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Biomedical subjects

J A Tortosa

Publications and source records attributed to J A Tortosa.

18 recordsLinked to original sources
PubMed2003

Anesthetic technique and development of pneumocephalus after posterior fossa surgery in the sitting position.

OBJECTIVE: Pneumocephalus is a well-known complication of surgical procedures performed with the patients placed in the sitting position. Its incidence and intensity were prospectively studied in 90 consecutive patients undergoing a posterior fossa procedure in this position. Various anesthetic agents, with different effects on cerebral hemodynamics, were used. MATERIAL AND METHODS: Patients were randomly assigned to one of three groups. In group 1 (n=30), anesthesia was induced and maintained with propofol. In group 2 (n=30), anesthesia was induced with thiopental and maintained with isoflurane. In group 3 (n=30), anesthesia was induced with thiopental and maintained with nitrous oxide and low-dose isoflurane. All patients received a load dose and an infusion of fentanyl. A cerebral computed tomography scan was performed to all patients 8 hours after surgery for detecting the presence and location of intracranial air. The size of pneumocephalus was ascertained using the formula for calculating the volume of a spheroid: v = PI / 6. x. y. z. Preoperative diagnosis, existence of shunted or non-shunted hydrocephalus, type and duration of the surgical procedure, detection of intraoperative venous air embolism, and appearance of new neurological symptoms in the postoperative period, were recorded. RESULTS: All patients included in the study developed postoperative pneumocephalus. There were no significant differences (P = 0.133) in the estimated volume of intracranial air between the groups (group 1, volume = 38.3 -/+ 35.4 ml; group 2, volume = 48.9 -/+ 36.3 ml; group 3, volume = 31.5 -/+ 28.4 ml). Only two patients in the group 2 manifested symptoms of neurological involvement due to the pressure exerted by the intracranial air. CONCLUSIONS: Despite the hypothetical diverse effects of the three anesthetic techniques used in this series on cerebral hemodynamics, our results suggest that none of them has a substantial effect on the amount of intracranial air detected after posterior fossa procedures performed in seated individuals. To the best of our knowledge this is the first report that addresses in a prospective manner the effects of several habitual anesthetic techniques on the development of pneumocephalus in patients submitted to posterior fossa procedures performed in the sitting position.

Adolescent↗
PubMed2001

Intravenous administration of propacetamol reduces morphine consumption after spinal fusion surgery.

We sought to determine the analgesic efficacy, opioid-sparing effects, and tolerability of propacetamol, an injectable prodrug of acetaminophen, in combination with morphine administered by patient-controlled analgesia (PCA) after spinal fusion surgery. Forty-two patients undergoing spinal stabilization surgery were randomized into two groups, which were given either an IV placebo or an IV injection of 2 g propacetamol every 6 h for 3 days after surgery. The postoperative opioid analgesic requirement was assessed with a PCA device used to self-administer morphine. Pain relief was evaluated by a visual analog pain scale and by verbal rating scores of pain relief at 8-h intervals for up to 72 h after surgery. The cumulative dose of morphine at 72 h was smaller in the Propacetamol group than in the Placebo group (60.3 +/- 20.5 vs 112.2 +/- 39.1 mg; P < 0.001). The pain scores were significantly lower in the Propacetamol group measured at two intervals of the study, although visual analog scale pain intensity scores were smaller than 3 in both groups. Most patients in the Placebo group obtained a greater degree of sedation on postoperative Day 3 (P < 0.05). This study demonstrates the usefulness of propacetamol as an adjunct to PCA morphine in the treatment of postoperative pain after spinal fusion.

Acetaminophen↗
PubMed2001

Rocuronium-induced neuromuscular blockade is affected by chronic phenytoin therapy.

