadol is an opioid agonist, it has lower risk of dependence on short-term use. Also, in comparison to narcotics, it causes a lower level of constipation. It works by blocking the reuptake of serotonin and norepinephrine and so may cause serotonin syndrome, particularly in patients who are already on serotonergic agents. 

(The clue in the question is the patient's PMH of depression - who has a high chance of being on SSRI).

#toxicity

#drug-interactions

#neurology

References:

1. Grond S, Sablotzki A. Clinical pharmacology of tramadol. Clin Pharmacokinet 2004; 43:879.

2. Beakley BD, Kaye AM, Kaye AD. Tramadol, Pharmacology, Side Effects, and Serotonin Syndrome: A Review. Pain Physician 2015; 18:395.

Diverticulosis and Diverticulitis

Q: 69 years old male is admitted to ICU with lower Gastrointestinal (GI) bleed causing syncope. Antibiotics should be initiated as diverticulosis and diverticulitis usually coexist.

A) True

B) False

Answer: B

Interestingly, diverticulosis and diverticulitis rarely coexist.

Diverticulitis is an inflammatory condition, while diverticulosis is a noninflammatory process. Diverticulitis occurs primarily in the left colon, whereas colonic diverticular bleeds occur mainly in right colon.

As a diverticulum herniates, the penetrating vessel responsible for the wall weakness at the point of herniation becomes draped over the dome of the diverticulum, separated from the bowel lumen only by mucosa. Over time, the vasa recta is exposed to recurrent injury along its luminal aspect, leading to the media's eccentric intimal thickening and thinning. These changes may result in segmental weakness of the artery, predisposing to rupture into the lumen. 

If diverticulitis is found to be present with diverticulosis or for both complications, bleeding and diverticulitis may be two different pathologies occurring together.

#GI

References;

1. Feuerstein JD, Falchuk KR. Diverticulosis and Diverticulitis. Mayo Clin Proc. 2016 Aug;91(8):1094-104. doi: 10.1016/j.mayocp.2016.03.012. Epub 2016 May 5. PMID: 27156370.

2. Bhatia M, Mattoo A. Diverticulosis and Diverticulitis: Epidemiology, Pathophysiology, and Current Treatment Trends. Cureus. 2023 Aug 8;15(8):e43158. doi: 10.7759/cureus.43158. PMID: 37565180; PMCID: PMC10410187.

3. Wan D, Krisko T. Diverticulosis, Diverticulitis, and Diverticular Bleeding. Clin Geriatr Med. 2021 Feb;37(1):141-154. doi: 10.1016/j.cger.2020.08.011. PMID: 33213768.

pulmonary manifestations of Amiodarone toxicity

Q: 62 years old male with known cardiac disease and on prolonged Amiodarone therapy is admitted to ICU with syncope and third-degree AV block. Further workup also showed pulmonary manifestations of Amiodarone toxicity. All of the following can be pulmonary effects of chronic Amiodarone therapy EXCEPT?

A) nonproductive cough 

B) bilateral inspiratory crackles

C) clubbing 

D) fever

E) alveolar hemorrhage

Answer: C

Pulmonary toxicity is the most common side effect of long-term amiodarone therapy. It usually occurs in patients who are treated with ≥400 mg/day, particularly in patients with pre-existing lung disease. Conventionally, it is believed to occur after months or even years of therapy (with progressive cumulation of drug). Still, case reports are present in literature where pulmonary side-effects of Amiodarone therapy are reported within 2-3 weeks of treatment. 

Chronic interstitial pneumonitis is the most common pulmonary toxicity with symptoms of a nonproductive cough and dyspnea. Pleuritic pain, weight loss, fever, malaise, and bilateral inspiratory crackles may occur.

Eosinophilic pneumonia, organizing pneumonia, acute respiratory distress syndrome (ARDS), alveolar hemorrhage, and pulmonary nodules have been reported - but clubbing exclusively due to Amiodarone is still off the list.

#pulmonary

#pharmacology

#cardiology

References:

1. Dusman RE, Stanton MS, Miles WM, et al. Clinical features of amiodarone-induced pulmonary toxicity. Circulation 1990; 82:51.

Zimetbaum P. Amiodarone for atrial fibrillation. N Engl J Med 2007; 356:935.

2.Kwok WC, Ma TF, Chan JWM, et al. A multicenter retrospective cohort study on predicting the risk for amiodarone pulmonary toxicity. BMC Pulm Med 2022; 22:128.

3. Wolkove N, Baltzan M. Amiodarone pulmonary toxicity. Can Respir J 2009; 16:43.

4. Kharabsheh S, Abendroth CS, Kozak M. Fatal pulmonary toxicity occurring within two weeks of initiation of amiodarone. Am J Cardiol 2002; 89:896.

Weight issue in chemo-Rx for early breast cancer

Q: 42 years old female is admitted to ICU with fever, neutropenia, and sepsis while going through chemotherapy cycles for her early-stage breast cancer. Electronic Medical Record (EMR) showed a significant increase in her weight. Weight gain is unlikely during chemotherapy and must be an error.

