Advanced Trauma Life Support

 

 Rajat Das Gupta

 

 

Advanced Trauma Life Support

Advanced Trauma Life Support (ATLS) is a training program for doctors and paramedics in the management of acute trauma cases, developed by the American College of Surgeons. The program has been adopted worldwide in over 40 countries,^[1] sometimes under the name of Early Management of Severe Trauma (EMST), especially outside North America. Its goal is to teach a simplified and standardized approach to trauma patients. Originally designed for emergency situations where only one doctor and one nurse are present, ATLS is now widely accepted as the standard of care for initial assessment and treatment in trauma centers. The premise of the ATLS program is to treat the greatest threat to life first. It also advocates that the lack of a definitive diagnosis and a detailed history should not slow the application of indicated treatment for life-threatening injury, with the most time-critical interventions performed early. However, there is mixed evidence to show that ATLS improves patient outcomes.

Primary Survey

The first and key part of the assessment of patients presenting with trauma is called the primary survey. During this time, life-threatening injuries are identified and simultaneously resuscitation is begun. A simple mnemonic, ABCDE, is used as a memory aid for the order in which problems should be addressed.

A	Airway
B	Breathing
C	Circulation
D	Disabilities
E	Expose/Environment

A - Airway Maintenance with Cervical Spine Protection

The first stage of the primary survey is to assess the airway. If the patient is able to talk, the airway is likely to be clear. If the patient is unconscious, he/she may not be able to maintain his/her own airway. The airway can be opened using a chin lift or jaw thrust. Airway adjuncts may be required. If the airway is blocked (e.g., by blood or vomit), the fluid must be cleaned out of the patient's mouth by the help of sucking instruments. in case of obstruction pass endotrachial tube.

B - Breathing and Ventilation

The chest must be examined by inspection, palpation, percussion and auscultation. Subcutaneous emphysema and tracheal deviation must be identified if present. The aim is to identify and manage six life threatening thoracic conditions as Airway Obstruction, Tension Pneumothorax, Massive Haemothorax, Open Pneumothorax, Flail chest segment with Pulmonary Contusion and Cardiac Tamponade. Flail chest, penetrating injuries and bruising can be recognized by inspection.

C - Circulation with Hemorrhage Control

Hemorrhage is the predominant cause of preventable post-injury deaths. Hypovolemic shock is caused by significant blood loss. Two large-bore intravenous lines are established and crystalloid solution given. If the patient does not respond to this, type-specific blood, or O-negative if this is not available, should be given. External bleeding is controlled by direct pressure. Occult blood loss may be into the chest, abdomen, pelvis or from the long bones.

D - Disability (Neurologic Evaluation)

During the primary survey a basic neurological assessment is made, known by the mnenomic AVPU (alert, verbal stimuli response, painful stimuli response, or unresponsive). A more detailed and rapid neurological evaluation is performed at the end of the primary survey. This establishes the patient's level of consciousness, pupil size and reaction, lateralizing signs, and spinal cord injury level.
The Glasgow Coma Scale is a quick method to determine the level of consciousness, and is predictive of patient outcome. If not done in the primary survey, it should be performed as part of the more detailed neurologic examination in the secondary survey. An altered level of consciousness indicates the need for immediate reevaluation of the patient's oxygenation, ventilation, and perfusion status. Hypoglycemia and drugs, including alcohol, may influence the level of consciousness. If these are excluded, changes in the level of consciousness should be considered to be due to traumatic brain injury until proven otherwise.

E - Exposure / Environmental control

The patient should be completely undressed, usually by cutting off the garments. It is imperative to cover the patient with warm blankets to prevent hypothermia in the emergency department. Intravenous fluids should be warmed and a warm environment maintained. Patient privacy should be maintained.

Secondary Survey

When the primary survey is completed, resuscitation efforts are well established, and the vital signs are normalizing, the secondary survey can begin. The secondary survey is a head-to-toe evaluation of the trauma patient, including a complete history and physical examination, including the reassessment of all vital signs. Each region of the body must be fully examined. X-rays indicated by examination are obtained. If at any time during the secondary survey the patient deteriorates, another primary survey is carried out as a potential life threat may be present. The person should be removed from the hard spine board and placed on a firm mattress as soon as reasonably feasible as the spine board can rapidly cause skin breakdown and pain while a firm mattress provides equivalent stability for potential spinal fractures.^[2]

Alternatives to ATLS

Anaesthesia Trauma and Critical Care (ATACC) is an international trauma course based in the United Kingdom. It is an advanced trauma course and represents the next level for trauma care and trauma patient management post ATLS certification. Accredited by two Royal Colleges and numerous emergency services, the course runs numerous times per year for candidates drawn from all areas of medicine and trauma care.^[3] Specific injuries, such as major burn injury, may be better managed by modified ATLS protocols such as EMSB (Emergency Management of Severe Burns: a training course and protocols developed by the Australian and New Zealand Burn Association (ANZBA) and also adopted by the British Burn Association).[1][2]

