Awam Medical

Rheumatologic

rasyaplp@gmail.com (Unknown) — Wed, 03 Sep 2008 13:24:00 +0000

Rheumatologic Conditions affecting the Hip

See Also
Hip Pain
Hip Exam

Normal Hip Range of Motion

Hip flexion: 110 to 120 degrees
Hip extension: 10 to 15 degrees
Hip abduction: 30 to 50 degrees
Hip adduction: 30 degrees
Hip lateral rotation: 40 to 60 degrees
Hip medial rotation: 30 to 40 degrees

Hip Anatomy

Osteoarthritis or Rheumatoid Arthritis

Unilateral or bilateral hip involvement
Groin Pain with ambulation
Pain reproduced on range of motion
Decreased hip range of motion

Avascular necrosis

Unilateral hip involvement
Predisposing factors

Alcohol Abuse
Corticosteroid use
Comorbid connective tissue disease

Hip MRI may be required for diagnosis

Other common hip conditions

Trochanteric Bursitis

Upper lateral Hip Pain without Groin Pain
Radiation to knee may occur
Worse with direct pressure (rolling onto side in bed)

Iliopectineal Bursitis

Pain below inguinal ligament and lateral to vessel

HIP PAIN

rasyaplp@gmail.com (Unknown) — Wed, 03 Sep 2008 11:02:00 +0000

Hip Pain

See Also

Rheumatologic Conditions affecting the Hip
Hip Exam
Hip Anatomy
Testicular Pain

Epidemiology: Groin Injury in Athletes

Groin injury accounts for 2-5% of sports injury
Higher risk sports for groin injury

Soccer (Incidence 5-7%)

·Definition

o Number of new disease cases per population at risk

§ High incidence implies high disease occurrence

§ Low incidence implies low disease occurrence

o Measured over a given time interval

· Usage

o Determine probability of developing a specific disease

o Used to detect etiologic factors

· References

o Hennekens (1987) Epidemiology Medicine, p.54-98

Ice hockey
Fencing
Handball
Cross Country Skiing

· Epidemiology

o Injury Incidence: 0.5 to 5.6 injuries per 1000 ski days

o Majority of injuries occur on downhill runs

· Benefits

o Lower impact than other aerobic sports (e.g. Running)

§ Safe after total hip replacement

· Gschwend (2000) Acta Orthop Scand 71(3):243

· van der Bogert (1999) Med Sci Sports Exerc 31:131

o Higher femoral Bone Mineral Density

§ Pettersson (2000) Calcif Tissue Int 67(3):199

o Moderate to strenuous aerobic Exercise

§ Energy cost is net VO2 to speed ratio

· Study calculated VO2 from Heart Rate

§ Energy cost equivalent to uphill treadmill walking

· Classic skiing: 162 ml/km-kg

· Skate skiing: 148 ml/km-kg

· Mognoni (2001) Eur J Appl Physiol 85(1-2):62

o Pole striding effective in Peripheral Vascular Disease

§ Improves Claudication pain and Exercise tolerance

§ Langbein (2002) J Vasc Surg 35(5):887

· Cross country skiing techniques

o Classical skiing (Diagonal Stride)

o Skate Skiing (Free style)

§ Offset (V1)

· Double pole plant to one side (e.g. left)

· Poling when weight is transferred to one ski

§ Two skate (V2A)

· Symmetrical pole plant

§ One skate (V2)

· Pole planted as weight is transferred to each ski

· Highest energy cost (VO2 to speed) and Heart Rate

o Millet (2003) J Sports Sci 21(1):3

o Pole striding

§ Often used for dry land training in off season

§ Walking with use of poles (especially on uphill)

§ Body position and leg movement similar to skiing

· Common Cross Country Skiing Injuries

o Hip and thigh

§ Hamstring Strain

o Knee

§ Medial Collateral Ligament Sprain (most common)

§ Anterior Cruciate Ligament Rupture

§ Medial or Lateral Meniscal Tear

§ Patellofemoral Syndrome

o Ankle and calf

§ Acute Lateral Ankle Sprain

§ Medial Tibial Stress Syndrome

§ Exertional Compartment Syndrome

o Foot

§ Hallux Rigidus (Skier's Toe)

