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Biomedical subjects

N R Connelly

Publications and source records attributed to N R Connelly.

At least 55 records · Page 3Linked to original sources
PubMed1994

Facilitation of fiberoptic orotracheal intubation with a flexible tracheal tube.

Advancement of a tracheal tube (TT) over a flexible fiberoptic bronchoscope (FOB) is often impeded by obstruction at the arytenoid cartilage or epiglottis. We tested the hypothesis that the use of a flexible, spiral-wound TT, rather than the standard, preformed TT would facilitate tube passage into the trachea over the FOB. Forty patients scheduled to undergo general anesthesia with tracheal intubation were randomized to two groups. Then the trachea was intubated with a FOB, followed by passage of either a standard, preformed TT or a flexible, spiral-wound TT over the FOB. Ease of TT advancement over the FOB into the trachea was graded on a 1 (easy) to 3 (difficult) scale, and differences between the two groups were compared with chi 2 analysis. The overall scores were compared with Wilcoxon's ranked sum test. Statistical significance was defined as P < 0.05. In patients randomized to the regular TT, only 35% (7/20) of first attempts to advance the TT over the FOB were successful. In the patients randomized to the spiral-wound TT, 95% (19/20) of first attempts were successful (P < 0.0001). Of the 13 regular TTs that were not successfully advanced on the first attempt, seven could not be passed after the second or third attempt (necessitating the use of the cross-over spiral-wound TT). In the only instance in which a spiral-wound tube was not successfully passed into the trachea on the first attempt, passage also was not achieved after the second or third attempt.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The use of fentanyl added to morphine-lidocaine-epinephrine spinal solution in patients undergoing cesarean section.

Because of its slow onset of action, intrathecal morphine may not be the optimal drug for intraoperative analgesia during short cases, such as cesarean sections. It is not known whether adding fentanyl to a morphine-lidocaine spinal solution would provide any benefits to patients undergoing cesarean sections. Sixty-two women scheduled for elective cesarean section received intrathecal 5% lidocaine with dextrose (50-70 mg), epinephrine 200 micrograms, preservative-free morphine 0.2 mg, and either 10 micrograms of fentanyl (study group) or preservative-free normal saline (placebo group) in a 0.2-mL volume. Patients were asked to rate their severity of pain on a visual analog scale (VAS) intraoperatively as the uterus was exteriorized and again when the dermatomal level had receded to L1. Intravenous fentanyl was administered if the patient experienced intraoperative discomfort. The VAS scores were 0.8 +/- 1.5 and 2.3 +/- 1.6 (mean +/- SD) in the placebo group at the time of uterine extrusion and in the post-anesthesia care unit (PACU). The corresponding scores in the fentanyl group were 0.4 +/- 1.1 and 2.7 +/- 2.2. There was a significant difference between the two groups in the VAS scores intraoperatively (P < 0.014) but not in the PACU (P not significant). There was also a significant difference (P < 0.015) in the need for supplementation with intravenous (i.v.) fentanyl. Six patients in the placebo group received i.v. fentanyl as compared with none of the patients in the fentanyl group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Epidural↗
PubMed1993

Liquid crystal skin thermometry: an accurate reflection of core temperature?

Oesophageal, rectal, bladder, tympanic and pulmonary artery sites are used intraoperatively to measure body temperature. However, the temperatures measured at each site have different physiological and practical importance. The present two-part study sought to compare liquid crystal (CR) skin temperature with other temperature monitors which are used routinely during surgery. The first part compared CR with oesophageal (OS) temperature during general inhalational anaesthesia. The second part compared CR with OS, pulmonary artery (PA), and bladder (BL) temperatures during the periods of rapid temperature change associated with cardiopulmonary bypass (CPB). During the first part, the mean difference between OS and CR was -0.14 +/- 0.85 degrees C; this difference remained consistent over time (P < 0.05 by repeated measures analysis of variance). During the second part, the difference in temperature readings between CR and each of the other monitors remained consistent except for CR vs PA and CR vs OS during the cooling period of CPB, when the iced cardioplegia slush directly affected the PA and OS temperatures. This study suggests that CR, an inexpensive and noninvasive means of temperature monitoring, reflects trends in temperature changes in the clinical setting.

Anesthesia, Endotracheal↗
PubMed1992

Accelographic train-of-four at near-threshold currents.

