Hematologic evaluation

Several Hematologic disorders may have an impact on the outcomes of surgery. Two of the more common clinical situations faced by the medical consultant are the patient with preexisting anemia and the assessment of bleeding risk. Most data suggest that morbidity and mortality increase as the preoperative hemoglobin level decreases. Hemoglobin levels below 7 or 8 g/dl appear to be associated with significantly more preoperative complications than higher levels. When the directed bleeding history is unreliable or incomplete or when abnormal bleeding is suggested, a formal evluation of hemostasis should be done prior to surgery and should include measurement of prothrombine time, the activated partial thromboplastin time, the platelet count, and the bleeding time.

endothelium injury

*neutrophil-endothelium interaction
The Accumulation and infiltration of inflammatory leukocytes, specifically neutrophils, at sites of injury contribute to the cytotoxity of vital tissues and result in organ dysfunction.
*nitric oxide
NO is derived from endothelial surfaces in response to acetylcholine stimulation, hypoxia,endotoxin,cellular injury, or mechanical shear stress from circulating blood. NO also can reduce microthrombosis by reducing platelet adhesion and aggregation.
*prostacyclin
It is an arachidonate product.
*endothelins
*platelet-activating factor
*atrial natriuretic peptides

Preoperative procedures associated with anesthesia

perioperative complications and deaths are frequently caused by a combination of factors, including concurrent disease, complexity of the operation, and adverse effects of anesthesia.
Patients were evaluated the night before surgery. Higher-risk patients should be evaluated in a preoperative evaluation clinic one or more days preoperatively.
*physical status classification
1. Patien has no organic, physiologic, biochemical or psychiatric disturbance
2. Patien has mild to moderate systemic disturbance (eg. Essential hypertension, diabetes mellitus)
3. Patien has severe systemic disturbance
(eg. Heartdisease)
4. Patient has severe systemic disturbance that is life-threatening with or without surgery (eg. Congestive heart failure, persistent angina pectoris)
5. Patien is moribund and has little chance for survival, but surgery is to be performed as a last resort (eg. Uncontrolled hemorhage as from a ruptured abdominal aneurysm.
History and physical examination
The history shuld include a review of the patients previous experience with anesthesia, and data should be elicited regarding any allergic reactions, delayed aweking, prolonged paralysis from neuromuscular blocking drugs, and jaundice. The presence and severity of any concurrent disease(eg. Hepatitis), coagulopathies, diabetes mellitus or cardiorespiratory dysfunction should be note. Social history : drug, alcohol, and tobacco use and famili history.
The physical examination should focus on the cardiovascular system, lungs, and upper airway. If abnormalities are found, additional test (ecg, pulmonary function tests, etc) may be indicated.
Laboratory test
Eg, Elective surgery should not be performed if the hemoglobin concentration is less than 10 g/dl. More important is the need to determine why the patient is anemic.
Informed consent
Key components of an informed consent include decision-making capacity, patient voluntariness, disclosure, preferences of the reasonable person, legal issues in disclosure, recommendations, the patients understanding, clinical decisions, and autonomous authorization. The patient should be allowed to ask questions.

Postoperative pain

The factors responsible for these differences includes duration of surgery, degree of operative trauma, type of incision, and magnitude of intraoperative retraction. Feelings such as helplessness, fear, and uncertainty contribute to anxiety and may heighten the patients perception of pain. The physiology of postoperative pain involves transmission of pain impulses via splanchnic (not vagal) afferent fibers to the central nervous system, where they initiate spinal, brain stem, and cortical reflexes. Spinal responses to skeletal muscle spasm, vasospasm, and gastrointestinal ileus. Brain stem responses to pain include alterations in ventilation, blood pressure, and endocrine function. Cortical responses include voluntary movements and psychologic changes, such as fear and apprehension. These emotional responses facilitate nociceptive spinal transmission, lower threshold for pain perception, and perpetuate the pain experience.
A. Physician-patient communication
Close attention, frequent reassurance, discussions with the patient every day.
B. Parental opioids
Side effects of Morphine include respiratory depression(rare because pain is powerful respiratory stimulant), nausea and vomitting, and clouded sensorium.
Meperidine is an opioid about one-eighth the potency of morphine. Hydromorphone in a dose of 1-2mg im every 2-3hours. Methadone in average dose 10mg im or orally every 4-6mg hours.
C. Nonopioid parental analgesic
Ketorolac(NSAID) 30mg has analgesic efficacy roughly equivalent to that of morphine 10mg. Complications (Nsaid) of ketorolac have not yet been reported with short-therm perioperative.
D. Oral analgesic
For more severe pain, oxycodon is an opioid with slightly less potency than morphine. Hydrocodone is a synthetic opioid with properties similar to those of codein.
E. Continous epidural analgesia
Epidural opioids produce intense, prolonged segmental analgesia with relatively less respiratory depression or sympathetic, motor, or other sensory disturbance. Epidural morphine is usually administered as a continuous infusion at a rate of 0,2-0,8 mg/h with or without the addition of 0,25% bupivacaine. Bladder catheterization is almost always required.

