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Mark T Keegan

Publications and source records attributed to Mark T Keegan.

At least 19 recordsLinked to original sources
PubMed2006

Bronchoscopy in ventilator-associated pneumonia: agreement of calibrated loop and serial dilution.

RATIONALE: Although the serial dilution technique for quantitative culture of bronchoalveolar fluid is considered to be the gold standard for the diagnosis of ventilator-associated pneumonia, it is more labor intensive than the calibrated loop technique. OBJECTIVE: We sought to determine the agreement between the calibrated loop and serial dilution techniques in the diagnosis of ventilator-associated pneumonia. METHODS: We prospectively measured bacterial colony counts by the serial dilution and calibrated loop techniques in 121 bronchoalveolar lavage samples of 104 patients with suspected ventilator-associated pneumonia. MEASUREMENTS AND MAIN RESULTS: At the time of bronchoscopy, patients had received mechanical ventilation for a median of 8 d. Patients were receiving antibiotics when 90 of the 121 (74.4%) bronchoalveolar samples were obtained. The colony counts of 13 bacterial isolates were too numerous to count by the calibrated loop technique; by serial dilution technique, their counts ranged from 4.70 to 6.74 log10 cfu/ml. Fifty other bacteria had paired colony counts measured by each of the two techniques: the bias (95% confidence interval) between the two techniques was -0.380 (-0.665 to -0.095) log10 cfu/ml, with precision of 1.002 log10 cfu/ml and 95% limits of agreement of -2.344 to 1.584 log10 cfu/ml. Using the threshold of 4 log10 cfu/ml as a criterion for the diagnosis of ventilator-associated pneumonia, there was discordance only for one bacterial organism between the two techniques. CONCLUSIONS: The calibrated loop technique can be used for the diagnosis of ventilator-associated pneumonia using bronchoalveolar lavage fluid.

Anti-Bacterial Agents↗
PubMed2006

Is there a role for inhaled nitric oxide as a rescue therapy in respiratory failure associated with hematologic malignancies?

Inhaled nitric oxide has been demonstrated to improve oxygenation in critically ill patients requiring mechanical ventilation. We therefore performed a retrospective review to determine the outcome of patients with hematological malignancies and acute respiratory failure who received inhaled nitric oxide (INO) in a multidisciplinary intensive care unit of a single tertiary referral medical center. Thirteen patients with hematological malignancies who required endotracheal intubation and mechanical ventilation and received INO for acute respiratory failure between January 1998 and December 2002 were identified. Mean +/- standard deviation (SD) age was 47.6 (+/-13.2) years. The mean +/- SD Acute Physiology and Chronic Health Evaluation (APACHE) III score on the day of ICU admission was 94.1 +/- 33.7 with a mean (SD) predicted probability of ICU death of 42.4% (+/-28.6). Mean APACHE III score on the day of initiating INO was 107.6 (+/-34.4) with a predicted mortality in the intensive care unit of 72.7% (+/-23.3). Mean PaO(2) to FiO(2) (PF) ratios (+/-SD) prior to, and immediately after, the initiation of INO were 62.6 (+/-28.2) and 111 (+/-65.1), respectively (P < 0.001). The median duration of INO therapy was 41.8 h (interquartile range, 6.3-98.2). Patients with hematological malignancies and acute respiratory failure to whom INO was administered had clinical deterioration since ICU admission. Despite a marked initial improvement in arterial oxygen tension, all patients ultimately died in the intensive care unit, 8 of them within 48 h of initiating INO. Therefore, despite initial improvement in oxygenation, we did not observe any survival benefit to INO in this setting.

APACHE↗
PubMed2006

Tracheostomy after major vascular surgery.

