Synthesis & Integration Unknown Case

1. Synthesis & IntegrationUnknown Case Infection & Immunity Elevated Temperature November 15th, 2010 Amanda Kocoloski, OMS IV

2. Patient Profile • Orvill R. Baker is a 58-year-old white male who exhibits a sudden elevation of body temperature during surgery

3. Subjective • CC/HxCC: Mr. Baker was undergoing radical prostatectomy under general anesthesia for prostate cancer. He suddenly began to spike a fever, and developed muscle rigidity on the OR table just after initial abdominal incision was made. A sterile dressing was applied to his incision and he was brought to the recovery room. Chart review discloses that his prostate cancer was diagnosed by his primary care physician who noted a firm irregular nodule on his prostate during a routine physical exam. When biopsy confirmed the diagnosis, he was scheduled for surgery.

4. Definitions • Fever • Regulated rise to a new “set point” of body temperature • Hyperthermia • Body metabolic heat production or environmental heat load exceeds normal heat loss capacity or when there is impaired heat loss • Why do we differentiate? • Hyperthermia can be rapidly fatal and characteristically does not respond to antipyretics

5. Temperature Regulation PO/AH

6. Differentials? • Severe infection • Thermoregulatory dysfunction • Malignant hyperthermia • Neuroleptic malignant syndrome • Serotonin syndrome • Thyrotoxicosis • Prolonged seizures • Illegal drugs • Amphetamines, cocaine, PCP, LSD

7. Subjective • Past Medical History: Prostate hypertrophy and doubling of PSA in one year to 8.0. • Injuries: Denies any past injuries. • Immunizations: No immunizations beyond childhood. • Medications: Presently takes no medication on a regular basis, including no OTC drugs. • Allergies: Denies any significant drug or environmental allergies. • Surgical History: Has had no prior surgery. • Hospitalizations: Never been hospitalized.

8. Health Influencing Behaviors • Diet: The patient eats a “balanced diet” but follows no special dietary restrictions. • Exercise: Follows no particular exercise plan. • Sleep patterns: Sleeps approximately six hours nightly. • Caffeine use: Denies. • Alcohol use: Denies. • Nicotine use: Denies. • Other substances: Denies.

9. Subjective • Family Medical History: 3 siblings and 2 sons, all alive and well. Mother died unexpectedly during routine hysterectomy 30 years ago. Father living, age 82, with metastatic cancer of prostate. • Sexual History: No sexual activity for past 5 years due to erectile dysfunction.

10. Social History • Family: Very supportive 58 year-old spouse whose only medical problem is DM Type II; 2 grown sons, healthy and living away from home. • Faith or spiritual beliefs: Attends a community church regularly. • Hobbies: Likes to travel and work around the house. • Occupation: Took early retirement from high school teaching last year.

11. Review of Systems

12. Objective • Vital Signs: • T: 40.5 ˚C (105˚F) • P: 150 bpm • R: 14 resp/min (mechanical ventilation) • BP:100/60 mmHg • General Appearance: Unconscious under general halothane anesthesia and succinylcholine muscle relaxation; mechanical ventilation via volume-cycled ventilator

13. Where Was the Temperature Taken? Modified from Iaizzo PA, Kehler CH, Zink RS, et al: Thermal response in acute porcine malignant hyperthermia. Anesth Analg 82:803-809, 1996.)

14. Objective: Physical Exam • Head, Eyes, Ears, Nose: Normocephalic; PERRL; EACs patent, TMs clear; nasal mucosa pink. • Throat: Mucosa dry; no pharyngeal inflammation or exudates. Remainder of exam hindered by presence of orotracheal tube. • Face: Symmetrical; no maxillary or frontal sinus tenderness. • Neck: Rigid and spastic; no palpable masses; no lymphadenopathy; thyroid is not palpable; trachea is midline and movable; no JVD; no carotid bruits. • Heart: Rapid, bounding rhythm; apical impulse palpated in left intercostal spaces four and five, lateral to midclavicular line; + S1 and S2; no S3 or S4; no murmurs, gallops or rubs.