Chest x-ray suggestive of an aortic tear

1. Widened mediastinum
2. Abnormal aortic contour
3. Tracheal shift
4. Nasogastric tube shift
5. Left apical cap
6. Left or right paraspinal stripe thickening
7. Depression of the left main bronchus
8. Obliteration of the aorticopulmonary window
9. Left pulmonary hilar hematoma

Antibiotic prophylaxis of surgical site infections

the use of prophylactic antibiotics has been demonstrated to reduce the incidence of postoperative wound infections significantly. A single dose of an apropriate intravenous antibiotics or combination of antibiotics is as effective as multiple-dose regimens that extend into the postoperative period. The dose should be repeated every 3-4 hours to ensure maintenance of a therapeutic serum level. A first generation cephalosporin is as effective as later generation agents. All prophylactic antibiotics should be given intravenously at induction of anesthesia or roughly 30-60 minutes prior to the skin incision.
*Cefazolin 1-2g iv : head and neck, neurologic, thoracic, non cardiac vascular, orthopedic, cesarean, hysterectomy, gastroduodenal, billiary, urologic,breast and hernia
*Cefotetan/cefoxitin 1-2g: appendectomy, colorectal

Clinical spectrum of infection and sirs

¥ infection= identifiable source of microbial insult.
¥ Sirs= two or more of following criteria T: >38'c or <36'c, Hr: >90 beats/min, Rr: >20 breaths/min, ^L: >12000/ml or <4000/ml or >10%band forms.
¥ sepsis= identifiable source of infection+sirs.
¥ severe sepsis= sepsis+organ dysfunction.
¥ septic shock= sepsis+cardiovascular collapse.

Specific musculoskeletal tumors

bone forming tumors
*osteoma
This small, sessile benign body tumor occurs most often in the skull and neither causes symptoms nor requires treatmen. It consists of an abnormal excrescence of surface bone. Similar lesions occur posttraumatically on the femur in the area of the adductor magnus insersion (rider's bone), or in relation to the medial collateral ligament of the knee(pellegrini-stieda lesion).
*osteoid osteoma
Patients prevent with local pain, which can be quite severse and is often relieved by aspirin. Radiographically, a small (less than 1 cm) lucent lesion (nidus) is seen, typically surrounded by marked reactive sclerosis. Sometimes areas of radiodensity are seen within the lucent lesion, corresponding histologically to disorganized woven bone formation.

Colon normal physiology

*fluid and electrolyte exchanges
- water, sodium, potassium, chloride, bicarbonate, and amonia.
Colon is a major site for waters absorption (1000-2000 mL/d) and electrolyte exchanges. Sodium is absorbed via Na-K ATPase. Water is absorbed passively along an osmotic gradient. Potassium is secreted into the colonic lumen and absorbed by passive diffusion. Chloride is absorbed via a chloride-bicarbonate exchange.
*short-chain fatty acids
Acetate, butyrate and propionate are produced by bacterial fermentation of dietary carbohidrates. Its important source of energi for the colonic mucosa
*colonic microflora and intestinal gas
Approximately 30% of fecal dry weight is composed of bacteria. endogenous microflora are crucial for the breakdown of carbohidrates and proteins in the colon and participate in the metabolism of bilirubin, bile acids, estrogen, and cholesterol also production of vit K.
*motility
The large intestine doesnt demonstrate cyclic motor activity. Colon displays intermitten contraction. Cholinergic activation increases colonic motility.
*defecation
Is a complex, coordinated mechanism involving colonic mass movement, increased intra-abdominal and rectal pressure, and relaxation of the pelvic floor.

