II.4. Control de Convencionalidad
II.4.1. Difuso
2. T e most common delayed complication ollowing carotid endarterectomy is
A. Arteriovenous stulae B. Myocardial in arction
C. Expanding neck hematoma D. Localized neurologic de cit
Answer: B
Complications o carotid endarterectomy include central or regional neurologic de icits or bleeding with an expanding neck hematoma. An acute change in mental status or the pres-ence o localized neurologic de icit requires an immediate return to the operating room (OR). An expanding hematoma may warrant emergent airway intubation and subsequent trans er to the OR or control o hemorrhage. Intraoperative anticoagulation with heparin during carotid surgery makes bleeding a postoperative risk. Other complications include arteriovenous istulae, pseudoaneurysms, and in ection, all o which are treated surgically.
Intraoperative hypotension during manipulation o the carotid bi urcation can occur and is related to increased tone rom baroreceptors that re lexly cause bradycardia. Should hypotension occur when manipulating the carotid bi ur-cation, an injection o 1% lidocaine solution around this structure should attenuate this re lexive response. he most common delayed complication ollowing carotid endarterec-tomy remains myocardial in arction. he possibility o a post-operative myocardial in arction should be considered a cause o labile blood pressure and arrhythmias in high-risk patients.
(See Schwartz 10th ed., p. 384.) 1. T e Donabedian model o measuring quality identi es all
o the ollowing as main types o improvements EXCEP A. Changes to structure
B. Changes to process C. Changes to culture D. Changes to outcomes
CHAPTER
Conte xt: Are we improving the s a fe ty culture ? Outcome P roce s s
S tructure
FIG. 12-1. Donabedian model for measuring quality. (From Makary MA, Sexton JB, Freischlag JA, et al, Patient safety in surgery. Ann Surg 243:628, 2006. With Permission.)
www.ketabpezeshki.com 66485457-66963820
www.ketabpezeshki.com 66485457-66963820 there are multiple surgeons involved in the same operation or multiple procedures are per ormed on the same patient, especially i the procedures are scheduled or per ormed on di erent areas o the body. ime pressure, emergency sur-gery, abnormal patient anatomy, and morbid obesity are also thought to be risk actors. Communication errors are the root cause in more than 70% o the wrong-site surgeries reported to he Joint Commission. Other risk actors include receiving an incomplete preoperative assessment; having inadequate 5. Which o the ollowing is the best test to predict success ul
Protocol-driven ventilator weaning strategies are ul and have become part o the standard o care. he use o a weaning protocol or patients on mechanical ventilation greater than 48 hours reduces the incidence o ventilator-associated pneumonia (VAP) and the overall length o time on mechani-cal ventilation. Un ortunately, there is still no reliable way o predicting which patient will be success ully extubated a ter a weaning program, and the decision or extubation is based on a combination o clinical parameters and measured pulmonary mechanics. he obin index ( requency [breaths per minute]/
tidal volume [L]), also known as the rapid shallow breath-ing index, is perhaps the best negative predictive instrument.
I the result equals less than 105, then there is nearly a 70%
chance the patient will pass extubation. I the score is greater than 105, the patient has an approximately 80% chance o ail-ing extubation. Other parameters such as the negative inspira-tory orce, minute ventilation, and respirainspira-tory rate are used, but individually have no better predictive value than the rapid shal-low breathing index. (See Schwartz 10th ed., p. 385.)
4. Prophylaxis using low-dose un ractionated heparin reduces the incidence o atal pulmonary embolisms (PE) by
A. 45%
B. 50%
C. 60%
D. 35%
Answer: B
Deep vein thrombosis (DV ) occurs a ter approximately 25%
o all major surgical procedures per ormed without prophy-laxis, and pulmonary embolism (PE) occurs a ter 7%. Despite the well-established e icacy and sa ety o preventive mea-sures, studies show that prophylaxis o ten is underused or used inappropriately. Both low-dose un ractionated heparin and low-molecular-weight heparin have similar e icacy in DV and PE prevention. Prophylaxis using low-dose un rac-tionated heparin has been shown to reduce the incidence o atal PEs by 50%. (See Schwartz 10th ed., p. 374.)
3. T e most appropriate treatment or a seroma a er a so -tissue biopsy is
A. Multiple attempts o aspiration with application o pressure dressings.
B. Immediate return to the OR or drainage.
C. Single attempt at aspiration with return to the OR i it recurs.
D. Observation.
Answer: A
Lymph node biopsies have direct and indirect complications that include bleeding, in ection, lymph leakage, and seromas.
