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R D Fitzgerald

Publications and source records attributed to R D Fitzgerald.

At least 19 recordsLinked to original sources
PubMed2005

[Brain natriuretic peptide for postoperative monitoring of the fluid balance in a cardiac surgery patient].

Brain natriuretic peptide is a neurohormone used for estimation of left ventricular wall tension and volume overload. We describe the use of this parameter in a postoperative cardiac surgery patient for detection and monitoring of left ventricular failure in a postoperative intensive care unit at a tertiary care center. Left ventricular failure was detected by brain natriuretic peptide levels, while x-ray and values obtained by the pulmonary artery catheter were inconclusive.

Aged↗
PubMed2004

Vital capacity manoeuvre in general anaesthesia: useful or useless?

As atelectasis occurs in most patients during general anaesthesia and may be one of the major causes for the development of hypoxaemia and nosocomial pneumonia, its prevention may be considered as an important objective in perioperative management. The major causative mechanisms are the loss of respiratory muscle tone, compression and gas absorption. Vital capacity manoeuvres have been proposed as a means to eliminate atelectasis in the vast majority of patients and restore normal pulmonary gas exchange during general anaesthesia. In this review we describe the pathogenesis of atelectasis in the perioperative period and discuss in the light of recent published investigations the suitability of the vital capacity manoeuvre as a tool during general anaesthesia. Reviewing the current literature, a vital capacity manoeuvre during general anaesthesia may only be useful under specific circumstances when mechanical ventilation with a high inspiratory fraction of oxygen is required or during cardiac surgery at the end of cardiopulmonary bypass to reduce the amount of atelectasis and to maintain adequate gas exchange.

Anesthesia, General↗
PubMed2004

[Clinical impact of recruitment maneuvers in patients with acute respiratory distress syndrome].

In patients with acute respiratory distress syndrome (ARDS), recruitment maneuvers have been proposed as an adjunct to mechanical ventilation to open up atelectasis and to keep these alveoli open by the application of adequate high levels of positive end-expiratory pressure (PEEP). Though several studies reported that the responsiveness to recruitment maneuvers resulted in a marked improvement of oxygenation with a concomitant decrease in airway pressure and/or inspiratory fraction of oxygen, the performance of recruitment maneuvers still remains a matter of dispute, especially in patients ventilated with a lung protective ventilation strategy. In this review we discuss the pathophysiological background, factors affecting the responsiveness to recruitment maneuvers and their clinical impact in the light of recently published studies. Successful recruitment depends on several factors like the applied recruitment pressure, the level of PEEP set before and after the recruitment maneuver, the stage and the underlying disease of the ARDS, chest wall mechanics and the transpulmonary pressure as well as the positioning of the patient. Regarding the current literature, recruitment maneuvers may be considered as a rescue therapy in the early stage of severe hypoxemic lung failure, if a lung protective ventilation strategy and other additive adjuncts like prone positioning or the application of inhaled vasodilators failed to induce adequate gas exchange.

Acute Disease↗
PubMed2003

Increasing the injection volume by dilution improves the onset of motor blockade, but not sensory blockade of ropivacaine for brachial plexus block.

BACKGROUND AND OBJECTIVE: Ropivacaine used for axillary plexus block provides effective motor and sensory blockade. Varying clinical dosage recommendations exist. Increasing the dosage by increasing the concentration showed no improvement in onset. We compared the behaviour of a constant dose of ropivacaine 150 mg diluted in a 30, 40 or 60 mL injection volume for axillary (brachial) plexus block. METHODS: A prospective, randomized, observer-blinded study on patients undergoing elective hand surgery was conducted in a community hospital. Three groups of patients with a constant dose of ropivacaine 150 mg, diluted in 30,40 or 60 mL NaCl 0.9%, for axillary plexus blockade were compared for onset times of motor and sensory block onset by assessing muscle strength, two-point discrimination and constant-touch sensation. RESULTS: Increasing the injection volume of ropivacaine 150 mg to 60 mL led to a faster onset of motor block, but not of sensory block, in axillary plexus block, compared with 30 or 40 mL volumes of injection. CONCLUSIONS: The data show that the onset of motor, but not of sensory block, is accelerated by increasing the injection volume to 60 mL using ropivacaine 150 mg for axillary plexus block. This may be useful for a more rapid determination of whether the brachial plexus block is effective. However, when performing surgery in the area of the block, sensory block onset seems more important.

