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Practical lessons / 3rd practice Venipuncture (blood sampling), intravenous drug application, peripheral venous catheterization (cannulation), cardiopulmonary resuscitation (reanimation), oxygen-therapy VENIPUNCTURE Aim: 1. blood sampling for laboratory analysis (average: 2-5 ml) 2. blood collection for transfusion ! Veins: 1. v. cephalica antebrachii (Figure 3-1, 3-2) 2. v. saphena lateralis – dog (Figure 3-3, usually not appropriate in cat Figure 3-4) 3. v. jugularis externa (Figure 3-7, 3-8) 4. v. femoralis ( v. saphena medialis) (Figure 3-5, 3-6) 5. v. dorsalis pedis – dog (Figure 3-9) Criteria of appropriate venipuncture site: - easy to visualize (superficial) - easy to access - easy to stabilize - properly thick/large 1

Transcript of Practical lessons / 3rd practice · Web viewPractical lessons / 3rd practice Venipuncture (blood...

Practical lessons / 3rd practice

Venipuncture (blood sampling), intravenous drug application, peripheral venous catheterization (cannulation), cardiopulmonary resuscitation (reanimation),

oxygen-therapy

VENIPUNCTURE

Aim:

1. blood sampling for laboratory analysis (average: 2-5 ml)

2. blood collection for transfusion

! Veins:

1. v. cephalica antebrachii (Figure 3-1, 3-2)

2. v. saphena lateralis – dog (Figure 3-3, usually not appropriate in cat Figure 3-4)

3. v. jugularis externa (Figure 3-7, 3-8)

4. v. femoralis ( v. saphena medialis) (Figure 3-5, 3-6)

5. v. dorsalis pedis – dog (Figure 3-9)

Criteria of appropriate venipuncture site:

- easy to visualize (superficial)

- easy to access

- easy to stabilize

- properly thick/large

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Methods:

Advantage Disadvantage

open system(Figure 3-11) easy to perform contamination (vet, surroundings, animalsample: air, bacteria, hair)

not suitable for blood gas and NH3 analysis, hemoculture

closed system(Figure 3-12) no contamination more difficult

more frequent hemolysis

may not be feasible in small patients

vacutainer system

(Figure 3-13)

no contamination difficult

only possible in large dogs and large veins (vacuum vein collapse

Contraindication:

- v. jugularis in case of hemorrhagic diathesis (thrombocytopenia, coagulopathy)

Equipment: (Figure 3-10)

- sharp needle of appropriate size

- syringe of appropriate size

- blood collection tube (EDTA tube, Eppendorf tube with/without heparin, Sodium citrate tube, Sodium fluoride tube, vacutainer tube with special needle)

- disinfectant (alcohol)

- hair clipper (razor, scissors)

- tourniquet (for vein occlusion)

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Positioning the animal:

- sternal recumbency (or sitting position): veins 1., 3.

- lateral recumbency: veins 2., 4., 5.; 3. - very small or very large animal

Procedure:

1. restrain the animal

2. remove the fur coat

3. disinfect the skin

4. distend the vein by moderate occlusion (visibility)

5. stabilize the leg & vein (Figure 3-3)

6. insert the needle - bevel facing up, 15-30o degree angle, 1/2-1 cm deep (try first at the distal part of the vein)

7. stabilize the needle (with fingers wrapped around the limb)

8. aspirate or drip the blood

9. remove occlusion (release pressure)

10. compression at insertion site

11. remove needle

Technical problems – blood is not coming

- opening of the needle is in contact with the vessel’s wall rotate the needle

- needle went through the vein withdraw slightly

- too strong occlusion closes the artery release/ease the strangulation

- accidental occlusion of vein distal from the needle reposition of your hand

- needle occluded by clots or skin parts remove, reinsert more proximal with a sterile new needle

- paravenous insertion remove, reinsert more proximal

- severe dehydration reinsert into thicker vein, (first rehydrate)

