bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relation between Quality of Recovery in Hospital and Quality of Life at 3 Months after Cardiac Surgery
Authors: Myles Paul S. , Hunt Jennifer O. , Fletcher Helen , Solly Robert , Woodward David , Kelly Susan 
Published: November 2003

Background
Improved quality of life (QoL) is a desirable outcome of cardiac surgery. The aim of the current study was to measure the association between quality of recovery 3 days after surgery and QoL measured 3 months later.

Methods
After obtaining ethics committee approval and consent, 120 adult cardiac surgical patients were studied. A 40-item quality of recovery score (QoR-40) was used to measure postoperative health status on days 1-3 and 1 month after surgery. QoL was measured using the short-form health survey (SF-36) at 1 and 3 months after surgery. The effect size (delta mean/SD) was used to define responsiveness, a clinically important difference in health. Associations were measured using correlation and reliability coefficients.

Results
There was a significant change in the mean QoR-40 for up to 1 month after surgery (P < 0.0005). QoL was improved at 3 months (P < 0.0005) but not 1 month (P = 0.29) after surgery. There was a moderate correlation between day-3 QoR-40 and 3-month SF-36 (r = 0.39; P < 0.0005). A poor-quality recovery in hospital predicted a poor QoL at 3 months (adjusted odds ratio, 4.20; 95% confidence interval, 1.41-12.5; P = 0.01).

Conclusions
The QoR-40 is a valid measure of quality of recovery after surgery and anesthesia. When compared with the SF-36, it is a better measure of early postoperative recovery. A poor-quality recovery on the days after surgery can predict a poor QoL at 3 months after surgery. This may allow earlier and more effective support strategies while patients are still in the hospital (counseling, home assistance, local doctor notification, cardiac rehabilitation).
Acute and Nonacute Complications Associated with Interscalene Block and Shoulder Surgery
Authors: Borgeat Alain , Ekatodramis Georgios , Kalberer Fabian , Benz Cedric 
Published: November 2003

Background
The incidence, etiology, and evolution of complications after interscalene brachial plexus block (ISB) are not well-known. The authors prospectively monitored 521 patients for complications during the first 9 months after ISB.

Methods
A total of 521 adults scheduled for elective shoulder surgery performed with an ISB were included in this prospective study. The ISB procedure was standardized for all patients Acute complications were recorded. Patients were observed daily (for 10 days) for paresthesias, dysesthesias, pain not related to surgery, and muscular weakness and were evaluated at 1, 3, 6, and 9 months after surgery. Persistence of paresthesias dysesthesias, pain not related to surgery, or muscular weakness was investigated at 1 or 3 months by means of electroneuromyography. Final evaluation was performed at 9 months.

Results
A total of 520 patients completed the study; one was excluded after surgical axillary nerve damage. Two hundred thirty-four patients had an interscalene catheter. Acute complications consisted of one pneumothorax (0.2%) and one episode of central nervous system toxicity (incoherent speech; 0.2%). A 10 days, 74 patients (14%) were symptomatic, and none had muscular weakness. At 1 month, 41 patients (7.9%) had symptoms, and none had muscular weakness. Thirty patients under went electroneuromyography; sulcus ulnaris syndrome (n = 8) carpal tunnel syndrome (n = 2), and complex regional pain syndrome (n = 1) were diagnosed. At 3 months 20 patient (3.9%) were symptomatic, and none had muscular weakness All underwent electroneuromyography; carpal tunnel syndrome (n = 2), complex regional pain syndrome (n = 4), plexus neuropathy (n = 1), and plexus damage (n = 1) were diagnosed. At 6 months, 5 patients (0.9%) were symptomatic. At 9 months 1 patient (0.2%) had persistence of dysesthesia.

Conclusions
Interscalene brachial plexus block performed with a standardized technical approach, material, and drugs is associated with an incidence of short- and severe long-term complications of 0.4%. In case of persistent paresthesia, dysesthesia, or pain not related to surgery after ISB, sulcus ulnaris syndrome, carpal tunnel syndrome, or complex regional pain syndrome should be excluded since specific treatment may be required.
Effect of Synchronized Intermittent Mandatory Ventilation on Respiratory Workload in Infants after Cardiac Surgery
Authors: Imanaka Hideaki , Nishimura Masaji , Miyano Hiroshi , Uemura Hideki , Yagihara Toshikatsu 
Published: November 2003

Background
Synchronized intermittent mandatory ventilation (SIMV) is commonly used in infants and adults. However, few investigations have examined how SIMV reduces respiratory workload in infants. The authors evaluated how infants' changing respiratory patterns when reducing SIMV rate increased respiratory load. The authors also investigated whether SIMV reduces infant respiratory workload in proportion to the rate of mandatory breaths and which rate of SIMV provides respiratory workloads similar to those after tracheal extubation.