§ Sesamoid inflammation of great toe

o Shoulder

§ Acromioclavicular joint separation

§ Rotator Cuff Tendinitis

o Elbow

§ Triceps tendinitis

o Hand and wrist

§ Ulnar Collateral Ligament Rupture (Skier's Thumb)

§ Wrist extensor tendinitis

o Cold related injury

§ Frostbite

§ Hypothermia

o Exercise Induced Bronchospasm (EIB)

§ X-C Skiing has highest EIB rate of all winter sports

· EIB in 50% of Olympic skiers (25% in other sports)

· Wilber (2000) Med Sci Sports Exerc 32(4):732

§ Slow warm-up prior to cold Exercise may reduce EIB

· Slowly build-up exertion level in a work-out

· Warm-up before a ski race

· Predictors of cross country skiing performance

o Best predictors on Exercise treadmill testing

§ Males: Onset of blood lactate accumulation

§ Females: Intensity when respiratory exchange ratio 1

§ Larsson (2002) Scand J Med Sci Sports 12(6):347

o Upper body conditioning is critical to performance

§ Hoff (1999) Med Sci Sports Exerc 31(6):870

§ Mahood (2001) Med Sci Sports Exerc 33(8):1379

§ Millet (2003) J Sports Sci 21(1):3

· References

o Morris (1999) Postgrad Med 105(1):89

Hurdling
High Jumping

Causes: Common pearls by location

Groin Pain

Consider Intra-articular hip pain

Lateral Pain

Trochanteric Bursitis

Buttock Pain

Referred pain from lumbosacral spine
Sacroiliac joint
Piriformis Syndrome (deep pain worse with sitting)

Causes: Anterior Hip Pain

Spontaneous onset without trauma in elderly

Consider inflammatory arthritis, infection
Ask about systemic symptoms
Start evaluation with CBC, ESR, RF

Insidious onset in elderly

Risks: age >65, ROM pain, cancer, trauma, Alcohol
Start with Hip XRay

Evaluate for Osteoarthritis
Consider Avascular necrosis, tumor or Fracture

Overuse or sports related anterior hip pain

Clicking or Snapping Hip

Tests: Thomas Test or Snapping Hip maneuver
Common Diagnoses (See Snapping Hip)

Iliopsoas Bursitis
Labral tear

Suspected Stress Fracture

Obtain MRI
Non-weight bearing

Resisted muscle testing and local tenderness

Consider hip flexor Muscle Strain

Causes: Lateral Hip Pain

Overuse or sports related

Consider Iliotibial Band Syndrome

Tender over greater trochanter

Greater Trochanteric Bursitis

Tender at gluteus medius, hip abductor weakness/pain

Gluteus medius muscle dysfunction

Anterolateral thigh neuropathic pain

Meralgia Paresthetica

Causes: Groin pain or hip pain in athletes

Idiopathic in 30% of cases
Adductor Strain or Adductor Tendinitis (Groin Pull)
Pubic Instability
Osteitis Pubis
Myositis Ossificans
Sports Hernia
Groin Disruption
Iliopsoas Strain or Iliopsoas Bursitis
Snapping Hip syndrome
Femoral Neck Stress Fracture
Pubic Ramus Stress Fracture
Avulsion Fracture (Adolescent Athletes)

Anterior Superior Iliac Spine Avulsion Fracture

Rapid sartorius contraction in jumping sport
Responds to non-operative conservative therapy

Anterior Inferior Iliac Spine Avulsion Fracture

Strong rectus femoris contraction in kicking sport
Responds to non-operative conservative therapy

Ischial Tuberosity Avulsion Fracture

Rapid hamstring contraction in sprinting, hurdling
Fragments >1-2 cm may require ORIF

Nerve entrapment

Genitofemoral nerve entrapment
Lateral Femoral Cutaneous Nerve Entrapment
Ilioinguinal Nerve Entrapment
Obturator Nerve Entrapment

Causes: Hip joint disorders with groin or hip pain by age

Pediatric Causes (under age 10 years)

See Pediatric Limp
Legg-Calve-Perthes Disease
Septic Joint
Toxic Synovitis

Adolescent causes

Slipped Capital Femoral Epiphysis
Hip Avulsion Fracture

Adult causes (See causes below)

Osteoarthritis of femoral head
Avascular necrosis of the femoral head
Acetabular labral tear

