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Glenn S Murphy

Publications and source records attributed to Glenn S Murphy.

At least 19 recordsLinked to original sources
PubMed2007

Correlation of the myocardial performance index with conventional echocardiographic indices of systolic and diastolic function: a study in cardiac surgical patients.

BACKGROUND: The aim of this investigation was to compare the myocardial performance index (MPI), a Doppler-derived parameter of global ventricular function, with standard echocardiographic measures of systolic and diastolic function in patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: Complete two-dimensional and Doppler examinations were performed on 46 CABG patients after induction of anesthesia (baseline), 15 minutes postcardiopulmonary bypass (CPB), and at the end of the surgical procedure. RESULTS: A strong inverse correlation between MPI and both fractional area change (adjusted r(2)= 0.588-0.802) and ejection fraction (adjusted r(2)= 0.576-0.656, both P < 0.001) of the left ventricle was observed throughout the intraoperative period. Following CPB, a weaker correlation was observed between MPI and overall diastolic heart function classification (adjusted r(2)= 0.224-0.268, P <0.001). Weak, though statistically significant, correlations were observed between MPI and deceleration time (P < 0.05), peak atrial reversal (AR) wave velocity (P < or =0.002), and duration of the AR wave (P < 0.05). CONCLUSION: Our data suggest that the MPI correlates well with standard echocardiographic measures of systolic function and modestly well with overall diastolic heart function classification. The MPI may be a useful, complementary marker of global left ventricular function in patients undergoing CABG surgery.

Aged↗
PubMed2006

Opioids and cardioprotection: the impact of morphine and fentanyl on recovery of ventricular function after cardiopulmonary bypass.

OBJECTIVES: Experimental studies have shown that opioids protect the myocardium from ischemic injury and that opioid cardioprotection is enhanced by the coadministration of volatile anesthetics. Previous data suggest that morphine produces a more potent cardioprotective effect than fentanyl. The present study investigated the effect of the choice of intraoperative opioid (morphine or fentanyl) on recovery of myocardial function after coronary artery bypass graft (CABG) surgery. DESIGN: Prospective, randomized study. SETTING: University hospital. PARTICIPANTS: Forty-six patients undergoing CABG surgery. INTERVENTIONS: Patients were randomly assigned to receive either morphine (40 mg) or fentanyl (1,000 mug) before cardiopulmonary bypass (CPB). Global cardiac function was assessed intraoperatively using the myocardial performance index (MPI), which combines echocardiographic parameters of both systolic and diastolic function. MEASUREMENTS AND MAIN RESULTS: The MPI (median [range]) was increased after CPB in the fentanyl group, indicating a significant worsening of global left ventricular function (0.43 [0.28-0.54] baseline; 0.49 [0.32-0.64] 15 minutes post-CPB; 0.51 [0.36-0.63] end of operation; p < 0.05 post-CPB compared with baseline). The MPI improved in the morphine group after CPB (0.44 [0.32-0.64] baseline; 0.36 [0.24-0.45] 15 minutes post-CPB; 0.34 [0.20-0.46] end of operation; p < 0.05 post-CPB compared with baseline and the fentanyl group). CONCLUSIONS: In patients undergoing CPB, global ventricular function is enhanced by the administration of morphine prior to the ischemic insult of cardioplegic arrest.

Aged↗
PubMed2006

Retrograde autologous priming of the cardiopulmonary bypass circuit: safety and impact on postoperative outcomes.

OBJECTIVES: Retrograde autologous priming (RAP) is a blood conservation technique used to limit the severity of hemodilution during cardiopulmonary bypass and reduce perioperative transfusions. The aim of this investigation was to examine the safety of RAP and to determine the effect of RAP on adverse outcomes after cardiac surgery. DESIGN: Retrospective cohort study. SETTING: University hospital. PARTICIPANTS: Five hundred fifty-nine undergoing cardiopulmonary bypass. INTERVENTIONS: Data were retrospectively collected on 2 cohorts of adult cardiac surgical patients operated on by a single surgeon. In the RAP group (n = 256), outcome data were analyzed on all subjects over a 2-year period during which RAP was used routinely. This group was compared with a similar cohort of patients undergoing cardiopulmonary bypass over a 2-year period immediately before the introduction of RAP into the clinical practice (no-RAP group, n = 287). MEASUREMENTS AND MAIN RESULTS: In-hospital mortality was not significantly different between the RAP group (2.7%) and the no-RAP group (3.8%, p = 0.636). The incidence of postoperative cardiac arrest was significantly less in the RAP group (1 patient) compared to the no-RAP group (9 patients, p = 0.040). There were no differences between the 2 groups in the incidence of several other postoperative complications, including postoperative delirium (1.6% RAP v 3.1% no RAP), heart block (1.6% RAP v 4.2% no RAP), atrial fibrillation (19.1% RAP v 22.7% no RAP), and requiring postoperative ventilation >24 hours (2.7% RAP v 5.2% no RAP). CONCLUSIONS: The authors observed no evidence of any increase in adverse events in the RAP group of this retrospective cohort study, but they did observe a decrease in the incidence of postoperative cardiac arrest in the RAP group. These findings suggest that RAP is a safe technique and may have a beneficial effect on postoperative outcomes.