The authors evaluated train-of-four (TOF) fade, as quantified by accelography, in response to neurostimulation at currents ranging from 10 to 60 mA. This was done to determine the range of currents over which measurements of fade remain consistent. In 31 patients (ASA Physical Status 1,2, and 3), anesthesia was induced with fentanyl, midazolam, and thiopental and was maintained with isoflurane and 66% nitrous oxide in oxygen. Surface stimulating electrodes were placed over the ulnar nerve, and an acceleration transducer was placed on the thumb. Succinylcholine was administered to facilitate tracheal intubation; after neuromuscular recovery, a bolus of vecuronium (0.01-0.05 mg.kg-1) and an infusion (0.25-1.5 micrograms.kg-1.min-1) were administered. After documentation of a stable TOF ratio, accelographic TOF responses were quantified in response to 200-microseconds stimulation at 10, 15, 20, 30, 40, 50, and 60 mA, in random order. A total of 95 data sets were collected at different depths of blockade. The TOF ratios maintained intercurrent consistency (P = not significant by nonparametric repeated measures analysis of variance), except at currents near the fourth-twitch (T4) threshold current. This inconsistency was eliminated by testing at greater than or equal to 10 mA above threshold. TOF ratios obtained at 10 mA above T4 threshold correlated highly with those at 60 mA (Spearman r value = 0.94). The authors conclude that the TOF ratio is consistent over a wide range of stimulating currents and that testing with submaximal currents can be performed reliably at greater than or equal to 10 mA above the T4 threshold.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Assessment of residual curarization using low-current stimulation.

The present study employed train-of-four (TOF) stimulation at a current of 20 mA to assess the incidence and degree of residual neuromuscular blockade in 64 randomly selected Post Anesthesia Care Unit (PACU) patients. Group C (Control, n = 10) had received anaesthesia without nondepolarizing muscle relaxant; Group V (n = 25) had received vecuronium; and Group P (n = 29) had received pancuronium. At the end of surgery, each patient had been considered by his anaesthetist to have adequate neuromuscular function on the basis of clinical signs and tactile or visual evaluation of responses to TOF stimulation. However, upon testing in the PACU 15 min later, 45% (13 of 29) of Group P patients and 8% (2 of 25) of Group V patients had a TOF ration less than 0.70. This study indicates that residual curarization may be commonly encountered following long-acting relaxants despite qualitative intraoperative TOF monitoring. The present incidence, detected at a current of 20 mA, is consistent with previous reports which employed supramaximal TOF stimulation. We conclude that despite intraoperative monitoring, residual curarization following long-acting nondepolarizing agents is common and that it may be detected with TOF at a low stimulating current (20 mA).

Adult↗
PubMed1991

Effect of tetanus on subsequent neuromuscular monitoring in patients receiving vecuronium.

The current study evaluated the effects of tetanic stimulation on neuromuscular responses to serial train-of-four (TOF) and double-burst stimulation (DBS). For TOF monitoring (n = 13), a degree of neuromuscular blockade was achieved with an intravenous vecuronium infusion such that the ratio of fourth twitch (T4) to first twitch (T1), T4/T1, was stable at a value between 0.1 and 0.7. Four seconds after a 5-s, 50-Hz tetanic stimulus was delivered, TOF monitoring was resumed at 10-s intervals. Significant changes were noted for T1, T4, and T4/T1, with median increases of 38, 250, and 93%, respectively. The median times for T1, T4, and T4/T1 to return to within 10% of their pretetanic (baseline) values were 34, 43, and 34 s, respectively (P = nonsignificant [NS] among times to recovery). A 100-Hz tetanic stimulus induced 50, 300, and 178% median increases of T1, T4, and T4/T1, while corresponding values for recovery times were 53, 73, and 54 s. For DBS monitoring (n = 14), tetanic stimulation (50-Hz, 5-s) induced 38, 300, and 153% median increases of the DBS3,3 parameters (first response [D1], second response [D2], and their ratio [D2 not equal to D1], respectively). The posttetanic effects on D1, D2, and D2/D1 persisted for 43, 66, and 46 s, respectively. For DBS3,2, median posttetanic (50-Hz, 5-s) increases were 41, 275, and 176%, while corresponding times to recovery were 43, 43, and 43 s. Although the data indicate that the posttetanic percent increase was at least 10 times larger at greater degrees of blockade (T4/T1 = 0.1) than at lesser degrees (T4/T1 = 0.7), all T4/T1 and D2/D1 ratios returned to within 10% of baseline in 125 s or less after 5-s tetanic stimulation.

Adult↗
PubMed1990

Continuous alfentanil infusion for extracorporeal shock wave lithotripsy of gallbladder stones.

