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PubMedDate not supplied

Systemic effects of intraoperative autotransfusion.

The hematological effects of autotransfusion have not been well characterized. A canine model was used in which a controlled 2000-ml blood loss was effected into the open peritoneum and replaced either by autotransfusion, using one of two devices, or by homologous transfusion. In each group hematological data were collected before, during, and after the operation. None of the parameters measured showed significant differences between the two autotransfused groups. However, intraoperative values for prothrombin time and activated partial thromboplastin time were significantly prolonged in the autotransfused groups compared with the homologous transfusion group. Fibrinogen levels and platelet counts fell significantly from baseline levels in the intraoperative period, but rose above even baseline levels postoperatively. White blood cell counts remained unchanged intraoperatively, but rose significantly and remained elevated at 24 hours and 1 week. No significant differences exist between the effects produced by the two autotransfusion systems. It is clear that prothrombin time and activated partial thromboplastin time are prolonged intraoperatively in the autotransfusion groups, whereas these parameters are unaffected by homologous transfusion.

Animals↗
PubMed1999

Does intensive perioperative dialysis improve the results of coronary artery bypass grafting in haemodialysed patients?

BACKGROUND: Between January 1996 and April 1998, 17 chronic haemodialysed patients underwent coronary artery bypass grafting (CABG). Two of them simultaneously had valve replacement. METHODS: Except for two cases in which CABG was performed in an emergency, 15 patients (CRF group) received 3 consecutive days of haemodialysis in the preoperative period, intraoperative haemodialysis connected to cardiac pulmonary bypass (CPB) and continuous hemodiafiltration in the early postoperative period. The perioperative clinical parameters of the CRF group were compared with those of 17 age-matched patients with normal renal function undergoing CABG as the control (NRF group). RESULTS: When the perioperative variables were compared, no significant differences were seen in total operation time and CPB time, but we noted significant increases in the mean volume of transfused blood in the 6 perioperative days, postoperative intubation time, postoperative fasting time, and time spent in the intensive care unit. Levels of central venous pressure, systolic blood pressure, respiratory index (PaO2/FiO2) and daily fluid balance of the CRF group were the same as the control group in the early postoperative period. In addition, the levels of serum creatinine, urea nitrogen, potassium and hematocrit of CRF group remained almost constant in the early postoperative period. After all, the hospital morbidity of the CRF group was not more serious than that of the NRF group, and hospital mortality of the CRF and NRF groups was 0%. CONCLUSIONS: Our intensive perioperative dialysis programme could successfully manage the perioperative clinical course of haemodialysed patients undergoing CABG.

Coronary Artery Bypass↗
PubMed1999

The in vitro effects of isoflurane, sevoflurane, and propofol on platelet aggregation.

UNLABELLED: We studied the in vitro effects of sevoflurane, isoflurane, and propofol anesthesia on platelet function. Thirty patients undergoing minor surgical procedures were divided into three groups (n = 10 each). Induction of anesthesia was achieved by using 5 mg/kg thiopental i.v., and 0.1 mg/kg vecuronium i.v. was used for muscle relaxation. Anesthesia maintenance was provided by sevoflurane in the first, isoflurane in the second, and propofol infusion in the third group with 70% N2O in O2. Hemoglobin, hematocrit, thrombocyte count, prothrombin time, activated partial thromboplastin time, international normalized ratio, arterial pH, von Willebrand factor, viscosity, platelet aggregation, and bleeding time were measured 1 h pre-, intra-, and postanesthesia. There was no difference among the platelet aggregation ratios of the pre-, intra-, and postoperative periods in the isoflurane group. The aggregation ratios in the sevoflurane and propofol groups were significantly reduced at intraoperative periods compared with preoperative values. Diminished aggregation values were also found 1 h postoperatively compared with the control values in the sevoflurane and propofol groups. We conclude that, in patients with a bleeding tendency during the intra- and early postoperative period, isoflurane may be preferred as a general anesthetic. IMPLICATIONS: In our study, using vacuum-operated tubes, we demonstrated that sevoflurane and propofol had a significant inhibitory effect on intraoperative and early postoperative platelet aggregation, whereas isoflurane had no effect. Therefore, isoflurane may be preferred as a general anesthetic in patients with a clinically relevant bleeding tendency.

Adult↗
PubMed2002

Audit of intraoperative and early postoperative complications after introduction of mesorectal excision for rectal cancer.

