Ventilator mode and sleep in ICU

Q; Which of the ventilator modes has so far shown that it causes more sleep disturbances in the ICU patients? - select one

A) Assist Controlled (AC)

B) Pressure Controlled (PC)

C) Synchronized Intermittent Mandatory Ventilation (SIMV)

Answer: B

Although the data is not robust and the evidence is weak, PC mode has so far shown to cause most sleep disturbances in the ICU. Unfortunately, sedation is not equivalent to a normal sleep cycle in ICU patients.

AC mode is widely believed to be easiest for the patient because it has the least impact on the patient's contribution to ventilation.

Although intensivists are hopeful that future data will show greater promise for other modes, such as Adaptive Support Ventilation (ASV) or Neurally adjusted ventilatory assist (NAVA).

#ventilators

#sleep

References:

1. Parthasarathy S, Tobin MJ. Effect of ventilator mode on sleep quality in critically ill patients. Am J Respir Crit Care Med 2002; 166:1423.

2. Cabello B, Thille AW, Drouot X, et al. Sleep quality in mechanically ventilated patients: comparison of three ventilatory modes. Crit Care Med 2008; 36:1749.

3. Locihová H, Žiaková K. The effects of mechanical ventilation on the quality of sleep of hospitalised patients in the Intensive Care Unit. Rom J Anaesth Intensive Care. 2018 Apr;25(1):61-72. doi: 10.21454/rjaic.7518.251.ven. PMID: 29756065; PMCID: PMC5931186.

Paradoxical Effect of Acetazolamide in the Kidneys and Lungs

Acetazolamide is a carbonic anhydrase inhibitor and is frequently used to treat hypercarbia and metabolic alkalosis. Acetazolamide affects three major organs of the body: the brain, lungs, and kidneys. It is imperative to understand the paradoxical effect of acetazolamide in kidneys and lungs.

In the kidneys, acetazolamide increases hydrogen ion retention and bicarbonate excretion, causing metabolic acidosis over several hours. This also has a secondary effect: metabolic acidosis further increases respiratory drive.

In the lungs, acetazolamide blocks the reciprocal conversion of bicarbonate to CO2 in pulmonary capillaries and impairs the lungs' ability to excrete the CO2. The intended effect is to increase minute ventilation and thereby reduce hypercarbia. But the patients who are not able to increase their ventilation, like patients on ventilators, and, to make it worse, on neuromuscular blockade, may have further deterioration in hypercarbia.

Clinical significance: In the ICU, acetazolamide may 'fire back' if the patient's kidneys are not working well and the patient is on a ventilator. Therefore, it should be used with much greater caution.

Centrally, acetazolamide blocks the CO2 conversion to bicarbonate in tissue capillaries and acutely raises the local tissue partial pressure of carbon dioxide (PCO2). This locally elevated PCO2 and lower pH in the brain increase the central ventilatory drive and lower PaCO2. This central effect, combined with its pulmonary effect, makes acetazolamide an effective prophylactic and therapeutic agent for acute and chronic mountain sickness in healthy individuals.

#pulmonary

#acid-base

References:

1. Swenson ER, Hughes JM. Effects of acute and chronic acetazolamide on resting ventilation and ventilatory responses in men. J Appl Physiol (1985) 1993; 74:230.

2. Richalet JP, Rivera M, Bouchet P, et al. Acetazolamide: a treatment for chronic mountain sickness. Am J Respir Crit Care Med 2005; 172:1427.

3. Alkhuzaee FS, Aldardeer NF, Althobaiti OA, Aljuaid AS, Alshehri AM. Acetazolamide for the Management of Diuretic-Induced Chloride Depletion Alkalosis: A Systematic Review. J Clin Med. 2025 Feb 7;14(4):1041. doi: 10.3390/jcm14041041. PMID: 40004571; PMCID: PMC11857046.

4. Van Berkel MA, Elefritz JL. Evaluating off-label uses of acetazolamide. Am J Health Syst Pharm. 2018 Apr 15;75(8):524-531. doi: 10.2146/ajhp170279. PMID: 29626002.

Wrist BP

Q: Blood Pressure (BP) taken at the wrist level is usually? - select one

A) falsely elevated

B) falsely lowered

Answer: A

Measuring non-invasive BP at the radial artery, i.e., wrist level, is not desirable, though it may be necessary in a few patients, such as those with axillary lymph node resection.