Methods
When 11 post-cardiac surgery infants aged 2-11 months were to be weaned with SIMV, the authors randomly applied five levels of mandatory breathing: 0, 5, 10, 15, and 20 breaths/min. All patients underwent ventilation with SIMV mode: pressure control ventilation, 16 cm H2O; inspiratory time, 0.8 s; triggering sensitivity, 0.6 l/min; and positive endexpiratory pressure, 3 cm H2O. After establishing steady-state conditions at each SIMV rate, arterial blood gases were analyzed, and esophageal pressure, airway pressure, and airflow were measured. Inspiratory work of breathing, pressure-time products, and the negative deflection of esophageal pressure were calculated separately for assisted breaths, for spontaneous breaths, and for total breaths per minute. Measurements were repeated after extubation.

Results
As the SIMV rate decreased, although minute ventilation and arterial carbon dioxide tension were maintained at constant values, spontaneous breathing rate and tidal volume increased. Work of breathing, pressure-time products, and negative deflection of esophageal pressure increased as the SIMV rate decreased. Work of breathing and pressure-time products after extubation were intermediate between those at a SIMV rate of 5 breaths/min and those at 0 breaths/min.

Conclusion
When the load to breathing was increased progressively by decreasing the SIMV rate in post-cardiac surgery infants, tidal volume and spontaneous respiratory rate both increased. In addition, work of breathing and pressure-time products were increased depending on the SIMV rate.
Effects of Rapacuronium on Respiratory Function during General Anesthesia
Authors: Tobias Joseph D. , Johnson Joel O. , Sprague Kelly , Johnson Garry 
Published: November 2003

Background
With its introduction for widespread clinical use, there has been an increase in reports of bronchospasm related to the administration of rapacuronium. As it is commonly used for rapid sequence intubation, it has been suggested that these effects may be related to an inadequate depth of anesthesia. The current study examines the airway effects of rapacuronium in tracheally intubated, anesthetized adults.

Methods
Endotracheal intubation was accomplished without the use of neuromuscular blocking agents. Dynamic compliance, tidal volume, peak inspiratory flow rate, peak expiratory flow rate, and peak inflating pressure were measured after administration of either rapacuronium (1.5 mg/kg) or cis-atracurium (0.2 mg/kg) to 20 adult patients (10 received rapacuronium and 10 received cis-atracurium) anesthetized with propofol-remifentanil.

Results
Statistically significant increases in peak inflating pressure (22 +/- 6 to 28 +/- 9 cm H2O, P = 0.0012) and decreases in dynamic compliance (108 +/- 43 to 77 +/- 41 ml/cm H2O, P = 0.0001), peak inspiratory flow rate (0.43 +/- 0.11 to 0.39 +/- 0.09 l/s, P = 0.0062), peak expiratory flow rate (0.67 +/- 0.10 to 0.59 +/- 0.09 l/s, P = 0.0015), and tidal volume (744 +/- 152 to 647 +/- 135 ml, P = 0.0293) occurred after administration of rapacuronium. No changes were seen after administration of cis-atracurium.

Conclusion
These data demonstrate that rapacuronium, but not cis-atracurium, has significant airway effects in intubated, mechanically ventilated adults.
Nitrogen at Raised Pressure Interacts with the GABAAReceptor to Produce Its Narcotic Pharmacological Effect in the Rat
Authors: David Hélène N. , Balon Norbert , Rostain Jean-Claude , Abraini Jacques H. 
Published: November 2003

Background
Strong evidence supports the concept that conventional anesthetics, including inhalational agents and inert gases, such as xenon and nitrous oxide, interact directly with ion channel neurotransmitter receptors. However, there is no evidence that nitrogen, which only exhibits narcotic potency at increased pressure, may act by a similar mechanism.

Methods
We compared the inhibitory and sedative effects of gamma-aminobutyric acid (GABA) and nitrogen pressure on locomotor activity and striatal dopamine release in freely moving rats and investigated the pharmacologic properties of the GABA-induced and nitrogen pressure-induced narcotic action using the highly selective competitive GABA(A) receptor antagonist bicuculine.