Amides↗
PubMed2003

Intraoperative catecholamine release in brain-dead organ donors is not suppressed by administration of fentanyl.

BACKGROUND AND OBJECTIVE: Endogenous catecholamines are released in brain-dead organ donors following painful stimulation during retrieval surgery, and might be harmful to harvested organs. Our hypothesis was that inhibition of pain by fentanyl would inhibit such catecholamine release. METHODS: We tested 17 brain-dead organ donors in a randomized, placebo-controlled, double-blinded study. Blood samples for determination of epinephrine and norepinephrine concentrations were obtained before and 10 min after in take of either fentanyl 7 microg kg(-1) or an equivalent volume of placebo. Further points of measurement were taken after skin incision and sternotomy. Mean arterial pressure and heart rate at these points were recorded. RESULTS: Catecholamine concentrations rose following painful stimuli. No differences in haemodynamics, between the fentanyl and the placebo group were detectable. Epinephrine concentrations, but not those of norepinephrine, were higher in the fentanyl group, reaching significance following sternotomy. CONCLUSION: We conclude that the use of fentanyl (7 microg kg(-1)) was not effective in suppressing the catecholamine release, following painful surgical stimulation in brain-dead organ donors.

Adult↗
PubMed2002

Remifentanil or propofol for sedation during carotid endarterectomy under cervical plexus block.

BACKGROUND: During carotid endarterectomy under regional anaesthesia, patients often require medication to control haemodynamic instability and to provide sedation and analgesia. Propofol and remifentanil are used for this purpose. However, the benefits, side-effects, and optimal dose of these drugs in such patients are unclear. METHODS: Sixty patients were included in a prospective, randomized, single blinded study. All patients received a deep cervical plexus block with 30 ml ropivacaine 0.75% and were randomized to receive either remifentanil 3 micro g kg(-1) h(-1) or propofol 1 mg kg(-1) h(-1). The infusions were started after performing the regional block and were stopped at the end of surgery. Arterial pressure, ECG, ventilatory rate, and Pa(CO(2)) were measured continuously and recorded at predetermined times. Twenty-four hours after surgery, patient comfort, and satisfaction were also evaluated. RESULTS: In three patients, the infusion of remifentanil had to be stopped because of severe respiratory depression or bradycardia. No significant differences were found between the two groups in haemodynamic variables or sedative effects, but there was a significantly greater decrease in ventilatory frequency and increase in Pa(CO(2)) in the remifentanil group. The patient's subjective impressions and pain control were excellent in both groups. CONCLUSION: As a result of the higher incidence of adverse respiratory effects with remifentanil and similar sedative effects, propofol is preferable for sedation during cervical plexus block in elderly patients with comorbid disease at the dosage used.

Aged↗
PubMed2001

Equi-lasting doses of rocuronium, compared to mivacurium, result in improved neuromuscular blockade in patients undergoing gynecological laparoscopy : [Des doses de durée équivalente de rocuronium, comparé au mivacurium, améliorent la curarisation chez des patientes qui subissent une laparoscopie gynécologique].

PURPOSE: To compare equi-lasting doses of a short-acting (mivacurium) to an intermediate-acting (rocuronium) neuromuscular relaxant, with regard to intubating conditions, efficacy, number of maintenance doses, hemodynamic alterations, adverse events and costs, in patients undergoing laparoscopic gynecological surgery. METHODS: Sixty patients were randomly allocated to receive either 0.2 mg*kg(-1) (3 x ED(95)) mivacurium or 0.5 mg*kg(-1) (1.7 x ED(95)) rocuronium, under propofol/fentanyl anesthesia. T1, first twitch of the train-of-four (TOF) and TOF ratio (T4:T1) were used to evaluate neuromuscular block using the Relaxometer(R) mechanomyograph. The trachea was intubated when T1 was maximally suppressed. Neuromuscular block was maintained at 25% T1 with equi-lasting doses of 0.075 mg*kg(-1) mivacurium or 0.15 mg*kg(-1) rocuronium. RESULTS: Mean (min) +/- SD mivacurium onset time (1.9 +/- 0.4) was longer than that of rocuronium (1.3 +/- 0.3). This did not yield a statistical difference in intubating conditions between the two groups. Interval 25-75% T1 recovery and time to 0.8 TOF recovery were prolonged following rocuronium (11.9 +/- 3.9, 52.6 +/- 15.5 respectively) compared to mivacurium (6.7 +/- 2.3, 39.2 +/- 8.1 respectively). More patients, 22/30, required mivacurium maintenance doses compared to 14/30 patients in the rocuronium group. Arterial blood pressure declined and 13/30 patients manifested erythema following mivacurium administration. The acquisition costs of rocuronium (6.93 Euro/patient) were 23% lower compared to mivacurium (8.96 Euro/patient). CONCLUSION: Equi-lasting doses of rocuronium resulted in favourable intubating conditions more rapidly, improved hemodynamic stability, required less frequent administration of maintenance doses and were not associated with erythema, compared to mivacurium.