BP at wrist level is falsely elevated due to the hydrostatic pressure related to the lower position of the wrist relative to the heart. Additionally, the relatively small-diameter vessels in older adults are calcified and exhibit reduced elastance. Although BP can be measured with the wrist at heart level, wrist flexion may interfere with sensor positioning.

Wrist BP measurement requires equipment specifically designed for wrist BP, and devices used for brachial BP measurement should not be used.

#hemodynamics

References:

1. Muntner P, Shimbo D, Carey RM, et al. Measurement of Blood Pressure in Humans: A Scientific Statement From the American Heart Association. Hypertension 2019; 73:e35.

2. Palatini P, Asmar R, O'Brien E, et al. Recommendations for blood pressure measurement in large arms in research and clinical practice: position paper of the European society of hypertension working group on blood pressure monitoring and cardiovascular variability. J Hypertens 2020; 38:1244.

3. Zweiker R, Schumacher M, Fruhwald FM, Watzinger N, Klein W. Comparison of wrist blood pressure measurement with conventional sphygmomanometry at a cardiology outpatient clinic. J Hypertens. 2000 Aug;18(8):1013-8. doi: 10.1097/00004872-200018080-00004. PMID: 10953991.

chloride in adrenal insufficiency

Q: Patients with adrenal insufficiency tend to have? - select one

A) Hyperchloremia

B) Hypochloremia

Answer: A

Adrenal insufficiency, as defined by mineralocorticoid deficiency, causes hyperkalemia and hyperchloremic acidosis. 

Mechanism of action: The loss of aldosterone reduces hydrogen ion excretion in the renal collecting duct, leading to hyperchloremic normal anion gap metabolic acidosis. 

Other imbalances that may occur

• Hyponatremia 
• hypercalcemia (though rare)
• hypoglycemia

#electrolytes

#endocrinology

References:

1. Sagar N, Lohiya S. A Comprehensive Review of Chloride Management in Critically Ill Patients. Cureus. 2024 Mar 6;16(3):e55625. doi: 10.7759/cureus.55625. PMID: 38586759; PMCID: PMC10995984.

2. Kromah F, Tyroch A, McLean S, Hughes H, Flavin N, Lee S. Relative adrenal insufficiency in the critical care setting: debunking the classic myth. World J Surg. 2011 Aug;35(8):1818-23. doi: 10.1007/s00268-011-1126-3. PMID: 21533963; PMCID: PMC7101698.

3. Fries C, Fenske W. Elektrolytentgleisungen unter endokrinologischen Gesichtspunkten [An Endocrinological Perspective on Electrolyte Imbalances]. Dtsch Med Wochenschr. 2025 Aug;150(15):883-889. German. doi: 10.1055/a-2318-7580. Epub 2025 Jul 21. PMID: 40690933.

Nimodipine prophylaxis in aneurysmal subarachnoid hemorrhage

Q: Why, despite no convincing angiographic evidence of nimodipine's effect on Subarachnoid Hemorrhage (SAH), does it continue to be the standard of care in SAH?

Answer: Although it is true that so far Nimodipine failed to show any concrete evidence of objective improvement of either angiographic or symptomatic vasospasm in SAH, it is considered essential, and not using it, a malpractice, in SAH management. This is because nimodipine likely dilates small arteries that are not visible on angiograms.

Other beneficial effects of nimodipine are due to the combination of:

• reduction of calcium-dependent excitotoxicity
• diminished platelet aggregation
• inhibition of ischemia triggered by red blood cell products

#neurology

#neurosurgery

#pharmacology

References:

1. Barker FG 2nd, Ogilvy CS. Efficacy of prophylactic nimodipine for delayed ischemic deficit after subarachnoid hemorrhage: a metaanalysis. J Neurosurg 1996; 84:405.

2. Dayyani M, Sadeghirad B, Grotta JC, et al. Prophylactic Therapies for Morbidity and Mortality After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Network Meta-Analysis of Randomized Trials. Stroke 2022; 53:1993.

3. Bellapart J, Laupland KB, Malacova E, Roberts JA, Paratz J. Nimodipine prophylaxis in aneurysmal subarachnoid hemorrhage, a question of tradition or evidence: A scoping review. J Clin Neurosci. 2024 May;123:91-99. doi: 10.1016/j.jocn.2024.03.016. Epub 2024 Apr 1. PMID: 38564967.

4. Hao G, Chu G, Pan P, Han Y, Ai Y, Shi Z, Liang G. Clinical effectiveness of nimodipine for the prevention of poor outcome after aneurysmal subarachnoid hemorrhage: A systematic review and meta-analysis. Front Neurol. 2022 Sep 21;13:982498. doi: 10.3389/fneur.2022.982498. PMID: 36212656; PMCID: PMC9533126.

