Jugular venous pressure
The jugular venous pressure is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. It can be useful in the differentiation of different forms of lung disease. Classically three upward deflections and two downward deflections have been described; the upward deflections are the "a", "c" and "v" = venous filling The downward deflections of the wave are the "x" and the "y" descent. The patient is positioned at a 45° incline, the filling level of the external jugular vein determined. Visualize the internal jugular vein when looking for the pulsation. In healthy people, the filling level of the jugular vein should be less than 4 centimetres vertical height above the sternal angle. A pen-light can aid in discerning the jugular filling level by providing tangential light; the JVP is easiest to observe if one looks along the surface of the sternocleidomastoid muscle, as it is easier to appreciate the movement relative to the neck when looking from the side.
Like judging the movement of an automobile from a distance, it is easier to see the movement of an automobile when it is crossing one's path at 90 degrees, as opposed to coming toward one. Pulses in the JVP are rather hard to observe, but trained cardiologists do try to discern these as signs of the state of the right atrium; the JVP and carotid pulse can be differentiated several ways: multiphasic – the JVP "beats" twice in the cardiac cycle. In other words, there are two waves in the JVP for each contraction-relaxation cycle by the heart; the first beat represents that atrial contraction and second beat represents venous filling of the right atrium against a closed tricuspid valve and not the mistaken'ventricular contraction'. These wave forms may be altered by certain medical conditions; the carotid artery only has one beat in the cardiac cycle. Non-palpable – the JVP cannot be palpated. If one feels a pulse in the neck, it is the common carotid artery. Occludable – the JVP can be stopped by occluding the internal jugular vein by pressing against the neck.
It will fill from above. The jugular venous pulsation has a biphasic waveform; the a wave corresponds to right atrial contraction and ends synchronously with the carotid artery pulse. The peak of the'a' wave demarcates the end of atrial systole; the x descent follows the'a' wave and corresponds to atrial relaxation and rapid atrial filling due to low pressure. The c wave corresponds to right ventricular contraction causing the tricuspid valve to bulge towards the right atrium during RV isovolumetric contraction; the x' descent follows the'c' wave and occurs as a result of the right ventricle pulling the tricuspid valve downward during ventricular systole.. The x' descent can be used as a measure of right ventricle contractility; the v wave corresponds to venous filling when the tricuspid valve is closed and venous pressure increases from venous return – this occurs during and following the carotid pulse. The y descent corresponds to the rapid emptying of the atrium into the ventricle following the opening of the tricuspid valve.
A classical method for quantifying the JVP was described by Borst & Molhuysen in 1952. It has since been modified in various ways. A venous arch may be used to measure the JVP more accurately; this sign is used to determine. Feel the radial pulse while watching the JVP; the waveform, seen after the arterial pulsation is felt is the'v wave' of the JVP. The term "hepatojugular reflux" was used as it was thought that compression of the liver resulted in "reflux" of blood out of the hepatic sinusoids into the inferior vena cava, thereby elevating right atrial pressure and visualized as jugular venous distention; the exact physiologic mechanism of jugular venous distention with a positive test is much more complex and the accepted term is now "abdominojugular test". In a prospective randomized study involving 86 patients who underwent right and left cardiac catheterization, the abdominojugular test was shown to correlate best with the pulmonary arterial wedge pressure. Furthermore, patients with a positive response had lower left ventricular ejection fractions and stroke volumes, higher left ventricular filling pressure, higher mean pulmonary arterial, higher right atrial pressures.
The abdominojugular test, when done in a standardized fashion, correlates best with the pulmonary arterial wedge pressure, therefore, is a reflection of an increased central blood volume. In the absence of isolated right ventricular failure, seen in some patients with right ventricular infarction, a positive abdominojugular test suggests a pulmonary artery wedge pressure of 15 mm Hg or greater. Certain wave form abnormalities, include cannon a-waves, or increased amplitude'a' waves, are associated with AV dissociation, when the atrium is contracting against a closed tricuspid valve, or in ventricular tachycardia. Another abnormality, "c-v waves", can be a sign of tricuspid regurgitation; the absence of'a' waves may be seen in atrial fibrillation. An elevated J
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries when the surrounding temperature is different. A thermoconforming organism, by contrast adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation; the internal thermoregulation process is one aspect of homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from thermal equilibrium with its environment. If the body is unable to maintain a normal temperature and it increases above normal, a condition known as hyperthermia occurs. For humans, this occurs when the body is exposed to constant temperatures of 55 °C, with prolonged exposure at this temperature and up to around 75 °C death is inevitable. Humans may experience lethal hyperthermia when the wet bulb temperature is sustained above 35 °C for six hours; the opposite condition, when body temperature decreases below normal levels, is known as hypothermia.
