[Does decompressive craniectomy improve other parameters besides ICP? Effects of the decompressive craniectomy on tissular pressure?]. / ¿Mejora la craniectomía descompresiva otros parámetros además de la PIC? Efectos de la craniectomía descompresiva en la presión tisular.

Second level therapeutic maneuvres for controlling intracranial hypertension (ICH) proposed by the European Brain Injury Consortium and the American Association of Neurological Surgeons include barbiturates, moderate hypothermia and more recently the decompressive craniectomy (DC).In most patients, ICP can be maintained below 25 mmHg after a DC. However, the exact effect of DC on brain oxygenation (PtiO2) still unclear. From our point of view the ptIo2 monitoring with the probe located in the healthy area of the most severely damaged cerebral hemisphere is not only a important tool for timing craniectomy in the future but also for evaluating the therapeutic effectivity of DC.

Prognostic value of early computerized tomography scanning following craniotomy for traumatic hematoma.

OBJECT: Patients with head injuries traditionally were categorized on the basis of whether their lesions appeared to be diffuse, focal, or mass lesions on admission computerized tomography (CT) scanning. In the classification of Marshall, et al., the presence of a hematoma (evacuated or not evacuated) is more significant than any diffuse injury (DI). The CT scan appearance after evacuation of a mass lesion has not been analyzed previously in relation to outcome. The authors have investigated the importance of: 1) neurological assessment at hospital admission; 2) the status of the basal cisterns and associated intracranial lesions on the admission CT scan; and 3) the degree of DI on the early CT scan obtained after craniotomy to identify patients at risk for development of raised intracranial pressure (ICP) and lowered cerebral perfusion pressure (CPP) and to discover the influence of the postoperative CT appearance of the lesion on patient outcome. METHODS: The authors prospectively studied 82 patients with isolated, severe closed head injury (Glasgow Coma Scale [GCS] score < or = 8), all of whom had intracranial hematoma. Both ICP and CPP were continuously monitored, and a CT scan was obtained within 2 to 12 hours after craniotomy. The CT images were categorized according to the classification of Marshall, et al. The mortality rate during the hospital stay was 37%, and 50% of the patients achieved a favorable outcome. Compression of the basal cistern on the admission (preoperative) CT scan was associated with raised ICP and a CPP of less than 70 mm Hg but not with any other features or with poor patient outcome. In 53 patients the postoperative CT scan revealed DIs III or IV and 29 patients had DIs I or II. The percentages of time during the hospital stay in which ICP was higher than 20 mm Hg and CPP was lower than 70 mm Hg as well as unfavorable outcome were higher in the group of patients in whom DI III or IV was present (p < 0.001). Raised ICP, CPP lower than 70 mm Hg, DI III or IV, and unfavorable outcome were more frequently observed in patients who presented with a motor (m)GCS score of 3 or less, bilateral unreactive pupils, associated intracranial injuries, and hypotension (p < 0.001). When logistic regression analysis was performed, an mGCS score of 3 or less (p = 0.0013, odds ratio [OR] 10.8), bilateral unreactive pupils (p = 0.0047, OR 31.8), and DI III or IV observed on CT scanning after surgery (p = 0.015, OR 8.9) were independently associated with poor outcome. CONCLUSIONS: Features on CT scans obtained shortly after craniotomy constitute an independent predictor of outcome in patients with traumatic hematoma. Patients in whom DI III or IV appears on postoperative CT scanning, who often present with an mGCS score of 3 or less and nonreactive pupils, are at high risk for the development of raised ICP and lowered CPP.

Diffuse axonal injury with or without an evacuated intracranial hematoma in head injured patients. Are they different lesions?

