A mild form of cold injury that is reversible, characterized by numbness, pain, and pallor. Frequent on exposed digits, ears, and nose.
What is frostbite?
Irreversible tissue damage caused by ice crystal formation leading to cellular death. Characterized by initial tissue freezing injury, followed by reperfusion injury during rewarming.
How is frostbite severity graded?
First degree: No blistering; tissue is frozen with hyperemia and edema Second degree: Frozen tissue with hyperemia, edema, and large, clear blisters Third degree: Death of subcutaneous tissues and skin leading to small, hemorrhagic blisters Fourth degree: Necrosis, gangrene, and full-thickness tissue loss.
What are chilblain and pernio?
Terms describing local cold injury characterized by pruritic skin lesions on the face, anterior surface of the tibia, or dorsum of the hands and feet. Associated with a chronic vasculitis of the dermis, provoked by repeated exposure to cold (not freezing) temperatures. Can be managed with antiadrenergics or calcium channel blockers.
What is trench foot?
Nonfreezing injury to hands or feet caused by chronic exposure to wet conditions just above freezing. Involves alternating vasospasm and vasodilatation leading to eventual ulceration.
What is the management of frostbite?
1. Remove patient from cold environment. Do not rub or exercise the extremity. 2. Manage ABCs, addressing systemic hypothermia and fluid resuscitation. 3. Rapidly rewarm tissue by immersion in a warm water bath of 40-42 degrees C. 4. Provide narcotic analgesia as necessary. 5. Address tetanus status. 6. Cleanse and dry skin of affected area. 7. Keep affected extremity elevated to minimize edema, with cotton between digits to prevent maceration. 8. Consider angiography and thrombolytic therapy 9. Allow demarcation of tissue necrosis. 10. Monitor for compartment syndromes during the rewarming phase
When is amputation and surgical debridement recommended?
Delayed for 2-3 months, unless tissue becomes infected or sepsis intervenes.
Often, permanent tissue loss is less than expected. "...of all the factors in the treatment of frostbite that may influence outcome, premature surgical intervention by any means, in any amount, was by far the greatest contributor to poor results."
Allow the devitalized tisue to demarcate!
Besides tissue necrosis, what are some skin complications after frostbite?
Hyperhidrosis Neuropathy Decreased nail and hair growth Persistent Raynaud's phenomenon
Late... SG
Source: Jurkovich GJ. Environmental Cold-Induced Injury. Surg Clin N Am 2007; 87: 247-267.
Grey's Anatomy (ABC) has recently presented a series of episodes that has examined the management of a situation of mass casualty. However, in a plot twist that has been milked for a couple weeks, our heroine, Dr. Meredith Grey, had been pushed into the Pacific Ocean after skillfully tying off a major vessel in a trauma patient, tourniquet unnecessary. After rescue from drowning by her dashing suitor, Dr. Derek 'McDreamy' Shepherd, she now presents to good old Seattle Grace... hypothermic and unresponsive. What ever shall we do?
Remember, a moist, cold Meredith isn't dead... until she's warm and dead.
Are there any recommendations for how to remove a drowning victim out of the water?
It has been suggested that patients be lifted in the prone position.
Immersion in water results in an increase in cardiac output due to decreased resistance to flow. Removing a person from water in an upright position can cause venous pooling from circulatory collapse that is attributed to deaths seen within minutes of rescue in responsive patients.
What measures should be done at the scene of a drowning victim?
Wet clothing should be removed and the patient wrapped in thick blankets. Don't waste time rewarming patient. Transfer patient to facility that has available extracorporeal rewarming. Intubate the patient if unconscious. Continuous chest compressions should be applied for cardiopulmonary arrest. Protect C-spine
What about defibrillation at the scene?
When the myocardium is cold, this will be ineffective...
What factors have favorable outcomes with near drowning?
Submersion less than 5 minutes Heart beat that is restored immediately Immersion in ice cold water (less than 5 degrees C) Buoyancy devices decrease aspiration risk
What factors have possible complications?
Fresh water causes more V/Q mismatch than salt water River water causes potential risk of infection (leptospirosis) Shallow water raises possibility of fractures
What is hypothermia?
Core body temperature below 35 degrees C Mild: 32-35 degrees C (89.6-95.0 F) Moderate: 28-32 degrees C (82.4-89.6 F) Severe: <28 degrees C (<82.4 F)
What is primary hypothermia?