Adolescent↗
PubMed2001

Nalbuphine by PCA-pump for analgesia following hysterectomy: bolus application versus continuous infusion with bolus application.

The analgesic properties of the partial agonist-antagonist nalbuphine in the postoperative period are well known. When used for patient-controlled analgesia (PCA) the effectiveness of this substance is comparable to that of morphine or tramadol. However, the optimal programme for administration of nalbuphine in PCA-pumps has not been investigated. In particular, the combination of bolus administration vs bolus administration plus continuous basal administration is disputable. We hypothesized that the administration of an extra basal rate of nalbuphine in addition to the patient- triggered bolus administration and supplemental doses of diclofenac when required, would lead to a significant improvement in analgesia, without affecting the differences in vital signs and side effects. After approvement by the institutional ethics committee, 50 female patients (ASA I or II) scheduled for elective hysterectomy were included in a prospective, single-blinded study and randomized either into bolus-continuous (BC-)group (3 mg base rate/h, 1 mg bolus, 20 min lock out) or bolus (B-)group (no base rate, 1 mg bolus, 10 min lock out). During the observation period (up to 24 h postoperative) vital parameters, extent of analgesia (10-step VAS), and vigilance (5-step scale) were registered. Groups were compared by using unpaired Student t-test. A p<0.05 was considered to be significant. No differences were found in demographic data or vital parameters (MAP, PaO2, PaCO2, respiratory rate, heart rate, peripheral SaO2) during the observation period. Vital parameters showed no pathological changes in any group. With an identical rate of requirement for diclofenac (32 and 36%), analgesia in BC-group showed a decrease in VAS from 4.28+/-2.11 to 2.04+/-1.21 and from 3.64+/-2.20 to 2.08+/-0.96 in B-group. Vigilance was only marginally diminished in both groups. No serious side effects were found in either group. The consumption of nalbuphine (mg) was significantly higher in BC-group (70.28+/-13.85 vs. 47.44+/-22.99;p =0.0002) when compared to B-group. Subjective rating of effectiveness by the patients was similar in both groups. The two administration settings of nalbuphine by PCA pump have shown to be equally effective in the treatment of postoperative pain following hysterectomy. However, as the total amount of nalbuphine was significantly lower in B-group, the use of this administration schedule should be encouraged.

Adult↗
PubMed2001

Direct current auditory evoked potentials during wakefulness, anesthesia, and emergence from anesthesia.

Direct current auditory evoked potentials (DC-AEPs) are a sensitive indicator of depth of anesthesia in animals. However, they have never been investigated in humans. To assess the potential usefulness of DC-AEPs as an indicator of anesthesia in humans, we performed an explorative study in which DC-AEPs were recorded during propofol and methohexital anesthesia in humans. DC-AEPs were recorded via 22 scalp electrodes in 19 volunteers randomly assigned to receive either propofol or methohexital. DC-AEPs were evoked by binaurally presented 2-s, 60-dB, 800-Hz tones; measurements were taken during awake baseline, anesthesia, and emergence. Statistical analysis included analysis of variance and discriminant analysis of data acquired during these three conditions. About 500 ms after stimulus presentation, DC-AEPs could be observed. These potentials were present only during baseline and emergence-not during anesthesia. Statistically significant differences were found between baseline and anesthesia and between anesthesia and emergence. In conclusion, similar effects, as reported in animal studies of anesthetics on the DC-AEPs, could be observed in anesthetized humans. These results demonstrate that DC-AEPs are potentially useful in the assessment of cortical function during anesthesia and might qualify the method for monitoring anesthesia in humans.

