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Biomedical subjects

P H Manninen

Publications and source records attributed to P H Manninen.

At least 19 recordsLinked to original sources
PubMed2001

Anesthesia for cerebral aneurysms: a comparison between interventional neuroradiology and surgery.

PURPOSE: To review the anesthetic management of patients with cerebral aneurysms during treatment in the interventional neuroradiology (INR) suite compared with in the operating room. METHODS: This was a retrospective chart review of 100 consecutive patients treated by endovascular coiling compared with 100 patients treated by surgical clipping of a cerebral aneurysm. Information compared and analyzed included demographics, pre-procedure medical history, neurological status including location and size of aneurysm, anesthetic management, complications and patient outcome. P < 0.05 was considered significant. RESULTS: Patients in the INR group were older (54 +/- 15 vs 49 +/- 12 yr), had a greater incidence of pre-procedure cardiorespiratory problems (55 vs 34 patients) and had more aneurysms located in the posterior fossa (68 vs 11) (P < 0.05). General anesthesia was used in all except seven INR patients who received conscious sedation. There were some differences in the anesthetic agents and techniques. There was less monitoring of INR patients; temperature (33 vs 99 patients), intraarterial catheter (22 vs 100), central venous catheter (4 vs 78), and evoked potential monitoring (0 vs 100). There were no differences in the incidence of documented complications or in patient outcome. CONCLUSION: There were some differences in the anesthetic management of patients undergoing endovascular treatment of a cerebral aneurysm compared with treatment in the operating room. The patients in the INR suite were sicker and somewhat older and they received less invasive monitoring, but the complication rate and outcome did not differ.

Adult↗
PubMed2001

Pulmonary edema in the neuroradiology suite: a diagnostic dilemma.

PURPOSE: To present the case of an initially unexplained complication of sudden pulmonary edema in a patient during stenting of the carotid artery in the interventional neurology suite. CLINICAL FEATURES: A 46-yr-old woman (ASA III) having an intracavernous carotid artery angioplasty and stenting procedure under neurolept anesthesia developed sudden pulmonary edema on completion of an otherwise uneventful stenting procedure. The patient responded well to initial management of pulmonary edema although the cause of the edema remained unclear. On retrospective examination of data and with the evolution of clinical signs it became apparent that the patient had suffered a subarachnoid hemorrhage which eventually resulted in her death. CONCLUSIONS: Clinical signs of intracerebral events may be slow to evolve. The cause of sudden pulmonary edema in patients undergoing an interventional neuroendovascular procedure is likely to be neurogenic in origin despite the initial lack of neurological signs.

Angioplasty↗
PubMed2001

Awake craniotomy for removal of intracranial tumor: considerations for early discharge.

UNLABELLED: We retrospectively reviewed the anesthetic management, complications, and discharge time of 241 patients undergoing awake craniotomy for removal of intracranial tumor to determine the feasibility of early discharge. The results were analyzed by using univariate analysis of variance and multiple logistic regression. The median length of stay for inpatients was 4 days. Fifteen patients (6%) were discharged 6 h after surgery and 76 patients (31%) were discharged on the next day. Anesthesia was provided by using local infiltration supplemented with neurolept anesthesia consisting of midazolam, fentanyl, and propofol. There was no significant difference in the total amount of sedation required. Overall, anesthetic complications were minimal. One patient (0.4%) required conversion to general anesthesia and one patient developed a venous air embolus. Fifteen patients (6%) had self-limiting intraoperative seizures that were short-lived. Of the 16 patients scheduled for ambulatory surgery, there was one readmission and one unanticipated admission. It may be feasible to discharge patients on the same or the next day after awake craniotomy for removal of intracranial tumor. However, caution is advised and patient selection must be stringent with regards to the preoperative functional status of the patient, tumor depth, surrounding edema, patient support at home, and ease of access to hospital for readmission. IMPLICATIONS: It may be feasible to perform awake craniotomies for removal of intracranial tumor as an ambulatory procedure; however, caution is advised. Patient selection must be stringent with respect to the patient's preoperative functional status, tumor depth, surrounding edema, patient support at home, and ease of access to hospital for readmission.