- too strong vacuum decrease the vacuum or change the blood sampling method to open system

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- ! Complications:

- hemorrhage at insertion site longer, stronger compression at insertion site

- hematoma

- thrombosis

- phlebitis (thrombophlebitis)

- septic infection (abscess, phlegmone, septicemia)

INTRAVENOUS DRUG APPLICATION

Aim:

- rapid effect (e.g. anesthesia, life threatening disorders – CPR, seizure, shock, hypoglycemia, pulmonary edema)

- tissue irritative drug

Appropriate veins

1. v. cephalica antebrachii

2. v. saphena lateralis (dog)

3. v. femoralis ( v. saphena medialis)

4. NOT v. jugularis externa

Procedure: (Figure 3-14)

1-7. steps of venipuncture

8. aspirate to make sure IV placement

9. remove occlusion (release pressure)!

10. inject drug at moderate rate + watch for signs of paravenous application (swelling, resistance, pain)

11. check needle placement with repeated blood aspiration (if necessary)

12. aspirate blood before pulling out needle to prevent leakage of irritative drugs to paravenous tissue

13. apply direct pressure at insertion site

14. remove needle

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! Complications:

- see venipuncture, +

- paravenous injection: swelling, inflammation, necrosis

- embolism (air, oil)

- allergy to injected material (anaphylaxis, urticaria): e. g. IV penicillins, blood products: slowly!

- apnea: IV anesthesia slowly!

- arrhythmia cordis: IV calcium, potassium slowly!

- transmission of infection (ie. babesiosis, FeLV)

- drug overdose

VENOUS CATHETERIZATION: central – peripheral

1. Central venous catheterization

Indication – intensive care procedures

- total parenteral nutrition

- monitoring central venous pressure (CVP)

2. Peripheral venous catheterization

Indication:

- continuous access to peripheral circulation (fluid therapy, partial parenteral nutrition, repeated IV treatment)

- multiple blood samples

Appropriate veins

1. v. cephalica antebrachii

2. v. saphena lateralis (dog)

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3. v. femoralis ( v. saphena medialis)

4. v. jugularis externa in puppies & kittens <0,8 kg: catheter is directed centrally!!!

Parts of the over-the-needle catheter:

- catheter with wings

- stylet (needle) with finger holding element

- apertures: - end of catheter with closing cap:

for blood sampling (at time of catheterization only!); infusion line; drug application; free access to circulation

- top of catheter with valve: only for injections and filling up with diluted heparin

Equipment: (Figure 3-15)

- IV catheter of appropriate size

- hair clipper

- disinfectant

- adhesive tape

- syringe with diluted heparin

- gauze

- (3-way stop cock)

Procedure: (Figure 3-16 a-e)

1-5. steps of venipuncture

6. advance the catheter with the stylet bevel upward 1/2-1 cm into the vein

7. withdraw the stylet (few mm) & check proper placement (blood appears at the end of the stylet)

8. slide up the catheter (should go easily)

9. remove stylet and place closing cap

10. wrap with adhesive tape (not too tight) (Figure 3-16f)

11. (take blood sample if necessary)

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12. flush with diluted heparin

13. mark date on tape

14. connect the 3-ways stop cock and wrap (Figure 3-17a,b)

! Complications:

- see venipuncture and intravenous drug application, +

- pyoderma under adhesive tape

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CARDIOPULMONARY RESUSCITATION (CPR)

Other name: Cardiopulmonary / cerebral / resuscitation (CPCR)

Indication

Cardiac and/or pulmonary arrest (CPA)

! Clinical manifestation of CPA:

- loss of consciousness

- absence of spontaneous ventilation, or agonial breathing (gasping)

- absence of heart sounds on auscultation

- absence of palpable pulse

Predisposing factors for CPA:

e.g. : SIRS (systemic inflammatory response syndrome), sepsis, cardiac failure, severe pulmonary disease, neoplasia, brain trauma, polytrauma, coagulopathy, toxicosis, and anesthesia

