1 What is hypertonic saline? Normal saline is 0.9% sodium chloride. Hypertonic saline is 7.5% sodium chloride (eight times as concentrated as normal saline). Key Points: Ion Concentrations in Crystalloid Solutions 1. One-half normal saline or 0.45% NaCl: 77 mEq of Na+, 77 mEq of Cl- 2. Normal saline or 0.9% NaCl: 154 mEq of Na+, 154 mEq of Cl- 3. Hypertonic normal saline or 7.5%…
1 Is breathing really overrated? It may be. A Japanese yoga master survived just fine breathing once per minute for 1 hour (see reference ). But, when medical students and residents prioritize activities that they really enjoy, year after year, “breathing” consistently ranks very high. 2 Mr. O’Flaherty has just undergone an inguinal herniorrhaphy under local anesthesia. The recovery room nurse asks permission to sedate him.…
1 Why do patients need mechanical ventilation? There are three basic categories of need when it comes to mechanical ventilation (MV): (1) inadequate respiratory drive; (2) inability to maintain adequate alveolar ventilation; and (3) hypoxia. The decision to provide MV should be based on clinical examination and assessment of gas exchange by arterial blood gas (ABG) analysis as needed. It is an individualized decision because arbitrary…
1 What is congested in CHF? The lungs. 2 Why the lungs? When cardiac output falls, the kidney releases renin. Renin converts angiotensinogen to angiotensin I in the liver. Angiotensin I is converted to angiotensin II by angiotensin-converting enzyme (ACE) in the lung. Angiotensin II stimulates release of aldosterone from the adrenal and antidiuretic hormone (ADH) from the posterior pituitary. Both aldosterone and AHD collaborate to…
1 Define shock Shock is: Not just low blood pressure Not just decreased peripheral perfusion Not just limited systemic oxygen delivery Ultimately, shock is decreased tissue respiration. Shock is suboptimal consumption of oxygen and excretion of carbon dioxide (CO 2 ) at the cellular level. 2 Is shock related to cardiac output? Yes. A healthy medical student can redistribute blood flow preferentially to vital organs. After…
1 Are all cardiac dysrhythmias clinically important? Most are not. Many of us have isolated premature ventricular contractions (PVCs) or premature ventricular depolarizations (PVDs) all the time. Superbly conditioned athletes frequently exhibit resting heart rates in the 30s. A clinically important cardiac dysrhythmia is a rhythm that bothers the patient. As a rule, if the patient’s ventricular rate is 60–100 beats per minute (regardless of mechanism),…
1 What is cardiac arrest and sudden cardiac death? Cardiac arrest is the sudden cessation of effective cardiac pumping function. Sudden cardiac death is the unexpected natural death from a cardiac cause within 1 hour of onset of symptoms, in a person without a previous condition that would appear fatal. 2 What is the most common dysrhythmia encountered during sudden cardiac death and what is its…
Surgery is a participatory, team, and contact sport. Present yourself to patients, residents, and attendings with enthusiasm (which covers a multitude of sins), punctuality (type A people do not like to wait), and cleanliness (you must look, act, and smell like a doctor). 1 Why should you introduce yourself to each patient and ask about his or her chief complaint? Symptoms are perception, and perception is…
Abbreviations 2D Two-dimensional 3D Three-dimensional AR Augmented reality AVM Arteriovenous malformation CT Computed tomography CTA Computed tomography angiography FDA Food and Drug Administration LITT Laser interstitial thermal therapy MCA Middle cerebral artery MRI Magnetic resonance imaging TOF MRA Time-of-flight magnetic resonance angiography VR Virtual reality Introduction The technology of three-dimensional (3D) printing has emerged since a few decades now and it has been described as a…
Introduction Three-dimensional (3D) printing is an engineering process during which a 3D object is created by applying various materials using a computer-generated model. Materials are usually applied layer by layer. , The process can be broken down into the following components: Image acquisition/creation Modeling: In which computer-aided design (CAD) software, a scanner, or a digital camera creates a digital 3D rendering of an object Printing: Several…