Measures to prevent direct complications include proper sur-gical hemostasis, proper skin preparation, and a single preop-erative dose o antibiotic to cover skin lora 30 to 60 minutes be ore incision. Bleeding at a biopsy site usually can be con-trolled with direct pressure. In ection at a biopsy site will appear 5 to 10 days postoperatively and may require opening o the wound to drain the in ection. Seromas or lymphatic leaks resolve with aspiration o seromas and the application o pres-sure dressings, but may require repeated treatments or even placement o a vacuum drain. (See Schwartz 10th ed., p. 383.)
www.ketabpezeshki.com 66485457-66963820
www.ketabpezeshki.com 66485457-66963820
83
PatientSafetyCHAPTER12
8. In order to reduce the overall risk o stress gastritis in ICU patients mechanically ventilated or >48 hours, their gas-tric pH level should be kept greater than
A. 3 gastritis, the mortality risk is as high as 50%. It is important to keep the gastric pH greater than 4 to decrease the overall risk or stress gastritis in patients mechanically ventilated or 48 hours or greater and patients who are coagulopathic. Pro-ton pump inhibitors, H2-receptor antagonists, and intragas-tric antacid installation are all e ective measures. However, patients who are not mechanically ventilated or who do not have a history o gastritis or peptic ulcer disease should not be placed on gastritis prophylaxis postoperatively because it carries a higher risk o causing pneumonia. (See Schwartz 10th ed., p. 387.)
Pharmacologic agents commonly used to stimulate bowel unction include metoclopramide and erythromycin. Meto-clopramide’s action is limited to the stomach and duodenum, and it may help primarily with gastroparesis. Erythromycin is a motilin agonist that works throughout the stomach and bowel. Several studies demonstrate signi icant bene it rom the administration o erythromycin in those su ering rom an ileus. Alvimopan, a newer agent and a mu-opioid receptor antagonist, has shown some promise in many studies or ear-lier return o gut unction and subsequent reduction in length o stay. Neostigmine has been used in re ractory pan-ileus patients (Ogilvie syndrome) with some degree o success. It is recommended or patients receiving this type o therapy to be in a monitored unit. (See Schwartz 10th ed., p. 386.)
procedures in place to veri y the correct surgical site; or hav-ing an organizational culture that lacks teamwork or reveres the surgeon as someone whose judgment should never be questioned. (See Schwartz 10th ed., p. 378.)
9. T e treatment o choice or a biloma a er laparoscopic cholecystectomy is
A. Reoperation, closure o the leak, and drainage B. Percutaneous drainage
C. Biliary stent D. Observation
Answer: C
A bile leak due to an unrecognized injury to the ducts may present a ter cholecystectomy as a biloma. hese patients may present with abdominal pain and hyperbilirubinemia.
he diagnosis o a biliary leak can be con irmed by computed tomography (C ) scan, endoscopic retrograde cholangiopan-creaticogram (ERCP), or radionuclide scan. Once a leak is con irmed, a retrograde biliary stent and external drainage are the treatment o choice. (See Schwartz 10th ed., p. 387.)
10. T e most requent nosocomial in ection is A. Urinary tract in ection (U I) in ection (U I). hese in ections are classi ied into compli-cated and uncomplicompli-cated orms. he uncomplicompli-cated type is a U I that can be treated with outpatient antibiotic therapy.
he complicated U I usually involves a hospitalized patient with an indwelling catheter whose U I is diagnosed as part o a ever workup. he interpretation o urine culture results o less than 100,000 CFU/mL is controversial. Be ore treating such a patient, one should change the catheter and then repeat the culture to see whether the catheter was simply colonized with organisms. Cultures with more than 100,000 CFU/mL
www.ketabpezeshki.com 66485457-66963820
www.ketabpezeshki.com 66485457-66963820
84
PatientSafetyCHAPTER12
14. racheostomy may decrease the incidence o VAP, overall length o ventilator time, and the number o ICU patient days when per ormed
A. Be ore the h day o ventilator support B. Be ore the 10th day o ventilator support C. Be ore the 15th day o ventilator support D. Be ore the 20th day o ventilator support
Answer: B
Although not without risk, tracheostomy decreases the pul-monary dead space and provides or improved pulpul-monary toilet. When per ormed be ore the 10th day o ventilatory support, tracheostomy may decrease the incidence o VAP, the overall length o ventilator time, and the number o ICU patient days. (See Schwartz 10th ed., p. 385.)