Decrease in core temperature from environmental stress
What is secondary hypothermia?
Unintentional hypothermia from abnormal thermoregulation. Risk factors include age, hypothyroidism, hypoadrenalism, trauma, hypoglycemia, anesthetics.
Below what temperature is shivering abolished?
Somewhere between 30-33 degrees C.
What happens to the cardiac conduction system with moderate to severe hypothermia?
Below 30 degrees C atrial fibrillation, bradycardia, and ventricular dysrhythmias become common. Below 25 degrees C asystole occurs.
What is the eponym attributed to hypothermia-related gastric erosions?
Wischnevsky's ulcers
What does mild, postoperative hypothermia do to surgical wound infection rates?
-1.9 degrees C core hypothermia triples the incidence of SSIs and increases the hospital stay by 20%
What is the mortality rate for trauma patients with moderate primary hypothermia?
Approximately 20%
Does intentional hypothermia (32-33 degrees C) protect against severe traumatic brain injury?
No. A multicenter randomized clinical trial for GCS 3-7 patients showed no difference in mortality (28% vs. 27%) and greater hospital days and complications when comparing 48hrs of intentional hypothermia with normothermia.
Does intentional hypothermia protect against complications of cardiac arrest?
Yes. A prospective multicenter randomized clinical trial of patients in ventricular fibrillation found cooled patients had better neurologic outcomes (55% vs 39%), lower mortality (41% vs 55%), but higher rates of bleeding, sepsis, and pneumonia.
What is the triad of death?
Acidosis, Hypothermia, and Coagulopathy
How does hypothermia cause coagulopathy?
1. Decrease in clotting factor enzymatic function 2. Qualitative platelet dysfunction
What is passive external rewarming?
Allowing the ambient air to spontaneously warm the patient.
What is active external rewarming?
Placing blankets, heating pads, bair huggers, or applying heat lamps on the patient Immersing the patient in warm water
What are methods of active core rewarming?
Heated intravenous fluids Heated bladder, gastric, or colonic lavage Heated peritoneal or thoracic lavage Heated humidified inhaled air Extracorporeal circulatory rewarming
What maximum temperatures are safe for intravenous rewarming?
Blood heated to 42 degrees C Crystalloids heated to 65 degrees C
What are methods of extracorporeal circulatory rewarming?
Connecting the patient to a counter-current heat exchange circuit but relying on the intrinsic cardiac pump
How much effort does it take to warm a 70kg patient by 1 degree C?
Using 41 degree C humidified inspired air - more than 6 hours Using 44 degree C body cavity lavage - 14 L of fluid Using 40 degree C extracorporeal rewarming - 10 times faster than lavage
What is the pathophysiology of "rewarming shock"?
Peripheral rewarming results in peripheral vasodilatation. In the absence of adequate volume resuscitation this will result in decreased cardiac output.
What is "afterdrop"?
A decrease in core central temperature after cold peripheral blood returns to circulation secondary to vasodilation from rewarming measures.
Late... SG
Sources: Harries M. Near drowning. BMJ 2003; 327: 1336-1338. Jurkovich GJ. Environmental Cold-Induced Injury. Surg Clin N Am 2007; 87: 247-267.
What are factors posing a risk for abdominal compartment syndrome?
Major trauma; damage control Extensive burns Large volume fluid resuscitation Bowel distension from ileus, obstruction, or third spacing Closure of abdomen under tension Ischemia-reperfusion injury Coagulopathy
What is abdominal compartment syndrome?
Intra-abdominal hypertension associated with end-organ dysfunction.
What are the three clinical findings associated with abdominal compartment syndrome?
What is the pathophysiology of abdominal compartment syndrome?
-Intra-abdominal hypertension decreases venous return and stroke volume, while increasing afterload, leading to a decrease in cardiac output. -Decreased renal blood flow and GFR stimulates the renin-angiotensin-aldosterone system. However, direct renal vascular compression may lead to oliguria not responsive to volume. -The diaphragm is displaced, decreasing TLC and FRC and increasing inspiratory pressures. -Mesenteric flow decreases leading to splanchnic venous congestion, bowel mucosal edema, and acidosis.
What is intra-abdominal hypertension?