OBJECTIVE: To compare complication rates after rectal resection using a conventional surgical technique (1983-1992) and mesorectal excision (1993-2000), and to find out whether the rate of complications changed with time after the introduction of mesorectal excision. DESIGN: Prospective, observational study. SETTING: University hospital, Norway. PATIENTS: All patients who had rectal resections for cancer in the period 1983-2000. INTERVENTIONS: In the conventional surgery period 217, and in the mesorectal excision period 176, patients had rectal resections. The mesorectal excision period was split in two, the early and the late mesorectal excision period, 88 rectal resections being performed in each period. Total mesorectal excision was done in 118 patients, and partial mesorectal excision in 58. MAIN OUTCOME MEASURES: Major surgical complications in both periods; intraoperative bleeding, transfusions during the hospital stay, and cardiovascular complications in the mesorectal excision period. RESULTS: 23/217 (11%) developed major surgical complications in the conventional surgery period, compared with 17/88 (19%) in the early mesorectal excision period (p = 0.04). This was caused by an increased incidence of anastomotic leaks after low anterior resection, being 11/122 (9%) in the conventional surgery period and 12/52 (23%) in the early mesorectal excision period (p = 0.01). The incidence of anastomotic leaks declined to 5/61 (8%) in the late mesorectal excision period (p = 0.03). Multiple regression analysis identified a low anastomosis, major bleeding, and age over 75 years as significant risk factors for the development of anastomotic leaks. Major intraoperative bleeding occurred in 36/84 (43%) of the patients in the early and 22/82 (27%) in the late mesorectal period (p = 0.04). Blood transfusions were given to 61/84 (74%) in the early mesorectal period and 41/82 (50%) in the late period (p < 0.01). CONCLUSIONS: The incidence of surgical complications increased significantly after the introduction of mesorectal excision, but declined with time.

Adult↗
PubMed2005

Analgesic effects of epidurally administered levogyral ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy.

OBJECTIVE: To evaluate the analgesic and adverse effects of epidurally administered levogyral (S[+]) ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy. ANIMALS: 30 dogs scheduled for ovariohysterectomy. PROCEDURE: Dogs were randomly allocated to 1 of 3 groups. Dogs in group 1 received S(+) ketamine (1 mg/kg), dogs in group 2 received S(+) ketamine (0.5 mg/kg) and morphine (0.05 mg/kg), and dogs in group 3 received S(+) ketamine (1 mg/kg) and morphine (0.025 mg/kg). The skin was incised 15 minutes after epidural administration of analgesics. Heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), oxygen saturation as measured by pulse oximetry, and arterial blood gases were obtained before anesthesia, 15 minutes after epidural administration of analgesics, 15 and 30 minutes after initiation of surgery, and at the end of surgery. During the intraoperative period, an increase of > or =20% in baseline values for HR, RR, and SBP was considered a sign of intraoperative pain. Signs of pain and adverse effects were assessed at 2, 4, and 8 hours postoperatively. RESULTS: There were no significant differences in intraoperative or postoperative measurements among the 3 groups. No dogs had intraoperative signs of pain. Mean postoperative pain assessment scores were <3.5 in all 3 groups. Salivation was the most frequent adverse effect in dogs in groups 1 and 3, and sedation occurred more frequently in dogs in groups 2 and 3. CONCLUSIONS AND CLINICAL RELEVANCE: All 3 analgesic regimens provided good respiratory and cardiovascular stability intraoperatively and adequate postoperative analgesia with minimal adverse effects.

Analgesia, Epidural↗
PubMed1991

[The ambulatory anesthesia unit: a problem of organization].

A specialized unit in outpatient anaesthesia and surgery needs an adapted planning. During the preoperative period, it is particularly important to preserve the time of the patients. Different types of structures are possible for the intraoperative period depending on their degree of independence to a hospital. The hospital based unit, with independent facilities, offers various advantages. Its size and its conception must be adapted to the constraints of ambulatory technique, and to the expected needs. During the postoperative period, a special medical organization must be planned to help the patient if necessary. The part of the secretarial work is important for the success of such a unit. Its efficiency may be improved by computerised treatment of part of the information.

Ambulatory Surgical Procedures↗
PubMed2001

Ondansetron is no more effective than supplemental intraoperative oxygen for prevention of postoperative nausea and vomiting.