13. Which o the ollowing is the only thing that has been shown to decrease wound in ections in surgical patients with contaminated wounds?
A. Use o iodophor-impregnated polyvinyl drapes.
B. Saline irrigation o the peritoneum and wound.
C. Antibiotic irrigation o the peritoneum and wound.
D. 24 hours o appropriate antibiotics postoperatively (in addition to preoperative dose).
Answer: B
No prospective, randomized, double-blind, controlled stud-ies exist that demonstrate antibiotics used beyond 24 hours in the perioperative period prevent in ections. Prophylactic use o antibiotics should simply not be continued beyond this time. Irrigation o the operative ield and the surgical wound with saline solution has shown bene it in controlling wound inoculum. Irrigation with an antibiotic-based solution has not demonstrated signi icant bene it in controlling postoperative in ection. (See Schwartz 10th ed., p. 389.)
12. VAP in ventilated ICU patients reaches a 70% probability at A. 5 days
B. 15 days C. 30 days D. 45 days
Answer: C
Pneumonia is the second most common nosocomial in ection and is the most common in ection in ventilated patients. VAP occurs in 15 to 40% o ventilated ICU patients, with a prob-ability rate o 5% per day, up to 70% at 30 days. he 30-day mortality rate o nosocomial pneumonia can be as high as 40% and depends on the microorganisms involved and the timeliness o initiating appropriate antimicrobials Protocol-driven approaches or prevention and treatment o VAP are recognized as bene icial in managing these di icult in ectious complications. (See Schwartz 10th ed., pp. 384–385.)
11. T e rst step in treating a 70-kg patient with a platelet count o 12,000 due to heparin-induced thrombocyto-penia is platelet count less than 20,000/mL when invasive procedures are per ormed, or when platelet counts are low and ongoing bleeding rom raw sur ace areas persists. One unit o platelets will increase the platelet count by 5000 to 7500/mL in adults.
It is important to delineate the cause o the low platelet count.
Usually there is a sel -limiting or reversible condition such as sepsis. Rarely, it is due to heparin-induced thrombocytopenia I and II. Complications o heparin-induced thrombocyto-penia II can be serious because o the di use thrombogenic nature o the disorder. Simple precautions to limit this hyper-coagulable state include saline solution lushes instead o heparin solutions and limiting the use o heparin-coated cath-eters. he treatment is anticoagulation with synthetic agents such as argatroban. (See Schwartz 10th ed., pp. 388–389.)
should be treated with the appropriate antibiotics and the catheter should be changed or removed as soon as possible.
Under-treatment or misdiagnosis o a U I can lead to urosep-sis and septic shock. (See Schwartz 10th ed., p. 390.)
www.ketabpezeshki.com 66485457-66963820
www.ketabpezeshki.com 66485457-66963820
85
PatientSafetyCHAPTER12
16. T e most common cause o postrenal ailure is A. A clogged urinary catheter
B. An unintentional ligation o ureters C. A large retroperitoneal hematoma D. Acute kidney ailure
Answer: A
Renal ailure can be classi ied as prerenal ailure, intrin-sic renal ailure, and postrenal ailure. Postrenal ailure, or obstructive renal ailure, should always be considered when low urine output (oliguria) or anuria occurs. he most com-mon cause is a misplaced or clogged urinary catheter. Other, less common causes to consider are unintentional ligation or transection o ureters during a di icult surgical dissection (eg, colon resection or diverticular disease) or a large retroperito-neal hematoma (eg, ruptured aortic aneurysm). (See Schwartz 10th ed., p. 387.)
15. Which o the ollowing is a dominant cytokine in the pathogenesis o systemic inf ammatory response syn-drome (SIRS)?
A. Interleukin-2 (IL-2) B. IL-5
C. IL-6 D. IL-7
Answer: C
he systemic in lammatory response syndrome (SIRS) and the multiple organ dys unction syndrome (MODS) carry signi icant mortality risks ( able 12-1). Speci ic criteria have been established or the diagnosis o SIRS ( able 12-2), but two criteria are not required or the diagnosis o SIRS: lowered blood pressure and blood cultures positive or in ection. SIRS is the result o proin lammatory cytokines related to tissue malper usion or injury.
he dominant cytokines implicated in this process include interleukin (IL)-1, IL-6, and tissue necrosis actor ( NF).