Results
Intracerebroventricular GABA infusion up to 60 micromol or exposure to nitrogen pressure up to 3 MPa decreased to a similar extent striatal dopamine release (r2= 0.899, df = 4, P < 0.01) and locomotor activity (r2 = 0.996, df = 28, P < 0.001). However, both agents only showed small effects on striatal dopamine release, reducing dopamine currents by only 12-13% at sedative concentrations. Pretreatment with bicuculline at 0.5, 1, and 2.5 pmol reduced the sedative action of GABA on locomotor activity by 10, 20, and 41%, respectively. Bicuculline in the nanomole range at 1, 2.5, and 5 nmol but not in the picomole range reduced the sedative action of nitrogen pressure by 5, 37, and 73%, respectively. Schild plot analysis is consistent with the fact that bicuculline is a competitive antagonist of both GABA and nitrogen at pressure.

Conclusions
These results suggest (1) that the presynaptic effects of both GABA and nitrogen pressure on striatal dopamine transmission are modest and not mainly involved in their sedative action and (2) that nitrogen at increased pressure may interact directly with the GABA(A) receptor. However, because the antagonistic effect of bicuculline on nitrogen sedation only occurred at much higher bicuculline concentrations than seen with GABA, it is suggested that nitrogen does not compete for the same site as GABA.
Cerebral Blood Volume (CBV) in Humans during Normo- and Hypocapnia
Authors: Reinstrup Peter , Ryding Erik , Ohlsson Tomas , Dahm Peter Lee , Uski Tore 
Published: November 2003

Background
It is generally argued that variations in cerebral blood flow create concomitant changes in the cerebral blood volume (CBV). Because nitrous oxide (N(2)O) inhalation both increases cerebral blood flow and may increase intracranial pressure, it is reasonable to assume that N(2)O acts as a general vasodilatator in cerebral vessels both on the arterial and on the venous side. The aim of the current study was to evaluate the effect of N(2)O on three-dimensional regional and global CBV in humans during normocapnia and hypocapnia.

Methods
Nine volunteers were studied under each of four conditions: normocapnia, hypocapnia, normocapnia + 40-50% N(2)O, and hypocapnia + 40-50% N(2)O. CBV was measured after (99m)Tc-labeling of blood with radioactive quantitative registration via single photon emission computer-aided tomography scanning.

Results
Global CBV during normocapnia and inhalation of 50% O(2) was 4.25 +/- 0.57% of the brain volume (4.17 +/- 0.56 ml/100 g, mean +/- SD) with no change during inhalation of 40-50% N(2)O in O(2). Decreasing carbon dioxide (CO(2)) by 1.5 kPa (11 mmHg) without N(2)O inhalation and by 1.4 kPa (11 mmHg) with N(2)O inhalation reduced CBV significantly (F = 57, P < 0.0001), by 0.27 +/- 0.10% of the brain volume per kilopascal (0.26 +/- 0.10 ml x 100 g(-1) x kPa(-1)) without N(2)O inhalation and by 0.35 +/- 0.22% of the brain volume per kilopascal (0.34 +/- 0.22 ml x 100 g(-1) x kPa(-1)) during N(2)O inhalation (no significant difference). The amount of carbon dioxide significantly altered the regional distribution of CBV (F = 47, P < 0.0001), corresponding to a regional difference in Delta CBV when CO(2) is changed. N(2)O inhalation did not significantly change the distribution of regional CBV (F = 2.4, P = 0.051) or Delta CBV/Delta CO(2) in these nine subjects.

Conclusions
Nitrous oxide inhalation had no effect either on CBV or on the normal CBV-CO(2) response in humans.
Relation of the Static Compliance Curve and Positive End-expiratory Pressure to Oxygenation during One-lung Ventilation
Authors: Slinger Peter D. , Kruger Marelise , McRae Karen , Winton Timothy 
Published: November 2003

Background
Positive end-expiratory pressure (PEEP) is commonly applied to the ventilated lung to try to improve oxygenation during one-lung ventilation but is an unreliable therapy and occasionally causes arterial oxygen partial pressure (PaO(2)) to decrease further. The current study examined whether the effects of PEEP on oxygenation depend on the static compliance curve of the lung to which it is applied.

Methods
Forty-two adults undergoing thoracic surgery were studied during stable, open-chest, one-lung ventilation. Arterial blood gases were measured during two-lung ventilation and one-lung ventilation before, during, and after the application of 5 cm H(2)O PEEP to the ventilated lung. The plateau end-expiratory pressure and static compliance curve of the ventilated lung were measured with and without applied PEEP, and the lower inflection point was determined from the compliance curve.

