Thinking like a pancreas: perioperative glycemic control.
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Blood Glucose↗
Biomedical subjects
Elizabeth A Martinez
Publications and source records attributed to Elizabeth A Martinez.
Removing "orange wires": surfacing and hopefully learning from mistakes.
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Humans↗
Operating room debriefings.
This tool helps assess factors that positively and negatively contributed to an adverse event, near miss, or inefficiency during an operation-or any procedure.
Efficiency, Organizational↗
Team care: beyond open and closed intensive care units.
PURPOSE OF REVIEW: Evidence supporting dedicated intensivist staffing in intensive care units is growing. Despite clinical and economic benefits, medical staff politics and a shortage of intensivists impede the intensivist model. The purpose of this paper is to accelerate patient's exposure to the benefits of intensivists, and introduce team care in the intensive care unit. RECENT FINDINGS: The cost savings achieved through intensivist staffing range from $510,000 to $3.3 million. The intensivist model may only have been adopted by 4% of intensive care units. Barriers to implementing the model are shortage of intensivists, reimbursement for intensivists, and political will. Four attributes make the model ideal: physical presence, knowledge of critical care practice, coordination of team care, and unit management. It may be helpful to not label intensive care units as open or closed and consider team care, whereby hospitals seek to achieve the attributes of the model given their resources and culture. SUMMARY: Intensivists save lives and costs. By working toward team care, hospitals may achieve a successful intensivist model, and patients may realize the benefits of spending less for healthcare and living longer. To achieve this model, physician and hospital leaders must form a partnership.
Cost Savings↗
Intermittent cardiac troponin-I screening is an effective means of surveillance for a perioperative myocardial infarction.
OBJECTIVE: Several studies suggest that cardiac troponin-I (cTn-I) is a more sensitive indicator of cardiac injury compared with other biochemical markers of injury, but the strategy with the highest diagnostic yield (true positive and true negative) for perioperative surveillance is unknown. The authors undertook a prospective evaluation of the perioperative incidence of myocardial infarction (MI) and evaluated surveillance strategies for the diagnosis of MI. DESIGN: Prospective, cohort study. SETTING: Two university hospitals. PARTICIPANTS: Four hundred sixty-seven high-risk patients requiring noncardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The diagnosis of myocardial injury was determined by cardiac protein markers combined with either postoperative changes on 12-lead electrocardiography or 1 of 3 clinical symptoms consistent with MI (chest pain, dyspnea, requirement for hemodynamic support). A receiver operating characteristic curve evaluating troponin in the diagnosis of MI revealed a value of 2.6 ng/mL as having the highest sensitivity and specificity. The sensitivity and specificity of cTn-I value > or =2.6 ng/mL, troponin > or =1.5 ng/mL, total creatine kinase (CK) > or =170 IU/L with MB > or =5%, and CK-MB > or =8 ng/mL were compared. Surveillance strategies were determined on a subset of patients (n = 257). The incidence of MI was 9.0% by cTn-I > or =2.6 ng/mL criteria, 19% by cTn-I > or =1.5 ng/mL, 13% by CK-MB mass, and 2.8% by CK-MB%. The specificity of cTn-I > or =2.6 ng/mL as an indicator of MI was 98%, and its positive predictive value (PPV) was 85%. Cardiac troponin-I > or =2.6 ng/mL had equal specificity but greater PPV than the cTn-I > or =1.5 ng/mL (specificity 98% and PPV 79%). If surveillance of cTn-I > or =2.6 ng/mL was used to detect MI, then the strategy with the highest diagnostic yield was surveillance on postoperative days 1, 2, and 3. CONCLUSIONS: Perioperative cardiac injury continues to occur frequently after noncardiac surgery, as detected by cTn-I. Serial monitoring of cardiac troponin-I on postoperative days 1, 2, and 3 provides the strategy with the highest diagnostic yield for surveillance of MI.
Aged↗
Effect of medetomidine and its antagonism with atipamezole on stress-related hormones, metabolites, physiologic responses, sedation, and mechanical threshold in goats.
