TIPS for patients in shock

Dr. James Manos (MD)

April 15, 2020

                      TIPS for patients in shock

Image (free to use): The Trauma Room in the E.R. of the University Hospital in Mannheim, Germany (September 4, 2009). Author: Belle Chasse, LA, October 25, 2005. Author: Director84. Uploaded by: Director84. Source: Wikipedia. Link: https://en.wikipedia.org/wiki/File:Schockraum_Uniklinik_MA.jpg

Investigations on patients with shock

Vitals (pulse, respiratory rate (RR), blood pressure (BP), temperature (T), glucose (initially with finger stick), SaO2 (oxygen saturation)

Blood glucose (initially fingerstick measure) 

ABGs (arterial blood gases) (e.g., if oxygen saturation is abnormal)

Place on a monitor (in Europe: Right for Red, YelLow for Left, and Green for splEen) & perform a 12 lead ECG. 

ECG (including V4R, if suspected right ventricular infarction) 

Limb electrodes mnemonic: ''Ride Your Green Bike''

Red: Right-arm – ulnar styloid process at the wrist

Yellow: Left-arm – ulnar styloid process at the wrist

Green: Left leg – at the ankle – medial/lateral malleolus

Black: Right leg – at the ankle – medial/lateral malleolus.

Blood for lab tests (also type & crossmatch if needed) 

HISTORY 

Subjective symptoms?/ First time?/ When did it start?/ Has it worsened?/ Other in the family or environment with the same symptoms? Hazards? Need for decontamination? / Count pain from 1 to 10 scale. // Any rash recently, e.g., measles encephalitis. 

(S)AMPLE

Signs & Symptoms 

Allergies (including drugs, bees, nuts, seafood, etc.)

Medications [anything, including non-prescribed drugs, herbs & lifestyle drugs such as for sex (especially in case of myocardial infarction in which PDE5 inhibitors, such as Viagra (R), may cause severe hypotension if nitrates are administered for chest pain) or obesity (amphetamines?)]

Past medical history (PMH)

Last meal (When? What? Any other with the same symptoms?)

Environment/ Events (e.g., surrounding the time of injury) (e.g., (What happened? // kinetics on traffic accident)

Imaging tests 

Chest X’ Ray (CXR) [(pneumothorax? (perform both inspiration and expiration XCR; on an expiratory film, a pneumothorax will appear relatively larger, taking up a larger percentage of the thoracic cavity), cardiomegaly? Widened mediastinum? Subcutaneous emphysema?], abdominal X’ Ray (AXR) (free air?), echocardiography (transesophageal echocardiography for aortic dissection), Focused assessment with sonography (FAST) in trauma, CT/ MRI.

Labs

CBC (FBC) (complete/ full blood count), BUN, creatinine, electrolytes (potassium K, sodium Na, magnesium Mg, phosphate P, calcium Ca – ionized or corrected for low albumin), coagulation studies (platelets, PT, APTT, INR, D’ Dimers), LFTs (lever function tests), CK, cardiac enzymes & markers (especially troponin), LDH, ESR, CRP, amylase (if increased check urine amylase), lipase (more sensitive than amylase for pancreatitis), serum lactate (may spuriously increase if the sample is hemolyzed), urine color (increased CPK with dark indicate rhabdomyolysis), urinalysis, cultures (in suspected sepsis take samples for cultures: blood, midstream urine, feces (if diarrhea), throat/ vagina/ sputum/ wound swab; also gram Stain, sensitivity to antibiotics), pregnancy test (childbearing age women – a positive test may also indicate ectopic or molar pregnancy), toxicology (aspirin, paracetamol, antiepileptics, digoxin, lithium, illicit drugs, etc.), drug levels (e.g. anticonvulsants, gentamycin, vancomycin, etc.), +_HbCO levels, +_ TFTs (thyroid function tests), cortisol/ ACTH levels, blood type & crossmatch (ask 4 – 6 units). 

Notes

1. Blood with chocolate, brown color may indicate methemoglobinemia. There is cyanosis with falsely normal arterial oxygen tension (PaO2), but the oxygen saturation may be low or overestimated. The key feature is the disparity between those 2. Pulse oximetry measurements with low levels of methemoglobinemia often result in falsely low values for oxygen saturation and are often falsely high in those with high-level methemoglobinemia. Cyanosis does not improve with the administration of Oxygen. 

2. In the case of carbon monoxide (CO) poisoning, carboxyhemoglobin (HbCO) causes pulse oximeters to register artificially high oxygen saturation (Spo2) values. Blood gas oxygen tension (PO2) measurements tend to be normal. A carboxyhemoglobin measurement is essential for determining exposure. Do not forget to check the ECG & cardiac markers.

