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At least 325 records · Page 18Linked to original sources
PubMed2004

Evaluation of serial haemodynamic changes during coronary artery anastomoses in patients undergoing off-pump coronary artery bypass graft surgery: initial experiences using two deep pericardial stay sutures and octopus tissue stabilizer.

OBJECTIVE: This study was designed to evaluate the serial haemodynamic changes during coronary artery anastomoses using two deep pericardial stay sutures and octopus tissue stabilizer in patients undergoing initial experiences of off-pump coronary artery bypass graft surgery (OPCAB) using continuous cardiac output and mixed venous oxygen saturation (SvO(2)) monitoring. METHODS: With IRB approval, thirty patients undergoing OPCAB were studied. Pulmonary artery catheter (PAC) for continuous cardiac output and SvO(2) monitoring was inserted before anaesthesia. Haemodynamic measurements were recorded after pericardiotomy for baseline value. During each coronary artery anastomosis, haemodynamic variables were measured at 1,3,5,10, and 15 min after the application of tissue stabilizer and after the removal. Vasopressors were used to maintain mean arterial pressure (MAP) higher than 60 mmHg. RESULTS: MAP and heart rate (HR) were maintained without significant change during the anastomoses of all three arteries. Cardiac index (CI), and SvO(2) decreased significantly after stabilizer application in all three arteries. CI was below 2.5 l/min/m(2) and SvO(2) was under 70% during left circumflex artery (LCX) anastomosis. The decrease in CI and SvO(2) were significantly greater during LCX anastomosis. The increase in mean pulmonary artery pressure (MPAP) and pulmonary capillary wedge pressure (PCWP) was significant only in left anterior descending artery (LAD). Central venous pressure (CVP) increased significantly during the anastomosis of all three coronary arteries. The differences in MPAP, PCWP and CVP among the three coronary arteries were not statistically significant. The highest dose of vasoconstrictor was used during LCX anastomosis. CONCLUSIONS: When the coronary anastomoses were performed with two deep pericardial stay sutures and octopus tissue stabilizer on the beating heart, CI and SvO(2) decreased significantly during all coronary artery anastomoses immediately after the stabilizer application and the degree of reduction in CI and SvO(2) increased with time, though MAP was maintained constantly. CI and SvO(2) during LCX anastomosis were consistently below normal values. Therefore close monitoring and proper managements are needed during graft anastomoses.

Aged↗
PubMed2001

[Transesophageal echocardiography and air embolism during posterior fossa neurosurgery. Intraoperative detection in the foramen ovale].

Sitting position during neurosurgery is discussed because the risk of venous air embolism and paradoxical air embolism is increased. Preoperative transoesophageal echocardiography is proposed to screen patients with patent foramen ovale to avoid them for the sitting position. This work reported 2 patients in conflict with this screening. It is discussed the physiological principles governing the paradoxical air embolism and the actual recommended monitoring for this position.

Astrocytoma↗
PubMed2002

Anaesthesia for advanced rectal cancer patients treated with combined major resections and intraoperative radiotherapy.

BACKGROUND AND OBJECTIVE: Multimodality treatment for patients with locally advanced primary or locally recurrent rectal cancer, including high-dose preoperative external beam radiotherapy, extensive surgery and intraoperative radiation therapy, decreases the local recurrence rates and improves survival. During this aggressive operation, the anaesthesiologist is faced with potential problems such as major transfusion requirements, hypothermia, intraoperative position changes, the need to transport the patient to the intraoperative radiation therapy applicator, and the risks associated with remote monitoring of the patient during the 10 min intraoperative radiation therapy application. The anaesthetic management and perioperative results were evaluated for the anaesthetic results and the complications. METHODS: One-hundred-and-six patients undergoing the multimodality treatment between February 1994 and March 2000 for locally advanced primary (n = 50) and locally recurrent rectal cancer (n = 56) were retrospectively evaluated for their anaesthetic results and complications. RESULTS: All patients were operated upon using a combination of general and epidural anaesthesia. The average duration of anaesthesia was 6 (range 3-10.5) h and the mean blood loss 3.6 (range 0.4-14) L. All patients recovered well from anaesthesia. Two patients (2%) died in the intensive care unit (34 and 48 days postoperatively) because of adult respiratory distress syndrome following postoperative haemorrhage. Severe haemorrhage during or after the operation was significantly related with the development of adult respiratory distress syndrome (P < 0.0001). CONCLUSION: With adequate preoperative assessment and optimalization of the patient's condition, maintaining peroperative haemodynamic stability with the help of adequate remote monitoring, early and fast transfusion, and multidisciplinary communication, anaesthetic complications can be minimized.