History

ATLS has its origins in the United States in 1976, when James K. Styner, an orthopedic surgeon piloting a light aircraft, crashed his plane into a field in Nebraska. His wife was killed instantly and three of his four children sustained critical injuries. He carried out the initial triage of his children at the crash site. Dr. Styner had to flag down a car to transport him to the nearest hospital; upon arrival, he found it closed. Even once the hospital was opened and a doctor called in, he found that the emergency care provided at the small regional hospital where they were treated was inadequate and inappropriate.^[10]
Upon returning to work, he set about developing a system for saving lives in medical trauma situations. Styner and his colleague Paul 'Skip' Collicott, with assistance from advanced cardiac life support personnel and the Lincoln Medical Education Foundation, produced the initial ATLS course which was held in 1978. In 1980, the American College of Surgeons Committee on Trauma adopted ATLS and began US and international dissemination of the course. Styner himself recently recertified as an ATLS instructor, teaching his Instructor Candidate course in the UK and then in the Netherlands.^{[citation needed]}
Since its inception, ATLS has become the standard for trauma care in American emergency departments and advanced paramedical services. Since emergency physicians, paramedics and other advanced practitioners use ATLS as their model for trauma care it makes sense that programs for other providers caring for trauma would be designed to interface well with ATLS. The Society of Trauma Nurses has developed the Advanced Trauma Care for Nurses (ATCN) course for registered nurses. ATCN meets concurrently with ATLS and shares some of the lecture portions. This approach allows for medical and nursing care to be well coordinated with one another as both the medical and nursing care providers have been trained in essentially the same model of care. Similarly, the National Association of Emergency Medical Technicians has developed the Prehospital Trauma Life Support (PHTLS) course for basic Emergency Medical Technicians (EMT)s and a more advanced level class for Paramedics. The International Trauma Life Support committee publishes the ITLS-Basic and ITLS-Advanced courses for prehospital professionals as well. This course is based around ATLS and allows the PHTLS-trained EMTs to work alongside paramedics and to transition smoothly into the care provided by the ATLS and ATCN-trained providers in the hospital.

References

1. ^ ^{a b} Bouillon, B., Kanz, K.G., Lackner, C.K., Mutschler, W., & Sturm, J. The importance of Advanced Trauma Life Support (ATLS) in the emergency room [Article in German]. Unfallchirurg, 107(10), 844-850.
2. ^ Amal Mattu; Deepi Goyal; Barrett, Jeffrey W.; Joshua Broder; DeAngelis, Michael; Peter Deblieux; Gus M. Garmel; Richard Harrigan; David Karras; Anita L'Italien; David Manthey (2007). Emergency medicine: avoiding the pitfalls and improving the outcomes. Malden, Mass: Blackwell Pub./BMJ Books. pp. 60. ISBN 1-4051-4166-2. 
3. ^ Anaesthesia Trauma and Critical Care
4. ^ Jayaraman S, Sethi D (2009). "Advanced trauma life support training for hospital staff". Cochrane Database Syst Rev (2): CD004173. doi:10.1002/14651858.CD004173.pub3. PMID 19370594. 
5. ^ Hedges, J.R., Adams, A.L., & Gunnels, M.D. ATLS practices and survival at rural level III trauma hospitals, 1995-1999. Prehospital Emergency Care, 6(3), 299-305.
6. ^ Sethi, Dinesh D; Habibula, Shakiba; Kelly, Anne-Maree; Sethi, Dinesh D (2003). "Advanced trauma life support training for hospital staff". Cochrane database of systematic reviews (Online) (3): CD004173. doi:10.1002/14651858.CD004173.pub2. PMID 15266521. 
7. ^ van Olden, G.D., Meeuwis, J.D., Bolhuis, H.W., Boxma, H., & Goris, R.J. (2004, November). Clinical impact of advanced trauma life support. American Journal of Emergency Medicine, 22(7), 522-525.
8. ^ Barsuk, D., Ziv, A., Lin, G., Blumenfeld, A., Rubin, O., Keidan, I., Munz, Y., & Berkenstadt, H. (2005, March). Using advanced simulation for recognition and correction of gaps in airway and breathing management skills in prehospital trauma care. Anesthesia and Analgesia, 100(3), 803-809.
9. ^ Roettger, R. H., Taylor, S. M., Youkey, J. R., & Blackhurst, D. W. (2005, August). The general surgery model: A more appealing and sustainable alternative for the care of trauma patients. The American Surgeon, 71(8), 633-638.
10. ^ Carmont MR (2005). "The Advanced Trauma Life Support course: a history of its development and review of related literature". Postgraduate medical journal 81 (952): 87–91. doi:10.1136/pgmj.2004.021543. PMID 15701739.

Basal cell carcinoma

Rajat Das Gupta

Causes, incidence, and risk factors Si

Skin cancer is divided into two major groups: nonmelanoma and melanoma. Basal cell carcinoma is a type of nonmelanoma skin cancer, and is the most common form of cancer in the United States. According to the American Cancer Society, 75% of all skin cancers are basal cell carcinomas.

Basal cell carcinoma starts in the top layer of the skin called the epidermis. It grows slowly and is painless. A new skin growth that bleeds easily or does not heal well may suggest basal cell carcinoma. The majority of these cancers occur on areas of skin that are regularly exposed to sunlight or other ultraviolet radiation. They may also appear on the scalp. Basal cell skin cancer used to be more common in people over age 40, but is now often diagnosed in younger people.

Your risk for basal cell skin cancer is higher if you have:

• Light-colored skin
• Blue or green eyes
• Blond or red hair
• Overexposure to x-rays or other forms of radiation

Basal cell skin cancer almost never spreads. But, if left untreated, it may grow into surrounding areas and nearby tissues and bone.

Symptoms

Basal cell carcinoma may look only slightly different than normal skin. The cancer may appear as skin bump or growth that is:

• Pearly or waxy
• White or light pink
• Flesh-colored or brown

In some cases the skin may be just slightly raised or even flat.

You may have:

• A skin sore that bleeds easily
• A sore that does not heal
• Oozing or crusting spots in a sore
• Appearance of a scar-like sore without having injured the area
• Irregular blood vessels in or around the spot
• A sore with a depressed (sunken) area in the middle 
  
  
  
  
  
  
  

Signs and tests

Your doctor will check your skin and look at the size, shape, color, and texture of any suspicious areas.