Causes: Musculoskeletal causes of groin or hip pain

Bone Causes

Hip Fracture
Femoral head avascular necrosis
Cancer (primary site or metastases)

Joint Causes

Hip Osteoarthritis
Septic Arthritis
Gouty Arthritis
Osteoid Osteoma
Osteitis Pubis

Muscle or tendon Causes

Iliotibial Band Syndrome
Trochanteric Bursitis
Iliopsoas Bursitis
Pyriformis Syndrome
Myositis Ossificans

Neurologic Causes

Lumbar Disc Disease
Lumbar Spinal Stenosis
Coccygodynia
Meralgia Paresthetica (see nerve entrapment above)

Causes: Non-musculoskeletal causes of groin or hip pain

General

Inguinal Hernia
Inguinal Lymphadenopathy or lymphadenitis
Lumbar Disc Disease with L1-2 radiculopathy
Nephrolithiasis
Abdominal Aortic Aneurysm
Appendicitis
Diverticulitis
Inflammatory Bowel Disease
Malignancy

Women

Ovarian Cyst
Urinary Tract Infection
Pelvic Inflammatory Disease

Epididymitis
Hydrocele
Varicocele
Prostatitis
Testicular Cancer

References

Fields (1997) Lecture: AAFP Sports Medicine, Dallas
Ruane (1998) Physician SportsMed 26(4):78-103
Brunner (2003) Am Fam Physician 67(3):537
Fricker (1997) Br J Sports Med 31:97
Lynch (1999) Sports Med 28:137
Morelli (2001) Am Fam Physician 64(8):1405

FLUID AND ELECTROLYTE THERAPY

rasyaplp@gmail.com (Unknown) — Fri, 29 Aug 2008 13:12:00 +0000

1. What is plasma osmolality?

Plasma osmolality is a function of the ratio of body solute to body water; it is regulated by changes in water balance. Water intake is derived primarily from three sources: Ingested water, water contained in food, and water produced from oxidation of carbohydrates, proteins, and fats. Water losses occur in the urine and stool, as well as evaporation from the skin and respiratory tract. Alterations in plasma osmolality of as little as 1% - 2% are sensed by osmoreceptors in the hypothalamus. These receptors initiate mechanisms that affect water intake (via thirst) and water excretion (via antidiuretic hormone [ADH]) to return plasma osmolality to normal.

2. Define "effective circulating volume".

Effective circulating volume is defined as that part of the extracellular fluid (ECF) that is in the vascular space and effectively perfusing tissues. It varies directly with ECF volume and also with total body sodium, since sodium salts are the primary ECF solutes holding water in the extracellular space. Therefore, regulation of sodium balance, by changes in renal sodium ion, and the maintenance of effective circulating volume, are closely related.

3. What are the major effectors of effective circulating volume?

Three major effectors alter effective circulating volume: 1) The sympathetic nervous system, 2) angiotensin II, and 3) renal sodium excretion. Volume depletion, sensed by arterial baroreceptors as hypotension, causes an increase in peripheral sympathetic tone. Increased sympathetic tone returns volume to normal by initiating specific compensatory changes. These compensatory changes include the following:

o Venous constriction: Increased venous return

o Increased myocardial contractility and heart rate: Increased cardiac output

o Arterial vasoconstriction: Increases systemic vascular resistance and blood pressure

o Increased renin secretion: Increases levels of angiotensin II which is a potent vasoconstrictor

o Increased renal tubular sodium resorption (due to increased levels of angiotensin II and aldosterone).

Sympathetic tone induced changes in effective circulating volume are transient and compensatory; appropriate changes in renal sodium excretion are required to restore normal volume.

4. What is the body’s main defense against hyperosmolality?

The major defense against hyperosmolality (accumulation of solute in excess of body water) is increased thirst. Although the kidney can minimize water losses via the action of ADH, water deficits can be corrected only by increased dietary intake.

5. When can hypo-osmolality result?

Hypoosmolality can result from excessive body water retention with subsequent dilution of body solutes or from solute loss in excess of water loss (e.g., diarrhea). Because the kidney excretes large volumes of water daily, persistent water retention resulting in hypoosmolality occurs only in the presence of decreased renal water excretion. In patients with normal renal function, hypoosmolality must therefore be due to solute loss in excess of body water loss.