Adult↗
PubMed2003

Reliability of perioperative SSEP recordings in spine surgery.

OBJECTIVE: The reproducibility and clinical reliability of perioperative somatosensory-evoked potentials (SSEP) were prospectively evaluated in uneventful scoliosis surgery. The influence of anesthesia owing to induction of total intravenous anesthesia (TIVA) upon preoperative SSEP and the variability of intraoperative SSEP were calculated. The potential effect of spine surgery was assessed by comparing pre- to postoperative SSEP. METHODS: A total of 2,143 pre-, intra- and postoperative tibial and median SSEP recorded in 25 patients undergoing spine surgery owing to idiopathic scoliosis were analyzed. The anesthesia protocol consisted of a computerized target controlled infusion (TCI) device for propofol and intravenous application of an opioid. RESULTS: Anesthesia induced a significant and comparable prolongation of the tibial SSEP onset, P40 and P60 latencies, while the N50 latency was less changed. Throughout anesthesia, latencies of median (onset, N20, P25 and N35) and tibial (onset, P40, N50 and P60) SSEP showed mean variations of less than 6%. The intraoperative SSEP amplitudes were less stable with a relative standard deviation of 30-40%. In uneventful spine surgery, the postoperative tibial SSEP were not significantly changed in comparison to preoperative recordings. CONCLUSIONS: By using a standardized anesthesia protocol, the impact of anesthesia on preoperative SSEP can be predicted. Furthermore, the controlled application of sedatives and analgesics allows recording of stable SSEP parameters for intraoperative monitoring purposes. As in uneventful spine surgery pre- to postoperative SSEP are unchanged the latter comparison can be applied as an additional perioperative neuromonitoring procedure to assess the influence of spine surgery or other invasive interventions on spinal cord function.

Adolescent↗
PubMedDate not supplied

Predictors and outcomes of cardiac complications following elective coronary bypass grafting.

Our objective was to determine the predictors of cardiac complications among a cohort of elective coronary artery bypass graft (CABG) surgery patients and to determine the relationship of such complications to subsequent quality of life and symptoms. A total of 248 patients were enrolled and 237 completed 6 month follow-up. The combined rate of both major and minor cardiac complications was 9.7% (n = 24). Patients in this study were evaluated preoperatively, monitored intraoperatively, followed immediately postoperatively and at 6 months. Major cardiac complications accounted for 3.6% (n = 9) and minor complications for 6% (n = 15). Using multivariable logistic regression analysis, the predictors of major cardiac complications were receiving diuretics preoperatively (p = .01) and increased time during cross-clamping (p = .006). At 6 months after surgery, 19% of the patients with postoperative cardiac complications experienced worsening of symptoms, in contrast to only 8% of those without cardiac complications (p = .03). We concluded that patients who were on preoperative diuretics and those who had longer cross-clamp times were at higher risk of cardiac complications. The majority of patients who had acute cardiac complications had improved function and symptoms at 6 months postoperatively.

Aged↗
PubMed2000

Intraoperative electromyography of the superior gluteal nerve during lateral approach to the hip for arthroplasty: a prospective study of 12 patients.

