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A 54- year- old woman with a history of coronary artery dis­ease and congestive heart failure is in the operating room for exploratory laparotomy due to toxic megacolon. Her men­tal status is altered, urine output is low, and kidney injury is acute. Hemoglobin level is 7.4 g/ dL. Blood pressure is 84/

the cell’s use of oxygen, causing more cellular injury, microcir­culatory damage, and poor tissue perfusion from maldistribu­tion of blood ow (Figure 9.1).2 Cellular dysoxia, or loss of interdependence in oxygen delivery and metabolism, produces

for approximately 25%– 30% of the total volume trans­ferred back to theheart.

tive thrombocytosis, which can progress to thrombocyto-

Elevated levels are associated with impaired oxygen uti­lization and oxidative phosphorylation or inadequate tissue oxygenation. Type Alactic acidosis results from insucient oxygen delivery that decreases mitochondrial metabolism. Pyruvate is converted to lactate. Type B lactic acidosis is not related to oxygen delivery or poor lactate metabolism. In Type B lactic acidosis, renal or hepatic disease reduces clearance, or clearance is aected by drugs or inborn errors of metabolism. Compared to a normal ratio of lactate to pyruvate, a higher ratio supports a hypoxic mechanism of lactate production associated with increased risk of mortal­ity in septic shock.31 e amount of lactate produced may correlate with total oxygen debt, the magnitude of hypo­perfusion, and the severity ofshock.

3. What laboratory tests would you order in this patient to guide her resuscitation? Assume her SvO2 is 90%. What conditions could explain her elevated SvO2? What conditions would cause the SvO2 to be low? Her lactate is 6mmol/ L. What would you expect the lactate level to be in sepsis?Why?

experience major perioperative morbidities as non- heart-

of HF is increasing, there is a paucity of published guide-

lines with regard to its management, as most pertain to the

management of patients with coronary artery disease, and

practitioners are oen le to make inferences with regard

to the care of this population.

symptoms of dyspnea on minimal exertion and he is main­tained on carvedilol, lisinopril, simvastatin, spironolactone, and furosemide. He had nothing by mouth for 8 hours prior to the colonoscopy, and took all of his medications with a sip of water this morning before the procedure. He has a biventricular pacemaker with an implantable cardioverter debrillator (BiV/ ICD). Plan is for preinduction arterial line, general anesthesia with endotracheal intubation, and

undertaken, an overview of the pathophysiology of each is

presentedbelow. a central line aer induction.

Le heart failure, from either systolic or diastolic dysfunc-

tion (although the two oen coexist), decreases cardiac Heart failure (HF) is a syndrome of inadequate systemic perfusion caused by decreased myocardial pump function. is can be due to right or le heart dysfunction, and can be further subdivided into systolic or diastolic dysfunction, although these entities oen coexist. e American Heart Association estimates that there are nearly 6million adults in the United States with HF, and that there are approx­imately 800,000 new cases diagnosed annually, predicting that the prevalence of this disease will increase to greater than 8million adults by 2030.1 As HF becomes more prev­alent and the number of advanced therapies oered to this patient population increases, it is clear that there will be an increase in the number of planned and emergent surgical procedures performed in patients with HF.2 ese patients are at signicantly increased risk of major perioperative complications and oen require specialized perioperative care. One recent retrospective study found that patients with worsening perioperative heart failure were almost twice as likely to die and were 40%– 69% more likely to

oconstriction. e increase in preload and aerload ini-