Adolescent↗
PubMed2001

Somatosensory evoked potential monitoring during carotid endarterectomy in patients with a stroke.

UNLABELLED: The aim of our study was to assess the characteristics and feasibility of somatosensory evoked potential (SSEP) monitoring in patients who have had a stroke undergoing carotid endarterectomy. We retrospectively reviewed the medical and SSEP records of 204 patients. The patients were divided into two groups: Stroke (n = 65) and No-Stroke (n = 139). The amplitude and latency of the N20-P25 cortical complex on the ipsilateral side (surgical) were compared with the contralateral side in each group and between groups. Stroke patients showed asymmetry of their cortical waveforms; the ipsilateral N20-P25 baseline amplitude was 1.5 +/- 1.0 microv versus 1.9 +/- 1.2 microv for the contralateral (P = 0.001), for No-Stroke patients 2.0 +/- 1.1 microv versus 2.1 +/- 1.1 microv (P = 0.2). Forty-eight percent of Stroke patients had a ratio (ipsilateral/contralateral amplitude) of <1.0 +/- 0.2 compared with 26% for No-Stroke patients (P = 0.01). There were no differences in latency measurements, in the incidences of significant SSEP changes (four Stroke, six No-Stroke) and immediate postoperative neurological deficits (two Stroke, six No-Stroke) between the two groups. Nine patients (three Stroke, six No-Stroke) had a decrease in ipsilateral N20-P25 amplitude >50% after cross-clamping, and had a shunt inserted. In conclusion, patients with a history of a stroke before surgery had a decrease in the amplitude of the ipsilateral cortical peak. There were no differences in the incidences of SSEP changes or neurological deficits. IMPLICATIONS: Patients who have had a preoperative stroke may show asymmetry of their cortical baseline somatosensory evoked potential waveforms; however, this does not interfere with the ability to use somatosensory evoked potential as a monitor during surgery.

Aged↗
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↗
PubMed1999

Early postoperative complications following neurosurgical procedures.

PURPOSE: To assess the incidence and characteristics of early postoperative complications in patients following neurosurgical procedures. METHODS: All patients undergoing neurosurgery during a four month period were followed postoperatively for up to four hours in the post anesthetic care unit or intensive care unit. Patient information and all complications were documented by the investigators on a standardized form. Complications were classified as respiratory, cardiovascular, nausea and vomiting, shivering and other. Risk factors analyzed for the occurrence of complications included age, sex, ASA status, type of surgery, elective or emergency surgery and postoperative placement. RESULTS: Four hundred eighty six adult patients were followed, but in 55 patients the trachea remained intubated during the four hour study period and they were eliminated from the analysis of postoperative complications. At least one complication occurred in 54.5% of the remaining 431 patients. Respiratory problems occurred in 2.8%, trauma to the airway in 4.4%, cardiovascular complications in 6.7%, neurological in 5.7% and nausea and/or vomiting in 38%. The highest incidence of patients with complications was during spine (65%) and vascular (66%) surgery, compared with tumour (47%) and other (43%) surgery, P < 0.05. Other risk factors included age < 70 yr for nausea and vomiting (P < 0.02), and elective surgery for spine and vascular surgery (P < 0.001). CONCLUSION: There was a high incidence of early postoperative complications in neurosurgical patients. The most common problem was nausea and vomiting especially in the younger patient undergoing elective spine surgery.

Adult↗
PubMed1999

Intraoperative localization of an epileptogenic focus with alfentanil and fentanyl.