Extracorporeal shock wave lithotripsy has recently been introduced in clinical trials for the treatment of cholelithiasis. General anesthesia, epidural anesthesia, and intravenous opiates have been used in the anesthetic management of patients undergoing this procedure. This report details our anesthetic management, which was used in 23 patients who underwent 27 procedures, and presents three illustrative cases. A continuous infusion of alfentanil and a 0.625-2.5-mg dose of droperidol were administered to the patients who were easily arousable during the procedure, and were able to cooperate with positioning change requests. Our patients did not develop apnea, hemodynamically significant bradycardia, or chest wall rigidity. One patient became nauseated, and one patient experienced a hypotensive episode that was unheralded by a change in respiratory rate, heart rate, or oxygen saturation. The patients were comfortable throughout the procedure, alert upon arrival to the postanesthesia care unit, and satisfied with this technique. A continuous infusion of alfentanil can be successfully used for the management of patients undergoing biliary lithotripsy.

Alfentanil↗
PubMed1990

Subjective responses to train-of-four and double burst stimulation in awake patients.

The present study was undertaken to determine whether the discomfort associated with the sequential bursts of stimuli comprising the two recommended forms of double burst stimulation (DBS) is comparable to that associated with the repetitive stimuli of train-of-four (TOF). Twenty-one unmedicated volunteers rated on a visual analog scale the discomfort associated with randomly applied DBS and TOF stimulations at 20, 30 and 50 mA. All participants were blinded to the mode of stimulation, as well as to the current intensity. At each amperage tested, TOF produced significantly less discomfort than either form of DBS (P less than 0.01). Stimulation at 50 mA produced median visual analog scale scores of 7.5, 7.0, and 5.0 for DBS3,2, DBS3,3, and TOF, respectively. At 30 mA the corresponding median visual analog scale scores were 4.5, 5.5, and 3.0, whereas at 20 mA the scores were 4.0, 4.5, and 2.0, respectively. Thus, DBS is more uncomfortable than TOF at each current tested; however, in light of reports of its higher sensitivity, DBS may be the preferred means of assessing neuromuscular function in the awake as well as the anesthetized patient when a force transducer and recorder are not readily available.

Adult↗
PubMed1990

Correlation of train-of-four and double burst stimulation ratios at varying amperages.

The present study was undertaken to document the relationship between train-of-four (TOF) and double burst stimulation (DBS) at varying degrees of blockade, and to determine whether this relationship remained constant over a range of stimulating currents. The neuromuscular responses to the two most commonly employed modes of DBS stimulation, DBS3,3 and DBS3,2, and the responses to TOF nerve stimulation were recorded and compared at 20, 30, and 50 mA. Twenty-two consenting patients undergoing general anesthesia received a vecuronium infusion to achieve a TOF ratio within the range of 0.1-1.0. Train-of-four, DBS3,3, and DBS3,2 were delivered at 20, 30, and 50 mA in random sequence after a steady state of neuromuscular blockade was achieved. At a stimulating current of 50 mA, there was a significant linear correlation between DBS3,3 and TOF (P less than 0.0001; r = 0.98) over the range of blockade. Similarly, there was a high degree of correlation between DBS3,2 and TOF at 50 mA, as the increased "fade" associated with DBS3,2 was maintained throughout the spectrum of blockade (P less than 0.0001; r = 0.95). The high degrees of correlation were maintained at stimulating currents of 20 and 30 mA (P less than 0.0001). In conclusion, the present study revealed that there is a high degree of linear correlation between DBS and TOF, and that this mechanographic relationship is maintained over a wide range of stimulating currents during varying degrees of clinical neuromuscular blockade.

Adult↗
PubMedDate not supplied

Use of single-dose epidural morphine in a patient undergoing an abdominal aortic aneurysm resection.

To avoid possible trauma to the epidural venous plexus in a 56-year-old male who presented for abdominal aortic aneurysm resection, the authors preoperatively injected a single dose of epidural morphine rather than inserting an indwelling epidural catheter. The patient's intraoperative anesthetic requirements appeared to have been decreased, he was extubated shortly after the end of the procedure, and he experienced good postoperative analgesia. No untoward neurologic sequelae occurred. The authors feel that a single dose of epidural morphine, compared to epidural catheter placement when systemic heparinization is planned, decreases intraoperative anesthetic requirements, provides good postoperative analgesia, and may have the benefit of decreasing the possibility of epidural hematoma formation.

Anesthesia, Epidural↗
PubMedDate not supplied

Temporal correlation of succinylcholine-induced fasciculations to loss of twitch response at different stimulating frequencies.