It results when the homeostatic control mechanisms of heat within the body malfunction, causing the body to lose heat faster than producing it. Normal body temperature is around 37 °C, hypothermia sets in when the core body temperature gets lower than 35 °C. Caused by prolonged exposure to cold temperatures, hypothermia is treated by methods that attempt to raise the body temperature back to a normal range, it was not until the introduction of thermometers that any exact data on the temperature of animals could be obtained. It was found that local differences were present, since heat production and heat loss vary in different parts of the body, although the circulation of the blood tends to bring about a mean temperature of the internal parts. Hence it is important to identify the parts of the body that most reflect the temperature of the internal organs. For such results to be comparable, the measurements must be conducted under comparable conditions; the rectum has traditionally been considered to reflect most the temperature of internal parts, or in some cases of sex or species, the vagina, uterus or bladder.
The temperature of the urine as it leaves the urethra may be of use in measuring body temperature. More the temperature is taken in the mouth, ear or groin; some animals undergo one of various forms of dormancy where the thermoregulation process temporarily allows the body temperature to drop, thereby conserving energy. Examples include hibernating bears and torpor in bats. Thermoregulation in organisms runs along a spectrum from endothermy to ectothermy. Endotherms create most of their heat via metabolic processes, are colloquially referred to as warm-blooded; when the surrounding temperatures are cold, endotherms increase metabolic heat production to keep their body temperature constant, thus making the internal body temperature of an endotherm more or less independent of the temperature of the environment. One metabolic activity, in terms of generating heat, that endotherms are able to do is that they possess a larger number of mitochondria per cell than ectotherms, enabling them to generate more heat by increasing the rate at which they metabolize fats and sugars.
Ectotherms use external sources of temperature to regulate their body temperatures. They are colloquially referred to as cold-blooded despite the fact that body temperatures stay within the same temperature ranges as warm-blooded animals. Ectotherms are the opposite of endotherms. In ectotherms, the internal physiological sources of heat are of negligible importance. Living in areas that maintain a constant temperature throughout the year, like the tropics or the ocean, has enabled ectotherms to develop a wide range of behavioral mechanisms that enable them to respond to external temperatures, such as sun-bathing to increase body temperature, or seeking the cover of shade to lower body temperature. Vaporization: Evaporation of sweat and other bodily fluids. Convection: Increasing blood flow to body surfaces to maximize heat transfer across the advective gradient. Conduction: Losing heat by being in contact with a colder surface. For instance: Lying on cool ground. Staying wet in a river, lake or sea.
Covering in cool mud. Radiation: releasing heat by radiating it away from the body. Convection: Climbing to higher ground up trees, rocks. Entering a warm water or air current. Building an insulated nest or burrow. Conduction: Lying on a hot surface. Radiation: Lying in the sun. Folding skin to reduce exposure. Concealing wing surfaces. Exposing wing surfaces. Insulation: Changing shape to alter surface/volume ratio. Inflating the body. To cope with low temperatures, some fish have developed the ability to remain functional when the water temperature is below freezing. Amphibians and reptiles cope with heat loss by behavioral adaptations. An example of behavioral adaptation is that of a lizard lying in the sun on a hot rock in order to heat through radiation and conduction. An endotherm is an animal that regulates its own body temperature by keeping it at a constant level. To regulate body temperature, an organism may need to prevent heat gains in arid environments. Evaporation of water, either across respiratory surfaces or across the skin
Annals of Internal Medicine
Annals of Internal Medicine is an academic medical journal published by the American College of Physicians. It is one of the most cited and influential specialty medical journals in the world. Annals publishes content relevant to the field of related sub-specialties. Annals' mission is to promote excellence in medicine, enable physicians and other health care professionals to be well-informed members of the medical community and society, advance standards in the conduct and reporting of medical research, contribute to improving the health of people worldwide. To achieve this mission, the journal publishes a wide variety of original research, review articles, practice guidelines, commentary relevant to clinical practice, health care delivery, public health, health care policy, medical education and research methodology. In addition, the journal publishes personal narratives that convey the feeling and the art of medicine. Selected articles in the journal are open access; the most recent Impact Factor for Annals of Internal Medicine is 19.384.
