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Biomedical subjects

P Ravussin

Publications and source records attributed to P Ravussin.

At least 19 recordsLinked to original sources

Human errors in a multidisciplinary intensive care unit: a 1-year prospective study.

OBJECTIVES: To determine the incidence and identify risk factors of critical incidents in an ICU. DESIGN: Prospective observational study of consecutive patients admitted over 1 year to an ICU. Critical incidents were recorded using predefined criteria. Their causes and consequences were analysed. The causes were classified as technical failure, patient's underlying disease, or human errors (subclassified as planning, execution, or surveillance). The consequences were classified as lethal, leading to sequelae, prolonging the ICU stay, minor, or without consequences. The correlation between critical incidents and specific factors including patient's diagnosis and severity score, use of monitoring and therapeutic modalities was analysed by uni- and multivariate analysis. SETTING: An 11-bed multidisciplinary ICU in a non-university teaching hospital. PATIENTS: 1,024 consecutive patients admitted to the ICU. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The median length of ICU stay by the 1,024 patients was 1.9 days. Of the 777 critical incidents reported 2% were due to technical failure and 67 % to secondary to underlying disease. There were 241 human errors (31%) in 161 patients, evenly distributed among planning (n = 75), execution (n = 88), and surveillance (n = 78). One error was lethal, two led to sequelae, 26 % prolonged ICU stay, and 57 % were minor and 16 % without consequence. Errors with significant consequences were related mainly to planning. Human errors prolonged ICU stay by 425 patient-days, amounting to 15 % of ICU time. Readmitted patients had more frequent and more severe critical incidents than primarily admitted patients. CONCLUSIONS: Critical incidents add morbidity, workload, and financial burden. A substantial proportion of them are related to human factors with dire consequences. Efforts must focus on timely, appropriate care to avoid planning and execution mishaps at the beginning of the ICU stay; surveillance intensity must be maintained, specially after the fourth day.

Adolescent↗

Ejection as a key word for the dispatch of a physician staffed helicopter: the Swiss experience.

We evaluated the type and severity of injuries and the possible influence of a helicopter staffed by a physician on the outcome of 71 consecutive occupants ejected from a four-wheel vehicle ejected occupants who were cared for by the Swiss Air Rescue Helicopter team from January 1994 to February 1999. The investigation and the data collection were planned prospectively. The following data were collected for each patient ejected from a four wheel vehicle: (1) demographic information; (2) type of injury; (3) vital signs on scene, in flight and at hospital; (4) hospital diagnosis; (5) injury severity score; (6) secondary transfer; (7) length of stay in hospital and on intensive care; and (8) outcome at hospital discharge. A control group included consecutive patients cared for by the same rescue team during the same period but who were not ejected out of their vehicle. Forty-four percent of the ejected patients had a GCS < or = 8, 21% were hypotensive and 22% had respiratory problems. Nine patients died at the scene. A total of 53% of the 62 ejected patients who were transported had an ISS > or = 16. The median ISS was 17. A total of 37% of the patients were intubated at the scene, needle chest decompression was performed in 5% and major analgesia was used in 27% of the cases. A total of 38% of the patients needed surgery in the first 4 h, 34% needed intensive care. No patient needed secondary transfer to the Trauma Centre if they were not brought there in the first instance. The outcome was poor in 27 cases (38%): 17 died and 10 needed transfer to specialised institutions. Non-ejected patients suffered mostly from head and neck injuries (50%) of which 9% were severe (head and neck AIS > or = 4, P < 0.05). Thoracic injuries were less frequent (35%) of which 13% were severe (thorax AIS > or = 4, P < 0,05). The median ISS was 9 for the non-ejected patients, P < 0.05. In conclusion, ejection from a four-wheel vehicle causes more severe injuries and requires a high number of advanced life support manoeuvres. Based on the mechanism of injury alone, patients ejected from four-wheel vehicles should automatically receive a response from the best available pre-hospital team. In our system, this means the dispatch of a physician staffed helicopter.