Other mediators include nitric oxide, inducible macrophage-type nitric oxide synthase, and prostaglandin I2. (See Schwartz 10th ed., ables 12-17 and 12-18, p. 391.)
TABLE 12-1 Mortality associated with patients
exhibiting two or more criteria or systemic inf ammatory response syndrome (SIRS)
PROGNOSIS MORTALITY (%)
2 SIRS criteria 5
3 SIRS criteria 10
4 SIRS criteria 15–20
TABLE 12-2 Inclusion criteria or the systemic inf ammatory response syndrome
Temperature >38°C or <36°C (>100.4°F or <96.8°F) Heart rate >90 beats/min
Respiratory rate >20 breaths/min or Paco2 <32 mm Hg
White blood cell count <4000 or >12,000 cells/mm3 or >10%
immature forms
Paco2 = partial pressure of arterial carbon dioxide.
17. Laryngoscopic ndings a er a superior laryngeal nerve injury include
A. Ipsilateral vocal cord in a paramedian position B. Ipsilateral vocal cord in a middling position C. Asymmetry o the glottic opening
D. Normal examination
Answer: C
Superior laryngeal nerve injury is less debilitating, as the common symptom is loss o projection o the voice. he glottis aperture is asymmetrical on direct laryngoscopy, and management is limited to clinical observation. (See Schwartz 10th ed., p. 384.)
www.ketabpezeshki.com 66485457-66963820
www.ketabpezeshki.com 66485457-66963820
86
PatientSafetyCHAPTER12
20. T e primary cause o hyperbilirubinemia in the surgical patient is
A. Sepsis
B. Hematoma rom trauma C. Cholestasis
D. Increased unconjugated bilirubin due to hemolysis
Answer: C
Hyperbilirubinemia in the surgical patient can be a complex problem. Cholestasis makes up the majority o causes or hyperbilirubinemia, but other mechanisms o hyperbiliru-binemia include reabsorption o blood (eg, hematoma rom trauma), decreased bile excretion (eg, sepsis), increased unconjugated bilirubin due to hemolysis, hyperthyroidism, and impaired excretion due to congenital abnormalities or acquired disease. Errors in surgery that cause hyperbiliru-binemia largely involve missed or iatrogenic injuries. (See Schwartz 10th ed., p. 387.)
19. T e most common cause o an empyema in the postop-erative patient is
A. Pneumonia B. Systemic sepsis
C. Esophageal per oration D. Retained hemothorax
Answer: A
One o the most debilitating in ections is an empyema, or in ection o the pleural space. Frequently, an overwhelm-ing pneumonia is the source o an empyema, but a retained hemothorax, systemic sepsis, esophageal per oration rom any cause, and in ections with a predilection or the lung (eg, tuberculosis) are potential etiologies as well. (See Schwartz 10th ed., pp. 390–391.)
18. All o the ollowing are true statements regarding wound in ection EXCEP
A. Irrigation o the operative eld and surgical wound with saline solution is bene cial.
B. Prophylactic use o antibiotics continued beyond 48 hours is bene cial.
C. Irrigation with an antibiotic-based solution has not been shown to be bene cial.
D. Antibacterial-impregnated polyvinyl placed over the operative wound area or the duration o the surgical procedure is not bene cial.
Answer: B
No prospective, randomized, double-blind, controlled stud-ies exist that demonstrate antibiotics used beyond 24 hours in the perioperative period prevent in ections. Prophylactic use o antibiotics should simply not be continued beyond this time. Irrigation o the operative ield and the surgical wound with saline solution has shown bene it in controlling wound inoculum. Irrigation with an antibiotic-based solution has not demonstrated signi icant bene it in controlling postoperative in ection.
Antibacterial-impregnated polyvinyl placed over the oper-ative wound area or the duration o the surgical procedure has not been shown to decrease the rate o wound in ection.
Although skin preparation with 70% isopropyl alcohol has the best bactericidal e ect, it is lammable and could be hazard-ous when electrocautery is used. he contemporary ormu-las o chlorhexidine gluconate with isopropyl alcohol remain more advantageous. (See Schwartz 10th ed., p. 389.)
www.ketabpezeshki.com 66485457-66963820
www.ketabpezeshki.com 66485457-66963820