UNLABELLED: Supplemental oxygen maintained during and for 2 h after colon resection halves the incidence of nausea and vomiting. Whether supplemental oxygen restricted to the intraoperative period is sufficient remains unknown. Similarly, the relative efficacy of supplemental oxygen and ondansetron is unknown. We tested the hypothesis that intraoperative supplemental oxygen reduces the incidence of postoperative nausea and vomiting. Patients (n = 240) undergoing gynecological laparoscopy were given a standardized isoflurane anesthetic. After induction, they were randomly assigned to the following three groups: routine oxygen administration with 30% oxygen, balance nitrogen (30% Oxygen group), supplemental oxygen administration with 80% oxygen, balance nitrogen (80% Oxygen group), and Ondansetron 8 mg (immediately after induction), combined with 30% oxygen, balance nitrogen (Ondansetron group). The overall incidence of nausea and/or vomiting during the initial 24 postoperative h was 44% in the patients assigned to 30% oxygen and 30% in the Ondansetron group, but only 22% in those given 80% oxygen. The incidence was thus halved by supplemental oxygen and was significantly less than with 30% oxygen. There were, however, no significant differences between the 30% oxygen and ondansetron groups, or between the ondansetron and 80% oxygen groups. We conclude that supplemental oxygen effectively prevents postoperative nausea and vomiting after gynecological laparoscopic surgery; furthermore, ondansetron is no more effective than supplemental oxygen. IMPLICATIONS: Supplemental oxygen reduces the risk of postoperative nausea and vomiting (PONV) as well or better than 8 mg of ondansetron. Because oxygen is inexpensive and essentially risk-free, supplemental oxygen is a preferable method of reducing PONV.

Adult↗
PubMed1986

Cefamandole distribution in serum, adipose tissue, and wound drainage in morbidly obese patients.

Distribution and elimination of cefamandole 2 g iv were studied in 11 morbidly obese patients during a gastric bypass operation and again on the first postoperative day. Serum, subcutaneous adipose tissue, wound drainage, and urine were analyzed by high performance liquid chromatography for cefamandole and pharmacokinetic parameters from the intraoperative period were compared to those obtained postoperatively. Total body clearance was significantly greater (p less than 0.001) postoperatively (297 ml/min) than intraoperatively (254 ml/min). Volume changes were unpredictable but the elimination rate constant tended to increase postoperatively. Renal clearance and percentage of urinary recovery were significantly increased (p less than 0.01) postoperatively. The patients had a mean (+/- SD) volume of the central compartment of 10.3 (+/- 2.3) L, volume at steady state of 18.3 (+/- 3.9) L, and elimination rate constant of 1.67 (+/- 0.63) h-1. Tissue concentrations of cefamandole were highest during the first hour after drug administration and were less than 1 microgram/g after 3.5 hours. Mean wound drainage concentrations ranged between 10 and 12 micrograms/ml during a dosing interval and dropped to 7 micrograms/ml 12 hours after the last dose. Intraoperative dosing of cefamandole is required to maintain subcutaneous adipose tissue concentrations greater than 1 microgram/g during procedures longer than three hours in morbidly obese patients. A postoperative dose of cefamandole 2 g iv q6h will provide sustained and therapeutic concentrations in the wound drainage of morbidly obese patients.

Adipose Tissue↗
PubMed2001

Diagnosis of progressive compression of the aortic true lumen with intraoperative transesophageal echocardiography during repair of dissection of thoracic aorta--a case report.

We report an incident of progressive compression of the true lumen of aorta which happened immediately after cardiopulmonary bypass (CPB) and was diagnosed with intraoperative transesophageal echocardiography (TEE) in a patient undergoing an emergent repair of type A aortic dissection under femoral perfusion. During the CPB period, intraoperative TEE revealed gradual expansion of the false lumen which nearly obstructed the true lumen of the dissected aorta. The possible mechanism was related with distension of the false lumen by a dominant flow from retrograde femoral perfusion of CPB. With the application of intraoperative TEE, we could easily detect the hemodynamic changes of thoracic aorta and find the real causes so as to solve the perfusion abnormalities.

Adult↗
PubMed2002

Role of dopamine in renal dysfunction during laparoscopic surgery.