Adult↗
PubMed2000

Right atrial pressure predicts hemodynamic response to apneic positive airway pressure.

OBJECTIVE: To evaluate if the preexistant filling state, assessed by right atrial pressure (RAP), pulmonary artery occlusion pressure (PAOP), and right ventricular end-diastolic volume index (EDVI), would define the subsequent hemodynamic effects of increases in airway pressure (Paw). DESIGN: Prospective open clinical study. SETTING: Postoperative intensive care unit, university hospital. PATIENTS: Twenty-two consecutive ventilator-dependent patients with mild to severe acute lung injury with Murray scores (scoring infiltrates on chest radiograph, oxygenation index, lung compliance, and the level of positive end-expiratory pressure) ranging from 0.5 to 3.0 without history of preexisting cardiopulmonary disease. INTERVENTIONS: Paw varied during apnea from 0 to 10, 20, and 30 cm H2O using inspiratory hold maneuvers of 15 secs. MEASUREMENTS AND MAIN RESULTS: Cardiac index and right ventricular ejection fraction were measured by the thermodilution technique. We made measurements in triplicate using manual injection of iced saline. Right ventricular volumes were calculated. Increasing Paw induced variable changes in cardiac index among subjects (+6% to -43% change from baseline 0 cm H2O Paw values), which correlated with percentage changes in both stroke index (r2 = .89) and right ventricular EDVI (r2 = .75), whereas heart rate and right ventricular ejection fraction did not change. The change in cardiac index from 0 to 30 cm H2O Paw correlated with baseline values for RAP, PAOP, and right ventricular EDVI (r2 = .68, .43, and .34, respectively, p < 0.01). Increases in RAP correlated with lung compliance if baseline RAP was >10 mm Hg but did not if it was < or =10 mm Hg. Similarly, patients with baseline RAP < or =10 mm Hg had a greater decrease in cardiac index than patients with a RAP >10 mm Hg (for 30 cm H2O Paw: -30% +/- 9% vs. -8% +/- 7%, p < .01). CONCLUSIONS: Apneic positive Paw decreased cardiac output mainly by reducing venous return. From the investigated filling variables, RAP was most sensitive in predicting the hemodynamic response, followed by PAOP and right ventricular EDVI. Patients with RAP < or =10 mm Hg, if subjected to aggressive positive pressure ventilation, are at risk of hemodynamic deterioration and organ hypoperfusion.

Adult↗
PubMed2000

Influence of positive airway pressure on the pressure gradient for venous return in humans.

To study the effect of positive airway pressure (Paw) on the pressure gradient for venous return [the difference between mean systemic filling pressure (Pms) and right atrial pressure (Pra)], we investigated 10 patients during general anesthesia for implantation of defibrillator devices. Paw was varied under apnea from 0 to 15 cmH(2)O, which increased Pra from 7.3 +/- 3.1 to 10.0 +/- 2.3 mmHg and decreased left ventricular stroke volume by 23 +/- 22%. Episodes of ventricular fibrillation, induced for defibrillator testing, were performed during 0- and 15-cmH(2)O Paw to measure Pms (value of Pra 7.5 s after onset of circulatory arrest). Positive Paw increased Pms from 10.2 +/- 3.5 to 12.7 +/- 3.2 mmHg, and thus the pressure gradient for venous return (Pms - Pra) remained unchanged. Echocardiography did not reveal signs of vascular collapse of the inferior and superior vena cava due to lung expansion. In conclusion, we demonstrated that positive Paw equally increases Pra and Pms in humans and alters venous return without changes in the pressure gradient (Pms - Pra).

Aged↗
PubMed1999

Complications following the use of the Combitube, tracheal tube and laryngeal mask airway.

In a prospective, randomised trial, 75 patients scheduled for routine surgery were randomly allocated to one of three groups to evaluate trauma and postoperative complications after insertion of the Combitube, tracheal tube or laryngeal mask airway. Insertion of the Combitube was associated with a higher incidence of sore throat (48% vs. 16% vs. 12% [p < 0.01]) and dysphagia (68% vs. 12% vs. 8% [p < 0.01]) compared with tracheal intubation or insertion of the laryngeal mask airway, respectively. Hoarseness was significantly less common in both the Combitube and the laryngeal mask groups (both 12%) than in the tracheal tube group (44%; p < 0.01). Haematoma occurred in 36% of the Combitube group compared with 4% in both the laryngeal mask and the tracheal tube groups (p < 0.01). The higher incidence of complications should be considered when using the Combitube.