OBJECTIVE: To evaluate the effects of medetomidine and its antagonism with atipamezole in goats. STUDY DESIGN: Prospective randomized crossover study with 1 week between treatments. ANIMALS: Six healthy 3-year-old neutered goats (three male and three female) weighing 39.1-90.9 kg (60.0 +/- 18 kg, mean +/- SD). METHODS: Goats were given medetomidine (20 microg kg(-1), IV) followed, 25 minutes later, by either atipamezole (100 microg kg(-1), IV) or saline. Heart and respiratory rate, rectal temperature, indirect blood pressure, and mechanical threshold were measured, and sedation and posture were scored and blood samples obtained to measure epinephrine, norepinephrine, free fatty acids, glucose, and cortisol concentrations at baseline (immediately before medetomidine), 5 and 25 minutes after medetomidine administration, and at 5, 30, 60, and 120 minutes after the administration of antagonist or saline. Parametric and nonparametric tests were used to evaluate data; p < 0.05 was considered significant. RESULTS: Medetomidine decreased body temperature, heart rate, and respiratory rate and increased mean arterial blood pressure, cortisol, and glucose. Recumbency occurred 89 +/- 50 seconds after medetomidine administration. All goats were standing 86 +/- 24 seconds after atipamezole administration whereas all goats administered saline were sedate and recumbent at 2 hours. Tolerance to compression of the withers and metacarpus increased with medetomidine. From 5 to 120 minutes after saline or atipamezole administration, there were differences in body temperature, glucose, and cortisol but none in heart rate or blood pressure. Three of the six goats receiving saline developed bloat; five of six urinated. After atipamezole, four of six goats developed piloerection and all goats were agitated and vocalized. CONCLUSION: At the doses used, atipamezole antagonized the effects of medetomidine on recumbency, sedation, mechanical threshold, and the increase in glucose. Atipamezole increased the rate of return of cortisol toward baseline, and prevented further decline in rectal body temperature. CLINICAL RELEVANCE: Atipamezole may be used to antagonize some, but not all effects of medetomidine.
Adrenergic alpha-Agonists↗
Pharmacologic control of rhythm: American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery.
Of the 128 articles evaluated on the overall topic of atrial fibrillation (AF) after cardiac surgery, only 19 studies dealing with pharmacologic heart rhythm control were relevant for inclusion in this analysis, indicating the relative paucity of evidence-based studies addressing this topic. We found limited data on guiding treatment for the rhythm control of AF following cardiac surgery in patients who do not require urgent cardioversion; therefore, the choice of an antiarrhythmic drug needs to be guided by patient characteristics. Based on limited available evidence, amiodarone is recommended for pharmacologic conversion of postoperative AF and AFL in patients with depressed left ventricular function who do not need urgent electrical cardioversion. This recommendation is made largely because of the effectiveness of amiodarone and also because of its relatively favorable side-effects profile. Sotalol and class 1A antiarrhythmic drugs are reasonable choices for patients with coronary artery disease who do not have congestive heart failure. There are currently no definitive data to guide the decision about the duration of antiarrhythmic drug therapy for patients with AF following cardiac surgery. Most protocols continue therapy with the antiarrhythmic drug for 4 to 6 weeks following surgery, but evidence from randomized studies is lacking.
Adrenergic beta-Antagonists↗
Pharmacologic control of ventricular rate: American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery.
While there is a deficiency in the number of randomized control studies dealing with the pharmacologic control of the ventricular response to atrial fibrillation (AF) or atrial flutter (AFL) after cardiac surgery, evidence-based recommendations are presented from those studies that are available. Because of the hyperadrenergic state after surgery, beta-blockers are recommended as the first line of therapy for patients with AF or AFL who do not require urgent cardioversion. Calcium channel blockers are recommended as second-line therapeutic agents. Digoxin has little efficacy because of the heightened adrenergic tone that is present postoperatively. Agents that are proarrhythmic, such as dofetilide, or agents that are contraindicated in patients with coronary artery disease, such as flecainide and propafenone, are not recommended.