BACKGROUND: Sympathetic vascular insult and hemodynamic changes represent the most reliable explanation of renal impairment resulting from acute intraabdominal pressure. We evaluated the effects of low-dose dopamine administration during a long-lasting surgical laparoscopic procedure. METHODS: For this study 40, patients submitted to a colorectal laparoscopic procedure with 15 mmHg of intraabdominal pressure were randomly allocated to two groups: 20 receiving 2 mg/kg/min of dopamine and 20 receiving the same perfusion of saline. Hemodynamic parameters, renal function, urinary output, and creatinine clearance, were studied. RESULTS: The hemodynamic parameters were similar in both groups. The urinary output decreased during the intraoperative period only the saline group (p = 0.4). Then 2 h postoperatively, it increased in both groups, and no statistically significant differences were found between the groups. The creatinine clearance decreased in both groups during the intraoperative time, but it was worse in the saline group (-28 +/- 120 vs -194 +/- 106; p = 0.022). During the postoperative period, both groups showed improvement, but in control group the values remained lower than at baseline (p = 0.04), and significantly lower than in the dopamine group (230 +/- 337 vs 100 +/- 192; p = 0.012). CONCLUSIONS: An intrabdominal pressure of 15 mmHg induces a time-limited renal dysfunction, and low doses of dopamine could prevent this undesirable effect.

Colorectal Neoplasms↗
PubMed1992

Effects of intraoperative progress reports on anxiety of elective surgical patients' family members.

The purpose of this experimental study was to examine the effects of intraoperative progress reports on family members' state anxiety level (STAI S-Anxiety), mean arterial pressure (MAP), and heart rate during elective surgical procedures. Family members of randomly selected surgical patients were eligible to participate. Control group family members (n = 50) received usual care. Family members in the experimental group (n = 50) received a 5- to 10-minute progress report protocol about halfway through a surgical procedure. Families' STAI S-Anxiety scores, MAP, and heart rates were compared between the control and experimental groups using multivariate analysis of variance (MANOVA). Family members in the experimental group reported lower STAI S-Anxiety scores (p < .001), and had significantly lower MAP and heart rates than did the control group (p < .001). Progress reports appear to be a beneficial nursing intervention for reducing anxiety in family members during the intraoperative period.

Adolescent↗
PubMed1989

[Cytomorphological characteristics and verification of tumors of the adipose tissue].

Analysis of histo-cytologic findings in 171 cases with various tumors of the fatty tissue has shown that the cytograms of such tumors are sufficiently specific, this permitting a correct identification of the type of involvement from the puncture biopsy specimen in 81% of cases and from impressions in 92.3%, and helping diagnose the histologic variety in 28 and 57% of cases, respectively. Therefore, cytologic examinations of puncture biopsy specimens and impressions of the soft tissue tumors may become an obligatory component of a multiple-modality diagnosis, in both preoperative interventions and in the intraoperative period.

Adipose Tissue↗
PubMed2003

The dilemma of immediate preoperative hypertension: to treat and operate, or to postpone surgery?

STUDY OBJECTIVE: To evaluate the efficacy and complications of immediate preoperative reduction of arterial blood pressure (BP) in patients with well-controlled hypertension but with diastolic blood pressure (DBP) between 110 and 130 mmHg on arrival at the operating room (OR). DESIGN: Prospective, randomized, large-sample study. SETTING: University-affiliated, 550-bed community hospital. PATIENTS: 989 patients with well-controlled hypertension, who were scheduled for surgery, and who had no previous myocardial infarction, unstable or severe angina pectoris, renal failure, pregnancy induced hypertension, left ventricular hypertrophy, previous coronary revascularization, aortic stenosis, preoperative dysrhythmias, conduction defects, or stroke. INTERVENTIONS: Patients with DBP between 110 and 130 mmHg were randomly allocated to two groups: 400 patients in the control group and 589 patients serving as the study group. The control group had their surgery postponed and they remained in hospital for BP control, and the study patients received 10 mg of nifedipine intranasally delivered. The patients were observed for cardiovascular and neurological complications during the intraoperative period and over the first three postoperative days. MEASUREMENTS AND MAIN RESULTS: The two groups were similar in age, gender, type of surgery, duration of anesthesia, and intraoperative fluid administration. There were no statistically significant differences in postoperative complications. The hospitalization time was considerable shorter in the study group than in the control group. CONCLUSIONS: Immediate preoperative reduction of DBP with intranasal nifedipine is safe in patients with well-controlled arterial hypertension but they presented with severe to very severe hypertension for patients in the OR. We were able to avoid unnecessary surgery postponement and attendant costs.

Administration, Intranasal↗
PubMed1997

Metyrosine and pheochromocytoma.