The purpose of this study was to evaluate the incidence of intraoperative superior gluteal nerve irritation and to identify specific surgical maneuvers that may harm the nerve. Continuous intraoperative electromyography (EMG) monitoring of the superior gluteal nerve-innervated muscles (gluteus medius and tensor fascia lata muscles) was performed in 12 patients undergoing total hip arthroplasty. A modified lateral approach was used, including a partial anterior osteotomy of the greater trochanter with splitting of the gluteus medius and vastus lateralis muscles. All patients had a clinical follow-up examination 1 year postoperatively to evaluate abductor muscle function. Irritation of the nerve occurred first during splitting of the gluteus medius muscle, then with increased gluteus medius retraction for exposure of the acetabulum, and finally during positioning of the leg for preparation of the femur. The detected EMG alterations were important because they were found in a single patient with persistent abductor muscle weakness.

Aged↗
PubMed1999

Haemodynamic changes detected during open prostatectomy and transurethral resection for benign prostatic hyperplasia.

To detect possible intraoperative haemodynamic differences, 60 patients undergoing transurethral (n = 18) or open prostatectomy (n = 42) for benign prostatic hyperplasia were evaluated. The same type of general anaesthesia was used in the two groups. Data, including temperature and cardiac output, were collected at five standard times during the procedures. No significant differences were found between the two groups. However, in all patients, irrespective of the operation, significant decreases in cardiac output and increases in systemic resistance occurred during surgery. Body temperature showed a mild, insignificant decrease, which may play a role in determining the mild haemodynamic derangement observed in all patients. Our patients subjected to open prostatectomy and transurethral resection presented the same kind of haemodynamic derangement, with no significant differences. Therefore it seems unlikely that the kind of surgery could play a relevant role in the late mortality rate of these patients.

Aged↗
PubMed1997

Effect of extradural analgesia on the paradoxical arousal response of the electroencephalogram.

Despite widespread recognition of the potential role of the processed electroencephalogram (pEEG) as a monitor of depth of anaesthesia, few studies have examined the effects of surgical stimuli on the intraoperative pEEG. Two groups of gynaecological patients (n = 10 in each group), with or without pre-incisional extradural analgesia, undergoing gynaecological laparotomy under nitrous oxide and isoflurane anaesthesia were monitored with routine haemodynamic observations and pEEG. Patients who received pre-incisional extradural analgesia showed no significant changes in pEEG variables during surgery (mean spectral edge frequency 95 percentile (SEF95) 13.3 (SD 1.4) Hz), whereas in all patients without pre-incisional extradural analgesia, a significant decrease in SEF95 was noted (6.5 (1.1) Hz after incision compared with a pre-incisional value of 12.5 (1.4) Hz) together with an increase in arterial pressure (paradoxical response). In the latter group, SEF95 and arterial pressure returned to pre-incisional values after extradural analgesia was established during operation. During emergence from anaesthesia, both groups showed a significant increase in SEF95 (25.7 (1.4) Hz). This study suggests that intraoperative pEEG arousal response was different from changes detected when anaesthesia was terminated at the end of surgery. Surgical stimuli in the absence of adequate analgesia induced a paradoxical arousal response.

Adult↗
PubMed2004

Effects of mid-line thoracotomy on the interaction between mechanical ventilation and cardiac filling during cardiac surgery.