Adult↗
PubMed2006

Pharmacokinetics of midazolam, propofol, and fentanyl transfer to human breast milk.

BACKGROUND AND OBJECTIVES: Lactating women undergoing operations requiring general anesthesia are advised to pump and discard their milk for 24 hours after the procedure. Data on anesthetic drug transfer into breast milk are limited. This study determined the pharmacokinetics of midazolam, propofol, and fentanyl transfer into milk to provide caregivers with data regarding the safety of breast milk after administration of these drugs. METHODS: Five lactating women participated in this study after providing institutionally approved written informed consent. Patients underwent premedication with midazolam before induction of anesthesia with propofol and fentanyl. Anesthesia was maintained with a potent volatile anesthetic. Milk and blood were collected before drug administration. Milk was collected 5, 7, 9, 11, and 24 hours after drug administration. Venous blood was collected at intervals up to 7 hours. Plasma and milk midazolam, propofol, and fentanyl concentrations were measured by HPLC with tandem mass spectrometric or fluorescence detection. The pharmacokinetics of drug transfer into milk was modeled with plasma pharmacokinetics. RESULTS: Plasma midazolam, propofol, and fentanyl pharmacokinetics were consistent with reports of others. In 24 hours of milk collection, averages of 0.005% (range, 0.002%-0.013%) of the maternal midazolam dose, 0.027% (0.004%-0.082%) of the propofol dose, and 0.033% (0.006%-0.073%) of the fentanyl dose were collected in milk, representing averages of 0.009%, 0.025%, and 0.039% of the respective elimination clearances. CONCLUSION: The amount of midazolam, propofol, and fentanyl excreted into milk within 24 hours of induction of anesthesia provides insufficient justification for interrupting breast-feeding.

Adult↗
PubMed2006

Retrograde blood flow in the brachial and axillary arteries during routine radial arterial catheter flushing.

BACKGROUND: Flushing of radial arterial catheters may be associated with retrograde embolization of air or thrombus into the cerebral circulation. For embolization into the central circulation to occur, sufficient pressure must be generated during the flushing process to reverse antegrade blood flow in the arterial blood vessels of the upper extremity. This ultrasound study was designed to examine whether routine radial catheter flushing practices produce retrograde blood flow patterns in the brachial and proximal axillary arteries. METHODS: Duplex ultrasound examinations of the brachial and axillary arteries were conducted in 100 surgical patients to quantify direction and velocity of blood flow during catheter flushing. After obtaining Doppler spectral images of brachial and axillary arterial flow patterns, manual flushing was performed by injecting 10 ml flush solution using a syringe at a rate reflecting standard clinical practices. The flow-regulating device on the pressurized (300 mmHg) arterial flushing-sampling system was then opened for 10 s to deliver a rapid bolus of fluid (flush valve opening). RESULTS: The rate of manual flush solution injection through the radial arterial catheter was related to the probability of retrograde flow in the axillary artery (P < 0.001). Reversed arterial flow was noted in the majority of subjects (33 of 51) at a manual flush rate of less than 9 s and in no subjects (0 of 48) at a rate 9 s or greater. Retrograde flow was observed less frequently during flush valve opening (2 of 99 patients; P < 0.001 vs. manual flushing). CONCLUSIONS: Rapid manual flushing of radial arterial catheters at rates faster than 1 ml/s produces retrograde flow in the proximal axillary artery.

Adult↗
PubMed2005

Residual paralysis at the time of tracheal extubation.