6. How does hypovolemia (i.e., dehydration) increase the circulating volume?

Hypovolemia causes an increase in renin secretion. The subsequent increase in angiotensin II causes an increase in blood pressure (as a result of arterial vasoconstriction), as well as renal sodium retention (this is both a direct effect and also the result of increased aldosterone secretion). With sodium retention, water is also retained.

7. How do you determine the degree of dehydration in an animal?

Clinical assessment of dehydration is best accomplished by serial body weight monitoring. Experience has shown that the physical examination findings often underestimate the degree of dehydration. During the acute phase of volume depletion, these classical physical examination findings are all that are available. The chart below is offered as a general guideline and assumes more serious hypovolemia is present.

TABLE 1. Estimating the percentage dehydration based upon physical examination findings.

Estimated Percentage Dehydration	Physical Examination Findings
<5	History of fluid loss but no findings on physical examination
5	Dry oral mucous membranes but no panting or pathological tachycardia
7	Mild to moderate decreased skin turgor, dry oral mucous membranes, slight tachycardia, and normal pulse pressure.
10	Moderate to marked degree of decreased skin turgor, dry oral mucous membranes, tachycardia, and decreased pulse pressure.
12	Marked loss of skin turgor, dry oral mucous membranes, and significant signs of shock.

8. When and how much fluid can be given via the subcutaneous route?

In mild dehydration, subcutaneous fluids are useful. Isotonic fluids should be used and no more than 5 to 10 ml/lb should be given at each injection site. The rate of subcutaneous fluid flow usually is governed by patient comfort. These fluids are aseptically administered and multiple sites are required to provide adequate fluid volume. Generally, all subcutaneous fluids are resorbed within 6 to 8 hours. If fluids are still noted subcutaneously after this time, the use of intravenous fluids to reestablish peripheral perfusion should be considered.

9. How about using the intraperitoneal route for fluid administration?

The intraperitoneal route is quick, easy, and the fluids will generally be reabsorbed thus increasing the circulating volume. However, there is the potential of bacterial peritonitis, perforating viscera, and decreasing ventilation from impeding diaphragmatic excursion. Experience with peritoneal dialysis in dogs has shown that peritoneal fluids often traverse the diaphragm, entering the thoracic space, and further affecting ventilation. Currently, intraperitoneal fluids cannot be recommended.

10. When and how are you going to administer the intravenous fluids?

In general, intravenous fluid administration is indicated in dogs and cats with 7% or greater dehydration. There are numerous potential routes for intravenous fluid administration:

o Peripheral veins

o Jugular veins

o Intraosseous

11. When and how do you estimate the volume of fluids to be given an animal?

The amount of fluid needed for replacement depends on the patient's status. Of primary concern is the status of the blood volume and later concern is directed to restoration of total body water and electrolytes.

12. What are the three phases of fluid therapy?

o Emergency phase

o Replacement phase

o Maintenance phase

13. How much fluid should be given during replacement therapy?

The volume of fluid administered during the dehydration phase is based on an assessment of fluid needs for the following:

Returning the patient's status to normal (deficit volume)

Replacing normal ongoing losses (maintenance volume)

Replacing continuing abnormal losses (continuing losses volume)

14. How do you calculate the deficit volume?

The deficit volume is an estimate based on findings from the physical examination (Table I) or on known changes in body weight To make the calculation of deficit volume, the estimated dehydration is multiplied by the body weight. It must be remembered that it is difficult to replace all deficits in a 24-hour period. An attempt to do so may result in urinary losses furthering dehydration. Thus, it is recommended that only 75% to 80% of the deficit volume be replaced during the first 24 hours. Also, don’t forget that you must also add "daily maintenance volumes" to your calculated deficit volume if the animal is not eating nor drinking.

Example 1:

A 22-lb (10 kg) dog is assessed to be 7% dehydrated. What volume of fluid deficit should be given during the first 24 hours?