Fenoldopam

Q: A 64-year-old male with a past medical history of hypertension, diabetes mellitus, hyperlipidemia, and stage-3 renal insufficiency is admitted to the ICU with hypertensive crises. The intensivist picked Fenoldopam infusion. What is the added advantage of Fenoldopam in this patient?

Answer: It either maintains or increases kidney perfusion

Although Fenoldopam is not commonly used as an antihypertensive infusion in ICUs, it offers several advantages. It is a peripherally acting dopamine-1 receptor agonist that maintains or increases renal perfusion while controlling hypertension. It has shown to increase glomerular filtration rate (GFR), urine output, and sodium excretion.

Dose-wise, it is usually initiated at 0.1 mcg/kg/min and titrated at 15-minute intervals to a maximum of 1.6 mcg/kg/min. If needed can be titrated up to 2.0 mcg/kg/minute. It is very unlikely to cause any real toxicity, though it is contraindicated in glaucoma, and caution should be applied in patients with sulpha allergy, as it is premixed in a solution containing sodium metabisulfite.

# hemodynamics

#nephrology

#pharmacology

References:

1. Murphy MB, Murray C, Shorten GD. Fenoldopam: a selective peripheral dopamine-receptor agonist for the treatment of severe hypertension. N Engl J Med 2001; 345:1548.

2. White WB, Halley SE. Comparative renal effects of intravenous administration of fenoldopam mesylate and sodium nitroprusside in patients with severe hypertension. Arch Intern Med 1989; 149:870.

3. Shusterman NH, Elliott WJ, White WB. Fenoldopam, but not nitroprusside, improves renal function in severely hypertensive patients with impaired renal function. Am J Med 1993; 95:161.

Removal of stylet during intubation

Q: What's the best time to remove the stylet from the Endotracheal Tube (ETT) while intubating the patient? - select one

A) Once the tip of the ETT has passed the vocal cords

B) After the ETT is fully inserted inside the trachea

Answer: A

An inexperienced operator usually keeps the stylet in the ETT till the tube is fully inserted and set in the trachea. This approach may cause injury or obstruct the passage of the tube beyond the vocal cords. 

Ideally, once the tip of the ETT has passed the vocal cords, the operator should pause and ask the staff next to remove the stylet while maintaining a firm hold on the tube and a clear view of the ETT and the glottis.

#procedures

References/further reading:

1. Higgs A, McGrath BA, Goddard C, Rangasami J, Suntharalingam G, Gale R, Cook TM; Difficult Airway Society; Intensive Care Society; Faculty of Intensive Care Medicine; Royal College of Anaesthetists. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018 Feb;120(2):323-352. doi: 10.1016/j.bja.2017.10.021. Epub 2017 Nov 26. PMID: 29406182.

2. DeMasi SC, Casey JD, Semler MW. Evidence-based Emergency Tracheal Intubation. Am J Respir Crit Care Med. 2025 Jul;211(7):1156-1164. doi: 10.1164/rccm.202411-2165CI. PMID: 40238943; PMCID: PMC12264701.

3. Long B, Gottlieb M. Emergency medicine updates: Endotracheal intubation. Am J Emerg Med. 2024 Nov;85:108-116. doi: 10.1016/j.ajem.2024.08.042. Epub 2024 Sep 3. PMID: 39255682.

On FFP

Q: One unit of Fresh Frozen Plasma (FFP) is the plasma taken from a unit of whole blood. How quickly should it be frozen after collection?

Answer: within eight hours of collection.

Each unit of FFP contains approximately 225-250 ml of plasma derived from a single unit of whole blood. It is stored frozen at -18° C or colder to preserve all coagulation factors. FFP is thawed in a 37° C (waterbath) upon request (20-30 minutes) and can be stored after thawing for up to 24 hours at 1-6° C. FFP doesn't require crossmatching.

#hematology

References:

1. National Clinical Guideline Centre (UK). Blood Transfusion. London: National Institute for Health and Care Excellence (NICE); 2015 Nov. (NICE Guideline, No. 24.) 14, Fresh Frozen Plasma: thresholds and targets. Available from: https://www.ncbi.nlm.nih.gov/books/NBK338797/

2. Lauzier F, Cook D, Griffith L, Upton J, Crowther M. Fresh frozen plasma transfusion in critically ill patients. Crit Care Med. 2007 Jul;35(7):1655-9. doi: 10.1097/01.CCM.0000269370.59214.97. PMID: 17522577.