Results
Mean (+/- SD) PaO(2) values, with a fraction of inspired oxygen of 1.0, were not different during one-lung ventilation before (192 +/- 91 mmHg), during (190 +/- 90), or after ( 205 +/- 79) the addition of 5 cm H(2)O PEEP. The mean plateau end-expiratory pressure increased from 4.2 to 6.8 cm H(2)O with the application of 5 cm H(2)O PEEP and decreased to 4.5 cm H(2)O when 5 cm H(2)O PEEP was removed. Six patients showed a clinically useful (> 20%) increase in PaO(2) with 5 cm H(2)O PEEP, and nine patients had a greater than 20% decrease in PaO(2). The change in PaO(2) with the application of 5 cm H(2)O PEEP correlated in an inverse fashion with the change in the gradient between the end-expiratory pressure and the pressure at the lower inflection point (r = 0.76). The subgroup of patients with a PaO(2) during two-lung ventilation that was less than the mean (365 mmHg) and an end-expiratory pressure during one-lung ventilation without applied PEEP less than the mean were more likely to have an increase in PaO(2) when 5 cm H(2)O PEEP was applied.

Conclusions
The effects of the application of external 5 cm H(2)O PEEP on oxygenation during one-lung ventilation correspond to individual changes in the relation between the plateau end-expiratory pressure and the inflection point of the static compliance curve. When the application of PEEP causes the end-expiratory pressure to increase from a low level toward the inflection point, oxygenation is likely to improve. Conversely, if the addition of PEEP causes an increased inflation of the ventilated lung that raises the equilibrium end-expiratory pressure beyond the inflection point, oxygenation is likely to deteriorate.
Use of the Intubating LMA-Fastrach™ in 254 Patients with Difficult-to-manage Airways
Authors: Ferson David Z. , Rosenblatt William H. , Johansen Mary J. , Osborn Irene , Ovassapian Andranik 
Published: November 2003

Background
The laryngeal mask airway (LMA; LMA North America, Inc., San Diego, CA) has a well-established role in the emergency and elective treatment of patients with difficult-to-manage airways (DA). In this study, the authors report their clinical experience with the intubating LMA (LMA-Fastrach; LMA North America, Inc., San Diego, CA) in 254 patients with different types of DA.

Methods
The authors reviewed the anesthetic and medical records of patients with DA in whom the LMA-Fastrach was used electively or emergently at four institutions from October 1997 through October 2000. In each case, the number of insertion and intubation attempts was recorded. Success rates for blind and fiber optically guided intubation through the LMA-Fastrach were calculated, up to a maximum of five attempts per patient.

Results
The LMA-Fastrach was used in 257 procedures performed in 254 patients with DA, including patients with Cormack-Lehane grade 4 views; patients with immobilized cervical spines; patients with airways distorted by tumors, surgery, or radiation therapy; and patients wearing stereotactic frames. Insertion of the LMA-Fastrach was accomplished in three attempts or fewer in all patients. The overall success rates for blind and fiber optically guided intubations through the LMA-Fastrach were 96.5% and 100.0%, respectively.

Conclusions
The LMA-Fastrach was used successfully in a high percentage of patients who presented with a variety of DA. The clinical experience presented herein indicates that this device may be particularly useful in the emergency and elective treatment of patients in whom intubation with a rigid laryngoscope has failed and in the treatment of patients with immobilized cervical spines.
Interaction of Protamine with α- and β-Adrenoceptor Stimulations in Rat Myocardium
Authors: David Jean-Stéphane , Vivien Benoît , Lecarpentier Yves , Coriat Pierre , Riou Bruno 
Published: November 2003

Background
Protamine alters the inotropic responses to beta-adrenoceptor stimulation, but its mechanism of action is not well-understood. Moreover, its interaction with alpha-adrenoceptor stimulation and the lusitropic (relaxation) response to beta-adrenoceptor stimulation remain unknown.

Methods
The effects of protamine (10 or 100 microg/ml) on the responses induced by phenylephrine and isoproterenol were studied in rat left ventricular papillary muscles. Inotropic and lusitropic effects were studied under low and high loads. The authors also studied the interaction of protamine with forskolin (50 microm) and dibutyryl 3',5'-cAMP (0.5 mm). Data are mean percentage of baseline active force +/- SD.