Total Deficit Replacement Volume = Deficit Volume PLUS Maintenance Volume

Deficit replacement volume (ml) = % dehydration x body weight (lb) x 454^a x 0.80

Deficit replacement fluid volume (ml) = 0.07 x 22 lb x 454^ax 0.80 = 560 ml

^{a = 454 mls = 1 pound}

Deficit replacement volume (ml) = % dehydration x body weight (kg) x

1000^b x 0.80

Deficit replacement fluid volume (ml) = 0.07 x 10 x 1000 x 0.80 = 560

^{b = 1000 ml = 1 kilogram}

15. What are "maintenance volumes" for fluid therapy?

Maintenance volumes are normal ongoing losses. Ongoing losses are divided into sensible and insensible losses. Sensible losses can be measured and are water losses in the urine and feces. Insensible losses are normal but are not easily quantitated. These water losses occur during panting or sweating. One-third of the maintenance volume is made up of the insensibile volumes and two-thirds, sensible volumes.

16. How much fluid should you give for maintenance volume if the animal is not eating nor drinking?

There is a paucity of data regarding water needs for the dog and cat and many authors recommend dramatically different fluid and energy requirements. As you will recall, water and energy requirements are numerically the same (1 Kcal of energy = 1 ml of water). Unfortunately, many authors recommend dramatically different fluid and energy requirements. Data from recent research has been used to document that energy expenditure or consumption is less than published formulas and recommendations. Estimation of water needs include 50mls/kg/day, 132 kcal X Kg^0.75, 156 X Kg^0.667, (30 X kg) + 70, 70 X Kg^0.75. Indirect calorimetry is being used to estimate energy (and thus water) needs for the dog and cat. These studies reinforce that previously recommended formulae overestimate the energy (water) requirements of the cat and dog (Figures 1 and 2).

Figure 1. Maintenance fluid volumes for the cat. Recommended volumes are calculated from the formula (30 X BW_Kg) + 70.

Figure 2. Maintenance fluid volumes for the dog. Recommended volumes are calculated from the formula (30 X BW_Kg) + 70.

Example 2:

A 22-lb (10 kg) dog is assessed to be 7% dehydrated and has been vomiting. How much fluid should be given during the next 24 hours?

Volume (ml of fluid required) = deficit volume + maintenance volume

= [0.07 x 22 lb x 454 x 0.80] + [(10 x 30) + 70]

= [560] + [370] = 930 ml

= [0.07 x 10 kg x 1000 x 0.80] + [(10 x 30) + 70]

= [560] + [370] = 930 ml

17. Does the formula recommended above satisfy water needs in the sick animal?

The question regarding energy (water) requirements in sick animals continues to elicit controversy. Traditionally it has been taught that illnesses, injuries, and surgery resulted in the increased need for more energy (water). These teachings were extrapolated from human and rodent data. In the dog, there is mounting evidence that increased energy requirements are not common in the sick, injured, or surgical dogs. In fact, there are increased numbers of publications documenting the lower energy (water) requirements for both the normal and sick or traumatized dog. Additionally, from an evolutionary perspective, it seems logical to expect the dog to preserve available energy with illness or injury. The reserves are already minimal and it makes little sense to increase metabolic requirements in order to survive. It makes more sense to conserve available energy and to reduce metabolic (thus energy and water) requirements. Studies on dogs in a critical care unit have documented the presence of significant hypothyroid function. Thus, metabolic requirements are reduced.

The decision to change the formulae for calculating water requirements will only come with more objective evidence taken from normal and sick dogs and cats.

18. How do you account for continuing losses during the replacement phase of fluid therapy?

A crude but effective guideline for replacing continuing abnormal losses is to estimate the volume of fluid loss and then double this estimate. The result will be surprisingly close to the actual volume of vomitus, diarrhea, or urine.

19. How do you tell when an animal is receiving an inadequate fluid volume?

Any acute change in body weight results from losses or gains in water. If the animal is losing body weight while being given crystalloid fluids, the animal is likely receiving inadequate volumes of fluid. One group of patients where body weight may fool you is in animals that are third-spacing fluids (peritonitis, pyometritis, pleural effusions). In these animals the animal may still be dehydrated but the body weight may not have changed. Monitoring the central venous pressure will result in a value which is well below 5 cm H₂0. Additionally, if renal function is adequate, an animal which is dehydrated will have a urine specific gravity above 1.025.

20. What are the clinical signs of overhydration?

Classically, pulmonary edema is associated with overhydration. Clinically, pulmonary edema is the terminal event of overhydration! Before pulmonary edema results you will first note an increased serous nasal discharge, followed by chemosis, and finally pulmonary congestion will be ausculated before edema ensues.