Respiratory and pharyngeal muscle function are impaired during minimal neuromuscular blockade. Tracheal extubation in the presence of residual paresis may contribute to adverse respiratory events. In this investigation, we assessed the incidence and severity of residual neuromuscular block at the time of tracheal extubation. One-hundred-twenty patients presenting for gynecologic or general surgical procedures were enrolled. Neuromuscular blockade was maintained with rocuronium (visual train-of-four [TOF] count of 2) and all subjects were reversed with neostigmine at a TOF count of 2-4. TOF ratios were quantified using acceleromyography immediately before tracheal extubation, after clinicians had determined that complete neuromuscular recovery had occurred using standard clinical criteria (5-s head lift or hand grip, eye opening on command, acceptable negative inspiratory force or vital capacity breath values) and peripheral nerve stimulation (no evidence of fade with TOF or tetanic stimulation). TOF ratios were measured again on arrival to the postanesthesia care unit. Immediately before tracheal extubation, the mean TOF ratio was 0.67 +/- 0.2; among the 120 patients, 70 (58%) had a TOF ratio <0.7 and 105 (88%) had a TOF ratio <0.9. Significantly fewer patients had TOF ratios <0.7 (9 subjects, 8%) and <0.9 (38 subjects, 32%) in the postanesthesia care unit compared with the operating room (P < 0.001). Our results suggest that complete recovery from neuromuscular blockade is rarely present at the time of tracheal extubation.

Adolescent↗
PubMed2005

Is the pulmonary artery catheter useful?

In the United States more than 1.5 million pulmonary artery catheters (PACs) are inserted each year. Of these, approximately 55% are placed in high-risk surgical and trauma patients. Most clinicians believe that PAC use is beneficial in guiding therapy and may improve outcome. Despite these beliefs and hundreds of published articles related to PACs, appropriate use and impact on outcome remain unclear. A review of the current literature reveals conflicting data and significant flaws in most study designs. Inadequate sample size, lack of randomization, lack of standardization of therapies to PAC data, and deficiencies in user knowledge all significantly limit interpretation of clinical trials. Despite these deficiencies and the need for better-designed investigations, it is the opinion of the authors that access to hemodynamic data provided by the PAC, coupled with accurate interpretation of the data, may lead to reduced perioperative morbidity and mortality.

Catheterization, Swan-Ganz↗
PubMed2004

Retrograde air embolization during routine radial artery catheter flushing in adult cardiac surgical patients: an ultrasound study.

BACKGROUND: Rapid flushing of radial artery catheters may result in retrograde embolization of air into the cerebral circulation. This study examined the incidence of central air embolization during and after flushing of an arterial pressure monitoring system. METHODS: One hundred adult patients undergoing cardiac surgical procedures were enrolled in this study. Ten ml of saline and blood were withdrawn into a syringe in the arterial flushing-sampling pressure system and then readministered to the patient through a 20-gauge radial artery catheter over 3-12 s. The right carotid artery, left carotid artery, and aortic arch were visualized using ultrasound imaging techniques during three manual flushes of the system. The left and right common carotid arteries were examined for the presence of macrobubbles or microbubbles using a linear array ultrasound transducer. The aortic arch was imaged using transesophageal echocardiography to detect retrograde air emboli. The severity of air embolization was quantified using a modification of an established grading system. RESULTS: A total of 298 ultrasound studies in 100 patients were recorded and analyzed after radial artery catheter flushing. Two aortic arch images were not obtained because of an inability to place the probe. Most clinicians (54%) returned flush solution to patients at near-maximal injection rates (2-3 ml per second). No air emboli (macrobubbles or microbubbles) were detected in the carotid arteries or aortic arch of any subject. CONCLUSION: Retrograde air embolization is a rare event after routine radial artery catheter flushing in adult patients with stable hemodynamic conditions.

Aged↗
PubMed2004

Gene therapy in heart and lung disease.

PURPOSE OF REVIEW: Gene therapy utilizes viral and non-viral vectors to transfer genetic material into a host in the hope of treating disease. This article will review the potential applications of gene therapy in the treatment of cardiac and pulmonary diseases. RECENT FINDINGS: The results from several phase I and II clinical trials have recently been published. In patients with ischemic heart disease, evidence of coronary revascularization has been observed after the delivery of angiogenic factors. Several trials have demonstrated a reduction in anginal symptoms, increases in exercise tolerance, and objective improvements in myocardial perfusion. Evidence of the transfer of therapeutic genes has been observed in human trials of inherited pulmonary diseases. Unfortunately, there has been little evidence of clinical efficacy in these studies. A variety of gene therapy strategies are being explored in the treatment of thoracic malignancies. Partial antitumor responses have occurred in some of the subjects enrolled in these studies. SUMMARY: Significant progress has been made in the field of gene therapy in the past decade. Data from these early animal and human clinical trials will provide important information to guide future studies.