The general classification of head injury proposed by Marshall et al., based on admission CT scan findings, might mask a group of patients who have Diffuse Brain Injury (DI) in addition to intracranial haematomas. The aim of this study was to assess possible differences in outcome with respect to the level of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) between a group of patients with DI: III-IV (Marshall's classification) after the evacuation of an intracranial haematoma (group A) and another group with DI: III-IV in the absence of a mass lesion (group B). We prospectively studied 129 patients with isolated and closed severe head injury (GCS < 9). In group A (n = 61), the median percentage of hours with ICP > 20 mmHg and CPP < 70 mmHg was 42.8 and 18, respectively and 17 (28%) survived with GOS 4-5. In group B (n = 68), median values of 20 and 5.5 hours were obtained for ICP > 20 and CPP < 70 respectively, whilst 39 (57.3%) survived with favourable outcomes. When we analysed the effects of the DI: III-IV in both groups of patients, we found that the differences in percentage of time with ICP > 20 and CPP < 70 were statistically significant (p < 0.01) and patients in group A had a higher morbidity and mortality (p < 0.05). This study has demonstrated that the levels of ICP, morbidity and mortality in patients with DI: III-IV and an evacuated mass lesion were higher than in patients with DI: III-IV without a mass lesion.

Helicopter emergency medical service in Canary Islands, Spain.

This is a report on our first 2 years' experience of operating a helicopter emergency medical service in the Canary Islands, Spain. The two advanced life-support helicopters are staffed full time by a physician and a nurse. For the transport protocol, inter-hospital transport patients (secondary missions) were classified into three groups: group A, minor illnesses or injuries; group B, modified or middle critical condition; and group C, critical condition. On-scene patients (primary missions) were also divided into critical and non-critical condition. Cardiovascular and respiratory stabilization were necessary before transport. One thousand and fifty-four patients were transported, 19% of whom were primary missions and 81% of whom were secondary missions. Thirty per cent of the first group were in critical condition. The distribution of secondary missions was group A 16%, group B 44% and group C 40%. In group C, 60% of patients were mechanically ventilated, 70% needed cardiovascular drug support and 84% needed stabilization before transport. Thirty-two per cent were trauma patients and 12% neonates. The overall mortality rate was 0.8%. The cost per mission was US$2300. In the interests of safety and rationalization of the use of resources, transport of non-critical patients should be reduced. The presence of a trained physician and nursing crew and stabilization before transport could be responsible for the low mortality rate.

[Role of decompressive craniectomy in brain injury patient]. / Papel de la craniectomía descompresiva en el enfermo neurocrítico.

Second level therapeutic maneuvres for controlling intracranial hypertension (ICH) proposed by the European Brain Injury Consortium and the American Association of Neurological Surgeons include barbiturates, moderate hypothermia and decompressive craniectomy (DC). However, neither barbiturates nor hypothermia have been demonstrated to improve its outcome. DC could be a therapeutic option in the management of ICH without intracerebral masses. Therefore, our goal has been to review and analyze the clinical usefulness of DC in patients with brain injury in an attempt to deal with some concerns of the critical care physicians. Can DC improve patient outcome? Currently, there are no randomized and controlled clinical trials supporting or rejecting the practice of DC in adults. Most published reports provide level II of evidence. However, most of those studies have shown that the outcome is better in patients with DC. When should DC be performed? It should be performed early to prevent ICH from occurring more than 12 hours. What are the effects of DC on intracranial pressure and brain oxygenation? In most patients, ICP can be maintained below 25 mmHg after a DC. However, to improve brain oxygenation (PtiO(2)), the probe must be placed in the healthy area of the most severely damaged cerebral hemisphere. What is the suggested surgical procedure? Frontal-subtemporal-parietal-occipital craniectomies, including enlargement of the dura by duroplasty. And finally, what are the current contraindications of DC? Glasgow Coma Scale score 3 points post-resuscitation states with dilated and arreactive pupils, age > 65 years old, ICH > 12 hours, persistent (a-yv)DO(2) < 3.2% or PtiO(2) < 10 mmHg maintained from the moment of admission.

Computerized system in intensive care medicine.

A complete understanding of the computer's capabilities and an exact identification and definition of the ICU problems/needs are essential for the complete control of patient records and the full utilization of the computer as a clinical tool.

Pulmonary hypertension in acute respiratory failure.