If skin cancer is a possibility, a piece of skin will be removed from the area and examined under a microscope. This is called a skin biopsy. This must be done to confirm the diagnosis of basal cell carcinoma or other skin cancers. There are many types of skin biopsies. The exact procedure depends on the location of the suspected skin cancer.

Treatment

Treatment varies depending on the size, depth, and location of the basal cell cancer. It will be removed using one of the following procedures:

• Excision cuts the tumor out and uses stitches to place the skin back together.
• Curettage and electrodesiccation scrapes away the cancer and uses electricity to kill any remaining cancer cells.
• Surgery, including Mohs surgery, in which skin is cut out and immediately looked at under a microscope to check for cancer. The process is repeated until the skin sample is free of cancer.
• Cryosurgery freezes and kills the cancer cells.
• Radiation may be used if the cancer has spread to organs or lymph nodes or for tumors that can't be treated with surgery.
• Skin creams with the medications imiquimod or 5-fluorouracil may be used to treat superficial basal cell carcinoma.

Expectations (prognosis)

The rate of basal cell skin cancer returning is about 1% with Mohs surgery, and up to 10% for other forms of treatment. Smaller basal cell carcinomas are less likely to come back than larger ones. Basal cell carcinoma rarely spreads to other parts of the body.

You should follow-up with your doctor as recommended and regularly examine your skin once a month, using a mirror to check hard-to-see places. Call your doctor if you notice any suspicious skin changes.

Complications

Untreated, basal cell cancer can spread to nearby tissues or structures, causing damage. This is most worrisome around the nose, eyes, and ears.

Calling your health care provider

Call your health care provider if you notice any changes in the color, size, texture, or appearance of any area of skin. You should also call if an existing spot becomes painful or swollen, or if it starts to bleed or itch.

Prevention

The best way to prevent skin cancer is to reduce your exposure to sunlight. Ultraviolet light is most intense at midday, so try to avoid sun exposure during these hours. Protect the skin by wearing hats, long-sleeved shirts, long skirts, or pants.

Always use sunscreen:

• Apply high-quality sunscreens with SPF (sun protection factor) ratings of at least 15.
• Look for sunscreens that block both UVA and UVB light.
• Apply sunscreen at least 30 minutes before going outside, and reapply it frequently.
• Use sunscreen in winter, too.

Examine the skin regularly for development of suspicious growths or changes in:

• Color
• Size
• Texture
• Appearance

Also note if an existing skin sore bleeds, itches, is red and swollen (inflamed), or is painful.

MMCH interns to ‘continue strike’

Rajat Das Gupta
 
 
Intern doctors protesting attacks on their fellows and some students of Mymensingh Medical College Hospital declared on Saturday to continue their strike until the arrests of the attackers.
Earlier in the day, they sat in an hour long meeting with the college authorities which ended around 2:00pm without any decision.
The protestors gave a 72-hour ultimatum in the meeting to arrest the attackers, reports our Mymensingh correspondent.
They went on the strike on Friday noon after around 25 students and intern doctors were injured in the attacks by some local men on Thursday night.
In Saturday’s meeting, they placed seven-point demand including ensuring punishment of the criminals, stopping entrance of the outsiders to the campus and providing security to the intern doctors in the medical.
Local lawmaker Principal Motiur Rahman; municipality Mayor Iqramul Haque Titu; hospital Director Brig Gen Md Shahjahan; Principal of the college Prof Aminul Haque and Dr Md Motiar Rahman, secretary to the district unit of Bangladesh Medical Association, were present at the meeting.
Earlier on Friday, police arrested one Arif alias Dish Arif after the college principal filed a case with the local police station.

Ototoxicity

Rajat Das Gupta

Classification and external resources
ICD-10	H91.0
DiseasesDB	2874
eMedicine	ent/699

Ototoxicity is damage to the ear (oto-), specifically the cochlea or auditory nerve and sometimes the vestibular system, by a toxin. It is commonly medication-induced; ototoxic drugs include antibiotics such as the aminoglycoside gentamicin, loop diuretics such as furosemide, and platinum-based chemotherapy agents such as cisplatin. A number of nonsteroidal anti-inflammatory drugs (NSAIDS) such as Meloxicam have also be shown to be ototoxic. This can result in sensorineural hearing loss, dysequilibrium, or both. Either may be reversible and temporary, or irreversible and permanent.

Ototoxic agents 

Antibiotics

Antibiotics in the aminoglycoside class, such as gentamicin and tobramycin, may produce cochleotoxicity through a poorly understood mechanism.^[1] It may result from antibiotic binding to NMDA receptors in the cochlea and damaging neurons through excitotoxicity.^[2] Aminoglycoside-induced production of reactive oxygen species may also injure cells of the cochlea.^[3] Once-daily dosing^[4] and co-administration of N-acetylcysteine^[5] may protect against aminoglycoside-induced ototoxicity. The ototoxicity of gentamicin can be exploited to treat some individuals with Ménière's disease by destroying the inner ear, which stops the vertigo attacks but causes permanent deafness.^[6]
Macrolide antibiotics, including erythromycin, are associated with reversible ototoxic effects.^[7] The underlying mechanism of ototoxicity may be impairment of ion transport in the stria vascularis.^[7] Predisposing factors include renal impairment, hepatic impairment, and recent organ transplantation.^[7]

Loop diuretics

The loop diuretic furosemide is associated with ototoxicity, particularly when doses exceed 240 mg per hour.^[8] The related compound ethacrynic acid is particularly ototoxic.^[7] Bumetanide confers a decreased risk of ototoxicity compared to furosemide.^[7]