OBJECTIVES: Major vascular surgery such as aortic aneurysm repair may be associated with prolonged in-patient hospitalization. Certain patients undergo a tracheostomy to aid in weaning from mechanical ventilation or for secretion management. The authors hypothesized that tracheostomy after aortic reconstruction for aneurysmal disease was associated with poor outcomes. DESIGN: A retrospective, observational study. SETTING: Vascular surgical intensive care unit (ICU) of a tertiary referral hospital. PARTICIPANTS: Eighty-one patients who underwent a tracheostomy after open thoracoabdominal or abdominal aortic aneurysm (AAA) repair between 1993 and 2002. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 1,940 patients who underwent aneurysm repair, 81 (4.2%) had a tracheostomy during their index hospitalization. Of those patients, 40.7% did not survive to hospital discharge. Postoperative sepsis was associated with an increased mortality (relative risk 2.45, 95% confidence interval [CI] 1.22-4.90). Many developed postoperative renal failure and were more likely to die in the hospital (relative risk 1.53, 95% CI 1.00-2.33). The preoperative diagnosis of chronic obstructive pulmonary disease (COPD) was not associated with increased mortality (relative risk 0.471, 95% CI 0.23-0.96). Thirty-two (39.5%) patients were transferred from the ICU to a chronic ventilator dependency unit (CVDU). CONCLUSIONS: Tracheostomy in patients after aortic reconstruction for aneurysmal disease is associated with a high incidence of in-hospital mortality. Patients who survive to ICU discharge are likely to be transferred to a CVDU for further respiratory management. The preoperative diagnosis of COPD is associated with improved survival, whereas postoperative sepsis is associated with an increased mortality. These observations should be considered when counseling patients and their families regarding tracheostomy after aortic surgery.

APACHE↗
PubMed2006

Intraoperative tidal volume as a risk factor for respiratory failure after pneumonectomy.

BACKGROUND: Respiratory failure is a leading cause of postoperative morbidity and mortality in patients undergoing pneumonectomy. The authors hypothesized that intraoperative mechanical ventilation with large tidal volumes (VTs) would be associated with increased risk of postpneumonectomy respiratory failure. METHODS: Patients undergoing elective pneumonectomy at the authors' institution from January 1999 to January 2003 were studied. The authors collected data on demographics, relevant comorbidities, neoadjuvant therapy, pulmonary function tests, site and type of operation, duration of surgery, intraoperative ventilator settings, and intraoperative fluid administration. The primary outcome measure was postoperative respiratory failure, defined as the need for continuation of mechanical ventilation for greater than 48 h postoperatively or the need for reinstitution of mechanical ventilation after extubation. RESULTS: Of 170 pneumonectomy patients who met inclusion criteria, 30 (18%) developed postoperative respiratory failure. Causes of postoperative respiratory failure were acute lung injury in 50% (n = 15), cardiogenic pulmonary edema in 17% (n = 5), pneumonia in 23% (n = 7), bronchopleural fistula in 7% (n = 2), and pulmonary thromboembolism in 3% (n = 1). Patients who developed respiratory failure were ventilated with larger intraoperative VT than those who did not (median, 8.3 vs. 6.7 ml/kg predicted body weight; P < 0.001). In a multivariate regression analysis, larger intraoperative VT (odds ratio, 1.56 for each ml/kg increase; 95% confidence interval, 1.12-2.23) was associated with development of postoperative respiratory failure. The interaction between larger VT and fluid administration was also statistically significant (odds ratio, 1.36; 95% confidence interval, 1.05-1.97). CONCLUSION: Mechanical ventilation with large intraoperative VT is associated with increased risk of postpneumonectomy respiratory failure.

Aged↗
PubMed2006

Evidence-based red cell transfusion in the critically ill: quality improvement using computerized physician order entry.