Intra-abdominal pressures greater than 10 mmHg
In the setting of intra-abdominal hypertension, what happens to CVP and PCWP readings?
Both appear elevated, even though the patient may have intravascular volume depletion.
What is a grading system used for intra-abdominal hypertension?
Grade I 10-15 mmHg - Maintain euvolemia Grade II 15-25 mmHg - Volume expansion, may need surgery Grade III 25-35 mmHg - Consider abdominal decompression Grade IV >35 mmHg - Needs abdominal decompression with re-exploration
Signs of abdominal compartment syndrome usually do not manifest until Grade II intra-abdominal hypertension (greater than 15 mmHg or 20 cmH2O).
How do you measure abdominal pressures?
The most common surrogate is the measurement of bladder pressures. 1. Inject 50mL NS into the aspiration port of a Foley catheter. 2. Place an occlusive clamp distally, or use a 3-way stopcock. 3. Insert a needle into aspiration port and connect to a CVP manometer. 4. Zero the manometer at the pubic symphisis.
Note that different publications report their units in cmH2O (direct measurement of height of column of water) or mmHg (what most CVP manometers will read). The conversion factor is 1 mmHg = 1.36 cmH2O.
What are two independent predictors for the development of abdominal compartment syndrome in non-trauma surgical patients?
When is abdominal decompression generally recommended?
1. IAP greater than 20mmHg with UOP less than 0.5ml/kg/h, peak airway pressure greater than 45 cmH2O, and DO2 less than 600ml/min/m2. 2. IAP greater than 25mmHg.
There are no hard and fast rules here, but avoid signs of organ dysfunction!
What are outcomes of abdominal decompression?
80% of patients have improvement in organ function. Overall there is a mean survival rate of 53% (reports of 17-75%)!
Are there methods to prevent abdominal compartment syndrome?
Avoid primary fascial closure after damage control laparotomy or if the patient is at high risk at the time of the index operation. -Temporary towel clip closure -Prosthetic mesh closure -Vacuum-assisted closure device
What are some methods of dealing with an open abdomen after decompressive laparotomy?
1. Bogota bag - suture sterile irrigation bag to the skin to protect abdominal viscera 2. Pack abdomen with saline gauze then cover with Ioban, with or without sump drains 3. Prosthetic mesh closures (some have built-in zippers or velcro) 4. Vacuum-assisted closure devices
Protect the fascia if possible so it can be saved for definitive closure!
Late... SG
Sources: Schwartz' Principles of Surgery, 8th ed. Moore AFK, Hargest R, Martin M, Delicata RJ. Intra-abdominal hypertension and the abdominal compartment syndrome. Br J Surg 2004; 91: 1102-1110.
What are methods that can be used to help identify pancreatic ductal injury?
1. Operative pancreatography 2. Cannulation with a 1.5-2.0 mm coronary artery dilator 3. ERCP
What surgical options are appropriate for main duct transection at the neck, body, or tail of the pancreas?
1. Distal pancreatectomy with splenectomy 2. Distal pancreatectomy with splenic preservation 3. Distal Roux-en-Y pancreaticojejunostomy
What surgical option is most appropriate for transection at the head of the pancreas?
Roux-en-Y pancreaticojejunostomy
Pancreatic insufficiency will occur with loss of 85-90% of the gland.
What surgical option is appropriate for injury to the intrapancreatic common bile duct?
Roux-en-Y choledochojejunostomy
What surgical options are considered for pancreatoduodenal injuries?
1. Pyloric exclusion 2. Pancreatoduodenectomy
What are indications for a trauma Whipple?
1. Transection of intrapancreatic common bile duct and main pancreatic duct 2. Avulsion of the Ampulla of Vater 3. Destruction of the second portion of the duodenum
What is a common grading system for pancreatic traumatic injury?
Pancreatic organ injury scale from Moore et al. (1990) J Trauma.
Late! SG
Sources: Schwartz' Principles of Surgery, 8th ed. Moore EE et al. J Trauma. 1990; 30: 1427-1429.
The art of surgery is not yet perfect and advances now unimaginable are still to come. May you have the wisdom to live with them with grace and humanity.
-William Stewart Halsted
Failure to produce a scholarly environment for the embryonic surgeon will encourage unquestioning dogma that will be restrictive for future development.