15. Objective: Physical Exam • Lungs: (The patient is intubated and being ventilated with a volume-cycled respirator) clear to auscultation and percussion; full breath sounds bilaterally. • Breast: No masses, discharge or tenderness noted. • Abdomen: Slightly distended, firm; no masses or organomegaly; no fluid wave; no hepatojugular reflux; no inguinal lymphadenopathy; bowel sounds present in four quadrants; no bruits auscultated.

16. Objective: Physical Exam • Rectal: Deferred • Structural: Deferred • Extremities: Generalized muscular rigidity and spasm; no cyanosis or clubbing; no edema or varicosities. • Skin: Hot, dry. • Genital: Circumcised male; no scrotal masses or penile discharge. • Neurological: Generalized muscular rigidity and spasm; unresponsive to any stimuli (patient under general anesthesia); mechanical ventilation.

17. Diagnostic Studies?

18. Diagnostics- Urinalysis

19. Diagnostics- Electrolytes

20. Diagnostics- Electrolytes

21. Diagnostics- Arterial Blood Gases (ABGs)

22. Diagnostics- Arterial Blood Gases (ABGs)

23. Rhabdomyolysis • Muscle necrosis results in systemic manifestations • Related to muscle injury or excessive muscle contraction • A syndrome of multiple etiologies • Features include: • Myoglobinuria • Renal insufficiency • Markedly elevated creatinekinase (CK) levels • Frequently, multiorgan failure as a consequence of other complications of the trauma • Hyperkalemia in 10-40% of cases, due to release of K+ from injured skeletal muscle

24. Cause of Elevated Temperature?

25. Assessment • Primary Diagnosis: Malignant hyperthermia • Secondary Diagnoses: • Rhabdomyolysis • Myoglobinuria • Hyperkalemia • Tachycardia • Possible acute renal failure • Modifiable Risk Factors (MRF): None • Non- Modifiable Risk Factors (NMRF): None

26. Malignant hyperthermia • Genetic mutation of ryanodine receptor type 1; autosomal • Disorder causes increased intracellular calcium; prevents Ca2+ reuptake after contraction and prevents relaxation • Usually asymptomatic until anesthesia

27. Signs and Symptoms • Rigidity after induction of anesthesia • Sinus tachycardia or arrhythmias • Decrease in 02 saturation • Increase in PCO2 with ventilation • Increase in temperature above 38.8 ˚C (101.8 ˚F) • Elevated temperature can be a late finding • Extreme acidosis • Damage of skeletal muscle • Rhabdomyolysis • Myoglobinuria • Hyperkalemia • Acute renal failure

29. Plan • Treatment: • Stop surgery and anesthesia ASAP • Dantrolene • Inhibits the release of calcium from the sarcoplasmic reticulum, reducing actin-myosin contractile activity • Manage metabolic acidosis • Initiate core and surface cooling Avoid all future anesthesia using halothane and muscle relaxants

30. Plan • Diagnostic follow-up: • Monitor for myoglobinuria • Monitor for renal failure (kidney function studies) • Monitor for cardiac dysrhythmias • Patient Education: • Avoid all future anesthesia using halothane and muscle relaxants

31. Alcohol sponges Cold sponges Ice bags Ice-water enemas (burr) Ice baths Cooling Measures http://emedicine.medscape.com/article/149546-treatment

32. Quiz!

33. The elevated temperature in this patient is most likely caused by • increased hypothalamic set point • endogenous pyrogens • excessive heat production • fever

34. What is the likely cause of the abnormal urinalysis and serum potassium in this patient? • Acidosis • Excessive muscle contraction and loss of sarcolemma integrity • Acute renal failure • Severely elevated temperature

35. The muscle rigidity in this patient is caused by • excessive motor unit activation • excessive release of calcium from the sarcoplasmic reticulum • halothane induction of calcium influx into muscle cells • hyperkalemia

36. What is the most likely reason why homeostatic mechanisms were unable to defend the thermal challenge presented in the malignant hyperthermia case? • Body heat storage occurred too rapidly • General anesthetics impaired the normal shivering response • General anesthetics impaired normal behavioral thermoregulatory responses • Surgery-induced dehydration changed the gain in the feedback control system

37. The elevated temperature in this patient can be effectively controlled by • dantrolene sodium (inhibits Ca2+ release) • high-dose aspirin (inhibits PGE synthesis) • normalizing serum potassium • succinylcholine (neuromuscular blocking agent)