UNLABELLED: We evaluated the effectiveness of alfentanil and fentanyl in stimulating epileptogenic activity during surgery for intractable temporal lobe epilepsy under general anesthesia. Ten patients received a standardized anesthetic induction with i.v. fentanyl 5 microg/kg, propofol 3-5 mg/kg, and atracurium 0.5 mg/kg. Maintenance was with isoflurane, 70% N2O/30% O2, and an atracurium infusion. After dural opening, droperidol 0.02 mg/kg was administered i.v.. Both inhaled anesthetics were discontinued and verified to be at 0 end-tidal concentration before the study. Baseline electrocorticography over the surface of the temporal lobe and depth electrode recordings in the amygdala and hippocampus were obtained, followed by 10 min of recording before and after the i.v. administration of both alfentanil 50 microg/kg and fentanyl 10 microg/kg. Any changes in cardiovascular variables were documented. The number of interictal epileptiform spikes at the most active site for each patient was tabulated before and after the administration of each drug. Both alfentanil and fentanyl induced an increase in spike activity in all patients. Alfentanil was more potent, increasing the median number of spikes per epoch from 18 to 58, compared with fentanyl (20 to 42 spikes) (P < 0.05). Alfentanil had a shorter duration of action (4.9+/-1.3 min) compared with fentanyl (8.5+/-2 min) (P < 0.009). In nine patients, the most active site was the hippocampus or amygdala. There was a decrease in mean blood pressure, but only after the administration of alfentanil (P < 0.05). Two patients had electrographic evidence of seizure activity. These opioids can be used to assist in the localization of the epileptogenic focus during surgery. IMPLICATIONS: Both alfentanil and fentanyl activate epileptiform activity in patients with temporal lobe epilepsy. These opioids can be used to assist in the localization of the epileptogenic focus during surgery.

Adult↗
PubMed1998

Monitoring evoked potentials during spinal surgery in one institution.

PURPOSE: To review the experience of one tertiary care institution with somatosensory evoked potential (SSEP) monitoring during spinal surgery in order to assess the ability to monitor and predict neurological outcome effectively. METHODS: Records of all patients undergoing spinal surgery during 18 mo were retrospectively reviewed. Information from the patient chart included preoperative neurological status, surgical procedure, anaesthetic management, and postoperative neurological outcome. Information regarding the techniques used and interpretation of all SSEP tracings were obtained from evoked potential data sheets completed for each patient. The incidences of clinically important SSEP changes and new postoperative neurological deficits were analysed. RESULTS: Somatosensory evoked potential monitoring of the lower and upper extremities with non invasive techniques was used in 309 patients undergoing surgery on the cervical (88), thoracic (52), and lumbar spine (169). Thirty seven patients (11%) did not have suitable tracings for interpretation and 17 (5.5%) had baseline tracings described as poor. An intraoperative SSEP change occurred in 16 patients (6%) with SSEP and seven (2.6%) had a new neurological deficit postoperatively. Three persistent deficits were predicted by permanent SSEP change, and one transient deficit by a transient SSEP change. False positive results occurred in 12 patients (4.4%) and false negative results occurred in three (1.1%), with a sensitivity of 57% and a specificity of 95%. The incidence of SSEP changes was greater in the thoracic (18%) than in the cervical (1.2%) or lumbar (5.4%) groups (P < 0.05). CONCLUSION: Effective SSEP monitoring was possible despite the many factors which may have interfered with monitoring. More improvements in the techniques and conditions of monitoring are needed to decrease the incidence of false positive and negative results.

Evoked Potentials, Somatosensory↗
PubMed1997

Assessment of a new ultrafiltration blood processing system.