Patients receiving chronic anticonvulsant therapy have been reported to show resistance to certain nondepolarizing neuromuscular blockers. In this study, the effects of chronic phenytoin therapy on the onset, duration, and recovery of rocuronium action was assessed. Thirty-six patients scheduled for various neurosurgical procedures were studied: 18 receiving chronic phenytoin therapy (Group I) and 18 controls (Group II). Rocuronium 0.6 mg/kg (2 x DE95) was administered after induction of general anesthesia with 4-6 mg/kg thiopental sodium and 3-5 microg/kg intravenous (IV) fentanyl. Maintenance anesthesia consisted of N2O in O2, 0.5% end-tidal isoflurane, and a fentanyl infusion. Neuromuscular block was monitored with acceleromyography of the adductor pollicis-brevis muscle by using a TOF-GUARD Biometer monitor (Biometer International A/S, Odense, Denmark). According to the amplitude of the first response of train-of-four, neither the lag time nor the onset time differed between the two groups. However, the recovery index was significantly shorter in patients chronically treated with phenytoin (mean recovery index: control group, 8.3 +/- 1.7 minutes; phenytoin group, 6.7 +/- 2.3 minutes; P < .05). In addition, the times of recovery to 10%, 25%, 75%, and 90% of the baseline response were also significantly shorter in the phenytoin group than in the control group. We conclude that the duration of action of rocuronium and the recovery index were affected by chronic phenytoin therapy.

Adult↗
PubMed1999

Anesthesia for ruptured cerebral aneurysm surgery associated with chronic renal failure.

The management of patients with chronic renal failure (CRF) undergoing cerebral aneurysm surgery has been documented on only a few occasions. We report a 58-year-old man with CRF and subarachnoid hemorrhage (SAH) due to aneurysm rupture. We describe the patient's perioperative anesthetic management, discussing the current methods for maintaining an appropriate cerebral perfusion pressure and for preventing rehemorrhage from the aneurysm. We suggest that heparin-aided hemodialysis be avoided in these cases.

Anesthesia, General↗
PubMed1998

Anaesthetic management in patients suspected of, or at risk of, having Creutzfeldt-Jakob disease.

We report two young patients who had repeated neurosurgical procedures and who were thought to be at risk of developing Creutzfeldt-Jakob disease (CJD). The first patient had been given a lyophilized dural graft in the course of removal of a cerebellar medulloblastoma 15 yr previously. The second patient had received pituitary-derived growth hormone for treatment of growth hormone deficiency, secondary to a third ventricle teratoma, exised 13 yr earlier. The presence of cerebellar symptoms together with being recipients of growth hormone or dural graft of cadaveric extraction arose suspicion of a diagnosis of CJD in both individuals. Precautions in the anaesthetic and surgical management of these two patients are discussed, and pertinent literature is reviewed briefly.

Adolescent↗
PubMed1998

Cardiovascular disturbances caused by extradural negative pressure drainage systems after intracranial surgery.

Extradural drainage systems connected to a vacuum device for preventing postoperative haematoma formation are often used in neurosurgical practice. Cardiovascular complications, including bradycardia or low arterial pressure caused by intracranial hypotension, have been described associated with their use. We have investigated the relationship between the negative pressure applied to extradural drainage systems and intracranial pressure (ICP), and analysed the effects of negative pressure of the drains on systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressures and on heart rate (HR). We studied prospectively 15 patients undergoing neurosurgery for supratentorial tumours or aneurysms. Transient decreases in ICP (P < 0.001) and HR (P < 0.001), with no clinical effects, were observed after connecting the vacuum device to the drain. There were no significant changes in SAP, DAP or MAP.

Adult↗
PubMedDate not supplied

Biological monitoring of occupational exposure to isoflurane by measurement of isoflurane exhaled breath.

The relationship between isoflurane environmental concentrations in operating rooms and the corresponding isoflurane concentration in the exhaled air of the operating personnel at the end of the exposure has been investigated. Isoflurane was retained in an adsorbent cartridge and after thermal desorption the concentration was estimated by gas chromatography. Significant correlation between environmental and exhaled air isoflurane concentrations allowed the establishment of a biological exposure index and biological exposure limits corresponding to proposed atmospheric threshold values.

Air↗