Aim:

provide oxygen / blood to vital organs = heart & brain

Principles of CPR:

- „ The most successful CPR is the one avoided.” = detect and treat underlying disorders of CPA & monitor continuously the critically ill patients

- owner’s permission/wish

- start within 3-5 minutes from CPA (later: irreversible brain damage due to hypoxia)

- appropriate equipment (Figure 3-18) , personal training

- a minimum of 3 people (ideally)

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! The alphabet and sequential order of CPR:

A = Airway

B = Breathing

C = Circulation

D = Drugs & Defibrillation

E = ECG

F = Fluid therapy

Steps of CPR:

I. Short physical examination (10 seconds!) restricted to detect presence or absence of spontaneous breaths and heartbeats, and the degree of bradycardia (if present) (Figures 3-19a and 3-19b)

II. Basic life support = establishment of free airways (A), breathing (B) and circulation (C)

III. Advanced life support = pharmacologic support of circulation (D), detection of arrhythmias (E), fluid therapy (F) & placement of an advanced airway

IV. Monitoring of effectiveness and care of patients after successful CPR

I. Basic life support in CPR = in order of importance: C, A, B!!! (/ A, B, C) (SEE FLOWCHART!)

A = Airway

= establishment of free airways

1. remove materials causing occlusion (wipe, suction; small breeds – shake with head positioned downwards)

2. placement of endotracheal tube

- use laryngoscope (do not insult epiglottis, especially not in cats – laryngeal spasm!)

- check proper placement (visualization of chest wall excursions during ventilation)

- inflate cuff and tie tube on maxilla (brachycephal breeds: at occipital region)

3. if endotracheal intubation is not possible emergency tracheostomy

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B = Breathing

= check for breathing no, or agonial breathing positive pressure ventilation (preferably with 100% O2)

a. if only respiratory arrest: stimulate the Ren-zhong acupuncture point 2 punctures/sec (ventral nasal philtrum, puncture until the bone!) (Figure 3-20) spontaneous breathing?

b. ventilations with AMBU bag attached to O2 line (Figure 3-21)

- 10-12 breaths per minute (avoid hyperventilation!)

- don’t stop parallel chest compressions (if they are needed) for the time of ventilation!

- breaths given over 1 sec, visual rise in chest wall, normal relaxation (volume: 100ml/10 kg)

- avoid barotrauma of lungs (not too large volume, nor forcefully)

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C = Circulation

= check for heart rate (Figure 3-19b) ABSENT begin external chest compressions immediately

1. patient in left or right lateral recumbency (bulldogs: dorsal recumbency)

2. compressor: stand at the back of the patient, clutched hands, closed elbows, straight arms, bend from waist

3. hand placement:

a. medium-large dogs: clutched hands over the widest part of chest (Figure 3-22)

b. medium dogs: clutched hands directly over the heart (4th-6th intercostal area)

c. smaller dogs, cats: fingers of 1 hand at the area of heart (thumb on the other side) (Figure 3-23)

4. 100-120 compressions per minute (BeeGees: Stayin’ alive)

- compression: relaxation ratio = 1:1

- compression = 30 (-50) % of chest wall diameter (better too big than too small)

- let chest wall completely recoil after pressing! (let the heel of the hand up)

- NO pauses!!!

- rotate compressing person every 2 minutes; use this gap (maximum of 10 seconds!) for interventions needing a pause in chest compressions (e.g. cardiac auscultation, defibrillation etc.) (Figure 3-24)

5. internal cardiac massage = surgical route, if:

- penetrating chest wound, rib fracture, diaphragmatic hernia, etc.