Emergency care (burn)

1. Care at the scene
-airway
initial attention must be directed to the airway. Any patient should be placed on 100% oxygen via a nonrebreather mask if there is any suspicion of smoke inhalation. If the patient is unconscious or respiratory distress, ET should be performed
-other injuries and transport
The patient is assessed for other injuries and then transported. Patients should be kept flat and warm and be given nothing by mouth.
- cold application
After several minutes have elapsed, further cooling does not alter the pathologic process. Iced water should never be used, even on the smallest of burns. If ice or cold water is used on larger burns, systemic hypothermia often follows, and the associated cutaneous vasoconstriction can extend the thermal damage.
2. Emergency room care
protocol ABC must be strictly followed.
-emergency assesment of inhalation injury
Careful inspection of the mouth and pharynx should be done early. Hoarsness and expiratory wheezes are signs of potentially serious airway edema or inhalation injury. Copious mucus production and carbonaceous sputum are positif signs.
A decreased p:f ratio, the ratio PaO2 to FIO2 is the earliest indicator of smoke inhalation. Ratio 400-500 is normal, ratio less than 300, impending pulmonary problem. Ratio 250 is a indication ET.
- fluid resuscitation
- tetanus prophylaxis
- gastric decompression
- pain control
- psychosocial care
2. Care of the burn wound
- escharotomy

The physiologic response to burn injury

Sirs with infection is a major factor determining morbidity and mortality in thermally injured patients. Pathologic alterations of the metabolic, cardiovasculer, gastrointestinal, and coagulation systems occur, with resulting hypermetabolisme, increased cellular, endothelial and epithelial permeability, classic hemodynamic alterations, and often extensive microthrombosis.
A. Burn shock
It is not easily or fully repaired by fluid resuscitation. Tissue trauma and hypovolemic shock result in the formation and release of local and sistemic mediators, which produce an increase in vascular permeability and microvascular hydrostatic pressure.
-histamine, it predominantly disrupt venular endothelial tight junctions, permitting egress of fluid and proteins. Its involved only in the very early increase in microvascular permeability.
-seretonin, released immediately postburn via platelet aggregation, and acts directly to increase pulmonary vascular resistance, and indirectly to amplify the vasoconstrictive effects of norepinephrine, histamine, angiotensine II and select eicosanoids at the microvascular level
-eicosonoids, these subtances do not directly alter vascular permeability but increased levels of the vasodilator prostaglandins, such as PGE2, and prostacyclin /PGI2 result in arterial dilatation in burn tissue that increases blood flow and hydrostatic pressure in the injured microcirculation and accentuates edema formation.
-kinins, specifically the bradikinins, increase vascular permeability, primarily in the venule.
-as hematologically measured, it resembles disseminated intravascular coagulation and may correlate with organ failure and outcome.
B. Metabolic response to burn injury
*hypermetabolism
Resting energy expenditure/REE after burn injury can be as much as 100% above predictions based on standard calculations for size, age, sex, and weight. On average, the RRE is approximately 1,3 times the predicted BMR obtained using the harris-benedict equation.
Glucose is elevated in almost all critically-ill patient, including those with burn injuries.
Plasma insulin levels typically are elevated in burn patients. Which can be defined as hepatic insulin resistance
Lipolysis occured. The majority of released fatty acids are not oxidized, but rather re-esterified into triglycerides, resulting in fat accumulation in the liver.
Proteolisis is increased. Protein intake greater 1g/kg per day or 2g/kg per day with normal renal function.
*Neuroendocrine response
-catecholamine are massively elevated following burn injury, and appear to be the major endocrine mediators of the hypermetabolic response in thermally injured patient.
-growth hormone levels are attenuated following thermal injury.
-thyroid hormone serum concentrations are altered in patient with large burns. Total T3 and T4 are reduced and reverse T3 concentration are elevated.
C. Immunologic response to burn injury
The immune status of the burn patient has a profound impact on outcome in terms of survival and major morbidity.

Postoperative Care

the recovery from major surgery can be divided into three phases
1. An immediate or postanesthetic phases
2. An intermediate phase, encompassing the hospitalization period
3. A convalescent phase

An immediate post operative period
A. Monitoring
1. Vital signs
2. Central venous pressure
3. Fluid balance
4. Other types of monitoring
B. Respiratory care
C. Mobilization and position in bed
D. Diet
E. Administration of fluid and electrolytes
F. Drainage tubes
G. Medications
H. Laboratory examinations and imaging

The intermediate postoperative period
A. Care of wound
B. Management of drains
C. Pulmonary care
D. Fluid and electrolyte management
E. Gastrointestinal tract care
F. Pain