Chemotherapeutic agents

Platinum-containing chemotherapeutic agents, including cisplatin and carboplatin, are associated with cochleotoxicity characterized by high-frequency hearing loss and tinnitus (ringing in the ears).^[9] Ototoxicity is less frequently seen with the related compound oxaliplatin.^[10] Cisplatin-induced ototoxicity is dose-dependent, typically occurring with doses greater than 60 mg/m², and tend to occur when chemotherapy is given every two weeks compared to every one week.^[9] Cisplatin and related agents are absorbed by the cochlear hair cells and result in ototoxicity through the production of reactive oxygen species.^[11] The decreased incidence of oxaliplatin ototoxicity has been attributed to decreased uptake of the drug by cells of the cochlea.^[10] Administration of amifostine has been used in attempts to prevent cisplatin-induced ototoxicity, but the American Society of Clinical Oncology recommends against its routine use.^[12]
The vinca alkaloids, including vincristine, are also associated with reversible ototoxicity.^[7]

Others

Ototoxic effects are also seen with quinine and heavy metals such as mercury and lead.^[7] At high doses, aspirin and other salicylates may also cause high-pitch tinnitus and hearing loss in both ears, typically reversible upon discontinuation of the drug.^[7] Erectile dysfunction medications: Viagra, Levitra and Cialis^[13]

Mixed Exposures

Ototoxic chemicals interact with mechanical stresses on the hair cells of the cochlea in different ways. For organic sovlents such as Toluene, styrene or xylene, the combined exposure with noise increases the risk of hearing loss in a synergistic manner ^[14] Heavy metals, ashpyxiants and endocrine disruptors have a variety of interactions as well. Specific toxicity limits for combined exposures are not well established. However, given the potential for enhanced risk of hearing loss, the noise exposures should be kept below 85 decibels and the chemical exposures should be below the recommended exposure limits given by agencies such as OSHA, NIOSH, or ACGIH.

Symptoms

Symptoms of ototoxicity include partial or profound hearing loss, vertigo, and tinnitus.^[7]

Treatment

No specific treatment is available, but immediate withdrawal of the drug may be warranted in cases where the consequences of doing so are less severe than the consequences of the ototoxicity.^[7] 

References

1. ^ Dobie RA, Black FO, Pezsnecker SC, Stallings VL (March 2006). "Hearing loss in patients with vestibulotoxic reactions to gentamicin therapy". Archives of Otolaryngology--Head & Neck Surgery 132 (3): 253–7. doi:10.1001/archotol.132.3.253. PMID 16549744. http://archotol.ama-assn.org/cgi/pmidlookup?view=long&pmid=16549744. 
2. ^ Basile AS, Huang JM, Xie C, Webster D, Berlin C, Skolnick P (December 1996). "N-methyl-D-aspartate antagonists limit aminoglycoside antibiotic-induced hearing loss". Nature Medicine 2 (12): 1338–43. doi:10.1038/nm1296-1338. PMID 8946832. 
3. ^ Wu WJ, Sha SH, Schacht J (2002). "Recent advances in understanding aminoglycoside ototoxicity and its prevention". Audiology & Neuro-otology 7 (3): 171–4. doi:10.1159/000058305. PMID 12053140. http://content.karger.com/produktedb/produkte.asp?typ=fulltext&file=aud07171. 
4. ^ Munckhof WJ, Grayson ML, Turnidge JD (April 1996). "A meta-analysis of studies on the safety and efficacy of aminoglycosides given either once daily or as divided doses". The Journal of Antimicrobial Chemotherapy 37 (4): 645–63. doi:10.1093/jac/37.4.645. PMID 8722531. http://jac.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=8722531. 
5. ^ Tepel M (August 2007). "N-Acetylcysteine in the prevention of ototoxicity". Kidney International 72 (3): 231–2. doi:10.1038/sj.ki.5002299. PMID 17653228. 
6. ^ Perez N, Martín E, García-Tapia R (March 2003). "Intratympanic gentamicin for intractable Ménière's disease". The Laryngoscope 113 (3): 456–64. doi:10.1097/00005537-200303000-00013. PMID 12616197. 
7. ^ ^{a b c d e f g h i j} Roland, Peter S. (2004). Ototoxicity. Hamilton, Ont: B.C. Decker. ISBN 1-55009-263-4. 
8. ^ Voelker JR, Cartwright-Brown D, Anderson S, et al. (October 1987). "Comparison of loop diuretics in patients with chronic renal insufficiency". Kidney International 32 (4): 572–8. doi:10.1038/ki.1987.246. PMID 3430953. 
9. ^ ^{a b} Rademaker-Lakhai JM, Crul M, Zuur L, et al. (February 2006). "Relationship between cisplatin administration and the development of ototoxicity". Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology 24 (6): 918–24. doi:10.1200/JCO.2006.10.077. PMID 16484702. http://www.jco.org/cgi/pmidlookup?view=long&pmid=16484702. 
10. ^ ^{a b} Hellberg V, Wallin I, Eriksson S, et al. (January 2009). "Cisplatin and oxaliplatin toxicity: importance of cochlear kinetics as a determinant for ototoxicity". Journal of the National Cancer Institute 101 (1): 37–47. doi:10.1093/jnci/djn418. PMID 19116379. PMC 2639295. http://jnci.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=19116379. 
11. ^ Rybak LP, Whitworth CA, Mukherjea D, Ramkumar V (April 2007). "Mechanisms of cisplatin-induced ototoxicity and prevention". Hearing Research 226 (1-2): 157–67. doi:10.1016/j.heares.2006.09.015. PMID 17113254. http://linkinghub.elsevier.com/retrieve/pii/S0378-5955(06)00272-3. 
12. ^ Hensley ML, Hagerty KL, Kewalramani T, et al. (January 2009). "American Society of Clinical Oncology 2008 clinical practice guideline update: use of chemotherapy and radiation therapy protectants". Journal of Clinical Oncology 27 (1): 127–45. doi:10.1200/JCO.2008.17.2627. PMID 19018081. http://www.jco.org/cgi/pmidlookup?view=long&pmid=19018081. 
13. ^ http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2007/ucm109012.htm
14. ^ name=fechter Fechter L.D. "Promotion of noise-induced hearing loss by chemical conaminants," J. Tox. Env. Health Part A. 67:727-740 (2004)