Accidents, Traffic↗

[Hyponatremia in neurologic intensive care: cerebral salt wasting syndrome and inappropriate antidiuretic hormone secretion].

Hyponatraemia is a frequent complication in neurologically injured patients; it is a secondary cerebral injury. Hyponatraemia leads to consciousness problems, convulsions, worsening of the neurological status and thus the neurological evaluation. Hyponatraemia is secondary to free water retention (inappropriate ADH secretion) or to renal salt loss. The cerebral salt wasting syndrome (CSWS) has been described with head injury, subarachnoid haemorrhage and after several sorts of brain insults. It is characterised by an increased natriuresis and diuresis. Diagnosis is based on hyponatraemia, hypernatriuresis, increased diuresis and hypovolaemia. However, inappropriate ADH secretion and CSWS share several diagnostic criteria. The atrial natriuretic factor and the C-type natriuretic factors play a role in the development of the CSWS. The diagnostic approach and monitoring are based on the assessment of sodium and water losses. Therapy is based on correction of the circulating volume and natraemia. Speed of correction is a matter of debate: slow correction presents the risk of further neurological injury whereas rapid correction presents the risk of central pontine myelinosis.

Brain Chemistry↗

[Anesthesia for epilepsy surgery].

Epilepsy is rather common, affecting 0.5 to 2% of the population. Numerous patients, particularly those resistant to the antiepileptic therapy, can be surgically treated after a thorough evaluation. Surgery for epilepsy can be carried out either under general or local anaesthesia with sedation. This second approach is reserved for the extirpation of foci localised in motor, sensory or language areas. During the preoperative anaesthetic evaluation, two specific points have to be taken into account: the psychological aspect and the antiepileptic medication. During the procedure, an electrocorticography with or without stimulation may be indicated, particularly when a perioperative stimulation is scheduled. Low doses of volatile agents are chosen, and no curare and large doses of benzodiazepines and barbiturates. Awakening takes place on the operation table for a rapid and reliable neurological evaluation. During procedures performed under local anaesthesia, the anaesthetist must be ready at any time to intubate the patient in order to secure the airway.

Anesthesia↗

[Coronary artery bypass by mini-thoracotomy: noticeable benefits with clinical experience of the treatment team].

AIM OF THE STUDY: Minimally invasive coronary artery bypass surgery is fundamentally different as compared to open sternal approach under cardiopulmonary bypass. Modifications of the surgical, anesthesiologic and post-operative techniques are necessary before evaluation of its real benefit. We analyze the potential effect of a learning period on the short term results of this technique. METHODS: From July 1997 to February 1999, 20 patients were operated using this method. We compare the results of the first 10 patients (group 1: 8M/2F, 59.6 +/- 13.8 years) to those of the last 10 patients (group 2: 8M/2F; age = 63.2 +/- 6.1 years). DISCUSSION: Progress between the two groups is striking. Left anterior descending coronary clamping time could be reduced from 28.5 +/- 2.4 min. in group 1 to 22.2 +/- 1.8 min. in group 2 (p < 0.05), and operative time was reduced from 125 +/- 4 min. to 97 +/- 5 min. (p < 0.005). The post-operative atrial fibrillation rate diminished from 4/10 in group 1 to 1/10 in group 2.3/10 patients in group 1 suffered a post-operative pneumonia whereas none in group 2 had pulmonary complication. The stay in the intensive care unit could be reduced from 2.3 +/- 0.3 days to 1.4 +/- 0.2 days (p < 0.05) and the total post-operative stay diminished from 8.5 +/- 0.9 days to 4.7 +/- 0.5 days (p < 0.005). CONCLUSION: There are evidence for a learning period in minimally invasive cardiac surgery. Short term benefits of this technique are then evident as demonstrated by a reduction in the ICU stay and the hospital stay.

Adult↗

Comparison of the effects of clonidine and hydroxyzine on haemodynamic and catecholamine reactions to microlaryngoscopy.