Adrenergic beta-Antagonists↗
Platelet gene polymorphisms and cardiac risk assessment in vascular surgical patients.
BACKGROUND: Current perioperative cardiac risk assessment tools use historic and surgical factors to stratify patient risk. Polymorphisms in platelet glycoprotein (GP) IIIa and GPIbalpha are associated with myocardial ischemic risk in nonsurgical settings, but their relation to perioperative ischemia is unclear. The authors hypothesized that platelet genotype would be an independent predictor of postoperative myocardial ischemia and would improve risk assessment when added to clinical factors. METHODS: One hundred ninety-six patients who underwent infrainguinal, abdominal aortic, or thoracoabdominal vascular surgery were evaluated for clinical and genetic factors that might predict the development of postoperative myocardial ischemia. Genomic DNA was genotyped for the Leu33Pro polymorphism of GPIIIa and the Thr145Met polymorphism of GPIbalpha. Myocardial ischemic outcome was determined by review of the medical record for cardiac death or myocardial infarction and by surveillance troponin I and automated continuous 12-lead electrocardiographic analysis. RESULTS: Sixty-five patients (33%) experienced one or more ischemic endpoints (2% death, 5% myocardial infarction, 20% troponin+, 22% electrocardiogram+). The Pro33 (adjusted odds ratio [OR], 2.4 [95% confidence interval, 1.2-6.2]) and Met145 (OR 3.4 [1.4-9.3]) genotypes were independent predictors of composite ischemic outcome by multivariate regression, as were diabetes mellitus (OR 4.0 [1.7-12.5]), abdominal aortic surgery (OR 4.1 [1.7-14.4]), and thoracoabdominal aortic surgery (OR 6.4 [2.7-23.8]). The addition of platelet gene polymorphisms to clinical factors improved fit (likelihood ratio testing chi-square = 13.5, P < 0.001) of an ischemia prediction model. The derived risk assessment tool had a receiver operator characteristic curve of 0.73 (0.65-0.81) compared with 0.64 (0.57-0.74) for a model excluding genetic factors (P = 0.04). A significant relation between the GPIbalpha polymorphism and ischemic outcome remained after excluding electrocardiographic ischemia from the composite endpoint. CONCLUSIONS: Platelet polymorphisms are independent risk factors for postoperative myocardial ischemia and improve a risk prediction model when added to historic and surgical risk factors.
Aged↗
Sensitivity of routine intensive care unit surveillance for detecting myocardial ischemia.
OBJECTIVE: To assess the effectiveness of routine intensive care unit surveillance compared with frequent 12-lead electrocardiogram monitoring for detecting electrocardiogram evidence suggestive of prolonged myocardial ischemia in vascular surgery patients. DESIGN: Prospective cohort trial. SETTING: Intensive care unit. PARTICIPANTS: We studied 149 patients undergoing elective infrainguinal or aortic vascular surgery who were admitted to the intensive care unit postoperatively. INTERVENTIONS: Patients were simultaneously monitored with a 10-electrode/12-lead electrocardiogram obtained every 2 mins (criterion standard) and routine intensive care unit surveillance that included standard monitoring (five-electrode/two-lead electrocardiogram with ST segment trends and routine 12-lead electrocardiogram) and clinical assessment for detecting myocardial ischemia. The results of the criterion standard were not available to the caregivers. MEASUREMENTS AND MAIN RESULTS: We measured the ability of routine intensive care unit surveillance to detect the first 20 mins of electrocardiogram evidence suggestive of myocardial ischemia, defined as ST segment depression or elevation of >/=1 mm in two consecutive leads, during the first postoperative day. Seventeen patients (11%) had electrocardiogram evidence suggestive of prolonged myocardial ischemia, the majority of which occurred in leads V2-V4. The sensitivity of routine intensive care unit surveillance for detecting the first episode of electrocardiogram evidence suggestive of prolonged myocardial ischemia in a patient was 12% (95% confidence interval, 7-17%), and the specificity was 98% (95% confidence interval, 95-100%) with a positive predictive value of 40% (95% confidence interval, 32-48%), a negative predictive value of 90% (95% confidence interval, 85-94%), a positive likelihood ratio of 6, and a negative likelihood ratio of 1. The sensitivity of routine intensive care unit surveillance for detecting all episodes was 3% (95% confidence interval, 2-3%) and the specificity 99% (95% confidence interval, 99-100%) per 20-min monitoring interval, with a positive predictive value of 17% (95% confidence interval, 16-18%), negative predictive value of 95% (95% confidence interval, 95-96%), positive likelihood ratio of 3, and negative likelihood ratio of 1. CONCLUSIONS: Routine intensive care unit surveillance has low sensitivity for detecting electrocardiogram evidence suggestive of prolonged myocardial ischemia compared with frequent 12-lead electrocardiograms. Because detecting electrocardiogram evidence suggestive of prolonged postoperative myocardial ischemia is important, physicians should consider alternative strategies to detect myocardial ischemia.