BACKGROUND: Severe hemodynamic instability may occur during surgery for removal of pheochromocytoma, unless there is preoperative pharmacological treatment. OBJECTIVE: To evaluate the effects of metyrosine (alpha-methyl-p-tyrosine), a catecholamine synthesis inhibitor, and alpha-blockade with prazosin or phenoxybenzamine on cardiovascular morbidity during surgery for pheochromocytoma. METHODS: A retrospective analysis was made of patients followed up at the Medical College of Georgia, Augusta, during 28 years who received metyrosine and prazosin (n = 6), metyrosine and phenoxybenzamine alone (n = 14), phenoxybenzamine alone (n = 6), or no medication (n = 7) during 3 weeks before tumor removal. The percentage of patients not requiring pressors or phentolamine during the intraoperative period as well as the perioperative peak systolic pressures and peak heart rates were estimated in each group. RESULTS: There was a significant (P < .05) increase in intraoperative peak systolic pressures without preoperative treatment (mean +/- SD, 243 +/- 40 mm Hg) vs metyrosine (mean +/- SD, 168 +/- 27 mm Hg). Ninety-five percent of patients who received metyrosine did not require pressors intraoperatively vs 50% with phenoxybenzamine alone. Eighty-one percent of patients pretreated with metyrosine did not require intraoperative phentolamine vs 33% with phenoxybenzamine alone and 29% without medications. Two patients in the no medication group died as a results of hypertensive crisis. CONCLUSIONS: The combination of alpha-metyrosine and alpha-blockade results in better blood pressure control and less need for use of antihypertensive medication or pressors during surgery, compared with the classical method of single-agent adrenergic blockade. Preoperative treatment with metyrosine along with an alpha-blocker is a useful strategy for decreasing the surgical morbidity in patients with pheochromocytoma and assumes greater importance as long as the availability of phentolamine for intraoperative use is a problem.

Adolescent↗
PubMed1996

A prospective randomized study comparing short- and intermediate-term perioperative outcome variables after spinal or general anesthesia for lumbar disk and laminectomy surgery.

General or regional anesthesia may be used for lumbar laminectomy. To determine whether one method is superior, 122 patients were randomly assigned to receive either a standard general anesthetic (GA) or spinal anesthesia (SA) supplemented with intravenous (IV) propofol sedation. Data from the intraoperative period through hospital discharge were collected and compared. Demographically, both groups were similar. Total anesthesia (131.0 +/- 4.3 vs 106.6 +/- 3.2 min) and surgical times (81.5 +/- 3.6 vs 67.1 +/- 2.8 min) were longer in the GA group. Intraoperative hemodynamics were similar between groups except that the incidence of increased blood pressure was more frequent with GA (26.2% vs 3.3%). Blood loss was less during SA (133 +/- 18 mL vs 221 +/- 32 mL). Postanesthesia care unit (PACU) heart rates and mean arterial pressures were higher in the GA group. Peak pain scores in the PACU were higher after GA compared with SA (58 +/- 4 vs 22 +/- 3) as were the number of patients who required analgesics. Severe nausea was more common in the GA group both in the PACU and during the 24 h after surgery. Analgesic requirements after discharge from the PACU, urinary retention, and days in the hospital did not differ between groups. This study suggests that SA may be superior to GA both intraoperatively and postoperatively for lumbar spine procedures lasting less than 2 h.

Adult↗
PubMed1992

Electromyographic monitoring of profound surgical muscle relaxation during cardiac anesthesia.

Quantitative assessment of neuromuscular block produced by large doses of nondepolarizing neuromuscular blocking agents during cardiac surgery is not possible with conventional methods of monitoring. Various "posttetanic responses" can, however, be elicited, even when no twitch response is present. Posttetanic responses measured by electromyography were used in this study. Twenty-four male patients undergoing coronary bypass surgery were anesthetized with sufentanil plus diazepam. Neuromuscular block was provided either with pancuronium 0.1 mg/kg or with vecuronium 0.07 mg/kg initially and supplemented with small increments when indicated. Neuromuscular block was monitored from the hypothenar muscle. The ulnar nerve was stimulated by train-of-four, with superimposed periodic tetanic stimuli to evoke posttetanic responses, once every 7 to 15 minutes. The tetanically potentiated responses were detectable during 96% +/- 3.6 (vecuronium) and during 97% +/- 3.7 (pancuronium) of the entire intraoperative period, while the non-potentiated electromyographic responses were present for less than 50% of the time. The sum (of the amplitudes) of 6 posttetanic responses is significantly (p less than 0.05) greater than the sum of 6 nonpotentiated responses and than the size of a single-peak posttetanic response when compared with the normal, nonpotentiated responses. Higher-frequency tetanic stimuli (100 or 200 Hz) produced greater posttetanic responses (p less than 0.05) than did the 50-Hz tetanic stimulus. There were only slight or no significant differences in the degree of posttetanic potentiation between pancuronium and vecuronium either before, during, or after cardiopulmonary bypass.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed2006

