Biomedical subjects

H Panzardo

Publications and source records attributed to H Panzardo.

4 recordsLinked to original sources

PubMed2002

Comparison between two static autoregulation evaluation methods.

Cerebral static autoregulation (AR) was evaluated at bedside in 14 severely head injured patients. 16 investigations were performed. Cerebral perfusion pressure (CPP) was increased by infusing vasopressors during one hour, and registered every 2-5 minutes. CBF was simultaneously estimated by: 1) middle cerebral artery mean flow velocity (FV) monitoring with Transcranial Doppler (TDC), and 2) the reciprocal of arteriovenous oxygen content difference, calculated from basal and hypertensive arterial and jugular bulb blood samples. AR assessment: For TCD results, linear regression method was used, studying two pairs of variables: a) %FV-CPP (the regression slope was the main AR value adopted) and b) % cerebrovascular resistance (CVR)-%CPP. For the AVDO2 method, autoregulation was considered preserved if estimated % delta CBF/delta PPE < 1%/mm Hg. TCD method clearly defined three groups. Group 1 and 2 (8 and 5 investigations) were considered as two grades of preserved AR, and the third one (3 cases) as impaired AR. AVDO2 method: 12 studies were evaluated. 10 showed preserved AR, and 2 impaired AR. There was coincidence of results from both methods in 10 out of 12 studies. (0.83).

Adolescent↗

PubMed2002

[First tier measures in the treatment of intracranial hypertension in the patient with severe craniocerebral trauma. Proposal and justification of a protocol].

The management of severe head injuries in general and that of high intracranial pressure (ICP) in particular are among the most challenging tasks in neurocritical care. One of the difficulties still faced by clinicians is that of reducing variability among centers when implementing management protocols. The purpose of this paper is to propose a standardized protocol for the management of high ICP after severe head injury, consistent with recently published clinical practice guidelines and other clinical evidence such as that provided by the systematic reviews of the Cochrane Collaboration. Despite significant advances in neuromonitoring, deeper insight into the physiopathology of severe brain trauma and the many therapeutic options available, standardized protocols are still lacking. Recently published guidelines provide sketchy recommendations without details on how and when to apply different therapies. Consequently, great variability exists in daily clinical practice even though different centers apply the same evidence-based recommendations. In this paper we suggest a structured protocol in which each step is justified and integrated into an overall strategy for the management of severe head injuries. The most recent data from both the preliminary and definitive results of randomized clinical trials as well as from other sources are discussed. The main goal of this article is to provide neurotraumatology intensive care units with a unified protocol that can be easily modified as new evidence becomes available. This will reduce variation among centers when applying the same therapeutic measures. This goal will facilitate comparisons in outcomes among different centers and will also enable the implementation of more consistent clinical practice in centers involved in multicenter clinical trials.

Adrenal Cortex Hormones↗

PubMed2000

Does an increase in cerebral perfusion pressure always mean a better oxygenated brain? A study in head-injured patients.

The adequate management of cerebral perfusion pressure (CPP) continues to be a controversial issue in head-injured patients. The purpose of our study was to test two hypotheses. The first was that in patients with a CPP below 70 mm Hg, oxygen delivery is compromised and that therefore signs of tissue hypoxia would be reflected in low PtiO2 measurements. The second hypothesis was that manipulating mean arterial blood pressure to increase CPP improves oxygen delivery, particularly in patients with a CPP below 70 mm Hg. Twenty-five moderately or severely head-injured patients were included in the study. In all of them PtiO2 was monitored in the non-injured hemisphere using the Licox system (GMS, Kiel-Mielkendorf, Germany). Arterial hypertension was induced with phenylephrine 29 times. To quantify the effect of increasing mean arterial blood pressure (MABP) on oxygen delivery to the brain, the PtiO2-BP index was calculated (PtiO2-BP index = delta PtiO2/delta MABP). In 16 tests (55%) baseline CPP was above or equal to 70 mm Hg and in the remaining 13 (45%) it was below 70 mm Hg. Mean increase in MABP after phenylephrine was 23.7 +/- 10.2 mm Hg. Mean PtiO2 was 29.5 +/- 14.7 mm Hg in patients with a basal CPP of below 70 mm Hg and 28.9 +/- 10.6 mm Hg in patients in the high CPP group. These differences being not statistically significant. The PtiO2-BP index was 0.29 +/- 0.23 in patients with a basal CPP of below 70 mm Hg and in patients with a CPP of above 70 mm Hg this index was 0.16 +/- 0.11 Hg. These differences were not statistically significant (Student's t-test, P = 0.09). In our study a low PtiO2 was not observed in patients with marginally low CPPs (48-70 mm Hg) and readings below 15 mm Hg were observed in cases with both normal or supranormal CPPs. We conclude that episodes of low PtiO2 could not be predicted on the basis of CPP alone. On the other hand, raising CPP did not increase oxygen availability in the majority of cases, even if the CPP was markedly improved.

Adolescent↗

PubMed1997

Osmotherapy for increased intracranial pressure: comparison between mannitol and glycerol.

Osmotic agents are still the most common treatment for controlling intracranial hypertension (ICH). Mannitol, glycerol, sorbitol, and hypertonic serum saline are the agents currently available. This work was designed to compare mannitol and glycerol in a similar population of brain injured patients, randomly divided into two groups of eight. The following mean day parameters were obtained: number of infusions, hydric balance, mean arterial pressure (MAP), and intracranial pressure (ICP). Cerebral perfusion pressure (CPP) was calculated. Brain computed tomographies (CT) were obtained on arrival, at follow-up whenever justified and at discharge. For comparison of both groups a modified therapeutic intensity level (mTIL) was used. Both agents induced a statistically equally effective decrease on ICP and increase on CPP evaluated at one and two hours post infusion but the mean day mTIL showed a statistically significant difference in favour of glycerol. The possible explanations of this difference are discussed. According to our results mannitol would be most indicated as a bolus to control sudden rises in ICP whereas glycerol would be most indicated as a basal treatment.

Adolescent↗