BACKGROUND: Mid-line thoracotomy is a standard approach for cardiac surgery. However, little is known how this surgical approach affects the interaction between the circulation and mechanical ventilation. We studied how mid-line thoracotomy affects cardiac filling volumes and cardiovascular haemodynamics, particularly variations in stroke volume and pulse pressure caused by mechanical ventilation. METHODS: We studied 19 patients during elective coronary artery bypass surgery. Before and after mid-line thoracotomy, we measured arterial pressure, cardiac index (CI) and global end-diastolic volume index (GEDVI) by thermodilution, left ventricular end-diastolic area index (LVEDAI) by transoesophageal echocardiography and the variations in left ventricular stroke volume and pulse pressure during ventilation by arterial pulse contour analysis. RESULTS: After thoracotomy, CI increased from 2.3 (0.4) to 2.9 (0.6) litre min(-1) m(-2), GEDVI increased from 605 (110) to 640 (94) litre min(-1) m(-2), and LVEDAI increased from 9.2 (3.7) to 11.2 (4.1) cm(2) m(-2). All these changes were significant. In contrast, stroke volume variation (SVV) decreased from 10 (3) to 6 (2)% and pulse pressure variation (PPV) decreased from 11 (3) to 5 (3)%. Before thoracotomy, SVV and PPV significantly correlated with GEDVI (both P<0.01). When the chest was open, similar significant correlations of SVV (P<0.001) and PPV (P<0.01) were found with GEDVI. CONCLUSION: Thoracotomy increases cardiac filling and preload. Further, thoracotomy reduces the effect of mechanical ventilation on left ventricular stroke volume. However, also under open chest conditions, SVV and PPV are preload-dependent.

Adult↗
PubMed2005

Changes in the effect of propofol in response to altered plasma protein binding during normothermic cardiopulmonary bypass.

BACKGROUND: During normothermic cardiopulmonary bypass (CPB), the effect on propofol pharmacokinetics of changes in its binding to plasma proteins is consistent with the predictions of the well-stirred model of hepatic elimination for nonrestrictively cleared drug. However, whether changes in binding lead to clinically significant changes in the drug effect remains unclear. The purpose of this study was to assess changes in the drug effect of propofol in response to altered plasma binding using quantitative EEG measurements. METHODS: Thirty patients undergoing cardiac surgery were assigned randomly to receive propofol infusions at 4 (Group P-4) or 6 (Group P-6) mg kg(-1) h(-1) during surgery. The concentration of propofol in blood samples, collected from the radial artery at predetermined intervals, was determined by HPLC. The unbound fraction of drug in plasma was estimated using equilibrium dialysis. Bispectral index (BIS) and burst suppression ratio (BSR) were measured at the time blood samples were collected. RESULTS: The total concentration of propofol in blood was unchanged during CPB relative to the pre-CPB value in both groups. However, the fraction of unbound propofol in blood increased by 2-fold during CPB. While BIS values were unchanged during CPB in Group P-4, there was a slight, but significant, decrease in Group P-6. In both groups, BSR significantly increased during CPB. BIS values showed a weak correlation with the concentration of unbound propofol (r(2)=0.19, P<0.001). BSR showed a moderate correlation with the concentration of unbound propofol (r(2)=0.56, P<0.001). CONCLUSIONS: The anaesthetic effect of propofol significantly increased during CPB without any alteration in the total drug concentration. The enhanced efficacy may be caused by a reduction in plasma binding of the drug.

Adult↗
PubMed2006

Adenosine-induced cardiac arrest and EEG changes in patients with thoracic aorta endovascular repair.

BACKGROUND: We studied haemodynamic and metabolic variables, and cerebral function after cardiac arrest induced by high dose of adenosine in patients undergoing thoracic aorta endovascular repair. METHODS: Arterial blood pressure, blood gas values and EEG were recorded continuously in 15 patients undergoing anaesthesia (isoflurane) for endovascular thoracic aorta repair. Cardiac arrest was induced by different doses of adenosine (Adrekar, Sanofi-Synthelabo, Berlin, Germany; 0.4-1.8 mg kg(-1) body weight). Serum concentrations of neurone-specific enolase (NSE) were determined before and after stent graft implantation. Neurological function was assessed before and after surgery. RESULTS: After adenosine, the heart beat stopped immediately for 18-58 s in close relation to the adenosine dose. EEG power was significantly reduced to -57%, but reached normal values within 5 min after cardiac arrest. In particular, the fast alpha- and beta-EEG-frequencies sensitively reflected patients' EEG activity during the procedure. No intraoperative increases in NSE concentrations, and no neurological dysfunctions after surgery, were observed. CONCLUSION: After adenosine-induced cardiac arrest, changes in haemodynamic variables and EEG power spectra reversed completely within 1 and 5 min, respectively, without persistent brain dysfunction after stent graft implantation.