With 53,689 total cites in 2017, Annals is the most cited general internal medicine journal and one of the most influential journals in the world. The journal is abstracted and indexed in: The Annals of Internal Medicine was established in 1927 and has been published twice monthly since 1988. ACP produced two other journals; the Annals of Medicine was established in 1920 was discontinued after a short run due to financial problems of the publisher. The Annals of Clinical Medicine was renamed to the current title when the ACP took direct control and became publisher. Editors-in-chief have included Aldred Scott Warthin, Carl Weller, Maurice Pincoffs, Paul Clough, J. Russell Elkington, Edward Huth and Suzanne Fletcher, Frank Davidoff and Harold C. Sox. Peer review was introduced by Elkington; the current editor-in-chief is Christine Laine, MD, MPH, FACP. In May 2008, ACP Journal Club was merged into Annals of Internal Medicine as a monthly feature. Official website
The Weber test is a quick screening test for hearing. It can detect unilateral sensorineural hearing loss; the test is named after Ernst Heinrich Weber. Conductive hearing ability is mediated by the middle ear composed of the ossicles: incus, stapes. Sensorineural hearing ability is mediated by the inner ear composed of the cochlea with its internal basilar membrane and attached cochlear nerve; the outer ear consisting of the pinna, ear canal, ear drum or tympanic membrane transmits sounds to the middle ear but does not contribute to the conduction or sensorineural hearing ability save for hearing transmissions limited by cerumen impaction. The Weber test has had its value as a screening test questioned in the literature; the Weber and the Rinne test are performed together with the results of each combined to determine the location and nature of any hearing losses detected. In the Weber test a vibrating tuning fork is placed in the middle of the forehead, above the upper lip under the nose over the teeth, or on top of the head equi-distant from the patient's ears on top of thin skin in contact with the bone.
The patient is asked to report. A normal weber test has a patient reporting the sound heard in both sides. In an affected patient, if the defective ear hears the Weber tuning fork louder, the finding indicates a conductive hearing loss in the defective ear. In an affected patient, if the normal ear hears the tuning fork sound better, there is sensorineural hearing loss on the other ear. However, the aforegoing presumes one knows in advance which ear is defective and, normal and the testing is being done to characterize the type, conductive or sensorineural, of hearing loss, occurring. In the case where the patient is unaware or has acclimated to their hearing loss, the clinician has to use the Rinne test in conjunction with the Weber to characterize and localize any deficits; that is, an abnormal Weber test is only able to tell the clinician that there is a conductive loss in the ear which hears better or that there is a sensorineural loss in the ear which does not hear as well. For the Rinne test, a vibrating tuning fork is placed on the mastoid process behind each ear until sound is no longer heard.
Without re-striking the fork, the fork is quickly placed just outside the ear with the patient asked to report when the sound caused by the vibration is no longer heard. A normal or positive Rinne test is when sound is still heard when the tuning fork is moved to air near the ear, indicating that AC is equal or greater than. Therefore, AC > BC. In conductive hearing loss, bone conduction is better than air or BC > AC, a negative Rinne, the patient will report that they do not hear the fork once it is moved. The Rinne test is not ideal for distinguishing sensorineural hearing loss, as both sensorineural hearing loss and normal hearing report a positive Rinne test. In a normal patient, the Weber tuning fork sound is heard loudly in both ears, with no one ear hearing the sound louder than the other. A patient with symmetrical hearing loss will hear the Weber tuning fork sound well, with diagnostic utility only in asymmetric hearing losses. In a patient with hearing loss, the Weber tuning fork sound is heard louder in one ear than the other.