- (inadequate circulation after 2-5 min external chest compression)

II. Advanced cardiac life support in CPR = D, E, F

D = Drugs

= pharmacologic support of circulation

1. routes of administration

a. (the best: central venous catheter (IV)

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BUT: time-consuming placement)

b. peripheral venous catheter (IV)

- as bolus injection

- followed by 5 ml of 0.9% saline IV + raise extremity

- it takes 1-2 min to reach central circulation (chest compression should be performed for 2 min. after drug administration before checking ECG!)

c. intratracheal route (IT) (Figure 3-25a)

- put a catheter that is longer than the tube into the endotracheal tube to inject substance into the airways (Figure 3-25b)

- safe: atropine, epinephrine, vasopressin

- not first choice administration route!

- NO: in pulmonary disorders (pulmonary edema, etc.)

- 2-2,5 x dose required IT!

- dilute in 5 ml sterile water (or 0,9% saline)

- give 2 consecutive breaths right after IT drug admnistration

d. (Intraosseus administration (IO)- small breeds/puppies, femur or tibia)

e. (Intracardiac injections (IC))

- NOT recommended (numerous complications)

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2. drugs of CPR

asystole: epinephrine, low dose NO effect repeat NO effect epinephrine, high dose

epinephrine

- mixed adrenergic agonist

- indicated mainly for 2 adrenergic stimulant effect: peripheral arteriolar vasoconstriction coronary and cerebral perfusion pressure

- 0.01 mg/kg IV “low dose” (Tonogen inj.: 0,1 ml/10 ttkg), can be repeated even every 2 min.

- (in case of no effect of low dose for 2 consecutive times the dose can be increased: 0.1 mg/kg IV “high dose” (Tonogen inj. 1 ml/10 kg) )

atropine

- anticholinergic parasympatholytic

- heart rate , systemic vascular resistance , blood pressure

- in severe bradycardia; dogs: <30/min, cats: <60/min

- 0.04mg/kg IV (Atropinum sulphuricum inj.: 0,4 ml/10 ttkg)

- can be repeated every 2 min. for max. 3 doses

sodium-hydrogene-carbonate:

- for severe metabolic acidosis

- for severe hyperkalemia

- 0.5 mEq/kg IV = 3,2 ml Alkaligen infusion / kg

glucose: only in documented hypoglycemia

furosemide:

- in case of pulmonary oedema

- 4 mg/kg iv = 2 ml Furosemid inj./ 10 kg

D = Defibrillation

- for ventricular fibrillation

- needs to be charged regularly

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E = ECG

= evaluate different types of arrhythmias (Figure 3-26)

1. detect causes of pulseless cardiac arrest

a. asystole

b. pulseless electrical activity (PEA)

c. ventricular tachycardia

2. ventricular fibrillation

3. evaluate severe sinus bradycardia

a. dogs: < 40 bpm

b. cats: < 120-140 bpm

F = Fluids = IV fluid therapy

contraindicated in pulmonary oedema!

1. hypovolemic patients: shock dosages

a. crystalloids

- dogs: 90 ml/kg

- cats: 45 ml/kg

- ¼ dosage in 15 min than reevaluate, if necessary repeat

b. colloids (hetastarch)

- dogs: 5 ml/kg

- cats: 1-3 ml/kg

- in IV bolus

c. hypertonic saline (10%)

- 1-2 ml/kg over 5 min.

2. euvolemic patients: crystalloids in bolus as rapidly as possible

- dogs: 20 ml/kg bolus

- cats: 10 ml/kg bolus

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III. Monitoring of effectiveness and care of patients after successful CPR

- successful CPR is often/usually followed by another CPA in a short period of time!

- possible consequences of a CPR:

- irreversible damage of nervous system (permanent dysfunction followed by CPR should resolve within 24-48h)

- shock (affected organs: lungs, kidneys, GI tract)

- DIC

- reperfusion injuries

- increased intracranial pressure

- to be monitorized following CPR:

- pulse, mental state, neurological function, temperature, auscultatory findings of lungs, color of mucous membranes, CRT, urine output, ECG, pulse-oxymetry, electrolytes, acid-base status, hematocrit, blood glucose level, serum lactate level, central venous pressure, patient comfort

OXYGEN-THERAPY (oxygen supplementation)