21. List the common crystalloid fluids, their electrolyte composition, pH, and osmolality.

						Buffer	Calories	Osmolality
Solution	Na+	K+	Cl-	Ca++	Mg++	mEq/L	Kcal/L	mOsm/L
Dextrose 5% in Water	-	-	-	-	-	-	170	278
Dextrose 2.5% in 0.45% Saline	77	-	77	-	-	-	85	280
Ringer’s Lactate Solution	130	4	109	3	-	Lactate 28	9	272
Ringer’s Solution	147	4	156	4.5	-	-	-	309
Normosol-R (Multisol-R)	140	5	109	-	3	Acetate 27 Gluconate 23	15	294
Dextrose 5% in Ringer’s Lactate	130	4	109	3	-	Lactate 28	179	525
Normal Saline (0.9%)	154	-	154	-	-	-	-	308
Dextrose 50%	-	-	-	-	-	-	1700	2525
Dextrose 5% in Saline (0.9%)	154	-	154	-	-	-	170	-
Potassium Chloride	-	2	2	-	-	-	-	-

22. How do you select the parenteral fluid to be given?

In selecting a fluid, it is important to know which electrolytes are lost and to institute replacement therapy based on knowledge of the pathophysiology of the disease. Table II provides an overview of electrolyte changes and replacement recommendations.
After you have studied Table II, you might want to test your knowledge by taking a quick quiz on selecting the appropriate fluid (http://www.cvmbs.colostate.edu/clinsci/wing/fluids/fluids.htm).

Table II. Selection of fluids for selected diseases.

			SERUM
CONDITION	Na⁺	Cl^-	K⁺	HCO₃^-	Volume	FLUID OF CHOICE
Diarrhea	D	D	D	D	D	NORMOSOL^R-R + KCl or Lactated Ringer's + KCl
Pyloric obstruction	D	D	D	I	D	0.9% NaCl + KCl
Dehydration	I	I	N	N/D	D	NORMOSOL^R-R + KCl, Lactated Ringer's + KCl, 0.9% NaCl + KCl, 5% dextrose
Congestive heart failure	N/D	N/D	N	N	I	0.45% NaCl + 2.5% dextrose + KCl, 5% dextrose
End-stage liver disease	N/I	N/I	D	D	I	0.45% NaCl + 2.5% dextrose + KCl
Acute renal failure -Oliguria -Polyuria	I D	I D	I N/D	D D	I D	0.9% NaCl, NORMOSOL^R-R + KCl, Lactated Ringer's + KCl,
Chronic renal failure	N/D	N/D	N	D	N/D	NORMOSOL^R-R, Lactated Ringer's solution, 0.9% NaCl
Adrenocortical insufficiency	D	D	I	N/D	D	0.9% NaCl
Diabetic ketoacidosis	D	D	N/D	D	D	0.9% NaCl (+ KCl)

D = Decreased I = Increased N = Normal

Case Studies in Fluid Therapy

Suggested Reading

Aberman A: The ins and outs of fluids and electrolytes. Emerg Med 14(7):121-127, 1982.

Adams LG, Polzin DJ. Mixed acid-base disorders. Vet Clin N Amer: Small Anim Pract 19(2):307-326, 1989.

Bonner CW, Stidham GL, Westenkirchner DF, Tolley EA: Hypermagnesemia and hypocalcemia as predictors of high mortality in critically ill pediatric patients. Crit Care Med 18:921-928, 1990.

Concannon KT. Colloid oncotic pressure and the clinical use of colloidal solutions. J Vet Emer Crit Care. 3:49-62, 1993.

Dubick MA, Wade CE: A review of the efficacy and safety of 7.5% NaCl/6% dextran-70 in experimental animals and in humans. J Trauma 36:323-330, 1994.

Duval D. Use of hypertonic saline solutions in hypovolemic shock. Compend Contin Educ Pract Vet 17(10):1228-1231, 1995.

Garvey MS: Fluid and electrolyte balance in critical patients. Vet Clin North Am: Small Anim 19:1021-1057, 1989.

Haskins SC: A simple fluid therapy planning guide. Sem Vet Med Surg