STUDY OBJECTIVE: The present study was undertaken to determine the time courses of succinylcholine-induced fasciculations and adductor pollicis single-twitch responses at two stimulating frequencies. DESIGN: A prospective, randomized study. SETTING: The main operating room of a university teaching hospital. PATIENTS: Forty-four patients undergoing general anesthesia and requiring tracheal intubation. INTERVENTIONS: In 22 patients, anesthesia was induced with thiopental sodium, fentanyl, and midazolam and maintained with 70% nitrous oxide in oxygen prior to the administration of succinylcholine 1 mg/kg. In another 22 patients, end-tidal isoflurane 0.75% to 1% was included in the induction regimen. Patients in each group were randomly assigned to receive ulnar nerve stimulation at either 0.1 Hz or 1.0 Hz. MEASUREMENTS AND MAIN RESULTS: The times at which fasciculations were first noticed and no longer visible and the times to 25%, 50%, 75%, 90%, and 100% twitch depression were recorded. These times were compared for the two rates of neurostimulation. With single-twitch nerve stimulation at 1.0 Hz, 100% twitch depression occurred 6 +/- 16 seconds following the end of fasciculations, while at a stimulating frequency of 0.1 Hz, it occurred 52 +/- 32 seconds later (p less than 0.05). At the end of fasciculations, single-twitch depression of 50% or more was noted in only 19% of patients in the 0.1 Hz groups and in all patients in the 1.0 Hz groups (p less than 0.05). In the 0.1 Hz groups, 50% twitch depression occurred 19 +/- 27 seconds after the end of fasciculations, with more than three-quarters of the patients having achieved 50% twitch depression 30 seconds following the disappearance of fasciculations. The addition of isoflurane did not significantly alter any of these times. CONCLUSIONS: The data reveal that cessation of fasciculations may be an inaccurate clinical sign of the readiness for intubation and confirm that standardized methods of neurostimulation are necessary in the pharmacodynamic evaluation of neuromuscular blocking drugs. In settings where profound neuromuscular relaxation is not required, waiting at least 30 seconds beyond the disappearance of fasciculations should provide good intubating conditions.

Adolescent↗
PubMedDate not supplied

Intraoperative hypotension due to unrecognized bleeding from a continuous spinal catheter site.

We recently cared for a patient who had a rare complication from a continuous spinal catheter: extensive bleeding around the catheter insertion site. This complication went unrecognized intraoperatively because the bleeding was hidden from view. The possible etiologies for this bleeding are discussed, as well as methods to recognize this complication before significant bleeding occurs.

Anesthesia, Spinal↗
PubMedDate not supplied

Use of preincisional ketorolac in hernia patients: intravenous versus surgical site.

BACKGROUND AND OBJECTIVES: This study was designed to determine whether administration of ketorolac directly in the surgical site results in enhanced analgesia. METHODS: A randomized double-blind study was undertaken at a university-affiliated tertiary care hospital. Thirty outpatients undergoing unilateral inguinal hernia repair by one of two surgeons under local anesthesia with sedation were evaluated. Patients were invited to participate in this investigation at the time of the preoperative surgical visit. Patients who had a contraindication to the use of ketorolac or who refused repair under local anesthesia with sedation were excluded. Patients received ketorolac 60 mg either via the parenteral route or directly in the surgical site (mixed with the local anesthetic). The outcome measures included visual analog pain scores, measured at two different times in the hospital, pain scores at rest and with movement 24 hours after surgery, time to first analgesic, and total analgesic requirement. RESULTS: The study revealed lower 24 hour movement-associated pain scores (P < .02), increased time to first analgesic (P < .03), and decreased oral analgesic consumption (P < .0002) in the surgical site group. CONCLUSIONS: Ketorolac provides enhanced patient comfort when it is administered in the surgical site in patients undergoing inguinal hernia repair. It is recommended that clinicians add ketorolac to the local anesthetic solution in such patients.

Adult↗
PubMedDate not supplied

Ketorolac as an adjunct to patient-controlled morphine in postoperative spine surgery patients.

