Discuss the similarities in training and cardiovascular physiology between a triathlete and a patient in the ICU.

Describe the effect of exercise on a triathlete vs the effect on a patient in the ICU.

Identify the 4 generations present in the workforce and their specific characteristics.

Discuss how generational characteristics determine the actions necessary to improve the training of surgical residents.

Recognize the importance of innovation, ingenuity, and hard work for success in research.

Physiology of a Triathlete: Similarities to ICU Patients
Joseph M. Galante, MD, Assistant Professor, Department of Surgery, Division of Trauma and Emergency Surgery, University of California, Davis, School of Medicine

Cardiovascular physiology: cardiovascular system (CVS)—purpose to deliver adequate O2 to tissues and to dissipate heat; heart rate (HR) key for exercise and for intensive care unit (ICU) patients; maximum HR 220 minus age; HR increases to 90% of maximum early in exercise, until body adjusts; HR limited because of pulse wave reflection (when heart pushes blood out, pulse wave of energy generated that emanates out, hits against arterioles, and bounces back to heart); another wave cannot be generated until first pulse absorbed in heart; HR affected by height (shorter distance leads to less time), elasticity of vessels (stiffening results in less time), and time for heart to fill; 4 HR zones when exercising—zone 4, maximum effort (eg, swimming in Olympics); zone 3, anaerobic effort (eg, cyclist at mountain stage of Tour de France); zone 2, peak aerobic effort; zone 1, low aerobic effort; HR associated with each zone decreases as age increases (eg, for individual 33 yr of age, zone 4 maximum HR ≈167/min, but for individual 65 yr of age, zone 4 maximum HR ≈140/min); as individual ages, sustainable HR decreases; HR zones (aerobic vs anaerobic) overlap, but as zone increases (from zone 1-4), it becomes more anerobic and less aerobic (eg, zone 1 primarily aerobic and zone 4 primarily anaerobic)

Exercise: myocardial O2 consumption has effect on respiratory rate (RR); as individual exercises, he or she achieves ≈60% of vital capacity; with moderate exercise, RR increases to mid-20s (with strenuous exercise, RR increases to high 30s and 40s); O2 intake—drives mitochondria to convert pyruvic acid to energy; if O2 inadequate, pyruvate converted to lactate under anaerobic conditions; body normally clears majority of lactate it produces; small proportion of lactate used in citric acid cycle and Cori cycle for energy; problem occurs when there is overproduction of lactate (combines with hydrogen ions to form lactic acid); lactic acid— reason for feeling of soreness after exercise; causes muscle dysfunction during exercise; involves not just large muscle groups, but also intercostal muscles and heart; lactate threshold determines individual’s exercise performance capacity; as cardiac output increases to ≈158 mL/kg per minute in young individual, 2.5 times lactate concentration achieved (lactate threshold); in young individual, peak exercise tolerance HR ≈140/min (just below lactate threshold); actually 2 lactate thresholds (2 mmol/L and 4 mmol/L) related to increase in RR (difference between moderate and strenuous exercise)

ICU patients: after injury, patient hypotensive, not delivering adequate O2 to tissues, and converting from aerobic to anaerobic metabolism; lactate produced and lactic acid builds up to cause muscle dysfunction; for ICU patient on ventilator, work of breathing is exercise; as work of breathing increases, cardiac output increases

Training: takes ≈30 wk to adapt to iron-man training; training period allows for physiologic adjustments in blood volume and development of muscle needed for endurance and prevention of injury (gradual adaptation); similarly, in ICU, patients trained with ventilator workouts; prolonged use of ventilator has negative effect on muscles; typical workout one-half of what patient normally breathes on ventilator or minimal support; results in increase in HR, blood pressure, and RR; strategy for training in ICU to have patient rest, remove sedation when ready to start workout, exercise for 30 min maximum, and rest again; Lance Armstrong—weight 80 kg; generates ≈6.7 W/kg (total ≈532 W); key lactate clearance of 6 mmol/L; energy derived from glucose; if all glucose stores consumed, person unable to produce energy; iron-man triathlon—≈500 kcal/hr burned during race (6000 kcal/day or 80 kcal/kg); baseline resting energy expenditure ≈20 kcal/kg; constant intake of fluid during race necessary to avoid dehydration; drinks contain glucose and salt; triathlete takes in only 200 to 250 kcal/hr while racing; similar to intestinal stress test; triathletes suffer from belching, vomiting, reflux, and cramps, due to absence of blood flow to intestines; similarly, in ICU patients, no blood flow to intestines when in shock; with early goal or trickle feeding, patient becomes distended because of inability to absorb calories and compromised blood flow to intestines; force-feeding leads to dilation of intestines and, due to absence of blood flow, onset of necrosis

Improving performance: in professional athletes, blood doping (ie, transfusing one’s own or another person’s blood) used to increase hematocrit (Hct); acceptable Hct in professional cycling 50%; test for blood doping looks at reticulocytes; in ICU, Hct in patients without cardiac disease maintained at 7 mL/dL; risks from transfusion include febrile reaction, transfusion-related acute lung injury, immunosuppression, and infection; erythropoietin (EPO)—now used by professional athletes to produce red blood cells; also used in ICU to boost hemoglobin; not used in acute situations; success in iron-man triathlete and ICU —focus on O2 delivery and adequate HR; use principle of gradual adaptation when weaning patients with muscle weakness and dysfunction off ventilator; nutrition; performance enhancement

Educating Surgeons in the Future
Lynette Scherer, MD, Associate Professor, Department of Surgery, Division of Trauma and Emergency Surgery, University of California, Davis, School of Medicine