Introduction During the last three decades, advancements in bioprosthetics, biomaterials and tissue engineering have been accompanied by an outbreak in three-dimensional (3D) technology applications in several medical disciplines including plastic, reconstructive and aesthetic surgery. The philosophy behind plastic surgery lies on how basic surgical techniques attempt to close a wound defect and treat congenital anomalies by harvesting, molding (“ πλάσσειν ”) and moving tissues with similar…
Introduction The process of three-dimensional (3D) printing any object comprises a series of procedures that begin with scanning and obtaining several two-dimensional (2D) images of the organ. The images obtained are stacked together to form a structure, followed by a processing step with the aid of processing software, and, finally, built up layer-by-layer. The first references of 3D printing are found nearly 40 years ago, in…
Abbreviations 2D Two-dimensional 3D Three-dimensional 3DP Three-dimensional printing AVM Arteriovenous malformation CAD Computer-aided design CNS Central nervous system CSF Cerebrospinal fluid CT Computed tomography CTA Computed tomographic angiography DAVF Dural arteriovenous fistula DICOM Digital Imaging and Communications in Medicine DLGG Diffuse low-grade glioma DSA Digital subtraction angiography DTI Diffusion tensor imaging EANS European Association of Neurosurgical Societies EVD External ventricular drainage EVT Endoscopic third ventriculostomy fMRI…
Introduction The three-dimensional (3D) illustration technology developed throughout the 1980s, but it has made a huge progress over the last 10 years. While most of the printers have a commercial use, the 3D imaging and printing is a developing application, which helps doctors in diagnosis, therapeutic planning, and possibly the cure of patients with complicated diseases. The evolution has been significant especially during the last decade,…
Introduction: the introduction of three-dimensional printing in liver surgery During the last decade, the evolution of advanced imaging methods and computer-based technologies has led to the increased use of three-dimensional (3D) printing in the medical field and especially in general surgery and all the different surgical specialties and subspecialties as well. , 3D printing is a process of successive adding of a material in a layer-by-layer…
Introduction The first and foremost rule every general surgical trainee is taught early in their apprenticeship is to “Eat when you can, sleep when you can, and do not mess with the pancreas!” Indeed, even in modern-day surgical training, a combination of high commitment, exhaustive effort, and extreme level of stress causes trainees to neglect their personal health and risk burning out, at the beginning of…
Introduction Information and Communication Technologies (ICT) defined healthcare interventions from their inception. Reduced costs, increased efficacy toward growth, social equality, diagnostic efficacy, and treatment effectiveness were the outcomes of these interventions. Contemporary education for healthcare, in particular, has greatly advanced toward widely varying educational resources and activities in the ICT area. The incentive behind this lies in the need for unconstrained time and place to access…
Introduction: 3D bioprinting technology in a few words and its evolution through the years The need to overcome the restrictions of transplantation process such as the limited number of biocompatible donated organs, the increasing demand for organs, the transplants rejection, and/or the overall difficulties after transplantation has led the research to a new field knowing as tissue engineering and regenerative medicine. Currently, the new applications adjusted…
Acknowledgment L. T. gratefully acknowledges the Bodossaki Foundation for financial support. Introduction to additive manufacturing technologies and rapid prototyping The rapid prototyping has dramatically expanded over the last 20 yrs, with the two-dimensional (2D) and three-dimensional (3D) printing processes to be in the forefront and the most promising technologies among others. , 2D and 3D printing are additive manufacturing (AM) processes based on sequential addition of…
Computer-aided design—cost production More specifically, the pre- and postprinting cost amount to a significant proportion of total cost per printed part. So, even when the cost for printer materials decreases, the labor-cost penalty will remain. A “simple” rule says that if no computer-aided design (CAD) exists, then no 3D print could be done. Getting a CAD is challenging and may require several man-hours in order to…