3. Ichikawa, J., Iba, T., Okazaki, R. et al. Hemostatic capability of ultrafiltrated fresh frozen plasma compared to cryoprecipitate. Sci Rep 13, 21579 (2023). https://doi.org/10.1038/s41598-023-48759-1

Cannabis and Asthma

Q: Cannabis (Marijuana) makes asthma? - select one

A) better

B) exacerbate

Answer: B

The objective of this question is to highlight the fact that cannabis tends to cause bronchospasm, wheezing, and chest tightness. It can be a trigger for potentially fatal status asthmaticus.

Unfortunately, some internet as well as medical literature describes cannabis as a bronchodilator, but that should not be promoted for the benefit of society.

#toxicity

#pulmonary

References:

1. Malvi A, Khatib MN, Balaraman AK, Roopashree R, Kaur M, Srivastava M, Barwal A, Siva Prasad GV, Rajput P, Syed R, Sharma G, Kumar S, Singh MP, Bushi G, Chilakam N, Pandey S, Brar M, Mehta R, Sah S, Gaidhane AM, Shabil M, Daniel AS. Cannabis consumption and risk of asthma: a systematic review and meta-analysis. BMC Pulm Med. 2025 Jan 29;25(1):48. doi: 10.1186/s12890-025-03516-0. PMID: 39881272; PMCID: PMC11780798.

2. Sule-Saa S, Hein PP, Sackey JA, Pinkrah D, Towfig M, Akella A, Kotei R, DiCasoli R, Sherazi A, Panigrahi K. The Effect of Cannabis Use Disorder on Mortality and Other Outcomes in Asthma: A Nationwide Analysis (2016-2021). Cureus. 2025 Oct 20;17(10):e94969. doi: 10.7759/cureus.94969. PMID: 41281008; PMCID: PMC12631705.

3. Rustagi AS, Jeffers AM, Graham FJ, Cohen BE, Slatore CG, Byers AL, Glantz SA, Keyhani S. Inhaled Cannabis, Asthma, and Chronic Obstructive Pulmonary Disease: A Population-Based Cross-Sectional Study of n = 379,049. J Gen Intern Med. 2025 Sep 4:10.1007/s11606-025-09833-8. doi: 10.1007/s11606-025-09833-8. Epub ahead of print. PMID: 40906010; PMCID: PMC12681257.

Tricks for intractable hiccups

 Q: Which 2 relatively non-pharmacologic tricks can work in intractable hiccups in the ICU?

Answer:

1. Give 2 ml Nebulised 0.9% saline over 5 minutes. It helps to relieve hiccups by pharyngeal stimulation.

2. Give Peppermint Water. Peppermint water helps by relaxing the lower oesophageal sphincter.

#ICU-care

#GI

Reference:

1. Twycross R, Wilcock A. - Symptom Management in Advanced Cancer. 3rd Edt. Radcliffe Medical Press. 2008

2. Rouse S, Wodziak M. Intractable Hiccups. Curr Neurol Neurosci Rep. 2018 Jun 22;18(8):51. doi: 10.1007/s11910-018-0856-0. PMID: 29934880. 

3. Kishi Y, Nakawaga M, Inumaru A, Nambu M, Sakaguchi M, Murabata M, Matsuoka M, Kako J. Interventions for Hiccups in Adults: A Scoping Review of Western and Eastern Approaches. Palliat Med Rep. 2025 Apr 17;6(1):171-178. doi: 10.1089/pmr.2024.0109. PMID: 40308713; PMCID: PMC12040553.

C/I of Magnesium in Eclampsia

Q: Mention at least one disease where Magnesium is contraindicated in eclampsia?

Answer: Myasthenia gravis

High-dose magnesium has remained the standard of care for eclampsia over the decades, and under time pressure, it is difficult to recall magnesium's contraindications, particularly in patients with a history of myasthenia gravis. Magnesium can precipitate a severe myasthenic crisis.

Similarly, magnesium should be used with caution in the following situations:

• Severe renal failure (lack of excretion)
• Severe Coronary Artery Disease (CAD)
• Heart blocks
• Myocardial disease
• Hypocalcemia (exacerbates the situation)

#ob-gyn

#electrolytes

References:

1. Lake AJ, Al Khabbaz A, Keeney R. Severe Preeclampsia in the Setting of Myasthenia Gravis. Case Rep Obstet Gynecol. 2017;2017:9204930. doi: 10.1155/2017/9204930. Epub 2017 Feb 9. PMID: 28280642; PMCID: PMC5322431.