In order to examine the prognostic value of pulmonary arterial hypertension (PAH) in patients with moderate and severe acute respiratory failure (ARF), 225 patients with ARF who had been treated with mechanical ventilation and admitted to our ICU during a 3-yr period (January, 1983 to January, 1986) were prospectively studied. All 70 (31%) patients with moderate and severe ARF also had some form of hemodynamic or pulmonary instability, and were monitored with a pulmonary artery catheter. Of these 70 patients, 38 (54%) had PAH (mean BP 29 +/- 6 mm Hg); their mortality was 79% (30/38). The rest of the patients (n = 32) did not have PAH (mean BP was 15 +/- 3 mm Hg) and their mortality was 44% (14/32) (p less than .01). Thirty patients met all the criteria for adult respiratory distress syndrome (ARDS), and their mortality was 70% (21/30); all of them were included among the 38 PAH patients. ARDS patients who died had a significantly higher pulmonary vascular resistance and a significantly lower cardiac index than patients who survived (p less than .001). We conclude that PAH (present in all our ARDS patients) is a good predictor of mortality in ARF of diverse causes.

[Intermittent mandatory ventilation (author's transl)]. / Respiración con presión positiva intermitente mandatoria

Intermittent mechanical ventilation is a frequent form of therapy for respiratory failure in children. Due to its difficult application in patients with high respiratory rate and difficult synchronization with the respirator, intermittent mandatory ventilation (I.M.V.) was tried on these patients, introducing a unidirectional valve, connected to a continuous flow of gases, on the inspiratory side of the respirator. With I.M.V. the patient is able to breath spontaneously the gases coming from the unidirectional valve and at the same time the respirator provides periodical insuflations at a frequency previously determined by us. The pressure generated by the respirator in the respiratory circuit, closes the unidirectional valve sending gases to patient. This technique not only reduced time of application of mechanical ventilation but made weaning shorter, easier and safer.

Verbal communication of ventilator-dependent patients.

OBJECTIVE: To assess whether communication capabilities of ventilator-dependent patients are improved by the use of the Passy-Muir unidirectional valve. DESIGN: Prospective study. SETTING: An 18-bed multidisciplinary intensive care unit (ICU) at the University Hospital, Las Palmas, Spain. PATIENTS: Ten chronic ventilator-dependent patients who had undergone tracheostomy and met the following criteria: ability to eliminate tracheobronchial secretions in order to maintain a patent and unobstructed airway, adequate gas exchange while ventilated with an FIO2 of < or = 0.4 (Pao2 > 60 torr [8 kPa]), Paco2 of < 55 torr (7.3 kPa), normal hemodynamics without the need for administration of vasopressors, and normal mental state. Eight patients presented with pulmonary disease, and two presented with neuromuscular disease. INTERVENTIONS AND METHODS: Before attaching the Passy-Muir valve, the following procedures were performed: a) suction of tracheal and pharyngeal secretions; b) deflation of the tracheostomy tube cuff; c) increase in the ventilator's tidal volume setting to maintain the inspiratory pressure before cuff's deflation; d) set peak inspiratory pressure alarm and disconnect expiratory volume alarm. The valve was then connected between the tracheostomy tube and the Y-shaped piece of the ventilator's circuit. Respiratory movements, arterial blood gases, peak inspiratory pressure, respiratory rate, quantity of secretions, and changes in sense of smell were monitored during the study. The valve's efficacy was evaluated according to the patient's ability to talk and be understood during the entire respiratory cycle. RESULTS: The Passy-Muir valve was effective in improving communication in eight of ten patients who, during its use, presented insignificant cardiorespiratory changes, decreased secretions, and effected considerable improvement in well-being. Its use was impossible in two patients: one with severe pulmonary disease because cuff deflation prevented adequate ventilation, and one patient with neuromuscular disease and laryngopharyngeal dysfunction. CONCLUSIONS: The Passy-Muir unidirectional valve allows ventilator-dependent patients to talk and communicate without assistance. Patients felt better and were motivated to participate in their own care.