Adenosine↗
PubMed1994

Deliberate mild intraoperative hypothermia for craniotomy.

BACKGROUND: Despite enthusiasm for the use of mild hypothermia during neurosurgical procedures, this therapy has not been evaluated systematically. This study examined the feasibility and safety of deliberate mild hypothermia and rewarming. METHODS: Thirty patients scheduled for craniotomy were assigned to either a normothermic or mildly hypothermic group. Tympanic membrane temperature was monitored at anesthetic induction, throughout the isoflurane-fentanyl-N2O-O2 anesthetic, and for 18 h postoperatively. Normothermic patients were warmed to 36.5-37.0 degrees C after an initial temperature decrease, and hypothermic patients were cooled to 35 degrees C. In the hypothermic group temperatures were allowed to drift to 34.5 degrees C before rewarming was initiated. Water blankets and convective heating devices were used to cool and rewarm. RESULTS: The minimum temperature achieved by the hypothermic group was 34.3 +/- 0.4 degrees C. Cooling occurred at a rate of 1.0 +/- 0.4 degrees C/h. Rewarming took place at a rate of 0.7 +/- 0.6 degrees C/h (range 0.1-1.8) in the hypothermic group. Hypothermia did not delay emergence from anesthesia (20 +/- 15 min) compared with normothermia (15 +/- 15 min, P = .45). Mean temperature upon intensive care unit admission was 35.8 +/- 1.0 degrees C for the hypothermic group and 37.1 +/- 0.5 degrees C for the normothermic group (P < 0.0001). The hypothermic patients had more postoperative shivering. From 8 to 18 h postoperatively the temperatures of the two groups were similar except for a slightly greater temperature in the hypothermic patients at 12 h (37.6 +/- 0.5 vs. 37.3 +/- 0.4 degrees C, P = .029). CONCLUSIONS: Although deliberate mild hypothermia is easily achieved intraoperatively, complete rewarming may be difficult to attain during craniotomy with current methods. In addition to the need for determining whether deliberate mild hypothermia confers cerebral protection in humans, the potential risks of the therapy need to be further characterized.

Aged↗
PubMed1996

Myogenic motor-evoked potential monitoring using partial neuromuscular blockade in surgery of the spine.

STUDY DESIGN: The authors analyzed motor-evoked potentials using transcranial electrical cortical stimulation during spinal surgery in 40 patients under conditions of partial neuromuscular blockade. OBJECTIVES: The results were used to investigate the utility of motor-evoked potential monitoring to prevent neurologic injury in spinal surgery. SUMMARY OF BACKGROUND DATA: Noninvasive transcranial electrical motor-evoked potentials are reportedly effective in predicting postoperative spinal cord deficits caused by intraoperative occurrences. However, the sensitivity and specificity of these predictions have not been assessed under conditions of partial neuromuscular blockade during a wide variety of surgical procedures. METHODS: Compound muscle action potentials were recorded at the tibialis anterior muscle while general anesthesia was maintained with nitrous oxide, etomidate, and sufentanil. Surgery was performed at all spinal levels for a variety of diagnoses. RESULTS: Reference motor-evoked potential amplitudes, measured after induction of partial neuromuscular blockade, ranged from 25 to 7562 microV (median, 600 microV). Variation in intraoperative motor-evoked potential amplitude ranged from signal loss to a 3440% increase. A decrease to less than 20% of the individual reference value for motor-evoked potential amplitude occurred at least once in nine patients (22.5%) but as not associated with postoperative motor deficits. Two patients who had loss of motor-evoked potential signal without recovery did have postoperative motor deficits. Motor-evoked potentials predicted postoperative motor improvement in six patients. An improvement threshold of 160% of the reference amplitude predicted postoperative motor improvement with 100% sensitivity and 81% specificity. CONCLUSIONS: The authors support the utility of recording transcranial electrical motor-evoked potentials in spinal surgery under partial neuromuscular blockade. Recovery of lost motor-evoked potentials was not associated with postoperative motor deficits, whereas non-recovery of lost motor-evoked potentials was.

