PubMed Health⌕ Search

Biomedical subjects

L S Hart

Publications and source records attributed to L S Hart.

8 recordsLinked to original sources
PubMed1997

The value of end-tidal CO2 monitoring when comparing three methods of conscious sedation for children undergoing painful procedures in the emergency department.

BACKGROUND: Many studies have evaluated conscious sedation regimens commonly used in pediatric patients. Recent advances in capnography equipment now enable physicians to assess respiratory parameters, specifically end-tidal CO2 (et-CO2), more accurately in spontaneously breathing sedated children than was possible in the earlier studies. This study was designed to: 1) compare the safety and efficacy of intravenous fentanyl, intravenous fentanyl combined with midazolam, and intramuscular meperidine-promethazine-chlorpromazine (MPC) compound when used for painful emergency department (ED) procedures: and 2) to determine whether the addition of et-CO2 monitoring enabled earlier identification of respiratory depression in this population. METHODS: Forty-two children requiring analgesia and sedation for painful ED procedures were randomly assigned to receive either fentanyl, fentanyl-midazolam, or MPC compound. Vital signs, oxygen saturation, and et-CO2 were monitored continuously. Pain, anxiety, and sedation scores were recorded every five minutes. RESULTS: Respiratory depression (O2 saturation < or = 90% for over the minute or any et-CO2 > or = 50) occurred in 20% of fentanyl, 23% of fentanyl-midazolam, and 11% of MPC patients (P = NS). Of those patients manifesting respiratory depression, 6/8 were detected by increased et-CO2 only. MPC patients required significantly longer periods of time to meet discharge criteria than fentanyl and fentanyl-midazolam patients (P < 0.05). No differences were noted in peak pain, anxiety, or sedation scores. CONCLUSIONS: Fentanyl, fentanyl-midazolam, and MPC produced a high incidence of subclinical respiratory depression. End-tidal CO2 monitoring provided an earlier indication of respiratory depression than pulse oximetry and respiratory rate alone. MPC administration resulted in a significantly delayed discharge from the ED.

Capnography↗
PubMed1996

Lidocaine for lumbar punctures. A help not a hindrance.

OBJECTIVE: To determine whether premedication for lumbar puncture (LP) with lidocaine hinders collection of cerebrospinal fluid (CSF) through either increased number of attempts or increased incidence of traumatic punctures. DESIGN: A randomized controlled trial. SETTING: The pediatric emergency department of an innercity teaching hospital. PATIENTS: A convenience sample of 100 children, younger than 3 years, who required an LP as part of their diagnostic workup. INTERVENTION: Patients were randomized to receive either lidocaine or no local anesthetic before undergoing an LP. MAIN OUTCOME MEASURES: Comparison of the number of attempts needed to obtain CSF and the number of traumatic LPs between the lidocaine-treated and no local anesthetic groups. RESULTS: The 51 patients randomized to receive lidocaine did not differ markedly in age from the 49 patients randomized to receive no local anesthetic. Ease of obtaining CSF, as measured by number of attempts, did not differ with 59% of the patients in each group requiring 1 attempt. Defining a traumatic LP as more than 1000 x 10(6)/L red blood cells in the CSF showed notably more traumatic LPs in the lidocaine-treated group. Defining a traumatic LP as one with more than 10,000 x 10(6)/L red blood cells in the CSF showed no significant difference in the number of traumatic LPs whether or not the patient was premedicated with lidocaine. The level of experience of the physician performing the LP did not affect the outcome. CONCLUSIONS: Premedication with lidocaine for an LP does not binder the ease of obtaining CSF. The clinical relevance of a greater number of traumatic LPs in the lidocaine-treated group is questionable because this finding is negated when traumatic is defined as more than 10,000 x 10(6)/L CSF red blood cells. Based on these results, we advocate premedication with a local anesthetic when an LP is performed in the pediatric emergency department.

Anesthetics, Local↗
PubMed1987

Plasma beta-endorphin responses to one-hour bicycling and running at 60% VO2max.

Ten adult male volunteers were studied to examine the effect on plasma beta-endorphin (B-EN) of bicycling and running for 1 h at 60% VO2max. All subjects were physically active and accustomed to both exercise modes (mean VO2max in ml X kg-1 X min-1; bicycling, 54; running, 59). Following preliminary VO2max tests, subjects participated in randomly ordered experimental sessions of bicycling and running for 1 h at loads requiring 60% of their mode-specific VO2max. Five subjects also participated in control sessions. Blood samples were collected immediately pre- and immediately post-exercise, and hematocrits were determined. Samples were centrifuged, separated, and plasma was stored at -50 degrees C until analysis for B-EN. Analysis involved separation of B-EN from beta-lipotropin by short column chromatography followed by radioimmunoassay. Despite an observed trend for elevated B-EN following exercise, there were no significant pre- to post-exercise differences (P greater than 0.05) in mean B-EN levels in any of the three sessions. Expressed as percentage change in B-EN, there were no significant differences between bicycling, running, or control. These results indicate that 1 h bicycling or running exercise at 60% VO2max does not consistently increase B-EN, and that responses are variable between individuals.

Adult↗