OBJECTIVE: The implementation of evidence-based practice poses a significant challenge in the intensive care unit. In this quality improvement intervention we assessed the effect of an institutional protocol and computerized decision support for red cell transfusion in the critically ill. DESIGN: We compared processes of care and outcomes during the two 3-month periods before and after the introduction of a multidisciplinary quality improvement intervention. SETTING: Multidisciplinary intensive care units--medical, surgical, and mixed--in a tertiary academic center. PATIENTS: Consecutive critically ill patients with anemia (hemoglobin of <10 g/dL). INTERVENTION: Using the computerized provider order entry, we developed an evidence-based decision algorithm for red cell transfusion in adult intensive care units. MEASUREMENTS AND MAIN RESULTS: We collected information on demographics, diagnosis, severity of illness, transfusion complications, and laboratory values. The main outcome measures were number of transfusions, proportion of patients who were transfused outside evidence-based indications, transfusion complications, and adjusted hospital mortality. The mean number of red cell transfusions per intensive care unit admission decreased from 1.08 +/- 2.3 units before to 0.86 +/- 2.3 units after the protocol (p<.001). We observed a marked decrease in the percentage of patients receiving inappropriate transfusions (17.7% vs. 4.5%, p< .001). The rate of transfusion complications was also lower in the period after the protocol (6.1% vs. 2.7%, p = .015). In the multivariate analysis, protocol introduction was associated with decreased likelihood of red cell transfusion (odds ratio, 0.43; 95% confidence interval, 0.30 to 0.62). Adjusted hospital mortality did not differ before and after protocol implementation (odds ratio, 1.12; 95% confidence interval, 0.69 to 1.8). CONCLUSIONS: The implementation of an institutional protocol and decision support through a computerized provider order entry effectively decreased inappropriate red cell transfusions.

Algorithms↗
PubMed2006

Vasotrac arterial blood pressure and direct arterial blood pressure monitoring during liver transplantation.

During liver transplantation two arterial catheters are often placed. The Vasotrac is a noninvasive monitor that provides radial arterial blood pressures by a tonometric method. We investigated whether the Vasotrac would be an accurate substitute for an arterial catheter by comparing Vasotrac blood pressures with simultaneous direct radial blood pressures recorded from the contralateral arm in 14 patients undergoing liver transplantation. Correlation between the two methods was calculated and a Bland-Altman analysis performed to assess agreement. A total of 6468 simultaneous measurements were made over a duration of 1.5-7.5 h per case. For mean arterial blood pressure 57% of Vasotrac measurements were within 10% of direct arterial measurement. Correlation (r) was 0.82. Vasotrac bias was +5.4 mm Hg and limits of agreement were +/-18.6 mm Hg. For systolic arterial blood pressure 65% of Vasotrac measurements were within 10% of direct arterial measurement. Correlation was 0.78. Vasotrac bias was +7.6 mm Hg and limits of agreement +/-25 mm Hg. For diastolic arterial blood pressure 57% of Vasotrac measurements were within 10% of direct arterial measurement. Correlation was 0.82. Vasotrac bias was +3.3 mm Hg and limits of agreement +/-15 mm Hg. We conclude that the Vasotrac is not adequately accurate to substitute for direct arterial blood pressure monitoring in liver transplantation.

Adult↗
PubMed2006

Serotonin syndrome from the interaction of cyclobenzaprine with other serotoninergic drugs.

Serotonin syndrome is a potentially lethal adverse drug reaction that may occur in patients taking proserotoninergic medications. Drug interactions are often responsible for the causation of this syndrome. We report two cases of severe serotonin syndrome induced by the administration of cyclobenzaprine in postoperative patients already receiving another proserotoninergic drug (phenelzine in one case and duloxetine in the other). In both cases, symptoms of autonomic instability and severe agitation started within hours of initiation of cyclobenzaprine and fully resolved within 3 days after discontinuing the proserotoninergic drugs. We conclude that cyclobenzaprine should be used with extreme caution in patients receiving other serotonin-enhancing drugs; these patients should be closely monitored for manifestations of serotonin syndrome.

Aged↗
PubMed2006

Prolonged coma from refractory status epilepticus.