This clinical finding should be confirmed by repeating the procedure and having the patient occlude one ear with a finger. The results of both tests are noted and compared accordingly below to localize and characterize the nature of any detected hearing losses. Note: the Weber and Rinne are screening tests that are not replacements for formal audiometry hearing tests. A patient with a unilateral conductive hearing loss would hear the tuning fork loudest in the affected ear; this is because the ear with the conductive hearing loss is only receiving input from the bone conduction and no air conduction, the sound is perceived as louder in that ear. This finding is because the conduction problem of the middle ear masks the ambient noise of the room, while the well-functioning inner ear picks the sound up via the bones of the skull, causing it to be perceived as a louder sound in the affected ear. Another theory, however, is based on the occlusion effect described by Tonndorf et al. in 1966. Lower frequency sounds.
If an occlusion is present, the sound cannot escape and appears louder on the ear with the conductive hearing loss. Conductive hearing loss can be mimicked by plugging one ear with a finger and performing the Rinne and Weber tests, which will help clarify the above. Humming a constant note and plugging one ear is a good way to mimic the findings of the Weber test in conductive hearing loss; the simulation of the Weber test is the basis for the Bing test. If air conduction is intact on both sides, the patient will report a quieter sound in the ear with
A reflex, or reflex action, is an involuntary and nearly instantaneous movement in response to a stimulus. A reflex is made possible by neural pathways called reflex arcs which can act on an impulse before that impulse reaches the brain; the reflex is an automatic response to a stimulus that does not receive or need conscious thought. Myotatic reflexes The myotatic reflexes, provide information on the integrity of the central nervous system and peripheral nervous system. Decreased reflexes indicate a peripheral problem, lively or exaggerated reflexes a central one. A stretch reflex is the contraction of a muscle in response to its lengthwise stretch. Biceps reflex Brachioradialis reflex Extensor digitorum reflex Triceps reflex Patellar reflex or knee-jerk reflex Ankle jerk reflex While the reflexes above are stimulated mechanically, the term H-reflex refers to the analogous reflex stimulated electrically, tonic vibration reflex for those stimulated to vibration. A tendon reflex is the contraction of a muscle in response to striking its tendon.
The Golgi tendon reflex is the inverse of a stretch reflex. Newborn babies have a number of other reflexes which are not seen in adults, referred to as primitive reflexes; these automatic reactions to stimuli enable infants to respond to the environment before any learning has taken place. They include: Asymmetrical tonic neck reflex Palmomental reflex Moro reflex known as the startle reflex Palmar grasp reflex Rooting reflex Sucking reflex Symmetrical tonic neck reflex Tonic labyrinthine reflex Other reflexes found in the central nervous system include: Abdominal reflexes Gastrocolic reflex Anocutaneous reflex Baroreflex Cough reflex Cremasteric reflex Diving reflex Muscular defense Photic sneeze reflex Scratch reflex Sneeze Startle reflex Withdrawal reflex Crossed extensor reflexMany of these reflexes are quite complex requiring a number of synapses in a number of different nuclei in the CNS. Others of these involve just a couple of synapses to function. Processes such as breathing and the maintenance of the heartbeat can be regarded as reflex actions, according to some definitions of the term.
In medicine, reflexes are used to assess the health of the nervous system. Doctors will grade the activity of a reflex on a scale from 0 to 4. While 2+ is considered normal, some healthy individuals are hypo-reflexive and register all reflexes at 1+, while others are hyper-reflexive and register all reflexes at 3+. List of reflexes All-or-none law Automatic behavior Conditioned reflex Instinct Jumping Frenchmen of Maine Voluntary action Preflexes
Nursing assessment is the gathering of information about a patient's physiological, psychological and spiritual status by a licensed Registered Nurse. Nursing assessment is the first step in the nursing process. A section of the nursing assessment may be delegated to certified nurses aides. Vitals and EKG's may be delegated to nursing techs, it differs from a medical diagnosis. In some instances, the nursing assessment is broad in scope and in other cases it may focus on one body system or mental health. Nursing assessment is used to identify future patient care needs, it incorporates the recognition of normal versus abnormal body physiology. Prompt recognition of pertinent changes along with the skill of critical thinking allows the nurse to identify and prioritize appropriate interventions. An assessment format may be in place to be used at specific facilities and in specific circumstances. Before assessment can begin the nurse must establish a professional and therapeutic mode of communication.