Perioperative fluid therapy in children: a survey of current prescribing practice.

BACKGROUND: Fluid therapy in children may be associated with iatrogenic hyponatraemia. We surveyed anaesthetists' current fluid prescribing practice during the perioperative period, departmental fluid protocols and awareness of the concerns of the Royal College of Paediatrics and Child Health (RCPCH) about the use of dextrose 4%/saline 0.18% in children. METHODS: Questionnaire survey of 477 consultant anaesthetists in two training areas in the UK. RESULTS: Responses were received from 289 anaesthetists (60.6%)--responses from the 203 consultants that anaesthetized children were analysed. A total of 67.7% did not have a local departmental policy for fluid prescription, and 58.1% were unaware of the concerns of RCPCH. A total of 60.1% of anaesthetists said that they prescribed hypotonic dextrose saline solutions in the intraoperative period and 75.2% did so in the postoperative period. Anaesthetists working in specialist paediatric hospitals were 5.1 times more likely to prescribe isotonic fluids intraoperatively than those working in district hospitals (95% CI 1.48-17.65, P=0.01), but they all prescribed hypotonic dextrose saline solutions postoperatively. The Holliday and Segar formula for maintenance fluid was quoted by 81.8% of anaesthetists; only 5.9% of anaesthetists would restrict fluids in the immediate postoperative period. Anaesthetists working in specialist paediatric hospitals were 13.2 times more likely to restrict fluids postoperatively than those working in district hospitals (95% CI 2.8-61.8, P=0.001). CONCLUSIONS: The prescription of hypotonic dextrose saline solutions by anaesthetists may be putting children at risk from iatrogenic hyponatraemia. Departmental protocols for perioperative fluid prescription in children are uncommon. We suggest that national guidance is required.

Child↗
PubMed2005

Changes in transcranial motor evoked potentials during intramedullary spinal cord tumor resection correlate with postoperative motor function.

OBJECTIVE: Intraoperative monitoring of transcranial motor evoked potentials (TcMEPs) has been investigated recently as a means of preventing motor deficits associated with resection of intramedullary spinal cord tumors (IMSCTs). In this study, we hypothesized that changes in the intraoperative MEPs during tumor resection correlate with postoperative motor function deficits. METHODS: A retrospective record review was conducted for 28 patients who underwent resection of an IMSCT using myogenic or muscle-recorded TcMEPs during a 44-month period. Intraoperative MEP recordings and results from preoperative, immediate postoperative, and subsequent follow-up neurological examinations were analyzed. RESULTS: Of the 28 patients who underwent resection of an IMSCT using TcMEPs, MEP changes occurred in 13 patients (46%). Impaired motor conduction was detected by changes in pattern and duration of the MEP waveform morphology (polyphasic to biphasic in 9 patients and polyphasic to biphasic to loss of MEP response in 5 patients, 1 patient demonstrated both changes) and by an increase in voltage threshold (median, 175 V; range, 100-225 V; n = 22 extremities). Alterations in morphology and reduction in duration of the MEP response persisted despite significant increases in stimulation voltage. In 12 patients, reductions in the complexity and/or loss of the TcMEP waveform correlated with motor grade loss in the immediate postoperative period (P < 0.0001), at discharge (P < 0.001), and at follow-up (P < 0.001). The decrease in the duration of the response correlated with motor grade loss immediately after surgery (P < 0.001), at discharge (P < 0.0001), and at follow-up (P < 0.005). CONCLUSION: These results support the application of distal muscle-recorded TcMEPs to predict the occurrence and severity of postoperative motor deficits during resection of IMSCTs. Attention to such quantitative intraoperative monitoring data may help to minimize postoperative motor deficits by avoiding or correcting excessive spinal cord manipulation and modifying surgical technique during tumor resection.

Adult↗