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D Lomax

Publications and source records attributed to D Lomax.

6 recordsLinked to original sources
PubMed1995

Effect of inspired oxygen on the cardiovascular effects of protamine after cardiopulmonary bypass.

We have performed a randomized prospective study of the effects of inspired oxygen fraction (FIO2) on the haemodynamic changes after protamine infusion. Thirty-four patients undergoing first time coronary artery bypass surgery were allocated randomly to receive either an FIO2 of 1.0 (group O) or 0.35 (group A) after cardiopulmonary bypass. Before and after infusion of protamine, haemodynamic measurements were obtained, including mean arterial pressure (MAP), mean pulmonary artery pressure, central venous pressure, pulmonary capillary wedge pressure (PCWP), cardiac index (CI), pulmonary vascular resistance index (PVRI) and systemic vascular resistance index (SVRI). In group O, there were increases in mean MAP (8%), PVRI (48%) and SVRI (18%), and decreases in mean CI (10%) and PCWP (15%). Group A showed changes of 0%, -8%, -6%, +3% and +32%, respectively. We found a significant difference between groups in changes in PVRI (P < 0.0001), SVRI (P < 0.01), CI (P < 0.05) and PCWP (P < 0.001). During infusion of protamine, 31% of patients in group O and 6% of patients in group A had a decrease in systolic arterial pressure to less than 80 mm Hg (ns, chi-square test). These observations suggest that FIO2 alters the haemodynamic effects of protamine.

Aged↗
PubMed1993

A comparison of the laryngeal mask airway and Guedel airway, bag and facemask for manual ventilation following formal training.

Ten volunteers, with no previous experience of resuscitation, were formally trained in the use of the laryngeal mask airway and the oropharyngeal airway (Guedel), bag and facemask for manual ventilation of the lungs in 104 fit, anaesthetised adults. They then used both airways in turn. The order of insertion was randomly allocated, and the times taken for insertion were also recorded. Ventilation for each airway was deemed to be successful if an increase in end-tidal carbon dioxide partial pressure did not occur and arterial oxygen saturation remained greater than 90%. Success rates for the laryngeal mask airway and the Guedel airway, bag and facemask were 87% and 43% respectively (p < 0.001) and the average insertion times were 27.4 s (SEM 1.5) and 15.8 s (SEM 0.50) (no significant difference), respectively. The laryngeal mask airway proved to be easier to use for manual ventilation than the Guedel airway, bag and mask for inexperienced personnel who had received a period of formal training in both techniques.

Education, Nursing↗
PubMed1982

Implications of self-monitoring for smoking treatment: effects on adherence and session attendance.

The reactive effects of three self-monitoring procedures were evaluated with respect to compliance with the self-monitoring requirements and session attendance. A total of 50 smokers who agreed to participate in a smoking cessation program were randomly assigned to one of five conditions: three self-monitoring conditions and two no self-monitoring control conditions. Results indicate that groups were initially equal on the variables of age, sex, pack year history, estimated rate of consumption, and alveolar carbon monoxide level. Drop-out rates for the no self-monitoring control groups were equal at the second session (10% each) and significantly lower than those of the self-monitoring groups (40%, 40%, and 60%). This significant difference was still present at the sixth treatment session. The implications of increased drop-out rates in smoking cessation programs resulting from self-monitoring are discussed.

Adult↗
PubMedDate not supplied

Interventional MR-guided excisional biopsy of breast lesions.

Interventional MR (IMR) machines have produced unique opportunities for image-guided surgery. The open configuration design and fast pulse sequences allow intraoperative scanning to monitor procedures. This study was undertaken to assess the potential use of IMR for image-guided surgery. Benign breast lesion excision was chosen as an uncomplicated surgical model. Ten female patients with known benign tumors underwent excision biopsy under general anesthesia in a Signa SP10 .5-T IMR machine (General Electric Medical Systems, Milwaukee, WI). Lesions were localized with precontrast and postcontrast (intravenous gadolinium-diethylenetriamine pentaacetic acid, .2 mmol/kg) fast multiplanar spoiled gradient-recalled acquisition in the steady state (GRASS) sequences. Preoperative "real-time" fast gradient-recalled sequences were also obtained using the Flashpoint (General Electric Medical Systems, Milwaukee, WI) tracker device. The maximum dimensions of each lesion were measured from the resulting images. Excision was performed using titanium instruments and an ultrasonically activated scalpel. Intraoperative real-time scanning demonstrated the resection margin and confirmed complete excision. The maximum dimensions of the macroscopic specimens were compared with those from the MR images. All tumors were visualized with the Signa scanner and real-time imaging and the images were enhanced after intravenous contrast. Maximum dimensions on histologic examination were not significantly different from those measured from Signa (P > .17) or real-time images (P > .4). There was no significant difference between lesion size from Signa and real-time images (P > .25). All postprocedure scans demonstrated complete excision. There were six fibroadenomas, two foci of sclerosing adenosis, one area of fibrocystic disease, and one schwannoma. Intraoperative MR scanning reliably identifies palpable breast tumors and can accurately guide surgical excision. Further work using MR guidance can now be performed in other general surgical areas.

Adult↗