BACKGROUND AND OBJECTIVES: This randomized double-blind study was designed to determine whether administration of ketorolac either on schedule or as a component of patient-controlled analgesia (PCA) to patients who have undergone spinal stabilization would decrease PCA morphine use, decrease side effects, and/or enhance analgesia. METHODS: Eighty inpatients undergoing spine stabilization by one surgeon were evaluated after excluding patients with contraindications to the use of ketorolac or morphine. All patients received PCA morphine. The patients were divided into four groups, which were given either intravenous saline (control group); intravenous ketorolac 15 mg every 6 hours; intravenous ketorolac 30 mg every 6 hours; or ketorolac added to the PCA morphine on a milligram per milligram basis. The outcome measures included pain scores. 24-hour morphine use, level of sedation, and side effect profile at six times during the first 24 postoperative hours. RESULTS: The total dose of morphine (P < .0001) and the cumulative doses for each of the six time periods (P varied between .02 and .0001 for the six time periods) were significantly higher in the control group than in the other three groups. There were no differences in doses administered by the other three groups. The pain scores were also significantly higher in the control group than in the other three groups, with no differences in pain scores among the other three. The sedation scores were higher (ie, patients more sedated) in the control group than in the other three groups at two of the six time periods (periods I and 6; P < .001). CONCLUSIONS: Ketorolac should be as a component of the PCA morphine in patients undergoing spine stabilization surgery. This results in decreased morphine consumption, decreased somnolence, and enhanced analgesia in comparison with patients who do not receive ketorolac.

Adult↗
PubMedDate not supplied

Use of clonidine in hernia patients: intramuscular versus surgical site.

BACKGROUND AND OBJECTIVES: This study was designed to determine if administration of clonidine in hernia patients enhances analgesia. It was also designed to determine whether administration directly in the surgical site further improves the analgesia. METHODS: A randomized, double-blinded study was undertaken at a tertiary care hospital. Forty-five outpatients undergoing unilateral inguinal hernia repair by one of two surgeons (D.P. or M.A.) under local anesthesia with monitored anesthesia care were evaluated. Patients were invited to participate in this investigation at the time of the preoperative surgical visit. Patients who had a contraindication to the use of clonidine or who refused repair under local anesthesia with sedation were excluded. Patients were randomized to one of three groups: (a) clonidine 0.5 microg/kg intramuscularly and saline in the surgical site (mixed with the local anesthetic); (b) clonidine 0.5 microg/kg in the surgical site and saline intramuscularly; or (c) saline in both the surgical site and intramuscularly. The outcome measures included visual analog pain scores twice in the hospital, pain scores at rest and with movement 24 hours postoperatively, the time to first analgesic, and total analgesic requirement. RESULTS: The pain scores were lower in both clonidine groups at 2 hours postoperatively than in the control group (P < .03). No difference was observed with respect to the time to first analgesic, 24-hour analgesic use, or 24-hour pain scores among the groups. CONCLUSIONS: When clonidine is administered to patients undergoing hernia repair, the 2-hour pain scores are lowered. No difference was exhibited when clonidine was administered intramuscularly or directly into the hernia site.

Analgesics↗
PubMedDate not supplied

Use of clonidine as a component of the peribulbar block in patients undergoing cataract surgery.

BACKGROUND AND OBJECTIVES: This study was designed to determine whether administration of clonidine as a component of a peribulbar block enhanced analgesia increased sedation, improved akinesia, or decreased intraocular pressure. METHODS: A randomized, double-blinded study was undertaken at a University-affiliated tertiary care hospital. Forty outpatients undergoing unilateral cataract surgery by a single surgeon (J.P.) under peribulbar blockade were evaluated. Patients received either 100 microg (1 mL) clonidine or 1 mL preservative-free normal saline mixed with the local anesthetic (7 mL 1% preservative-free lidocaine). A Honan adapter was applied for 10 minutes after block placement. The outcome measures included sedation scores, intraocular pressure (IOP) before and after peribulbar block, need for supplemental block, 24-hour analgesic requirement, and patient satisfaction. RESULTS: There were no differences between groups with respect to pain, sedation, or satisfaction scores. There was no difference with respect to onset of akinesia. This study revealed no significant difference in baseline IOP and postperibulbar IOP. CONCLUSIONS: Clonidine did not alter, in any appreciable way, the perioperative course for patients undergoing cataract operations. We do not recommend clonidine as a component of a peribulbar block in patients undergoing cataract extraction operations.

Adjuvants, Anesthesia↗
PubMedDate not supplied

Does tranexamic acid decrease bleeding in patients undergoing cardiopulmonary bypass?

We reviewed the records of 66 patients who underwent cardiopulmonary bypass; half of these patients received the plasmin inhibitor, tranexamic acid. The demographics were not different between the group who received tranexamic acid and the group who did not (control group). There was no difference in the heparin or protamine requirements between the two groups. There was a significantly greater amount of 12-hr chest tube bleeding in the control group (495 +/- 484 vs. 863 +/- 655 in the control and tranexamic acid groups, respectively; p < .02). There was no difference between the groups in either the post-operative hematocrit, platelet count or the number of patients requiring transfusion. Although tranexamic acid decreased the amount of chest tube output, there was no demonstrable patient benefit derived from its use.

Antifibrinolytic Agents↗