Medicine Hack

Sick sinus syndrome is a term applied to a syndrome encompassing a number of sinus nodal abnormalities, including the following: (1) Persistent spontaneous sinus bradycardia not caused by drugs and inappropriate for the physiologic circumstance (2) Sinus arrest or exit block i.e. no P wave on ECG for > 2 s. (3) Combinations of SA and AV conduction disturbances and (4) Alternation of paroxysms of rapid regular or irregular atrial tachyarrhythmias and periods of slow atrial and ventricular rates (bradycardia-tachycardia syndrome). More than one of these conditions can be recorded in the same patient on different occasions, and their mechanisms often can be shown to be causally interrelated and combined with an abnormal state of AV conduction or automaticity. Incidence: 3 in every 10,000 persons are affected. Incidence increases with age, seen more after 65 years of age. Men and women are equally affected. Patients who have sinus node disease can be categorized

Definition: Barrett’s esophagus is characterized by an intestinal metaplastic change in the lining mucosa of the esophagus in response to chronic gastro­esophageal reflux.  The condition is named after Norman Barrett, an Australian surgeon who drew attention to the columnar-lined esophagus in 1950. It is still not well understood why some people develop esophagitis and others develop Barrett’s esophagus often without significant esophagitis.  Pathology: In Barrett’s esophagus the junction between squamous esophageal mucosa and gastric mucosa moves proximally. The columnar epithelium is more acid resistant than the squamous epithelium. So this metaplasia appears to be a protective adaptation. The patient of chronic reflux esophagitis will find his symptoms decrease when he has developed Barrett's esophagus. Incidence: It is mainly seen in white man and the prevalence increases with age.  Several types of gastric-type mucosa may be found in the lower esophagus. When inte

The triad is still a useful clue to the presence of severe pericardial tamponade. It was described by Dr Claude S. Beck, a thoracic surgeon, in 1935. It consists of : 1) hypotension, 2) muffled heart sounds, 3) elevated jugular venous pressure.

Third degree atrioventricular block is also known as complete heart block because there is complete failure of conduction between the atria and the ventricles. As a result of this there is complete independence between atrial and ventricular contractions. It is thus one type of AV dissociation. The classic characteristics of a complete heart block ECG are as follows : 1) P waves are present and the atrial rate is faster than the ventricular rate, 2) QRS complexes are present and are usually much slower than normal,  3) the P waves bear no relation to the QRS complexes and thus the PR intervals are completely variable. Since there is a block in the conduction, a subsidiary pacemaker will take over the function to make the ventricles contract. Depending at the level of block we can have different QRS complex morphologies.  Below is an ECG showing a complete heart block with the block occurring proximal to the His bundle, usually in congenital cases. The QRS complexes

 INTRODUCTION  Romberg's test is done to assess the integrity of the dorsal columns of the spinal cord. It is not a test to assess the cerebellar function. The test was first described by Moritz Heinrich von Romberg who found that patients with tabes dorsalis (neurosyphilis) often complained of increased unsteadiness in the dark. The test should be performed in all patients who complain of dizziness, imbalance or falls to rule out sensory ataxia.  HOW TO DO THE TEST?  The test is done by requesting the patient to keep his feet firmly together, arms by the side and the eyes open at first. The balance of the patient is noted. Now the patient is asked to close both eyes and the balance is now noted for around 1 minute. The physician should stand in front of the patient with his arms extended on either side of the patient but not touching him. This is done as the latter may fall.  INTERPRETATION  1) If with the eyes open, the balance is not good then there may be a probl

PCI consists of balloon angioplasty followed by stenting. Balloon angioplasty expands the coronary lumen by stretching and tearing the atherosclerotic plaque and vessel wall. The atherosclerotic plaque is also redistributed a little along its longitudinal axis. Elastic recoil of the stretched vessel wall generally leaves a 30 to 35 percent residual diameter stenosis. Although stand-alone balloon angioplasty is rarely used other than for very small (<2.25 mm) vessels, balloon angioplasty remains integral to PCI for predilating lesions before stent placement, deploying coronary stents, and further expanding stents after deployment. Coronary stents are currently used in more than 90 percent of PCI procedures worldwide. Coronary stents lowers the incidence of vessel closure. Restenosis after coronary stent placement occurs in some patients due to excessive intimal hyperplasia within the stent. While bare metal coronary stents reduce the incidence of angiographic and clinica