OBJECTIVE: Status epilepticus is a life-threatening medical condition. In its most severe form, refractory status epilepticus (RSE) seizures may not respond to first and second-line anti-epileptic drugs. RSE is associated with a high mortality and significant medical complications in survivors with prolonged hospitalizations. METHODS: We describe the clinical course of RSE in the setting of new onset lupus in a 31-year-old male who required prolonged barbiturate coma. RESULTS: Seizure stopped on day 64 of treatment. Prior to the resolution of seizures, discussion around withdrawal of care took place between the physicians and patient's family. Medical care was continued because of the patient's age, normal serial MRI studies, and the patient's reversible medical condition. CONCLUSION: Few evidence-based data exist to guide management of RSE. Our case emphasizes the need for continuous aggressive therapy when neuroimaging remains normal.

Adult↗
PubMed2006

Postoperative confusion and basilar artery stroke.

INTRODUCTION: Non-focal postoperative mental status changes can be challenging. METHODS: Single patient case report and medical literature review. RESULTS: We describe a 67-year-old male who was admitted for radical cystectomy and ileal conduit urinary diversion. General anesthesia was uneventful and the patient remained hemodynamically stable throughout the procedure. At the end of the procedure, the patient's trachea was extubated. Initially, he was arousable, able to move all extremities, and answer questions appropriately. Over the next 2 hours, his mental status waxed and waned and respirations became irregular. An emergent head computed tomogram without contrast revealed a hyperdense basilar artery consistent with acute thrombosis. Vascular radiology intervention occurred approximately 9 hours after the onset of symptoms, but there was no improvement in the patient's neurological status and he subsequently died. CONCLUSION: Although nonfocal postoperative mental status changes are common and often secondary to benign etiologies, they may herald more significant pathology, including stroke. Patients with postoperative mental status changes should be evaluated carefully to identify life-threatening and treatable etiologies. Recent advances in the acute care of stroke, such as thrombolysis and angioplasty, can improve outcome if instituted promptly.

Aged↗
PubMed2006

Inhaled nitric oxide for acute right-ventricular dysfunction after extrapleural pneumonectomy.

Increased pulmonary vascular pressure and decreased right-ventricular performance may occur following pneumonectomy. Inhaled nitric oxide decreases right-ventricular afterload and improves cardiac index by selectively decreasing pulmonary vascular resistance without causing systemic hypotension. We report the use of inhaled nitric oxide in a patient with acute right-ventricular dysfunction after extrapleural pneumonectomy.

Adult↗
PubMed2005

The influence of missing components of the Acute Physiology Score of APACHE III on the measurement of ICU performance.

OBJECTIVE: To determine the impact of missing Acute Physiology Score (APS) values on risk-adjusted mortality. DESIGN: Retrospective review of prospectively collected Acute Physiology and Chronic Health Evaluation (APACHE) III database. SETTING: The intensive care units (ICUs) of an academic medical center. PATIENTS: 38,411 patients admitted to ICU between October 1994 and December 2003. MEASUREMENTS AND RESULTS: Data were collected on ICU type, missing first ICU day APS values, predicted and observed hospital mortality, standardized mortality ratio (SMR), 95% confidence interval (CI), odds ratio (OR). The overall observed and predicted hospital mortality rates were 8.7% and 10.8%, respectively, with SMR of 0.806 (95% CI 0.779-0.834). Complete data were available in 829 (2.2%). Vital signs were missing in almost none and serum albumin and bilirubin in over 80% of the patients. The number of missing variables was higher in less sick and surgical ICU patients. Logistic regression analysis showed that the risk of dying in the hospital was significantly associated with the number of missing APS variables (OR 1.058, 95% CI 1.027-1.090) when adjusted for the severity of illness. The risk of death was also associated with the type of missing variables. CONCLUSIONS: Since missing APS values may lead to underestimation of the predicted mortality rates, the number and type of missing variables should be taken into consideration when assessing the performance of an ICU. Unless data collection is standardized, future prognostic models should use variables that are routinely measured in most critically ill patients without sacrificing statistical precision.