There are special pulse oximeters that measure methemoglobin and carboxyhemoglobin (HbCO).

3. Cyanide poisoning may occur from smoke inhalation of burned wool, paper, cotton, silk, and plastics and consuming stone fruit seeds of Prunus species such as bitter almonds. Patients with cyanide poisoning present with respiratory distress and normal oxygen saturation, while the arterial blood gases ABGs may show anion gap metabolic acidosis. Cyanide toxicity is characterized by normal arterial oxygen tension and abnormally high venous oxygen tension, resulting in a decreased arteriovenous oxygen difference (less than 10%). 

What to rule out on shock:

A. HYPOVOLAEMIC SHOCK

If the patient is shocked, then has cool and clammy skin (e.g. nose, toes, fingers), tachycardia (> 100 bpm), prolonged capillary refill time (more than 3 sec), hypotension (Systolic BP < 90) if blood volume loss is > 30% (> 40% on children!), postural hypotension (a drop of Systolic BP> 20 mmHg on standing), confusion, decreased urine output (< 30 ml/h). 

TIPS:

1. For < 15% blood loss early indicator is pale skin; for 15 – 30% will be additionally clammy and cool skin, tachycardia (>100 bpm), increased diastolic BP with narrowed pulse pressure (systolic BP – diastolic BP), delayed capillary refill (normal if <_3 sec, prolonged if >3sec).  

2. Tachycardia may be obscured in hypovolemic shock if the patient takes beta-blockers.

I. Blood loss.

Causes

a) Traumatic blood loss.

1. Exsanguination, e.g., severe bleeding, scalp lacerations (especially in children), etc.

2. Hemoperitoneum.

3. Hemothorax.

4. Fracture, especially of the femur and pelvis. 

TIPS: Stop any visible hemorrhage and check for bleeding in the chest and abdomen. Perform CXR (chest X-ray), and FAST/ ultrasound. Check for pelvic or long-bone/ pelvis fracture. If so, do immobilization and consider PAST (anti-shock trousers). Consult an orthopedic surgeon.

b) Non-traumatic blood loss.

1. GI (gastrointestinal) bleeding.

2. AAA (Abdominal aortic aneurysm) rapture.

3. Ectopic pregnancy rapture.

TIPS

1. Any difference between the pulses/ blood pressure estimation between the upper extremities (aortic dissection? subclavian artery stenosis?) and also between the upper and lower extremities (aortic dissection? aortic coarctation?). Consider abdominal aortic aneurysm if pulsatile abdominal mass and/ or if there is any difference in femoral artery pulses. Perform ultrasonography.

2. Is there hematemesis or melena? Perform PR (per rectum) examination. Is fluid on the nasogastric (NG) tube bloody? Emergency gastroscopy may be needed.

II. VOLUME LOSS

Causes

1. Burns.

2. Heatstroke with dehydration.

3. Skin integrity loss.

4. Vomiting (dehydration).

5. Diarrhea (dehydration).

6. Decreased fluid intake (elderly, dementia, disability/ no access).

7. DKA (Diabetic ketoacidosis) with dehydration. Rule it out, especially on children (fruity breath odor?). On the elderly, rule out the hyperosmolar hyperglycemic state (HHS) characterized by severe hyperglycemia, hyperosmolality, and dehydration in the absence of ketoacidosis

8. Third space accumulation, e.g., ascites (e.g., on heart failure, nephritic syndrome, protein loss enteropathy, malnutrition). 

B. CARDIOGENIC SHOCK

The skin may be pale and cool (‘cold & wet’), but sometimes there may be a ‘wet & warm’ type from SIRS). 

Causes

a. Dysrhythmia.

1. Tachyarrhythmia.

2. Bradyarrhythmia.

b. Cardiomyopathy.

1. MI (myocardial infarction).

2. RV (right ventricular) infarction (Always on an ECG, place a V4R i.e., V4 lead on the right). Avoid nitrates, diuretics, and morphine, which will decrease blood pressure steeply!

3. Dilated cardiomyopathy

c. Mechanical problems

1. Aortic regurgitation from an aortic dissection.

2. Papillary muscle rupture after a myocardial infarction (MI).

i. Ventricular aneurysm rupture.

ii. Free wall ventricular rupture.

For patients not in cardiac arrest (i.e., for patients with a pulse), cardiovert any unstable tachyarrhythmia with synchronized mode. Place transcutaneous pacing for unstable bradyarrhythmia (until official IV pacing is performed if recurrence).

