Search PubMed⌕ Search

Biomedical subjects

Michael A E Ramsay

Publications and source records attributed to Michael A E Ramsay.

18 recordsLinked to original sources
PubMed2006

Tracheal resection in the morbidly obese patient: the role of dexmedetomidine.

We present a case of respiratory distress in a morbidly obese woman, which was complicated by a severe tracheal stenosis of the third to sixth cartilage. She had a history of sleep apnea and could only breathe sitting upright. An anesthetic, technique using dexmedetomidine was selected because of its properties of anxiolysis and sedation, with lack of respiratory depression. No intraoperative or postoperative opioids were required. Dexmedetomidine in high doses offers another approach to managing the patient with a compromised airway. Opioids were avoided in this patient, who was at major risk of postoperative respiratory depression and sleep apnea.

Adrenergic alpha-Agonists↗
PubMed2005

Continuous transesophageal echo-Doppler assessment of hemodynamic function during laparoscopic cholecystectomy.

STUDY OBJECTIVE: The objective of this study was to examine the utility of the transesophageal echo-Doppler device in evaluating hemodynamic changes during laparoscopic cholecystectomy. DESIGN: This was a prospective, controlled, observational open study. SETTING: The study took place in a university hospital. PATIENTS: Twenty patients with ASA physical statuses II and III undergoing laparoscopic cholecystectomy were enrolled into the study. INTERVENTIONS AND MEASUREMENTS: A standardized general anesthetic and surgical technique was used for all patients. Similar depth of hypnosis (using bispectral index monitoring) was maintained in all patients. Hemodynamic parameters including mean arterial pressure (MAP), cardiac index (CI), left ventricular (LV) ejection time interval indexed to the heart rate, maximum acceleration, peak velocity, and systemic vascular resistance (SVR) were recorded at predetermined intervals: before incision, after peritoneal CO(2) insufflation and head-up tilt, every 10 minutes thereafter, and after deflation of the abdomen and return to supine position. MAIN RESULTS: The transesophageal echo-Doppler probe placement was achieved in 3 to 5 minutes in all patients, and the probe position was maintained after creation of pneumoperitoneum and change in positioning. Induction of pneumoperitoneum and head-up tilt resulted in a significant increase in MAP and SVR (P < .05) that remained higher until deflation. The CI, LV ejection time interval indexed to the heart rate (a measure of LV filling), and maximum acceleration (a measure of contractility and global ventricular function) remained stable. CONCLUSIONS: The transesophageal echo-Doppler device can be used during laparoscopic cholecystectomy. The LV function, as determined by measurement of CI and maximum acceleration, was preserved during laparoscopic cholecystectomy despite significant increases in afterload (ie, MAP and SVR).

Adult↗
PubMed2004

Hepatopulmonary syndrome and portopulmonary hypertension: a report of the multicenter liver transplant database.

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PortoPH) are pulmonary vascular consequences of advanced liver disease associated with significant mortality after orthotopic liver transplantation (OLT). Data from 10 liver transplant centers were collected from 1996 to 2001 that characterized the outcome of patients with either HPS (n = 40) or PortoPH (n = 66) referred for OLT. Key variables (PaO2 for HPS, mean pulmonary artery pressure [MPAP], pulmonary vascular resistance [PVR], and cardiac output [CO] for PortoPH) were analyzed with respect to 3 definitive outcomes (those denied OLT, transplant hospitalization survivors, and transplant hospitalization nonsurvivors). OLT was denied in 8 of 40 patients (20%) with HPS and 30 of 66 patients (45%) with PortoPH. Patients with HPS who were denied OLT had significantly worse PaO2 compared with patients who underwent transplantation (47 vs. 52 mm Hg, P <.005). Transplant hospitalization survival was associated with higher pre-OLT PaO2 (55 vs. 37 mm Hg; P <.005). MPAP was significantly higher (53 vs. 45 mm Hg; P <.015) and PVR was significantly worse (614 vs. 335 dynes. s. cm(-5); P <.05) in patients with PortoPH who were denied OLT compared with patients who underwent transplantation. Transplant hospitalization mortality was 16% (5/32) in patients with HPS and 36% (13/36) in patients with PortoPH. All of the deaths in patients with PortoPH occurred within 18 days of OLT; 5 of the 13 deaths in patients with PortoPH occurred intraoperatively. We concluded that patients with HPS (based on a combination of low PaO2 and nonpulmonary factors) and patients with PortoPH (based on pulmonary hemodynamics) were frequently denied OLT because of pre-OLT test results and comorbidities. For patients who subsequently underwent OLT, transplant hospitalization mortality remained significant for both those with HPS (16%) and PortoPH (36%).

Adult↗
PubMed2004

Intravascular thrombosis and thromboembolism during liver transplantation: antifibrinolytic therapy implicated?