Alpha-Methyl Dopa

Rajat Das Gupta

• Methyldopa is a prodrug which is metabolized to the active agent, alpha-methylnorepinephrine.
• Alpha-methylnorepinephrine acts in the brain, inhibiting adrenergic outflow from the brainstem. Inhibition of sympathetic outflow results in a decrease in blood pressure.
• Methyldopa produces no change in cardiac output in younger patients, but in older patients a decline in cardiac output results from reduced heart rate and stroke volume. The reduction in stoke volume occurs due to increased venous pooling (decreased preload).
• Since renal blood flow and function is maintained during methyldopa treatment, methyldopa maybe valuable in managing hypertensive patients with renal insufficiency.
• Adverse Effects:
  • Dry Mouth
  • Reduced libido
  • Parkinsonian signs
  • Hyperprolactinemia (gynecomastia, galactorrhea)
  • Bradycardia (in patients with SA nodal abnormality)
  • Hepatoxicity (avoid in patients with hepatic disease)
  • positive Coombs' test (20%)\
  • 1-5% of those with postive Coombs' develop hemolytic anemia (requiring immediate discontinuation of the drug)

Incised Wounds

 Rajat Das Gupta



Incised wounds are sharp cut-like injuries, made by knives or broken glass etc.

The edges of the wound will vary according to the nature of the cutting edge of the object, in that a razor will leave regular margins, whereas an axe may leave the wound margins crushed and bruised, resembling a laceration.

Slash Wounds

These are wounds where the length is greater than the depth, eg a slice wound across the skin. If the wound involves major blood vessels, it can be life threatening, but in general, they are not as serious as stab wounds.

Stab Wounds

These are wounds where the depth of injury is greater than the length. They penetrate more deeply than slash wounds and tend to come into contact with vital organs in the chest and abdomen.

Stabbing is the most common mode of homicide in the UK, due to the strict control of guns.

Stab wounds are caused most obviously by knives, but are also caused by bayonets and swords, as well as scissors and even blunter instruments such as screwdrivers.

These type of wounds have the following features,

• they are usually slit-like, but when the object is removed the skin contracts slightly, leaving a wound that is slightly shorter than the blade width. The centre of the wound often widens.

                                   

• muscle and skin contracture around the wound often obscures the size of the knife blade
• the size of the wound depends upon the depth of penetration of the knife, and whether, for example the parallel section of the knife has been reached (ie near to the hilt of the knife)
• if the blade is 'rocked' in the wound (ie either the assailant moves the knife around, or the victim moves in relation to the knife), the wound is longer than if the knife is inserted in and out rapidly and in the same direction
• irregular or 'V' shaped wounds arise when the knife is twisted in the wound
• most knives are single edged, and have a sharp cutting surface whilst the back of the blade is blunt. The wound may be sharp at one end, and blunt at the other. Unfortunately, this is not always the case, as the blunt edge of the knife may split the skin, and resemble a double edged knife wound.

A Single edged bladed knife (with blade guard or hilt)

Double edged blade on the left hand side, single           edged blade on the right hand side.

 

• knives that have a handle guard or 'hilt' may bruise the skin around the wound if they are forcefully stabbed into the victim
• the depth of the wound is often longer than the length of the knife because of the compressibility of skin and underlying structures, particularly in the abdominal cavity
• scissor stab wounds (closed scissors) leave a 'Z' shape

It is important to realise that stab wounds can be made with minimal force. The important factor is the sharpness of the tip of the blade - once it has penetrated clothing and skin, remarkably little force is required to follow through and create a deep knife wound. In addition, the faster the stabbing action, the easier it is to penetrate skin.

For a review of stab wounds, see Forensic Science International journal 52: 107 (1991).

 Defence Wounds

A victim of assault can sustain quite characteristic injuries during the course of the assault, as they try to defend themselves, and ward off blows. The photograph illustrates how someone may get wounds on their hands by warding off an attack with a knife.

When warding off knives, the victim usually has multiple incisions across the palmar surfaces of the hands, where attempts have been made to grab the knife blade.

Defence wounds on the hand of a victim of a knife attack

Defence wounds to the forearm of a knife attack victim

  

Aortic arch

Rajat Das Gupta

Source	ascending aorta
Branches	brachiocephalic artery, left common carotid artery, left subclavian artery
Precursor	fourth aortic arch

The arch of the aorta or the transverse aorta is the part of the aorta that begins at the level of the upper border of the second sternocostal articulation of the right side, and runs at first upward, backward, and to the left in front of the trachea; it is then directed backward on the left side of the trachea and finally passes downward on the left side of the body of the fourth thoracic vertebra, at the lower border of which it becomes continuous with the descending aorta.
It thus forms two curvatures: one with its convexity upward, the other with its convexity forward and to the left. Its upper border is usually about 2.5 cm. below the superior border to the manubrium sterni.
It lies within the mediastinum.