A) True

B) False

Answer: B

Although the conventional belief is that patients lose weight during chemotherapy, almost all women gain weight during chemotherapy for early-stage breast cancer, particularly premenopausal women. There are various reasons for this paradox, such as energy imbalances provoked by chemotherapy, hormonal alterations, and changes in adiposity that induce insulin resistance.

Moreover, obesity is associated with inferior outcomes in women treated for breast cancer. All endeavors should be applied to prevent obesity, such as diet management via nutritionists and exercise programs.

#oncology

References:

1. Vance V, Mourtzakis M, McCargar L, Hanning R. Weight gain in breast cancer survivors: prevalence, pattern and health consequences. Obes Rev 2011; 12:282.

2. Gadéa E, Thivat E, Planchat E, et al. Importance of metabolic changes induced by chemotherapy on prognosis of early-stage breast cancer patients: a review of potential mechanisms. Obes Rev 2012; 13:368.

3. Ligibel JA, Bohlke K, May AM, et al. Exercise, Diet, and Weight Management During Cancer Treatment: ASCO Guideline. J Clin Oncol 2022; 40:2491.

Refeeding edema

Q: 44 years old male who was rescued from a lost hiking trail after 4 days during Labor weekend, developed generalized body edema on feeding. What is refeeding edema?

Answer: Patients who have fasted for more than three days may develop generalized edema after refeeding, particularly with carbohydrates.

This is due to rise in insulin levels in response to renewed intake of carbohydrates. This causes enhanced reabsorption of sodium, which leads to edema.

#electrolytes

Reference:

DeFronzo RA, Cooke CR, Andres R, et al. The effect of insulin on renal handling of sodium, potassium, calcium, and phosphate in man. J Clin Invest 1975; 55:845.

DKA and phosphate

Q: 20 years old female with similar prior presentations, admitted to ICU with severe Diabetes Ketoacidosis (DKA). In acute severe presentation of DKA the serum phosphate concentration expected to be? - select one 

A) high

B) low

Answer: A

Both potassium and phosphate throw curveballs in DKA. Though whole-body potassium and phosphate depletion occur in DKA, the initial serum potassium and phosphate concentrations may be normal or elevated on presentation due to their movement out of the cells. Hypokalemia and hypophosphatemia get rapidly unmasked with insulin and intravenous fluid resuscitation.

Said that, unlike potassium, phosphate replacement is not recommended in DKA as phosphate replacement may lead to hypocalcemia and hypomagnesemia unless the level is too low, like below 1 mg/dL or 0.32 mmol/L) or clinical abnormalities of hypophosphatemia are expected, such as cardiac dysfunction, hemolytic anemia, and respiratory depression. In such cases, a combo of potassium and phosphate (potassium-phosphate) can be given.

#endocrinology

References:

1. Kebler R, McDonald FD, Cadnapaphornchai P. Dynamic changes in serum phosphorus levels in diabetic ketoacidosis. Am J Med 1985; 79:571.

2. Zipf WB, Bacon GE, Spencer ML, et al. Hypocalcemia, hypomagnesemia, and transient hypoparathyroidism during therapy with potassium phosphate in diabetic ketoacidosis. Diabetes Care 1979; 2:265.

3. van der Vaart A, Waanders F, van Beek AP, Vriesendorp TM, Wolffenbutel BHR, van Dijk PR. Incidence and determinants of hypophosphatemia in diabetic ketoacidosis: an observational study. BMJ Open Diabetes Res Care. 2021 Feb;9(1):e002018. doi: 10.1136/bmjdrc-2020-002018. PMID: 33597187; PMCID: PMC7893606.

4. Choi HS, Kwon A, Chae HW, Suh J, Kim DH, Kim HS. Respiratory failure in a diabetic ketoacidosis patient with severe hypophosphatemia. Ann Pediatr Endocrinol Metab. 2018 Jun;23(2):103-106. doi: 10.6065/apem.2018.23.2.103. Epub 2018 Jun 20. PMID: 29969883; PMCID: PMC6057019.

Pigtail in PTX

Q; 34 years old male with a history of HIV is recovering in ICU from a septic shock. Patient complained of acute right-sided chest pain after intensive spirometry (IS). Chest X-ray showed Right-sided pneumothorax (PTX). What is the advantage of using a small bore catheter over a large bore chest tube to relieve PTX?

A) Early resolution of PTX

B) Reduced pain at the insertion site

C) High success rate 

D) Less insertion-related complications

Answer: B

One advantage of placing a small-bore air drainage catheter in an uncomplicated pneumothorax is the reduced pain at the insertion site. For this type of pneumothorax, placement via the anterior midclavicular approach is usually preferred. 

Interestingly, at least in one study, the 'surgical technique' and small bore pigtail failed to show any added advantage besides reduced pain (choice B). 

With an experienced hand, the success rate (choice C) and complications (choice D) should be the same. Resolution of PTX depends highly on underlying pathology instead of insertion technique (choice A)

#procedures

Reference:

Kulvatunyou N, Erickson L, Vijayasekaran A, et al. Randomized clinical trial of pigtail catheter versus chest tube in injured patients with uncomplicated traumatic pneumothorax. Br J Surg 2014; 101:17.