Above is an electrophoresis of a patient suspected to have sickle cell disease. A blood sample was taken from him and the erythrocytes were separated. After lysis of the RBCs, hemoglobin was released and it was run on a polyacryamide gel. Electrophoresis was carried out and Western blot was performed to located the hemoglobin. The principle of electrophoresis is that the the more negatively charged particles move towards the positive pole and vice versa. In the case of sickle cell disease, glutamate is substituted by valine at the 6th position of the beta chain. This removes a negative charge from the chain and thus in the electric field the mutated chain will not move as far towards the positive pole as does the non-mutated chain. The interpretation is as follows: 1) X is a band that represents the mutated HbS. 2) Y is the normal Hb. 3) 1 is a carrier of HbS i.e. having one normal and one mutated chain. 4) 2 is a person who does not carry any mutant alleles. 5) 3 is a per

Narrow QRS complex     A.     Sinus tachycardia              B.     Paroxysmal supraventricular tachycardias (PSVTs)                      1.      Atrial tachycardias, including single-focus or multifocal (MAT) variants                        2.     AV nodal reentrant tachycardia (AVNRT)                       3.     AV reentrant tachycardia (AVRT) involving a bypass tract              C.     Atrial flutter              D.     Atrial fibrillation  Wide QRS complex     A.     Ventricular tachycardia                B.     SVT/AF or flutter, with aberrant ventricular conduction usually caused by either of the following:   1.     Bundle branch block patterns                          2.     Atrioventricular bypass tract (Wolff-Parkinson-White preexcitation patterns)  

Hemodialysis should be started when: 1) eGFR is < 6  mL/min/1.73  m 2 2) eGFR is < 15  mL/min/1.73  m 2   and patient is showing signs and symptoms of uremia, unable to control his hydration and blood pressure.  Cockcroft-Gault formula  is a very commonly used formula to get an estimate of the GFR. The unit for eGFR is  mL/min. The classification for stages of chronic kidney diseases  on the other hand is based on normalized eGFR i.e. the eGFR per 1.73  m 2  and the unit being mL/min/1.73   m 2 . Thus we also need to calculate the surface area of the patient's body. It is given by the formula as follows :  Body Surface Area ( m 2 ) = ( [Height(cm) x Weight(kg) ]/ 3600 )½ And the normalized eGFR ( mL/min/1.73   m 2 ) = (eGFR/BSA) x 1.73 A clinical example is given below.   A 45 year old man weighing 70 kg and 180 cm tall has been admitted to the hospital because of fluid overload. He has been treated for the past hours with diuretics but has not been im

It refers to the superficial peri-umbilical bruising of the subcutaneous fat. It can be seen in the following cases: 1) acute pancreatitis (classically), 2) bleeding from blunt abdominal trauma, rupture of abdominal aorta and ruptured ectopic pregnancy. The sign was actually first described by Thomas Cullen in 1916 in a case of ruptured ectopic pregnancy.

It is a Fab fragment of a humanized monoclonal antibody directed against the glycoprotein IIb/IIIa. The latter is a platelet surface integrin. It is a receptor for fibrinogen which binds platelets to each other causing aggregation. By inhibiting the receptor, abciximab acts as a potent antiplatelet agent.  Indications: 1) myocardial ischemia, 2) percutaneous coronary intervention. Dose: 1) For M.I - initially an I.V bolus of 0.25 mg/kg over 5 min followed by 0.125 µg/kg/min (to a maximum of 10 µg/min) for 12 hours. 2) For P.C.I - initially, 0.25 mg/kg I.V bolus over 5 min 20-60 min prior to angioplasty followed by 0.125 µg/kg/min (to a maximum of 10 µg/min) for next 12 hours. Contraindications: 1) bleeding disorder or use of anticoagulant within 7 days, 2) CVA within 2 years, 3) known allergy to this product, 4) major trauma or surgery within 6 weeks, 5) severe uncontrolled hypertension, 6) active internal bleeding, 7) thrombocytopenia i.e pla

Definition: Chickenpox is a benign viral disease of childhood, characterized by an exanthematous vesicular rash. It is an extremely common and contagious condition. It is caused by the varicella-zoster virus which is a herpes virus and contains a double stranded DNA in its center. Epidemiology: Age group affected- 5 to 9 years. The infection can be there at other ages too but it is less frequent. It is highly contagious and it affects all races and both sexes equally. The attack rate is around 90% among seronegative persons. Pathogenesis: Incubation period- 10 to 21 days but is usually 14 to 17 days. Patients are infectious around 48 hours from onset of vesicular rash, during the period of vesicular formation (around 4-5 days) and until all vesicles are crusted. Transmission occurs by respiratory route. The virus is believed to be localized in the nasopharynx, in the reticulo-endothelial system. It then enters the blood. This stage of viremia is characterized by diffused ski