Journal Article↗
PubMed2004

Sedation, analgesia, and neuromuscular blockade in sepsis: an evidence-based review.

OBJECTIVE: In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for sedation, analgesia, and neuromuscular blockade in sepsis that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis. DESIGN: The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee. METHODS: The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591. CONCLUSION: There is no preferred sedative or analgesic agent for use in the critically ill septic patient during mechanical ventilation. Protocols should be utilized for administration of sedation with predefined sedation scale targets. Either intermittent bolus sedation or continuous infusion sedation to predetermined end points with daily interruption/lightening of continuous infusion sedation with awakening and re-titration, if necessary, are recommended. Neuromuscular blockade should be avoided if possible and, if used continuously, requires twitch monitoring.

Analgesics↗
PubMed2004

Postanesthesia care unit recovery times and neuromuscular blocking drugs: a prospective study of orthopedic surgical patients randomized to receive pancuronium or rocuronium.

UNLABELLED: In this study, we examined the effect of choice of neuromuscular blocking drug (NMBD) (pancuronium versus rocuronium) on postoperative recovery times and associated adverse outcomes in patients undergoing orthopedic surgical procedures. Seventy patients were randomly allocated to a pancuronium or rocuronium group. On arrival to the postanesthesia care unit (PACU) and again 30 min later, train-of-four ratios were quantified by using acceleromyography. Immediately after acceleromyographic measurements, patients were assessed for signs and symptoms of residual paresis. During the PACU admission, episodes of hypoxemia, nausea, and vomiting were recorded. The time required for patients to meet discharge criteria and the time of actual PACU discharge were noted. Forty percent of patients in the pancuronium group had train-of-four ratios <0.7 on arrival to the PACU, compared with only 5.9% of subjects in the rocuronium group (P < 0.001). Patients in the pancuronium group were more likely to experience symptoms of muscle weakness (blurry vision and generalized weakness; P < 0.001) and hypoxemia (10 patients in the rocuronium group versus 21 patients in the pancuronium group; P = 0.015) during the PACU admission. Significant delays in meeting PACU discharge criteria (50 min [45-60 min] versus 30 min [25-40 min]) and achieving actual discharge (70 min [60-90 min] versus 57.5 min [45-61 min]) were observed when the pancuronium group was compared with the rocuronium group (P < 0.001). In conclusion, our study indicates that PACU recovery times may be prolonged when long-acting NMBDs are used in surgical patients. IMPLICATIONS: Clinical recovery may be delayed in surgical patients administered long-acting neuromuscular blocking drugs. During the postanesthesia care unit admission, patients randomized to receive pancuronium (versus rocuronium) were more likely to exhibit symptoms of muscle weakness, develop hypoxemia, and require more time to meet discharge criteria.

Adult↗
PubMed2004

The failure of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce blood use after cardiac surgical procedures.

UNLABELLED: Hemodilution during cardiopulmonary bypass (CPB) is a primary risk factor for blood transfusion in cardiac surgical patients. Priming of the CPB circuit with the patients' own blood (retrograde autologous priming, RAP) is a technique used to limit hemodilution and reduce transfusion requirements. We designed this study to examine the impact of RAP on perioperative blood product use. Using a retrospective cohort study design, the medical records of all patients undergoing CPB (excluding circulatory arrest cases) by a single surgeon were examined. Data were collected over a 24-mo period when RAP was routinely used as a blood conservation strategy (RAP group, n = 257). This group was compared with a cohort of patients during the 24 mo immediately preceding the introduction of RAP into clinical practice (no RAP group, n = 288). A small, statistically insignificant reduction in the percentage of patients receiving packed red blood cells was observed in the RAP group (44% versus 51% no RAP, P = 0.083). No differences were found between the groups in the number of units of packed red blood cells, platelets, or fresh frozen plasma transfused throughout the perioperative period. These results suggest that overall, RAP does not offer a clinically important benefit as a blood conservation technique. IMPLICATIONS: Priming of the cardiopulmonary bypass circuit with the patients' own blood (retrograde autologous priming) resulted in insignificant reductions in blood use in a large, unselected group of patients undergoing cardiac surgical procedures.

Adult↗
PubMed2003

Sleep apnea.

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Heart Arrest↗