This case report describes a patient who underwent orthotopic liver transplantation and developed extensive hyperacute venous and arterial intravascular thromboses and thromboemboli intraoperatively. The patient was receiving antifibrinolytic therapy with aprotinin. The safety of routine aprotinin therapy in liver transplantation is examined. The value of the thrombelastograph (TEG) as a qualitative assessment of the coagulation system is emphasized.

Adult↗
PubMed2004

AANA journal course: update for nurse anesthetists. The SLAM Emergency Airway Flowchart: a new guide for advanced airway practitioners.

Advanced airway practitioners in anesthesiology, emergency medicine, and prehospital care can suddenly and unexpectedly face difficult airway situations that can surface without warning during mask ventilation or tracheal intubation. Although tracheal intubation remains the "gold standard" in airway management, it is not always achievable, and, when it proves impossible, appropriate alternative interventions must be used rapidly to avoid serious morbidity or mortality. The SLAM Emergency Airway Flowchart (SEAF) is intended to prevent the 3 reported primary causes of adverse respiratory events (ie, inadequate ventilation, undetected esophageal intubation, and difficult intubation). The 5 pathways of the SEAF include primary ventilation, rapid-sequence intubation, difficult intubation, rescue ventilation, and cricothyrotomy. It is intended for use with adult patients by advanced airway practitioners competent in direct laryngoscopy, tracheal intubation, administration of airway drugs, rescue ventilation, and cricothyrotomy. The SEAF has limitations (eg, suitable only for use with adult patients, cannot be used by certain categories of rescue personnel, and depends heavily on assessment of Spo2). A unique benefit is provision of simple alternative techniques that can be used when another technique fails.

Algorithms↗
PubMed2003

Straight talk. New approaches in healthcare. Managing medical research: strategies for success.

Medical research programs are under significant pressure both from declines in the growth rates of government funding as well as from increases in government oversight of the privacy and safety of human research subjects. To cope, forward-thinking healthcare institutions are applying the same no-nonsense business rules to their research programs that they apply to other programs and departments. Modern Healthcare and PricewaterhouseCoopers present Straight Talk. In the session on medical research, we discuss how and why the world of medical research is changing, and what health systems should do to manage research programs successfully. The session was held on March 4, 2003 at Modern Healthcare's Chicago headquarters. Charles S. Lauer, publisher of Modern Healthcare, was the moderator.

Academic Medical Centers↗
PubMed2003

Pharmacokinetic analysis of rapacuronium and its metabolite during liver transplantation: an assessment of its potential as a pharmacodynamic probe.

The liver extracts aminosteroidal neuromuscular blocking drugs. We hypothesized that the duration of action of these drugs might provide a pharmacodynamic probe for assessing graft function during orthotopic liver transplantation. The pharmacokinetics of rapacuronium and its active metabolite, ORG 9488, were prospectively studied in 11 patients. Rapacuronium (1.5 mg/kg) was administered at induction of anesthesia, 2 minutes after clamping the portal vein, and 5 minutes after reperfusion of the new graft. Blood samples were drawn at intervals, and an independent laboratory analyzed plasma for both rapacuronium and ORG 9488. Rapacuronium's pharmacokinetics were characterized for 3 stages of the transplant using NONMEM software to construct mixed-effects compartmental models. Rapacuronium plasma clearance during the first stage of orthotopic liver transplantation was 7.25 mL/kg/min. Clearance decreased by only 44% during the anhepatic stage, to 3.91 mL/kg/min, and remained decreased after reperfusion. This effect suggests that an alternate clearance pathway exists. The clearance for ORG 9488 was 13.5 mL/kg/min during the paleohepatic and anhepatic stages, but it decreased 83% on reperfusion, suggesting accumulation after reperfusion. This pharmacokinetic analysis suggests that rapacuronium may not be suitable for use as a pharmacodynamic probe.

Journal Article↗
PubMed2002

Outcomes of a pain management educational initiative at Baylor University Medical Center.

Baylor University Medical Center established a pain initiative group in 1996 to research the effectiveness of pain management throughout the hospital. After analyzing 300 patient surveys, the group undertook an intensive program to educate physicians, nurses, and patients regarding newer pain management techniques. The outcome of this educational initiative was reassessed in 2001 based on surveys completed by 100 patients after discharge. Results showed marked improvement in patient education regarding pain management. In 2001, 93% of patients were offered education and choices regarding pain management vs only 36% in 1996. Fewer patients were afraid to "bother" their nurses to ask for pain medication (3% in 2001 vs 14% in 1996). Waiting time for administration of analgesics decreased considerably. The number of patients reporting moderate to severe pain decreased significantly since 1996, yet the overall satisfaction with pain relief remained high and did not change significantly. The overall incidence of patients reporting moderate to severe pain was significantly less at Baylor than the national average. In conclusion, attitudes, misconceptions, and fears about pain management can be changed with intensive educational programs.

Journal Article↗