Related structures

The ligamentum arteriosum connects the commencement of the left pulmonary artery to the aortic arch. The blood bypasses the lungs through the ductus arteriosus during embryonic circulation. This becomes the ligamentum arteriosum postnatal as pulmonary circulation begins.
The aortic knob is the prominent shadow of the aortic arch on a frontal chest radiograph.

 Diagram showing the origins of the main branches of the carotid arteries.

Front view of heart and lungs.

Heart left lateral view

The Arteria Dorsalis Pedis

Rajat Das Gupta

In human anatomy, the dorsalis pedis artery (dorsal artery of foot), is a blood vessel of the lower limb that carries oxygenated blood to the dorsal surface of the foot. It arises at the anterior aspect of the ankle joint and is a continuation of the anterior tibial artery. It terminates at the proximal part of the first intermetatarsal space, where it divides into two branches, the first dorsal metatarsal artery and the deep plantar artery.

Along its course, it is accompanied by a deep vein, the dorsalis pedis vein.

Palpation of the dorsalis pedis artery pulse

The dorsalis pedis artery pulse can be palpated readily lateral to the extensor hallucis longus tendon (or medially to the extensor digitorum tendons) on the dorsal surface of the foot, distal to the dorsal most prominence of the navicular bone which serves as a reliable landmark for palpation. It is often examined, by physicians, when assessing whether a given patient has peripheral vascular disease. It is absent, unilaterally or bilaterally, in 2-3 % of young healthy individuals

Artificial insemination

 Rajat Das Gupta


Artificial insemination, or AI, is the process by which sperm is placed into the reproductive tract of a female for the purpose of impregnating the female by using means other than sexual intercourse or NI. In humans, it is used as assisted reproductive technology, using either sperm from the woman's male partner or sperm from a sperm donor (donor sperm) in cases where the male partner produces no sperm or the woman has no male partner (i.e., single women, lesbians). In cases where donor sperm is used the woman is the gestational and genetic mother of the child produced, and the sperm donor is the genetic or biological father of the child.
Artificial insemination is widely used for livestock breeding, especially for dairy cattle and pigs. Techniques developed for livestock have been adapted for use in humans.
Specifically, freshly ejaculated sperm, or sperm which has been frozen and thawed, is placed in the cervix (intracervical insemination – ICI) or, after washing, into the female's uterus (intrauterine insemination – IUI) by artificial means.
In humans, artificial insemination was originally developed as a means of helping couples to conceive where there were 'male factor' problems of a physical or psychological nature affecting the male partner which prevented or impeded conception. Today, the process is also and more commonly used in the case of choice mothers, where a woman has no male partner and the sperm is provided by a sperm donor.

In humans

Preparations

A sperm sample will be provided by the male partner of the woman undergoing artificial insemination, but sperm provided through sperm donation by a sperm donor may be used if, for example, the woman's partner produces too few motile sperm, or if he carries a genetic disorder, or if the woman has no male partner. Sperm is usually obtained through masturbation or the use of an electrical stimulator, although a special condom, known as a collection condom, may be used to collect the semen during intercourse.
The man providing the sperm is usually advised not to ejaculate for two to three days before providing the sample in order to increase the sperm count.
A woman's menstrual cycle is closely observed, by tracking basal body temperature (BBT) and changes in vaginal mucus, or using ovulation kits, ultrasounds or blood tests.
When using intrauterine insemination (IUI), the sperm must have been “washed” in a laboratory and concentrated in Hams F10 media without L-glutamine, warmed to 37C.^[1] The process of “washing” the sperm increases the chances of fertilization and removes any mucus and non-motile sperm in the semen. Pre and post concentration of motile sperm is counted.
If sperm is provided by a sperm donor through a sperm bank, it will be frozen and quarantined for a particular period and the donor will be tested before and after production of the sample to ensure that he does not carry a transmissible disease. Sperm samples donated in this way are produced through masturbation by the sperm donor at the sperm bank. A chemical known as a cryoprotectant is added to the sperm to aid the freezing and thawing process. Further chemicals may be added which separate the most active sperm in the sample as well as extending or diluting the sample so that vials for a number of inseminations are produced. For fresh shipping, a semen extender is used.
If sperm is provided by a private donor, either directly or through a sperm agency, it is usually supplied fresh, not frozen, and it will not be quarantined. Donor sperm provided in this way may be given directly to the recipient woman or her partner, or it may be transported in specially insulated containers. Some donors have their own freezing apparatus to freeze and store their sperm. Private donor sperm is usually produced through masturbation, but some donors use a collection condom to obtain the sperm when having sexual intercourse with their own partners.