Generation spread: today’s workforce represents first time in which 4 distinct generations present; each generation has distinct set of personal and professional values and management styles; “baby boomers” and “millenials” huge cohort (80 million in each cohort); “gen X” cohort has 45 million members; “cuspers” help to work between generation gaps

Veterans: experienced Great Depression and World Wars I and II; family unit intact and strong; strong sense of community; value loyalty; patriotic and altruistic; willing to sacrifice family life for advancement of career and for patients; command-style similar to military; prefer clear hierarchy; respect seniority and value experience; flourish as surgeons; hard workers and good helpers

Baby boomers: born after World War II (1946-1964); experienced prosperity and abundance in their youth; optimism defining characteristic; believe that equal opportunity available if person works hard enough; believe in advancement based on merit; competitive; value status; command-style, chain of command; person in charge should be most appropriate for job; view career as priority; surgery good fit

Generation X: lived through various political/social scandals; skeptical; tripling of divorce rate seen in their youth; “latchkey kids” (grew up unattended); value independence and efficiency; responsible for technology boom (consequently, technologically savvy); place little value on authority and hierarchy; not particularly loyal to institutions and readily change jobs; do not care for bureaucracy and reluctant to serve on committees or take on administrative roles

Millenials: grew up with, eg, 3 computers in home and 2 cell phones; accustomed to easy access to information and expect instantaneous results; rely on constant communication; parents highly involved in their decisions; highly accomplished; somewhat competitive; optimistic; have multiple interests; require significant feedback

Additional considerations for future surgeons: training within constraints of 80-hr work week; personal satisfaction leading reason for choosing career in surgery; fellowship training; mentorship

Implications for training: current residents—computer savvy and prefer web-based curriculum; less tolerant of wasted time; due to multiple interests, usually older than traditional residents; multiple career changes; training program should be flexible to accommodate for changes in career path; implications for recruitment— need well-developed and easy web system and electronic application process; should have flexibility to accommodate different career paths

Surgical Council on Resident Education (SCORE): voluntary consortium composed of American Board of Surgery, American College of Surgeons, Association for Program Directors in Surgery, American Surgical Association, Association for Surgical Education, and Residency Review Committee for Surgery; developed critical core curriculum for surgery and technical skills curriculum

Educating surgeons for future: simulation training—critical; allows residents to develop cognitive and technical skills outside of operating room and 80-hr work week; tests competency; effect on safety unknown; reliance on alternative resources—computer technology (simulators); scenario training; residency program reform—switching to track training program (3 yr of basic general surgery training and 2-3 yr of focused training); unknown how fellowship training integrated; practical suggestions—accept that residents want to make difference and contribute in meaningful way; expect that veterans and boomers will clash with genXers (lack respect for authority and hierarchy but still get job done; unwilling to give freely of time); defining value inspires genXers to get involved; be specific in interactions with genXers and millenials; important to move to team approach, especially for millenials, who value collaboration; provide feedback; have understanding of expectations; recognize importance of social interactions

Preparation, Innovation, and Persistence Translates Into Research Success
Stanley J. Dudrick, MD, Professor of Surgery, Yale University School of Medicine, New Haven, CT, and Program Director in Surgery, St. Mary’s Hospital, Waterbury, CT

Development of total parenteral nutrition (TPN): TPN effective or ineffective, depending on indications; no truly unique ideas, only new data and new technology; speaker wrote first paper on TPN in 1960s (rejected by New England Journal of Medicine and criticized for being “how to do” paper); 6 basic challenges— formulate complete parenteral nutrition solutions; concentrate solution 5 to 6 times to fit within water limits that patient able to tolerate (2-2.5 L not easily done because of precipitation of contents); demonstrate long- term central venous catheterization (standard of care no urinary catheter, device, or needle in patient after 3 days); show that hypertonic nutrient infusion necessary (contrary to clinical practices at that time); maintain asepsis through entire process of solution preparation; change of delivery method; anesthesiologists at that time had no data to prove benefit of swabbing skin before inserting needle for intravenous (IV) infusion during surgery; also necessary to anticipate problems and prevent problem from occurring or find solution to problem; speaker had to violate standards of care to develop TPN

Other challenges: much thought and consideration required to insert catheter to infuse hypertonic solution through subclavian vein; 2 hydrolysates (fibrin and casein) only 2 complete proteins that could be given by vein; best protein fava beans; protein hydrolysates high in chloride and hydrochloride (problem in acidotic patient); necessary for amino acids to be converted to acetate salts to neutralize acid; also problem with contaminants, eg, zinc present in hydrolysate solution from galvanized iron pipes used to process amino acids; fortunately, enough zinc present in 2 L of TPN solution to meet daily requirement; empiric observations of good clinician as important as science; clinician must be good observer and listen to patients; crystalline amino acids modified to make solutions for various conditions, eg, renal failure, hepatic failure; in future, can be modified for genetically connected conditions or change substrates to match genetic expression; aluminum toxicity —occurred due to change from galvanized iron pipes to aluminum pipes and subsequent leaching of aluminum; aluminum displaces calcium and preferentially infiltrates bone, resulting in demineralization and aluminum toxicity; aluminum pipes converted to glass, then silicone, and finally, stainless steel (required industry to interact with scientists); speaker tried different combinations of magnesium that would remain in solution; gastrointestinal tract able to clear substances through vomiting and diarrhea, but vein cannot clear them; fundamental advantage of enteral or oral nutrition, ie, regulatory mechanism for absorption and assimilation, not present in TPN; another problem absence of complete IV vitamin formulations; required development of 4 mixtures for normal adult and child and pathologically affected adult and child; speaker convinced Revlon company to develop fat-soluble vitamins for use as multiple vitamin infusion in TPN; also persuaded another company to develop small Millipore in-line filters for use in TPN to reduce infection; development of TPN required innovation, ingenuity, and hard work