Adolescent↗
PubMed2000

A new frontier: magnetic resonance imaging-operating room.

Developments in technology have led to the merger of two distinct environments, that of magnetic resonance imaging and that of the operating room. The major advantage of this merger for neurosurgical procedures is the ability to perform real-time imaging to help guide surgery. This review discusses the role of the anesthesiologist in the planning and administration of safe anesthesia in this new and challenging environment.

Anesthesia↗
PubMed2006

Awareness under anesthesia during electroconvulsive therapy treatment.

Awareness under general anesthesia is an infrequent phenomenon during which patients become cognizant of some or all events during surgery or any procedure conducted under anesthesia. Awareness experiences can frighten patients and impact their memories in ways that can leave emotional and psychological problems that, over time, may develop into posttraumatic stress disorder. Inadequate anesthesia has been implicated in the causation of awareness under anesthesia. We report first case of patient gaining awareness while under anesthesia undergoing electroconvulsive therapy treatment. The case reported here would suggest that clinicians administering electroconvulsive therapy should be alert to the possibility of awareness during anesthesia and take appropriate measures to maintain professional conduct and adjust anesthetic medication dose to avoid reoccurrence.

Anesthesia, General↗
PubMed2006

Intraoperative somatosensory evoked potential monitoring during cervical spine corpectomy surgery: experience with 508 cases.

STUDY DESIGN: Retrospective review. OBJECTIVES: To review consecutive cases of cervical spine corpectomy surgery performed with intraoperative somatosensory-evoked potential (SSEP) monitoring. SUMMARY OF BACKGROUND DATA: There is controversy about the utility of SSEP monitoring during anterior cervical spine surgery. There is no study in the literature that has specifically evaluated the utility of SSEP monitoring for cervical spine corpectomy surgery. METHODS: Intraoperative SSEP tracings for 508 patients (average age, 55.7 years; 268 male, 240 female) who underwent anterior cervical fusion with single-level or multilevel corpectomies were reviewed. Intraoperative and postoperative records were analyzed to determine if any new neurologic deficits developed when the patients woke up from anesthesia. RESULTS: The overall incidence of a new postoperative neurologic deficit in this series of patients was 2.4% (11 with nerve root injury, 1 with quadriplegia). The incidence of significant SSEP changes was 5.3% (27 of 508 patients). The most common identifiable cause of SSEP changes was hypotension, and the most common neurologic deficit was deltoid (C5) weakness. One patient had irreversible SSEP changes, and he woke up with new-onset quadriplegia. The calculated sensitivity and specificity of intraoperative SSEP monitoring for detecting impending or resultant intraoperative iatrogenic neurologic injury were 77.1% and 100%, respectively. However, if the isolated nerve root injuries are removed from the analysis, then both the calculated sensitivity and the negative predictive values were 100%. CONCLUSIONS: Intraoperative SSEP monitoring can alert the surgeon to adverse iatrogenic intraoperative events with potential for neurologic injury. Most SSEP signal changes are reversible and do not result in a clinical deficit. Isolated nerve root injury appears to be the most common iatrogenic intraoperative injury during cervical spine corpectomy surgery.

Adult↗
PubMed1986

Intravenous fluids in minor surgery. Their effect on recovery from anaesthesia.

The value of infusing a total of 2 litres of intravenous fluids intra- and postoperatively was assessed in 212 fasting patients undergoing minor surgery procedures. The treated patients (108) recovered from the effects of surgery and anaesthesia more quickly than patients without fluids (104). The results of improved quality of the postoperative recovery, a shorter hospital stay and earlier return to work, especially in those patients who had some difficulty in recovering from anaesthesia on previous occasions, encourages the more frequent use of intravenous fluids in minor surgery.

Adolescent↗