Procedure

When an ovum is released, semen provided by the woman's male partner, or by a sperm donor, is inserted into the woman's vagina or uterus. The semen may be fresh or it may be frozen semen which has been thawed. Where donor sperm is supplied by a sperm bank, it will always be quarantined and frozen and will need to be thawed before use. Specially designed equipment is available for carrying out artificial inseminations.
In the case of vaginal artificial insemination, semen is usually placed in the vagina by way of a needleless syringe. A longer tube, known as a 'tom cat' may be attached to the end of the syringe to facilitate deposit of the semen deeper into the vagina. The woman is generally advised to lie still for a half hour or so after the insemination to prevent seepage and to allow fertilization to take place.
A more efficient method of artificial insemination is to insert semen directly into the woman's uterus. Where this method is employed it is important that only 'washed' semen be used and this is inserted into the uterus by means of a catheter. Sperm banks and fertility clinics usually offer 'washed' semen for this purpose, but if partner sperm is used it must also be 'washed' by a medical practitioner to eliminate the risk of cramping.
Semen is occasionally inserted twice within a 'treatment cycle'. A double intrauterine insemination has been theorized to increase pregnancy rates by decreasing the risk of missing the fertile window during ovulation. However, a randomized trial of insemination after ovarian hyperstimulation found no difference in live birth rate between single and double intrauterine insemination.^[2]
An alternative method to the use of a needless syringe or a catheter involves the placing of partner or donor sperm in the woman's vagina by means of a specially designed cervical cap, a conception device or conception cap. This holds the semen in place near to the entrance to the cervix for a period of time, usually for several hours, to allow fertilization to take place. Using this method, a woman may go about her usual activities while the cervical cap holds the semen in the vagina. One advantage with the conception device is that fresh, non-liquified semen may be used.
If the procedure is successful, the woman will conceive and carry to term a baby. A pregnancy resulting from artificial insemination will be no different from a pregnancy achieved by sexual intercourse. However, there may be a slight increased likelihood of multiple births if drugs are used by the woman for a 'stimulated' cycle.

Donor variations

Either sperm provided by the woman's husband or partner (artificial insemination by husband, AIH) or sperm provided by a known or anonymous sperm donor (artificial insemination by donor, AID or DI) can be used.

Techniques

Intrauterine insemination, Intravaginal insemination, Intracervical insemination, and Intratubal insemination

Intracervical insemination

ICI is the easiest way to inseminate. This involves the deposit of raw fresh or frozen semen (which has been thawed) by injecting it high into the cervix with a needle-less syringe. This process closely replicates the way in which fresh semen is directly deposited on to the neck of the cervix by the penis during vaginal intercourse. When the male ejaculates, sperm deposited this way will quickly swim into the cervix and toward the fallopian tubes where an ovum recently released by the ovary(s) hopefully awaits fertilization. It is the simplest method of artificial insemination and 'unwashed' or raw semen is normally used. It is probably therefore, the most popular method and is used in most home, self and practitioner insemination procedures.
Timing is critical as the window and opportunity for fertilization, is little more than 12 hours from the release of the ovum. For each woman who goes through this process be it AI (artificial insemination) or NI (natural insemination); to increase chances for success, an understanding of her rhythm or natural cycle is very important. Home ovulation tests are now available. Doing and understanding Basal Temperature Tests over several cycles; there is a slight dip and quick rise at the time of ovulation. She should note the color and texture of her vaginal mucous discharge. At the time of ovulation the protective cervical plug is released giving the vaginal discharge a stringy texture with an egg white color. A woman may also be able check the softness of the nose of her cervix by inserting two fingers. It should be considerably softer and more pliable than normal.
Advanced technical (medical) procedures may be used to increase the chances of conception.
When performed at home without the presence of a professional this procedure is sometimes referred to as intravaginal insemination or IVI.^[3]

Intrauterine insemination

'Washed sperm', that is, spermatozoa which have been removed from most other components of the seminal fluids, can be injected directly into a woman's uterus in a process called intrauterine insemination (IUI). If the semen is not washed it may elicit uterine cramping, expelling the semen and causing pain, due to content of prostaglandins. (Prostaglandins are also the compounds responsible for causing the myometrium to contract and expel the menses from the uterus, during menstruation.) The woman should rest on the table for 15 minutes after an IUI to optimize the pregnancy rate.^[4]
To have optimal chances with IUI, the female should be under 30 years of age, and the man should have a TMS of more than 5 million per ml.^[5] In practice, donor sperm will satisfy these criteria. A promising cycle is one that offers two follicles measuring more than 16 mm, and estrogen of more than 500 pg/mL on the day of hCG administration.^[5] A short period of ejaculatory abstinence before intrauterine insemination is associated with higher pregnancy rates.^[6] However, GnRH agonist administration at the time of implantation does not improve pregnancy outcome in intrauterine insemination cycles according to a randomized controlled trial.^[7]
It can be used in conjunction with ovarian hyperstimulation. Still, advanced maternal age causes decreased success rates; Women aged 38–39 years appear to have reasonable success during the first two cycles of ovarian hyperstimulation and IUI. However, for women aged ≥40 years, there appears to be no benefit after a single cycle of COH/IUI.^[8] It is therefore recommended to consider in vitro fertilization after one failed COH/IUI cycle for women aged ≥40 years.^[8]

Intrauterine tuboperitoneal insemination

Intrauterine tuboperitoneal insemination (IUTPI) is insemination where both the uterus and fallopian tubes are filled with insemination fluid. The cervix is clamped to prevent leakage to the vagina, best achieved with the specially designed Double Nut Bivalve (DNB) speculum. The sperm is mixed to create a volume of 10 ml, sufficient enough to fill the uterine cavity, pass through the interstitial part of the tubes and the ampulla, finally reaching the peritoneal cavity and the Pouch of Douglas where it would be mixed with the peritoneal and follicular fluid. IUTPI can be useful in unexplained infertility, mild or moderate male infertility, and mild or moderate endometriosis.^[9]

Intratubal insemination

IUI can furthermore be combined with intratubal insemination (ITI), into the Fallopian tube although this procedure is no longer generally regarded as having any beneficial effect compared with IUI.^[10] ITI however, should not be confused with gamete intrafallopian transfer, where both eggs and sperm are mixed outside the woman's body and then immediately inserted into the Fallopian tube where fertilization takes place.