APACHE↗
PubMed2005

Neostigmine-induced prolonged neuromuscular blockade in a patient with atypical pseudocholinesterase.

A patient with unrecognized atypical pseudocholinesterase was given succinylcholine and then vecuronium before neuromuscular monitoring was instituted. Subsequently, when neostigmine and glycopyrrolate were given to reverse what was thought to be a nondepolarizing block, the patient became further relaxed, and his trachea could not be extubated for more than 10 hours. In this report, we discuss drug interactions, phase II block, and the importance of timely neuromuscular monitoring.

Butyrylcholinesterase↗
PubMed2005

Preoperative assessment of the patient with liver disease.

Patients with liver disease are at appreciable risk when undergoing anesthesia and surgery. Attempts to quantify this risk have been thwarted by the diversity of disease states and illness severity that such patients bring to the operating theater and the myriad of procedures they may undergo. This review discusses the indications and contraindications for surgery in patients with liver disease and attempts to give specific recommendations for optimizing the clinical status of a patient with hepatic dysfunction prior to operative intervention.

Anesthesia↗
PubMed2005

Evaluating the performance of an institution using an intensive care unit benchmark.

OBJECTIVES: To describe the performances of selected intensive care units (ICUs) in a single institution using the Acute Physiology and Chronic Health Evaluation (APACHE) III benchmark and to propose interventions that may improve performance. PATIENTS AND METHODS: In this retrospective study, we analyzed APACHE III data from critically ill patients admitted to ICUs at the Mayo Clinic in Rochester, Minn, between October 1994 and December 2003. We retrieved ICU performance measures based on first ICU day APACHE III values. Standardized ratios were defined as ratios of measured to predicted values. The primary performance measure was the standardized mortality ratio, and secondary performance measures were length of stay (LOS) ratios, low-risk monitor ICU admission rates, and ICU readmission rates. We calculated 95% confidence intervals (CIs) for each performance, graded as good, average, or poor. RESULTS: Among 46,381 patients admitted during the study period, 57.5% were in surgical ICUs, 24.8% in a medical ICU, and 17.7% in a surgical-medical ICU. Low-risk monitoring accounted for 37.2% of admissions. Hospital standardized mortality ratios (95% CI) were 0.95 (0.90-0.99), 0.86 (0.81-0.91), and 0.70 (0.66-0.74) for medical, multispecialty, and surgical ICUs, respectively. Hospital LOS ratios (95% CI) were 0.83 (0.81-0.85), 0.91 (0.88-0.93), and 0.99 (0.97-1.00) for medical, multispecialty, and surgical ICUs, respectively. The ICU readmission rate for each ICU was higher than the 6.7% reported in the medical literature. Performances were good in mortality, average to good in LOS, average in low-risk admission, and poor in ICU readmission. CONCLUSIONS: A national benchmarking database can highlight the strengths and weaknesses of ICUs. The performances of ICUs in a single institution may differ; therefore, the performance of each unit should be evaluated individually.

APACHE↗
PubMed2004

Perioperative antibiotics and practice: little things that make a big difference.

Perioperative antibiotic administration and anesthetic practice have major impacts on infectious complications. Anesthesiologists need to place high importance on perioperative antibiotic administration to allow patients to receive optimal benefit from this therapy and to minimize risk. Many aspects of perioperative care ranging from thermoregulation to glycemic control may have profound longterm affects on infection rate and thereby patient outcome.

Anesthesia↗
PubMed2004

The transplant recipient for nontransplant surgery.

The transplant recipient has traded a life-threatening illness for a chronically immunosuppressed state. Subsequent anesthetic management for non-transplant surgical procedures may be challenging. The anesthesia provider must be aware of the degree of post-transplant organ dysfunction and alter anesthesia techniques accordingly. This article reviews the anesthetic concerns for patients who have undergone a variety of organ transplants.

Anesthesia↗