Biomedical subjects

R M Gracia

Publications and source records attributed to R M Gracia.

5 recordsLinked to original sources

PubMed1998

Incidence of intracranial hypertension after severe head injury: a prospective study using the Traumatic Coma Data Bank classification.

UNLABELLED: Intracranial hypertension (ICH) is a frequent finding in patients with a severe head injury. High intracranial pressure (ICP) has been associated with certain computerized tomography (CT) abnormalities. The classification proposed by Marshall et al. based on CT scan findings, uses the status of the mesencephalic cisterns, the degree of midline shift, and the presence or absence of focal lesions to categorize the patients into different prognostic groups. Our aim in this study was to analyze the ICP evolution pattern in the different groups of lesions of this classification. PATIENTS AND METHODS: We present the results of a prospective study in 94 patients with severe head injury, in whom ICP was monitored for at least 6 hours. ICP evolution was classified into three different categories: 1) ICP always < 20 mm Hg, 2) Intracranial hypertension at some time during monitoring, but controlled by medical or surgical treatment, 3) Uncontrollable ICP. The ICP pattern was correlated with the final CT diagnostic category. CONCLUSIONS: 3 patients had a normal CT scan, and none of them presented intracranial hypertension. In diffuse injury type II, the ICP evolution may be quite different. Patients with bilateral brain swelling (Diffuse Injury III) have a high risk of increased ICP (63.2%). Although in our study the frequency of Diffuse Injury IV was low, all patients in this category had a refractory ICP. In the category of evacuated mass lesions, two thirds of the patients presented an intracranial hypertension. In one third, ICP was refractory to treatment. 85% of patients with a non-evacuated mass lesion showed an increased ICP.

Adult↗

PubMed1997

Myocardial necrosis by electrocution: evaluation of noninvasive methods.

We present the case of a young man who suffered severe anteroapical myocardial necrosis caused by electrocution. In addition to the enzymatic and electrocardiographic changes suggesting necrosis, a clear positive segmental image on 99mTc-pyrophosphate scintigraphy and a defect on a 201Tl SPECT scan at rest were also found. Although these tests were indicative of extensive anteroapical transmural myocardial necrosis, the echocardiographic study only revealed mild anteroapical hypokinesia.

Adult↗

PubMed1996

Arterio-jugular differences of oxygen (AVDO2) for bedside assessment of CO2-reactivity and autoregulation in the acute phase of severe head injury.

Autoregulation and CO2-reactivity can be impaired independently of each other in many brain insults, the so-called 'dissociated vasoparalysis'. The theoretical combination of preserved CO2-reactivity and impaired or abolished autoregulation can have many clinical implications in the daily management of brain injured patients. To optimize their treatment, a bedside assessment of autoregulation and CO2-reactivity is desirable. When cerebral metabolic rate of oxygen is constant, changes in arterio-jugular differences of oxygen (AVDO2) reflect changes in CBF. In these situations relative changes in AVDO2 can be viewed as inverse changes in CBF and used as an evaluation method of CO2-reactivity and autoregulation. In 39 consecutive severe head injury patients with a mean age of 28 +/- 17 years and a diffuse brain injury, cerebrovascular response to changes in pCO2 was tested in the acute phase after injury (18 +/- 8 hours). In 28 of those cases autoregulation was also assessed. A relative CBF value (1/AVDO2) was calculated from baseline AVDO2 and was expressed as 100%. Changes in 1/AVDO2 after inducing pCO2 changes give a good estimate of changes in global CBF. Two different indexes were calculated for CO2-reactivity: 1) absolute CO2-reactivity (CO2RABS) and 2) percentage reactivity (CO2R%). CO2R% was used to separate patients with impaired/abolished CO2-reactivity from those with preserved CO2-reactivity. Patients with CO2R% above 1% were considered in the intact CO2-reactivity group and patients in whom CO2R% was below or equal to 1% were included in the impaired/abolished CO2-reactivity group. Only five cases (12.8%) presented an impaired/abolished CO2-reactivity. AVDO2 response to induced hypertension was studied in a subset of 28 patients. Phenylephrine was used to increase MABP about 25%. All AVDO2 values were corrected for changes in pCO2. Patients with changes in 1/AVDO2 less than or equal to 20% were included in the intact autoregulation group. Patients with estimated CBF changes above 20% were classified as having an impaired autoregulation (impaired/abolished). In 12 patients (43%) autoregulation was intact. In the remaining 16 patients (57%) autoregulation was imparied. Of the 28 cases, CO2-reactivity was impaired in only five cases. All patients with an impaired CO2-reactivity also had an impaired autoregulation. Monitoring relative changes in AVDO2 permits a reliable study of CO2-reactivity and autoregulation at the bedside. Introducing these variables into the day-to-day management should be considered in treatment protocols.

Adolescent↗

PubMed1982

The value of bedside wedge pulmonary angiography in the detection of pulmonary emboli: a predictive and prospective evaluation.

A predictive study involving 74 unequivocally positive conventional pulmonary angiograms was conducted to determine the value of bedside, flow-directed wedge pulmonary angiography (BWPA). The flow-directed position of Swan-Ganz catheters in these cases was obtained from anteroposterior chest radiographs. BWPA could detect the embolism in 48% of the cases in which the right lower lobe alone was embolized, in 10% of the cases in which the left lower lobe alone was embolized, and in 30% of the cases in which both lower lobes were embolized. It is concluded that BWPA has a low sensitivity and specificity and is of little value as either a screening procedure or a diagnostic tool.

Angiography↗

PubMed1975

Malignant hyperthermia.

Malignant hyperthermia is a genetic disease that may become apparent after exposure to drugs; some of these drugs are commonly used by the oral surgeon. One in 14,000 young, apparently health individuals may be affected; mortality is 64 percent. Many cases of malignant hyperthermia can be prevented if an adequate history is obtained. Oral surgeons should be familiar with the prevention, diagnosis, and initial treatment of malignant hyperthermia.

Adolescent↗