Aim:

- maintain arterial blood oxygen pressures (PaO 2 > 60 mmHg)

Indication:

- respiratory distress (dyspnoe)

- cyanosis

Complications and prevention:

a. anhydrous nature of pure oxygen use humidifiers, nebulization, esp. in chronic therapy

b. toxic effect of oxygen in high concentration

o pure (100%) O2 for short period

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o mix 100% O2 with room air

o 50% O2 for < 12h in duration

! Equipment

1. oxygen mask- short term- sometimes stressful and increases dyspnoe, especially in cats

2. oxygen hood- can be placed over a laterally recumbent and still animal’s head- adaptation of an Elizabethan collar is better tolerated

3. nasal catheter- long term- animal relatively free to move- usually well-tolerated

4. transtracheal catheter- emergency stabilization of animals with upper airway obstruction (even in CPR)- surgical placement (jugular catheter through the trachea)- short term

5. endotracheal tube- before surgical procedure- CPR- short term- NOT tolerated by alert animal

6. tracheal tube- upper airway obstruction- long term- surgical placement: tracheostomy + suturing- monitor for obstruction and cleaning after treatment

7. oxygen cage- long term- NO stress- Monitor and control: humidity, temperature, CO2 concentration

Suggested readings

1. Venipuncture, intravenous drug application, peripheral venous catheterization:a. McCurmin, Poffenbarger (1991): Small Animal Physical Diagnosis and Clinical

Procedures. pp. 129–133., 138–142. (NOT Figure 15-5 and Figure 15-9!)b. S. E. Crow, S. O. Walshaw (1987): Manual of Clinical Procedures in the Dog and Cat. pp.

33–34.

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2. Cardiopulmonary resuscitation:a. S. J. Plunkett, M. McMichael. Cardiopulmonary Resuscitation in Small Animal

Medicine. An Update. J. Vet. Intern. Med. 2008:22; 9–25.

3. Oxygen-therapy: a. R. W. Nelson, C. G. Couto: Ancillary Therapy: Oxygen Supplementation and

Ventilation. In: Small animal internal medicine. 2009. 4th ed. Chapter 27. pp. 345–348.

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Appendix

Figure 3-1. V. cephalica antebrachii in dog Figure 3-2. V. cephalica antebrachii in cat

Figure 3-3. Venipuncture of v. saphena lateralis in dog Figure 3-4. V. saphena lateralis in cat

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Figure 3-5. V. femoralis and v. saphena medialis in dog Figure 3-6. V. femoralis and v. saphena medialis in cat

Figure 3-7. Venipuncture of v. jugularis externa in dog Figure 3-8. V. jugularis externa in cat

Figure 3-9. V. dorsalis pedis in dog Figure 3-10. Equipment of venipuncture

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Figure 3-11. Blood sampling – open system Figure 3-12. Blood sampling – closed system

Figure 3-13. Blood sampling – vacutainer system Figure 3-14. Intravenous drug application

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Figure 3-15. Equipment of peripheral venous catheterization

Figure 3-16. Steps of peripheral venous catheterization (a, b)

Figure 3-16. Steps of peripheral venous catheterization (c, d, e)

Figure 3-16. Fixing of the peripheral venous catheter (f)

Figure 3-17. Attachement of a 3-way stop cock to the peripheral venous catheter (a, b)

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Figure 3-18. Equipment of CPR

Figure 3-19a. Short (10 sec) physical examination: breathing

Figure 3-19b. Short (10 sec) physical examination: heart sounds

Figure 3-20. Stimulating the Ren-zhong acupuncture point

Figure 3-21. Ventilating with AMBU bag attached to oxygene line

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Figure 3-22. External chest compressions – medium-large size dog

Figure 3-23. External chest compressions –

cat

Figure 3-24. Checking for the heartbeats and the pulse

Figure 3-25a. Intratracheal drug application

Figure 3-25b. Intratracheal drug application Figure 3-26. ECG examination

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