Definition: It is defined as the introduction of a fluid drug under pressure using a syringe equipped with a hollow needle into the loose connective tissue below the dermis i.e. into the hypodermis. It has a low absorption there because of the low vascularisation but since it contains pain receptors, injection can be painful depending on the volume administered. For structure of skin, consider this page :  Skin structure Sites: 1) outer sides of arm, 2) front of upper outer thigh, 3) above and below the spine of scapula, 4) abdomen extending from the costal margin to the iliac crest except 5 cm all around the umbilicus. Angle of insertion of needle: 1) 90 degrees with a short needle, 2) 45 degrees with a longer needle. Techniques: 1) Pinch skin slightly to make 3 cm fold, 2) Insert needle quickly and firmly, 3) Release skin, 4) Aspirate and make sure that needle is not in a vessel, 5) Remove needle by gentle pressure with antiseptic swab, 6) Massage

Erythropoiesis refers to the formation of erythrocytes. Tissue oxygenation is the most essential regulator for this continuous process. Thus conditions like anemia, high altitudes, pulmonary disorders or heart failure cause tissue hypoxia. As a result of this, erythropoietin (EPO) is released from kidneys. It is glycoprotein in nature and 90% of it is produced in the kidneys. The remaining 10% is produced in the liver. This is why in cases where the kidneys have been removed or damaged by diseases, anemia results. The hypoxic sensor is believed to be the high oxygen-consuming renal tubular cells. If the hypoxic blood is unable to deliver enough oxygen from the peritubular capillaries, then the renal tubular epithelial cells are thought to release the erythropoietin. There may also be a non renal sensor because at times localised hypoxia elsewhere in the body can also lead to erythropoietin secretion. The effect of EPO is that it stimulates the production of proerythroblasts from

After a myocardial infarction, the longer we wait, the better it is to decrease the risk of post operative attack. But unfortunately we cannot delay the surgery indefinitely. We have to balance the risk for a post-op heart attack versus the risk of delaying the surgery. Studies have shown that for: 1) 0-30 days, risk is around 33%, 2) 31-60 days, risk is around 19%, 3) 61-90 days, risk is around 8% and 4) 92-180 days, risk is around 6%. So waiting for at least 2 months after an M.I decreases the risk for post-op heart attack.

The double-ring test is clearly shown in this photo. It is also known as the ring sign or halo sign. The patient was brought following an injury to the head and was bleeding moderately from the nose but the blood was more watery than normal. CSF rhinorrhea was suspected. The dextrose stick test was positive to the sample and when placed on a filter paper, we got an inner ring of blood and a halo, followed by an outer ring of CSF. Though this has been a classical medical test, it is not 100% reliable.

It is a diarrheal disease and is commonly seen in cases of food poisoning. Pathogenesis: Man acquires this infection by ingesting contaminated water or food. Water is usually infected by feaces from an infected animal or human. Poultry and eggs also comprise an important source of salmonella. The organisms may be present on the outer shell or even in the yolk. The clinical syndromes that can occur in man includes gastroenteritis, enteric fever and septicaemia. In the case of enterocolitis, the salmonella bacilli attach themselves to the microvilli of the ileal mucosa by means of adhesins and then invade the cells. They cause massive efflux of fluids and electrolytes. Clinical presentaion: There is large volume watery diarrhea, fever, headache, chills, abdominal pain and tenesmus. In simple uncomplicated cases, the diarrhea will last for 3-7 days. Diagnosis is made by stool culture. The disease is self limited. Treatment consists only of correcting any fluid and electrolyte

1. For adults requiring a peripheral catheter, upper extremity site is preferred. If it is for a child, then we can use both upper or lower extremities as well as scalp sites. 2. The catheter site should be evaluated everyday and if there is any sign of phlebitis, the catheter should be removed immediately. 3. For central catheters in adults, it is better to use the jugular or subclavian route rather than the femoral one. 4. Systemic antimicrobial prophylaxis is not essential when using I.V catheters.

ECG shows an inferior wall infarct i.e ST segment elevation in leads II, III and aVF. The precordial V leads are actually right sided on this ECG. This is evident because the tracing in V6 does not resemble lead I and aVL. Also the P waves in V4 to V6 are flat. ST depression in I and aVL along with ST elevation in right sided V3-V6 indicates right ventricular infarct.

Depression is a mood disorder whereby mood is sad. About 30% of psychiatric cases deal with depression. Both males and females are affected but females are slightly more prone to be depressed. Cause: The biological cause is that there is a decrease in the serotonin neurotransmitter. Signs and symptoms: A simple mnemonic to remember is SIPS CAGE. 1) Sleep - There is late onset of sleep, intermittent awakening and early morning awakening i.e. around 2 hours before the normal waking up time. Rarely, the patient may over sleep. 2) Interest - Patient will have a decrease interest in the daily activities. This can result in social withdrawal, decreased ability to function in occupational and interpersonal areas. At times there is the inability to experience pleasure aka anhedonia . 3) Psychomotor activity - In younger patients, there is slowness in the thinking process and activities also are carried out at a slow pace. In elderly on the other hand, there is restlessness and inc