2. Smith JM, Lowe RF, Fullerton J, Currie SM, Harris L, Felker-Kantor E. An integrative review of the side effects related to the use of magnesium sulfate for pre-eclampsia and eclampsia management. BMC Pregnancy Childbirth. 2013 Feb 5;13:34. doi: 10.1186/1471-2393-13-34. PMID: 23383864; PMCID: PMC3570392.

3. Abdulhadi B, Agarwal M. The Unusual Suspect: Hypocalcemia in Preeclampsia After Magnesium Infusion. J Endocr Soc. 2021 May 3;5(Suppl 1):A227. doi: 10.1210/jendso/bvab048.461. PMCID: PMC8089210.

Eye and Semaglutide

Q: Ischemic optic neuropathy due to semaglutide is?

A) reversible

B) irreversible

Answer: B

The last decade has seen a tremendous rise in the use of Glucagon-like peptide 1 (GLP-1)-based therapies, which include GLP-1 receptor agonists, dual-acting GLP-1 and glucose-dependent insulinotropic polypeptide [GIP] receptor agonists. Unfortunately, the improper use of semaglutide has skyrocketed due to its property of quick weight loss.

Non-arteritic ischemic optic neuropathy (NAION) is a dreaded side effect of semaglutide, as it causes irreversible vision loss. Any patient who experiences worsening vision while taking semaglutide should discontinue it and consult their physician immediately.

# endocrinology

# ophthalmology

#pharmacology

References:

1. Grauslund J, Taha AA, Molander LD, et al. Once-weekly semaglutide doubles the five-year risk of nonarteritic anterior ischemic optic neuropathy in a Danish cohort of 424,152 persons with type 2 diabetes. Int J Retina Vitreous 2024; 10:97.

2. Hathaway JT, Shah MP, Hathaway DB, et al. Risk of Nonarteritic Anterior Ischemic Optic Neuropathy in Patients Prescribed Semaglutide. JAMA Ophthalmol 2024; 142:732.

3. Natividade GR, Spiazzi BF, Baumgarten MW, et al. Ocular Adverse Events With Semaglutide: A Systematic Review and Meta-Analysis. JAMA Ophthalmol 2025; 143:759.

Other labs in hyperthyroidism

Q; In patients with hyperthyroidism, serum total, low-density (LDL), and high-density lipoprotein (HDL) cholesterol tends to be? - select one

A) higher

B) lower

Answer: B

It is always interesting and a good clinical and academic exercise to look for nonspecific laboratory findings in patients with hyperthyroidism. These patients usually have

• lower total, LDL, and HDL cholesterol (due to high sympathathetic activity)
• increased red blood cell (RBC) mass*
• increased plasma volume*
• higher alkaline phosphatase level^
• higher osteocalcin concentrations^

*RBC mass is increased, but the plasma volume is even more increased, showing up as a normochromic, normocytic anemia

^ due to increased bone turnover

#endocrinology

#laboratory-medicine

References: 

1. O'Brien T, Katz K, Hodge D, et al. The effect of the treatment of hypothyroidism and hyperthyroidism on plasma lipids and apolipoproteins AI, AII and E. Clin Endocrinol (Oxf) 1997; 46:17.

2. Dorgalaleh A, Mahmoodi M, Varmaghani B, Kiani Node F, Saeeidi Kia O, Alizadeh Sh, Tabibian Sh, Bamedi T, Momeni M, Abbasian S, Kashani Khatib Z. Effect of thyroid dysfunctions on blood cell count and red blood cell indice. Iran J Ped Hematol Oncol. 2013;3(2):73-7. Epub 2013 Apr 22. PMID: 24575274; PMCID: PMC3915449.

3. Kumeda Y, Inaba M, Tahara H, Kurioka Y, Ishikawa T, Morii H, Nishizawa Y. Persistent increase in bone turnover in Graves' patients with subclinical hyperthyroidism. J Clin Endocrinol Metab. 2000 Nov;85(11):4157-61. doi: 10.1210/jcem.85.11.6979. PMID: 11095447.

Sildenafil and Heart

Q: Sildenafil may have an antiplatelet effect.