Adult↗
PubMed1999

Hemodynamic and catecholamine stress responses to insertion of the Combitube, laryngeal mask airway or tracheal intubation.

UNLABELLED: In a prospective, randomized, and controlled trial, we compared the stress responses after insertion of the Combitube (CT; Kendall-Sheridan Catheter Corp., Argyle, NY), the laryngeal mask airway (LMA), or endotracheal intubation (ET). Seventy-five patients scheduled for routine urological or gynecological surgery were randomly allocated to one of three groups and were ventilated via either an ET, a LMA, or a CT. All three devices could be inserted easily and rapidly, providing adequate ventilation and oxygenation. Insertion of the CT was associated with a significant increase in mean maximal systolic arterial pressure (160+/-32 mm Hg) and diastolic arterial pressure (91+/-17 mm Hg) compared with ET (140+/-24, 78+/-11 mm Hg; P < 0.05, P < 0.01, respectively) or insertion of the LMA (115+/-33,63+/-22 mm Hg, both P < 0.001). The mean maximal epinephrine and norepinephrine plasma concentrations after insertion of the CT (37.3+/-31.1 and 279+/-139 pg/mL, respectively) were significantly higher than those after ET (35.8+/-89.8 and 195+/-58 pg/mL, respectively) or insertion of a LMA (17.3+/-13.3 and 158+/-67 pg/mL, respectively). This might be attributed to the pressure of the pharyngeal cuff of the CT on the anterior pharyngeal wall. We conclude that insertion of the CT causes a pronounced stress response and that precautions should be taken when used in patients at risk of hypertensive bleeding. IMPLICATIONS: In this study, we showed that the hemodynamic and catecholamine stress responses after insertion of the Combitube (Kendall-Sheridan Catheter Corp., Argyle, NY) were significantly higher compared with laryngeal mask airway or endotracheal intubation. We conclude that the increased stress response to insertion of a Combitube may represent a serious hazard to patients with cardiovascular disease.

Adult↗
PubMed1998

Procalcitonin: a new parameter for the diagnosis of bacterial infection in the peri-operative period.

Procalcitonin, a new innovative inflammation parameter is presently being evaluated in clinical studies. It has been shown to be increased markedly in patients with severe bacteria induced inflammation, septic shock, endotoxinaemia and multiple organ failure. In contrast, severe viral infections or inflammatory reactions of non-infectious origin as well as auto-immune or allergic disorders do not or only very moderately increase procalcitonin serum levels. Because procalcitonin is observed at significantly higher concentrations in bacterial infections, it might assist differentiation between these infections and other aetiologies of critical illnesses. Furthermore, procalcitonin correlates with the severity of infection and sepsis and thus could serve as a useful marker for monitoring surgical high risk patients. Procalcitonin may serve as a valid and sensitive indicator for bacterial infection with important diagnostic potential in the peri-operative period and in intensive care medicine.

Bacterial Infections↗
PubMed1997

Clinical trial of a new device for fiberoptic orotracheal intubation (Augustine Scope).

Blind oral intubation using the Augustine Guide is helpful for intubating the trachea of patients presenting with difficult airways. This device has been modified by adding a fiberoptic scope with a built-in battery-powered light. We studied this Augustine Scope in 104 patients (Group AS) and compared the results with 96 patients managed by direct laryngoscopy (Group DL). No significant differences in Mallampati class, thyromental distance, laryngoscopic view, and patients height or weight were observed between the two groups. The Augustine Scope provided conditions for successful intubation in 102 of 104 patients (98%), compared with a 97% success rate in the group where DL was used. The three patients who failed DL were successfully intubated with AS. The mean +/- SD time needed to perform intubation was 19 +/- 10 s in Group AS and 21 +/- 13 s in Group DL (P = not significant). No traumatizing effects were observed. We conclude that the Augustine Scope is an effective and safe device for orotracheal intubation in routine and difficult airways.

Adult↗