This lays the foundation of a trusting, non-judgmental relationship. This will assure that the person will be as comfortable as possible when revealing personal information. A common method of initiating therapeutic communication by the nurse is to have the nurse introduce herself or himself; the interview proceeds to asking the client how they wish to be addressed and the general nature of the topics that will be included in the interview. The therapeutic communication methods of nursing assessment takes into account developmental stage, distractions, age-related impediments to communication such as sensory deficits and language, time, non-verbal cues. Therapeutic communication is facilitated by avoiding the use of medical jargon and instead using common terms used by the patient. During the first part of the personal interview, the nurse carries out an analysis of the patient needs. In many cases, the client requires a focused assessment rather than a comprehensive nursing assessment of the entire bodily systems.
In the focused assessment, the major complaint is assessed. The nurse may employ the use of acronyms performing the assessment: OLDCART Onset of health concern or complaint Location of pain or other symptoms related to the area of the body involved Duration of health concern or complaint Characteristics Aggravating factors or what makes the concern or complaint worse Relieving factors or what makes the concern or complaint better Treatments or what treatments were tried in the past or ongoing The patient history and interview is considered to be subjective but still of high importance when combined with objective measurements. High quality interviewing strategies include the use of open-ended questions. Open-ended questions are those that can not be answered with a simple "no" response. If the person is unable to respond family or caregivers will be given the opportunity to answer the questions; the typical nursing assessment in the clinical setting will be the collection of data about the following: In addition, the nursing assessment may include reviewing the results of laboratory values such as blood work and urine analysis.
Medical records of the client assist to determine the baseline measures related to their health. In some instances, the nursing assessment will not incorporate the typical patient history and interview if prioritization indicates that immediate action is urgent to preserve the airway and circulation; this is known as triage and is used in emergency rooms and medical team disaster response situations. The patient history is documented through a personal interview with the client and/or the client's family. If there is an urgent need for a focused assessment, the most obvious or troubling complaint will be addressed first; this is important in the case of extreme pain. A nursing assessment includes a physical examination: the observation or measurement of signs, which can be observed or measured, or symptoms such as nausea or vertigo, which can be felt by the patient; the techniques used may include inspection, palpation and percussion in addition to the "vital signs" of temperature, blood pressure and respiratory rate, further examination of the body systems such as the cardiovascular or musculoskeletal systems.
The nurse conducts a neurovascular assessment to determine sensory and muscular function of the arms and legs in addition to peripheral circulation. The focused neurovascular assessment includes the objective observation of pulses, capillary refill, skin color and temperature, sensation. During the neurovascular assessment the measures between extremities are compared. A neurovascular assessment is an evaluation of the extremities along with sensory and motor function. During the assessment and functioning are evaluated and documented; those specific items assessed include: orientation, mood, anxiety, hallucinations, insight speech patterns grooming, personal hygiene, appropriateness of clothing response to verbal and tactile stimuli, level of consciousness, alertness posture, appropriateness of movements Pain is no longer being identified as the fifth vital sign due to the prevalence of opioid abuse and over-prescribing of narcotic pain relievers. However, assessment for pain is still important.
Assessment of a patient's experience of pain is a crucial component in providing effective pain management. Pain is not a simple sensation that can be assessed and measured. Nurses should be aware of the many factors that can influence the patient's overall experience and expression of pain, these should be consid
Heart rate is the speed of the heartbeat measured by the number of contractions of the heart per minute. The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excrete carbon dioxide, it is equal or close to the pulse measured at any peripheral point. Activities that can provoke change include physical exercise, anxiety, stress and ingestion of drugs; the American Heart Association states. Tachycardia is a fast heart rate, defined as above 100 bpm at rest. Bradycardia is a slow heart rate, defined as below 60 bpm at rest. During sleep a slow heartbeat with rates around 40 -- 50 bpm is considered normal; when the heart is not beating in a regular pattern, this is referred to as an arrhythmia. Abnormalities of heart rate sometimes indicate disease. While heart rhythm is regulated by the sinoatrial node under normal conditions, heart rate is regulated by sympathetic and parasympathetic input to the sinoatrial node; the accelerans nerve provides sympathetic input to the heart by releasing norepinephrine onto the cells of the sinoatrial node, the vagus nerve provides parasympathetic input to the heart by releasing acetylcholine onto sinoatrial node cells.