For cardiogenic shock, give oxygen 100% high flow; consider if thrombolysis is needed (e.g., massive PE pulmonary embolism; ischemic stroke); consider under consultation gentle fluid challenges (e.g., 250 cc fluids) if no pulmonary edema. CPAP or intubation and mechanical ventilation (e.g., severe pulmonary edema; inotropes; Intra-aortic balloon pump, PCI (on MI). Consult early a senior cardiologist. The main TIP before any intervention (especially diuretics, nitrates/ nitroglycerin (TNG), and morphine) is to check for hypotension that will deteriorate. For the same reason, ask for any drugs, including lifestyle medication for sex (Viagra, Cialis, Levitra)! Is there any known drug allergy?   

C. DISTRIBUTIVE SHOCK 

The skin is warm and red!

Causes

1. Anaphylactic shock. Laryngeal edema, stridor, wheezing, hives, urticaria, angioedema (ACE inhibitors? hereditary angioedema? – in the latter, give FFP fresh frozen plasma or c1 esterase inhibitor). Give IM adrenaline, fluids (crystalloids), raise legs, give 100% oxygen high flow, give β’ agonists (salbutamol) on wheezing, hydrocortisone.

2. Septic shock. Suspect SIRS (systemic inflammatory response syndrome) if >_ 2 of the following: T (temperature) > 38 or < 36 degrees Celsius, HR (heart rate) >90, RR (respiratory rate) > 20/min (or hypocapnia), WCC (WBC) > 12,000 or < 4,000 or > 10% bands. Sepsis is SIRS with infection. Septic shock is sepsis with hypotension (SBP< 90 mmHg) despite fluid resuscitation.

In case of an erythematous rash, exclude TSST1 toxic shock syndrome toxin 1 (keep in mind that toxic shock syndrome may occur after tampon use on women and in nasal packing left for time).

3. Neurogenic shock (spinal cord lesion, surgery, spinal trauma). On trauma, exclude first hypovolemic shock (bleeding in abdomen, chest), which is commoner. Neurogenic shock is characterized by hypotension, bradycardia, motor/ sensory level, decreased rectal tone, and warm skin. The TIP here is bradycardia. In neurogenic shock, there is hypotension, while in case of increased intracranial pressure (e.g., head trauma), bradycardia will be accompanied by increased BP and irregular, decreased respirations (Cushing triad).   

4. Toxins. Consider decontamination (eyes, skin: meticulous washing), hazards (decontamination in a designated spot), clothes removal, antidotes, gastric lavage? / Whole bowel irritation? / Active charcoal? Dialysis? The key here is to administer antidotes when needed. Intravenous lipid emulsion may help in some cases.

Opioids and organophosphates will cause small pupils (pinpoint on opioids; pontine hemorrhage also causes pinpoint pupils).

CO (carbon monoxide) may cause a headache as an early symptom. Sometimes, the patient may have cherry-red lips.  

Organophosphates are used as insecticides, medications, and nerve agents. Symptoms include increased saliva and tear production, diarrhea, vomiting, small pupils, sweating, muscle tremors, and confusion.

5. Drugs – vasodilation e.g., β’ blockers or calcium channel blockers. These may cause shock without tachycardia (especially if given both).

Endocrinological problems.  

6. Adrenal insufficiency (recent abrupt stop of cortisone, or not increasing it in stress situations such as surgery or trauma?).

7. Thyrotoxic coma (it may also cause hyperthermia and atrial fibrillation (AF)).

8. Myxedema coma (it may also cause hypothermia and bradycardia).

9. Hypoglycemia (it may mimic stroke and cause focal neurological signs such as hemiparesis). Before the official Lab tests, always perform a ward finger stick test initially.

10. Hypopituitarism (in pregnancy, consider Sheehan’s syndrome from severe blood loss during delivery). 

D. OBSTRUCTIVE SHOCK

Causes

1. Tension pneumothorax: unilateral decreased breath sounds, tracheal deviation (away from the pneumothorax; late sign!), unilateral hyper-resonance of the hemithorax on percussion, and also jugular vein distension (JVD) – if not hypovolemic!). Don’t wait for a CXR (chest X-ray)! Perform needle decompression, and next insert a chest tube. For a CXR, remember that an expiratory film, if feasible, may show a pneumothorax better.

2. Pericardial disease.

i. Cardiac Tamponade. JVD (jugular veins distension), muffled heart sounds, Kussmaul's’ sign (an increase of JVP on inspiration), low ECG voltage, electrical alternans on ECG, pulsus paradoxus (decrease of Systolic BP and pulse on inspiration). Trauma is a common cause. It may also be iatrogenic. Other causes are less common (renal failure - uremia, lung cancer, TB, etc.). Perform FAST/ ultrasound.

ii. Constrictive pericarditis.

