How would each of these abnormalities affect his cardiac function? Explain.

One evening during a recent trip to Indonesia, Dr. Fugu Spork sat down to a meal of puffer fish and rice, also called “Fugu.” Because Dr, Spork and this dish share a name, he couldn’t resist ordering it. Within an hour of returning to his hotel room, Dr. Spork felt numbness in his lips and tongue, which quickly spread to his face and neck. Before he could call the front desk, he began to feel pains in his stomach, throat, and mouth. He then developed feelings of severe nausea and eventually severe vomiting. The vomit was positive for blood as well.

Fearing that he had eaten some “bad fish” for dinner, Dr. Spork called the local hospital to describe his condition.  The numbness in his lips and face made it almost impossible to communicate, but the ER nurse was able to get part of the address written down and an ambulance was dispatched. As Dr. Fugu Spork was rushed to the ER, his breathing became increasingly labored and he was showing signs that he could not protect his airway.

Part 2 – Numb, sweaty, and short of Breath…not love at first bite

Upon presenting to the ER, he was diaphoretic, exhibited significant motor dysfunction, paresthesias, nausea, an ascending paralysis starting in his legs and spreading to upper body, arms, face, and head. He also had problems with his breathing and was cyanotic and hypoventilating. Within 30 minutes of presenting in the ER, Dr. Spork developed bradycardia with hypotension. Atropine was administered in response to the bradycardia. Intravenous hydration, gastric lavage, and activated charcoal followed a presumptive diagnosis of tetrodotoxin poisoning. Five hours after treatment, the following vital signs were noted:

  • BP: 125/79 mmHg with HR: 78 bpm
  • Oxygen saturation: 97% with Respiration rate: 12 on ventilator in ICU
Blood Gas Analysis (prior to intubation) Biochemistry
pH 7.217 Total bilirubin 0.7 mg/dl
PaCO2 54.3 mmHg AST 35 U/L
PaO2 83 mmHg ALT 32 U/L
HCO3- 32.1 mEq/L Lactate 3.1 mmol/L
    Creatine kinase 123 U/L
CBC   BUN 22.3 mg/dl
WBC 7730 /mm3 Cr 0.7 mg/dl
RBC 4.21×104 /mm3 Na+ 154 mEq/L
Hct 38.1 % K+ 5.6 mEq/L
Hgb 12.9 g/dl Cl- 116 mEq/L
Plt 20.0×104 /mm3 Ca2+ 7.8 mg/dl
    Blood glucose 230 mg/dl
Phosphorus 2.1 mg/dL Mg2+ 1.2

After discussing Dr. Spork’s case with his physician, you learned that he had probably been the victim of pufferfish poisoning. Normal lab values are listed below.

 

 

Questions

  1. Interpret Dr. Spork’s ABG findings. What is the presenting acid-base disturbance? Is there any compensation? Do these lab findings make sense in light of the clinical picture in the Emergency Department? [5 POINTS]

 

 

  1. Describe the relevance of an elevated Na+ level in this patient. What does the serum sodium tell you about his water balance within the body? Explain your answer. [4 POINTS]

 

 

 

 

 

  1. It is noted that the patient has an elevated K+ level as well as a low Ca2+ level in his blood. How would each of these abnormalities affect his cardiac function? Explain. [4 POINTS]

 

 

 

 

 

 

  1. How would the endocrine system respond to low Ca2+ levels in the blood? What hormone would be secreted and how would that hormone raise blood Ca2+ levels? Be specific. [4 POINTS]

 

 

 

  1. Explain how tetrodotoxin causes this patient’s hypotension and hypoventilation. [4 POINTS]