Results
In control groups, phenylephrine (135 +/- 17%, P < 0.05) and isoproterenol (185 +/- 44%, P < 0.05) induced a positive inotropic effect. Isoproterenol induced positive lusitropic effects under low and high loads. Protamine abolished the inotropic responses to alpha- (102 +/- 23%, not significant) and beta-adrenoceptor stimulations (99 +/- 17%, not significant) but did not modify the lusitropic responses to isoproterenol. Protamine abolished the inotropic responses to forskolin (89 +/- 6 vs. 154 +/- 20%, P < 0.05) and markedly decreased that of dibutyryl 3',5'-cAMP (132 +/- 31 vs. 167 +/- 30%, P < 0.05) but did not modify their lusitropic responses.

Conclusions
Protamine abolished the inotropic responses to alpha- and beta-adrenoceptor stimulations but preserved the lusitropic responses to beta-adrenoceptor stimulation. Although protamine may act at several sites on the adrenoceptor stimulation cascade, one of its main sites of action is situated downstream from cAMP-mediated phosphorylation.
Differential Sensitivity of Abdominal Muscles and the Diaphragm to Mivacurium
Authors: Kirov Krassen , Motamed Cyrus , Dhonneur Gilles 
Published: November 2003

Background
Respiratory muscles are considered to be more resistant to muscle relaxants as compared with peripheral muscles. However, the relative sensitivity of respiratory muscles participating to the pump function has not been compared. We used electromyography to compare pharmacodynamic parameters of the diaphragm and abdominal muscles after mivacurium.

Methods
Forty adults undergoing elective surgery were randomly allocated in five dosing groups of mivacurium (50, 100, 150, 200, and 250 microg/kg). Patients anesthetized with propofol and fentanyl underwent intubation without relaxants. Anesthesia was maintained with nitrous oxide and propofol. The right phrenic nerve, the left 10th intercostal nerve, and the ulnar nerve were stimulated. Electromyography of the diaphragm and abdominal muscles was recorded from surface electrodes. Mechanomyography was used to measure adductor pollicis evoked contraction. After a 5-min stable recording period, patients received a single intravenous bolus (20 s) dose of mivacurium. By using log dose-probit effect regression analysis, dose-response curves were constructed. Effective doses and 95% confidence intervals were derived for the diaphragm and abdominal muscles and were compared.

Results
The dose-response regression line of abdominal muscles differed from that of the diaphragm. Calculated ED50 and ED90 were higher for the diaphragm than for the abdominal muscles (104 [82-127] and 196 [177-213] microg/kg, and 67 [51-82] and 161 [143-181] microg/kg, respectively). The onset of block was faster and recovery of control responses were shorter at the diaphragm than at the abdominal muscles.

Conclusion
Diaphragm and abdominal muscles have differential sensitivity to mivacurium. The diaphragm is more resistant to mivacurium than abdominal muscles are.
The Effect of Prone Positioning on Intraocular Pressure in Anesthetized Patients
Authors: Cheng Mary Ann , Todorov Alexandre , Tempelhoff René , McHugh Tom , Crowder C. Michael , Lauryssen Carl 
Published: November 2003

Background
Ocular perfusion pressure is commonly defined as mean arterial pressure minus intraocular pressure (IOP). Changes in mean arterial pressure or IOP can affect ocular perfusion pressure. IOP has not been studied in this context in the prone anesthetized patient.

Methods
After institutional human studies committee approval and informed consent, 20 patients (American Society of Anesthesiologists physical status I-III) without eye disease who were scheduled for spine surgery in the prone position were enrolled. IOP was measured with a Tono-pen XL handheld tonometer at five time points: awake supine (baseline), anesthetized (supine 1), anesthetized prone (prone 1), anesthetized prone at conclusion of case (prone 2), and anesthetized supine before wake-up (supine 2). Anesthetic protocol was standardized. The head was positioned with a pinned head-holder. Data were analyzed with repeated-measures analysis of variance and paired t test.

Results
Supine 1 IOP (13 +/- 1 mmHg) decreased from baseline (19 +/- 1 mmHg) (P < 0.05). Prone 1 IOP (27 +/- 2 mmHg) increased in comparison with baseline (P < 0.05) and supine 1 (P < 0.05). Prone 2 IOP (40 +/- 2 mmHg) was measured after 320 +/- 107 min in the prone position and was significantly increased in comparison with all previous measurements (P < 0.05). Supine 2 IOP (31 +/- 2 mmHg) decreased in comparison with prone 2 IOP (P < 0.05) but was relatively elevated in comparison with supine 1 and baseline (P < 0.05). Hemodynamic and ventilatory parameters remained unchanged during the prone period.

Conclusions
Prone positioning increases IOP during anesthesia. Ocular perfusion pressure could therefore decrease, despite maintenance of normotension.