3. Massive pulmonary embolism (PE). Hypoxemia, right ventricular strain on ECG, acute right ventricular overload, chest pain, cyanosis, syncope, hypotension, tachypnoea, tachycardia, JVD (jugular vein distention). Give unfractionated heparin IV. If massive, consider thrombolysis (e.g. with rTPA alteplase) or embolectomy (by a surgeon). Do D’ Dimers. Negative D – Dimers usually rule out a PE (negative predictive value). Check leg & pelvis veins for DVT (Deep Vein thrombosis) with a Doppler/ plethysmography. Risk stratification is the key to assessing pulmonary embolism/ DVT risk!

4. Auto-PEEP from mechanical ventilation!

GENERAL TIPS

Warm skin? If so, consider sepsis, neurogenic shock, anaphylactic shock, or medication overdose.

Rule out Poisons/ medication overdose or adverse effects/ illicit drug abuse, sepsis, and Adrenal Insufficiency.

JVD (jugular vein distension): exclude tension pneumothorax, cardiac tamponade, massive PE (pulmonary embolism), and CHF congestive heart failure (for heart failure, check for calf edema and fine lung crackles – end respiratory crepitations/ rales, especially at lung bases). JVD may not be visible in case of severe hypotension.  

ABGs (arterial blood gases)

Venous blood PH is usually 0,01 – 0,03 lower than arterial blood PH. Also, usually, PCO2 is 6 mmHg higher, and bicarbonate is 2 meq/L higher if using venous blood.

Anion gap is ([Na] + [K]) – ([Cl] + [HCO3]). Increased anion gap occurs on DM (diabetes mellitus), alcoholics, starvation, lactic acidosis, renal failure, exogenous toxins metabolized to lactate (cyanide – CN, CO, ibuprofen, strychnine, toluene, iron – Fe and INH - isoniazid), or exogenous toxins metabolized to acids (aspirin, methanol, ethanol, ethylene glycol, paraldehyde and rarely with isopropanol), severe hypotension, seizures, and hypoxemia.

Increased osmolar gap may occur in diabetic ketoacidosis (DKA; especially in children) and ethylene glycol, methanol, or ethanol, isopropanol poisoning. Osmolar gap ΔOsm = measured Osm – Calculated O

Delay in pulses between upper and lower extremity (radio-femoral delay) (Aortic dissection? Coarctation of Aorta? Thrombosis/embolism/ atherosclerosis of aorta/ aortoarteritis?) 

Brachioradial delay? (right brachial pulse and right radial pulse are simultaneously palpated: radial pulse is felt after the brachial pulse in severe aortic stenosis)

Is there any difference in femoral pulses between the two lower extremities? (Ruptured aneurysm? atherosclerosis?) Note: The presence or absence of femoral pulses cannot be relied on in establishing a diagnosis of a ruptured abdominal aneurysm since femoral pulses have been known to remain unchanged despite massive extravasation of blood at the site of rupture. 

Pulsatile mass? Pulsatile abdominal mass (abdominal aneurysm?) or groin mass (femoral aneurysm?), or popliteal fossa (popliteal artery aneurysm). 

Grey Turner sign (flank ecchymosis; represents retroperitoneal hemorrhage; examples with a positive sign are acute pancreatitis, retroperitoneal hemorrhage, aortic rupture from a ruptured abdominal aortic aneurysm, blunt abdominal trauma, ruptured ectopic pregnancy, spontaneous bleeding from coagulopathy?) 

Cullen's sign (hemorrhagic discoloration of the umbilicus; examples with a positive sign are acute pancreatitis, hemorrhage from blunt abdominal trauma, aortic aneurysm rupture, ruptured ectopic pregnancy)

Hyperthermia: Heatstroke may cause hyperthermia. Other causes of hyperthermia may include illicit drugs of abuse (e.g., cocaine, ecstasy), neuroleptic malignant syndrome, malignant hyperthermia from anesthesia (e.g., from the volatile anesthetic halothane or the depolarizing muscle relaxant succinylcholine), sepsis, thyrotoxicosis, pheochromocytoma, status epilepticus (prolactin levels will NOT be increased), psychotropics (SSRIs, TCAs, MAO-inhibitors) with serotonin syndrome, etc. Hyperthermia may be combined with rhabdomyolysis, especially in the case of illicit drug abuse.

Thanks for reading!

Reference:

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