Therefore, stimulation of the accelerans nerve increases heart rate, while stimulation of the vagus nerve decreases it. Due to individuals having a constant blood volume, one of the physiological ways to deliver more oxygen to an organ is to increase heart rate to permit blood to pass by the organ more often. Normal resting heart rates range from 60-100 bpm. Bradycardia is defined as a resting heart rate below 60 bpm. However, heart rates from 50 to 60 bpm are common among healthy people and do not require special attention. Tachycardia is defined as a resting heart rate above 100 bpm, though persistent rest rates between 80–100 bpm if they are present during sleep, may be signs of hyperthyroidism or anemia. Central nervous system stimulants such as substituted amphetamines increase heart rate. Central nervous system depressants or sedatives decrease the heart rate. There are many ways in which the heart rate slows down. Most involve stimulant-like endorphins and hormones being released in the brain, many of which are those that are'forced'/'enticed' out by the ingestion and processing of drugs.
This section discusses target heart rates for healthy persons and are inappropriately high for most persons with coronary artery disease. The heart rate is rhythmically generated by the sinoatrial node, it is influenced by central factors through sympathetic and parasympathetic nerves. Nervous influence over the heartrate is centralized within the two paired cardiovascular centres of the medulla oblongata; the cardioaccelerator regions stimulate activity via sympathetic stimulation of the cardioaccelerator nerves, the cardioinhibitory centers decrease heart activity via parasympathetic stimulation as one component of the vagus nerve. During rest, both centers provide slight stimulation to the heart; this is a similar concept to tone in skeletal muscles. Vagal stimulation predominates as, left unregulated, the SA node would initiate a sinus rhythm of 100 bpm. Both sympathetic and parasympathetic stimuli flow through the paired cardiac plexus near the base of the heart; the cardioaccelerator center sends additional fibers, forming the cardiac nerves via sympathetic ganglia to both the SA and AV nodes, plus additional fibers to the atria and ventricles.
The ventricles are more richly innervated by sympathetic fibers than parasympathetic fibers. Sympathetic stimulation causes the release of the neurotransmitter norepinephrine at the neuromuscular junction of the cardiac nerves; this shortens the repolarization period, thus speeding the rate of depolarization and contraction, which results in an increased heartrate. It opens chemical or ligand-gated sodium and calcium ion channels, allowing an influx of positively charged ions. Norepinephrine binds to the beta–1 receptor. High blood pressure medications are used to so reduce the heart rate. Parasympathetic stimulation originates from the cardioinhibitory region with impulses traveling via the vagus nerve; the vagus nerve sends branches to both the SA and AV nodes, to portions of both the atria and ventricles. Parasympathetic stimulation releases the neurotransmitter acetylcholine at the neuromuscular junction. ACh slows HR by opening chemical- or ligand-gated potassium ion channels to slow the rate of spontaneous depolarization, which extends repolarization and increases the time before the next spontaneous depolarization occurs.
Without any nervous stimulation, the SA node would establish a sinus rhythm of 100 bpm. Since resting rates are less than this, it becomes evident that parasympathetic stimulation slows HR; this is similar to an individual driving a car with one foot on the brake pedal. To speed up, one need remove one’s foot from the brake and let the engine increase speed. In the case of the heart, decreasing parasympathetic stimulation decreases the release of ACh, which allows HR to increase up to 100 bpm. Any increases beyond this rate would require sympathetic stimulation; the cardiovascular centres receive input from a series of visceral receptors with impulses traveling through visceral sensory fibers within the vagus and sympath