PURPOSE: To report our clinical experience with a new blood processing device which uses ultrafiltration. We assessed safety and efficacy by evaluating: 1 ) the quality and the quantity of intraoperative shed blood processed and reinfused to the patient 2) homologous blood requirements 3) clinical status of the patient post-transfusion. METHODS: With Ethics Committee approval, the ultrafiltration device was used in six consenting patients undergoing major elective spinal surgery. Blood samples for haematology and biochemistry tests were collected from patients post-induction of anaesthesia (baseline), 1 hr and 24 hr post-autotransfusion. Volumes of blood collected and processed, and all autologous and homologous transfusions were recorded. Patients were assessed post-operatively for any adverse effects. RESULTS: Five patients had donated blood preoperatively. One patient required homologous blood products in addition to autologous blood. In two patients, the filtration cartridge became blocked and required changing midprocessing. No patient sustained device-related complications. One patient had postoperative haematuria which resolved spontaneously within two hours. CONCLUSION: The ultrafiltration device was safe and effective in reducing homologous blood requirements in six patients undergoing elective spinal surgery. Further evaluation of the ultrafiltration device will be necessary, especially in view of the blockage of the filtration cartridge.

Blood Transfusion, Autologous↗
PubMed1997

Conscious sedation for interventional neuroradiology: a comparison of midazolam and propofol infusion.

PURPOSE: The aim of this study was to compare two conscious sedation techniques, midazolam (M) and propofol (P), for interventional neuroradiology by assessment of the incidence of complications and satisfaction scores. METHODS: Forty patients were randomized to receive 0.75 micrograms.kg-1 fentanyl and a M or P bolus followed by an infusion (M 15 micrograms.kg-1 + 0.5 micrograms.kg-1.min-1; P 0.5 mg.kg-1 + 25 micrograms.kg-1 min-1). The incidences of complications and untoward events requiring intervention were documented. These included respiratory depression, excessive pain, inappropriate movements and the inability to examine the patient. The satisfaction of the anaesthetic technique from the perspective of both the neuroradiologist and the patient was scored. RESULTS: The incidence and types of complications were no different between the two groups. Pain occurred in 12 patients (6M, 6P), inappropriate movements in 17 (7M, 10P) and respiratory changes in 10 patients (2M, 8P). CONCLUSIONS: Both techniques were satisfactory and the incidence of complications was similar for both groups.

Adult↗
PubMed1997

Comparison of cerebral oximeter and evoked potential monitoring in carotid endarterectomy.

PURPOSE: To assess the cerebral oximeter, which measures regional oxygen saturation (rSO2) continuously and noninvasively, as a cerebral monitor during carotid endarterectomy (CEA). The rSO2 was compared with Somatosensory Evoked Potentials (SSEPs) as an indicator for shunting and as a predictor of postoperative neurological deficits. METHODS: Seventy-two consenting patients undergoing CEA with general anaesthesia were studied. Normocarbia, normothermia and normotension were maintained. Cerebral monitoring consisted of bilateral median nerve SSEPs and the INVOS 3100 cerebral oximeter with the sensor pad placed on the ipsilateral forehead. Decreases in SSEP amplitude of 50% and in rSO2 of 10% were considered clinically significant. Neurological assessment was performed at emergence from anaesthesia, 24 hr postoperatively and at discharge. The rSO2 changes were compared with SSEP changes and with neurological deficits. Statistical analysis was with chi square and analysis of variance P < 0.05 was considered significant. RESULTS: During carotid artery clamping, rSO2 decreased from 72 +/- 8% to 68 +/- 9% and mean arterial blood pressure increased from 92 +/- 14 mmHg to 98 +/- 14 mmHg. In four patients, the carotid artery was shunted because of SSEP changes after cross-clamping. Five patients had > or = 10% decreases in rSO2 following clamp application. Changes in both SSEP and rSO2 occurred in two patients. Three of the four shunted patients had transient postoperative neurological deficits. One patients had a transient deficit without changes in either monitor. There were no persistent postoperative deficits. Compared with SSEPs, rSO2 had a sensitivity of 50% and a specificity of 96%. CONCLUSION: Clinical experience with this evolving technology is ongoing. Its role in neurovascular procedures has yet to be established.

Aged↗
PubMed1995

Anesthesia for interventional neuroradiology.