Pregnancy rate

Success rates, or pregnancy rates for artificial insemination may be very misleading, since many factors including the age and health of the recipient have to be included to give a meaningful answer, e.g. definition of success and calculation of the total population.^[11] For couples with unexplained infertility, unstimulated IUI is no more effective than natural means of conception.^[12][13]
Generally, it is 10 to 15% per menstrual cycle using ICI, and^[14] and 15-20% per cycle for IUI.^{[14][unreliable source?]} In IUI, about 60 to 70% have achieved pregnancy after 6 cycles.^[15]
As seen on the graph, the pregnancy rate also depends on the total sperm count, or, more specifically, the total motile sperm count (TMSC), used in a cycle. It increases with increasing TMSC, but only up to a certain count, when other factors become limiting to success. The summed pregnancy rate of two cycles using a TMSC of 5 million (may be a TSC of ~10 million on graph) in each cycle is substantially higher than one single cycle using a TMSC of 10 million. However, although more cost-efficient, using a lower TMSC also increases the average time taken before getting pregnant. Women whose age is becoming a major factor in fertility may not want to spend that extra time.

Approximate pregnancy rate as a function of total sperm count (may be twice as large as total motile sperm count). Values are for intrauterine insemination. (Old data, rates are likely higher today)

Samples per child

How many samples (ejaculates) that are required give rise to a child varies substantially from person to person, as well as from clinic to clinic.
However, the following equations generalize the main factors involved:
For intracervical insemination:

• N is how many children a single sample can give rise to.
• V_s is the volume of a sample (ejaculate), usually between 1.0 mL and 6.5 mL^[16]
• c is the concentration of motile sperm in a sample after freezing and thawing, approximately 5-20 million per ml but varies substantially
• r_s is the pregnancy rate per cycle, between 10% to 35% ^{[17] [14]}
• n_r is the total motile sperm count recommended for vaginal insemination (VI) or intra-cervical insemination (ICI), approximately 20 million pr. ml.^[18]

The pregnancy rate increases with increasing number of motile sperm used, but only up to a certain degree, when other factors become limiting instead.
With these numbers, one sample would on average help giving rise to 0.1-0.6 children, that is, it actually takes on average 2-5 samples to make a child.
For intrauterine insemination (IUI), a centrifugation fraction (f_c) may be added to the equation:

f_c is the fraction of the volume that remains after centrifugation of the sample, which may be about half (0.5) to a third (0.33).

On the other hand, only 5 million motile sperm may be needed per cycle with IUI (n_r=5 million)^[17]
Thus, only 1-3 samples may be needed for a child if used for IUI.

Approximate live birth rate (r_s) among infertile couples as a function of total motile sperm count (n_r). Values are for intrauterine insemination.

History

In the 1970s, direct intraperitoneal insemination (DIPI) was occasionally used, where doctors injected sperm into the lower abdomen through a surgical hole or incision, with the intention of letting them find the oocyte at the ovary or after entering the genital tract through the ostium of the fallopian tube.^[19]

Artificial insemination in livestock and pets

A breeding mount with built-in artificial vagina used in semen collection from horses for use in artificial insemination

Artificial insemination is used in many non-human animals, including sheep, horses, cattle, pigs, dogs, pedigree animals generally, zoo animals, turkeys and even honeybees. It may be used for many reasons, including to allow a male to inseminate a much larger number of females, to allow use of genetic material from males separated by distance or time, to overcome physical breeding difficulties, to control the paternity of offspring, to synchronise births, to avoid injury incurred during natural mating, and to avoid the need to keep a male at all (such as for small numbers of females or in species whose fertile males may be difficult to manage).
Semen is collected, extended, then cooled or frozen. It can be used on site or shipped to the female's location. If frozen, the small plastic tube holding the semen is referred to as a straw. To allow the sperm to remain viable during the time before and after it is frozen, the semen is mixed with a solution containing glycerol or other cryoprotectants. An extender is a solution that allows the semen from a donor to impregnate more females by making insemination possible with fewer sperm. Antibiotics, such as streptomycin, are sometimes added to the sperm to control some bacterial venereal diseases. Before the actual insemination, estrus may be induced through the use of progestogen and another hormone (usually PMSG).
Artificial insemination of farm animals is very common in today's agriculture industry in the developed world, especially for breeding dairy cattle. (75% of all inseminations^{[clarification needed]}) Swine are also bred using this method (up to 85% of all inseminations). It provides an economical means for a livestock breeder to improve their herds utilizing males having very desirable traits.
Although common with cattle and swine, AI is not as widely practised in the breeding of horses. A small number of equine associations in North America accept only horses that have been conceived by "natural cover" or "natural service" – the actual physical mating of a mare to a stallion. The Jockey Club being the most notable of these - no AI is allowed in Thoroughbred breeding.^[20] Other registries such as the AQHA and warmblood registries allow registration of foals created through AI, and the process is widely used allowing the breeding of mares to stallions not resident at the same facility - or even in the same country - through the use of transported frozen or cooled semen.
Modern Artificial Insemination was pioneered by Dr. John O. Almquist of the Pennsylvania State University. His improvement of breeding efficiency by the use of antibiotics (first proven with penicillin in 1946) to control bacterial growth, decreasing embrionic mortality and increase fertiilty, and various new techniques for processing, freezing and thawing of frozen semen significantly enhanced the practical utilization of AI in the livestock industry, and earned him the ^[21] 1981 Wolf Foundation Prize in Agriculture. Many techniques developed by him have since been applied to other species, including that of the human male.
The ^[22], John O. Almquist Dairy Breeding Research Center, at Penn State University, is a unique facility for research on reproduction in farm animals. It is one of only three centers worldwide providing substantial housing for mature bulls. The Center has a long-standing working relationship with the artificial insemination industry.

IA tools brought from the URSS by Dr. Ing. Luis Thomasset in 1935 to work at Cambridge Laboratories and South America.