A) True

B) False

Answer: A

Sildenafil exerts its mild antianginal effect via four mechanisms:

• It lowers the systolic blood pressure by approximately 8-10 mmHg 
• Dilation of epicardial coronary arteries
• Improving endothelial dysfunction, and 
• Inhibiting platelet activation

That said, all patients with cardiovascular disease should use sildenafil after risk-stratification and under the care of a physician, as its vasodilatory effect can be detrimental in some patients, particularly with undiagnosed or underlying Aortic Stenosis (AS).

#cardiology

#pharmacology

References:

1. Levine GN, Steinke EE, Bakaeen FG, et al. Sexual activity and cardiovascular disease: a scientific statement from the American Heart Association. Circulation 2012; 125:1058.

2. Herrmann HC, Chang G, Klugherz BD, Mahoney PD. Hemodynamic effects of sildenafil in men with severe coronary artery disease. N Engl J Med 2000; 342:1622.

3. Halcox JP, Nour KR, Zalos G, et al. The effect of sildenafil on human vascular function, platelet activation, and myocardial ischemia. J Am Coll Cardiol 2002; 40:1232.

4. Mittleman MA, Maclure M, Glasser DB. Evaluation of acute risk for myocardial infarction in men treated with sildenafil citrate. Am J Cardiol 2005; 96:443.

OTC anti-diarrheal and dizzyness

Case: 32-year-old male, healthy male with no past medical history, presented to the Emergency Department (ED) with dizziness. On telemetry patient is found to be in wide-complex tachycardia. Patient recently returned from a three-week trip and reported using over-the-counter (OTC) anti-diarrheal multiple times a day during vacation for traveler's diarrhea. Which dug is suspected?

Answer: Loperamide 

Less well-known is the fact that Loperamide is an opioid that acts as a peripherally acting mu-opioid receptor agonist and rarely affects the central nervous system (CNS). It is an effective anti-diarrheal and usually safe, so the FDA approved it as an OTC medicine. 

Interestingly, in overdose, it loses specificity for the gastrointestinal (GI) tract. Potentially fatal side effects of overdose are QRS and QT interval prolongation and wide-complex tachycardia.

#pharmacology

#toxicity

References:

1. Eggleston W, Nacca N, Marraffa JM. Loperamide toxicokinetics: serum concentrations in the overdose setting. Clin Toxicol (Phila) 2015; 53:495.

2. Spinner HL, Lonardo NW, Mulamalla R, Stehlik J. Ventricular tachycardia associated with high-dose chronic loperamide use. Pharmacotherapy 2015; 35:234.

3. Wightman RS, Hoffman RS, Howland MA, et al. Not your regular high: cardiac dysrhythmias caused by loperamide. Clin Toxicol (Phila) 2016; 54:454.

4. Eggleston W, Clark KH, Marraffa JM. Loperamide Abuse Associated With Cardiac Dysrhythmia and Death. Ann Emerg Med 2017; 69:83.

Sleep Disturbances in ICU

Q: ICU patients, particularly older patients, who sleep more during the day than at night, tend to have greater cognitive impairment during Post-ICU recovery.

A) True

B) False

Answer: A

Preserving physiological sleep during hospitalization remains a challenge for clinicians. Pragmatically, none of the patients achieve a normal sleep pattern in the ICU due to various environmental and pharmacological factors, some of which can be modified and some of which remain non-negotiable. Preservation of the normal sleep cycle remains more challenging in older, sedated, and ventilated patients.

Good sedation is not equivalent to a normal sleep cycle. This can be best described as "atypical sleep" or "pathologic wakefulness", due to sleep fragmentation and the absence of rapid eye (REM) movement.

Although all patients experience sleep disturbance in Post-ICU recovery, the older patients remained at high risk, particularly those patients who slept more during the day than at night while they were in the ICU.

#sleep

#PICS

References:

1. Elliott R, McKinley S, Cistulli P, Fien M. Characterisation of sleep in intensive care using 24-hour polysomnography: an observational study. Crit Care 2013; 17:R46.

2. Sun T, Sun Y, Huang X, et al. Sleep and circadian rhythm disturbances in intensive care unit (ICU)-acquired delirium: a case-control study. J Int Med Res 2021; 49:300060521990502.

3. Altman MT, Knauert MP, Pisani MA. Sleep Disturbance after Hospitalization and Critical Illness: A Systematic Review. Ann Am Thorac Soc 2017; 14:1457.

4. Elías MN, Munro CL, Liang Z. Daytime-to-Nighttime Sleep Ratios and Cognitive Impairment in Older Intensive Care Unit Survivors. Am J Crit Care 2021; 30:e40.