STUDY OBJECTIVE: To review the anesthetic management and the occurrence and treatment of complications in patients undergoing interventional neuroradiologic procedures for the treatment of intracranial vascular lesions. DESIGN: Retrospective chart review of 115 charts from 1988 to 1992. SETTING: University hospital. MEASUREMENTS AND MAIN RESULTS: Charts were reviewed for information regarding the anesthetic management, monitoring techniques, complications, treatment of complications, and clinical outcome. Group 1 patients (n = 92) were managed by an anesthesiologist; 8 received general anesthesia and 84 had conscious sedation. Group 2 patients (n = 70) were cared for by a neuroradiologist; 37 received intravenous analgesia (fentanyl) and 33 received no sedation other than premedication (benzodiazepine). No episodes of anesthetic or drug-related complications were documented. Complications directly related to technical aspects of the procedure were documented in 33 (20%) cases, 19 (21%) in Group 1 and 14 (20%) in Group 2. These complications consisted of ischemia (n = 14), hemorrhage (n = 9), catheter misplacement (n = 8), and pulmonary embolism (n = 2). Four patients, two in each group, required urgent assessment by an anesthesiologist. CONCLUSIONS: There was no difference in the incidence of complications between the two groups. As the use of interventional neuroradiology increases, the anesthesiologist will be more involved in the elective or emergency treatment of these patients.

Adult↗
PubMed1995

Association between electrocardiographic abnormalities and intracranial blood in patients following acute subarachnoid hemorrhage.

The etiological factors that influence the development of electrocardiographic (ECG) abnormalities following a subarachnoid hemorrhage are not fully understood. The purpose of this study was to assess if there was an association between ECG abnormalities and the amount of intracranial blood seen on computerized tomographic (CT) scanning following an acute bleed in patients with a cerebral aneurysm. The charts of 70 patients who had had a preoperative CT scan and a preoperative ECG within 96 h of bleed were reviewed. The neurological status of the patients was graded according to the Botterell classification and the amount of blood seen on the CT scan was graded by the Fisher classification. Thirty patients had an abnormal ECG. Seventy percent of these abnormalities involved the T wave or the ST segment. The incidence of ECG abnormalities was statistically greater for patients who had an increased amount of intracranial blood or an intracerebral clot, as seen on CT scan. All patients had treatment (surgical n = 69, embolization n = 1) of the aneurysm. Neither the amount of blood seen on CT scan nor the incidence of ECG abnormalities was useful in predicting patient outcome. In conclusion, an increased quantity of intracranial blood was associated with an increased incidence of ECG abnormalities.

Acute Disease↗
PubMed1994

Evoked potential monitoring during posterior fossa aneurysm surgery: a comparison of two modalities.

The purpose of this study was to compare and assess the ability of two different evoked potential (EP) modalities, median nerve somatosensory evoked potentials (SSEP) and brainstem auditory evoked potentials (BAEP) in monitoring for cerebral ischaemia and in predicting neurological outcome during posterior fossa aneurysm surgery. During 70 procedures, patients were monitored with both SSEP and BAEP. Temporary occlusion of an artery was used in 52 patients and permanent occlusion in 21 patients. A change was defined as a greater than 50% decrease in amplitude and/or an increase in latency greater than 1 msec of the N20 (cortical waveform) for SSEP monitoring and of the fifth peak for BAEP monitoring. Neurological assessment of the patient was performed immediately on emergence, after 24 hr and at the time of discharge. In total, 14 patients had an SSEP change which predicted a neurological deficit in eight patients (57%). Ten patients had a change in BAEP; six had a neurological deficit (60%). Five patients had a change in both, two had a deficit (40%). The incidence of false negative results (a neurological deficit but no EP change) for both modalities was 20% (SSEP 47%, BAEP 60%). The incidence of false positive results (an EP change but no deficit) was 13% overall (SSEP 11%, BAEP 7%). All patients who had a permanent EP change developed a neurological deficit. We did not find a difference in the ability of SSEP compared with BAEP in predicting neurological deficits but, using both modalities, the incidence of false negative results was decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