Aged↗
Cardiac troponin I predicts short-term mortality in vascular surgery patients.
BACKGROUND: Cardiac troponin I (cTnI) is a highly sensitive and specific marker for myocardial injury that predicts outcomes in patients with acute coronary syndromes. Cardiovascular complications are the leading cause of morbidity and mortality in patients who have undergone vascular surgery. However, postoperative surveillance with cardiac enzymes is not routinely performed in these patients. We evaluated the association between postoperative cTnI levels and 6-month mortality and perioperative myocardial infarction (MI) after vascular surgery. METHODS AND RESULTS: Two hundred twenty-nine patients having aortic or infrainguinal vascular surgery or lower extremity amputation were included in this study. Blood samples were analyzed for cTnI immediately after surgery and the mornings of postoperative days 1, 2, and 3. An elevated cTnI was defined as serum concentrations >1.5 ng/mL in any of the 4 samples. Twenty-eight patients (12%) had postoperative cTnI >1.5 ng/mL, which was associated with a 6-fold increased risk of 6-month mortality (adjusted OR, 5.9; 95% CI, 1.6 to 22.4) and a 27-fold increased risk of MI (OR, 27.1; 95% CI, 5.2 to 142.7). Furthermore, we observed a dose-response relation between cTnI concentration and mortality. Patients with cTnI >3.0 ng/mL had a significantly greater risk of death compared with patients with levels < or =0.35 ng/mL (OR, 4.9; 95% CI, 1.3 to 19.0). CONCLUSIONS: Routine postoperative surveillance for cTnI is useful for identifying patients who have undergone vascular surgery who have an increased risk for short-term mortality and perioperative MI. Further research is needed to determine whether intervention in these patients can improve outcome.
Aged↗
Neuromuscular blocking agents.
In summary, with proper vigilance, neuromuscular blocking agents can be used safely in anesthetized equine patients to optimize conditions for certain surgical procedures. By appropriate use of neuromuscular monitoring techniques and reversal agents, residual blockade and muscle weakness should be avoided, allowing the horse to recover to standing without difficulty. Research is ongoing to develop the ideal muscle relaxant, one that has a rapid onset, predictable duration and recovery times, and negligible hemodynamic effects. As newer agents become available, they should be evaluated for their suitability for use in equine patients.
Anesthesia↗
Perioperative beta-blockers in high-risk patients.
One major risk to patients in the preoperative period is that of myocardial ischemia or infarction and cardiovascular death in high-risk patients. Historically, attempts to decrease the incidence of perioperative cardiac complications have focused on preoperative evaluation and identification of patients at risk for complications with referral for additional testing and/or revascularization. Evidence suggests that the use of perioperative beta-blockers in high-risk individuals can reduce the incidence of perioperative cardiac events. The Agency for Healthcare Research and Quality has identified that the use of perioperative beta-blockers can reduce perioperative morbidity and mortality. The focus of this article is to describe the evidence supporting perioperative beta-blocker use, to discuss potential barriers to their use, and to propose a strategy to improve their use.
Adrenergic beta-Antagonists↗