BACKGROUND AND OBJECTIVE: This study compares the effect of oral clonidine vs. hydroxyzine on the haemodynamic and catecholamine responses to microlaryngoscopy. METHODS: Thirty-five ASA II-III patients were included in this double-blind randomized trial. The patients received either hydroxyzine 1 mg kg-1 (n = 18) or clonidine 3 micrograms kg-1 (n = 17) for their oral premedication 100 min before an intravenous induction of anaesthesia using propofol (2-3 mg kg-1) and fentanyl (2 micrograms kg-1). Arterial pressure and heart rate were measured before premedication, and throughout the procedure and recovery. Plasma catecholamine levels were determined before premedication, after induction, and 1.5, 30 and 120 min after laryngoscopy. RESULTS: Mean arterial pressure was significantly lower after clonidine, whereas there was no difference in heart rate and plasma catecholamine levels between the two groups. CONCLUSIONS: Clonidine for premedication significantly decreased mean arterial pressure during microlaryngoscopy and the following recovery phase but did not modify the overall haemodynamic response to the suspension microlaryngoscopic nociceptive stimulus.

Adrenergic alpha-Agonists↗

General anaesthesia for supratentorial neurosurgery.

Anaesthesia for the surgical treatment of supratentorial tumours requires an understanding of: the pathophysiology of a localised or generalised increase in intracranial pressure (ICP), the regulation and maintenance of intracerebral perfusion, avoidance of secondary systemic insults to the brain, and the effects of anaesthetic drugs on ICP, cerebral perfusion and cerebral metabolism. Knowledge of the therapeutic options available for decreasing ICP, brain bulk and brain tension perioperatively is also essential. Potential complications which may present during supratentorial neurosurgery include massive intraoperative haemorrhage and seizures. The fact that the surgeon is operating on a tensed brain is also a potential source of difficulty. The need to monitor brain function and environment during surgery poses a challenge to the anaesthesiologist, as does the achievement of rapid emergence from anaesthesia with the adequate use of anaesthetic drugs.

Anesthesia, General↗

Impact of duration of chest tube drainage on pain after cardiac surgery.

OBJECTIVE: This study was designed to analyze the duration of chest tube drainage on pain intensity and distribution after cardiac surgery. METHODS: Two groups of 80 cardiac surgery adult patients, operated on in two different hospitals, by the same group of cardiac surgeons, and with similar postoperative strategies, were compared. However, in one hospital (long drainage group), a conservative policy was adopted with the removal the chest tubes by postoperative day (POD) 2 or 3, while in the second hospital (short drainage group), all the drains were usually removed on POD 1. RESULTS: There was a trend toward less pain in the short drainage group, with a statistically significant difference on POD 2 (P=0.047). There were less patients without pain on POD 3 in the long drainage group (P=0. 01). The areas corresponding to the tract of the pleural tube, namely the epigastric area, the left basis of the thorax, and the left shoulder were more often involved in the long drainage group. There were three pneumonias in each group and no patient required repeated drainage. CONCLUSIONS: A policy of early chest drain ablation limits pain sensation and simplifies nursing care, without increasing the need for repeated pleural puncture. Therefore, a policy of short drainage after cardiac surgery should be recommended.

Adult↗

Effects of neck position and head elevation on intracranial pressure in anaesthetized neurosurgical patients: preliminary results.

This study reports the collective effect of the positions of the operating table, head, and neck on intracranial pressure (ICP) of 15 adult patients scheduled for elective intracerebral surgery. Patients were anesthetized with propofol, fentanyl, and maintained with a propofol infusion and fentanyl. Intracranial pressure was recorded following 20 minutes of stabilization after induction at different table positions (neutral, 30 degrees head up, 30 degrees head down) with the patient's neck either 1) straight in the axis of the body, 2) flexed, or 3) extended, and in the five following head positions: a) head straight, b) head angled at 45 degrees to the right, c) head angled at 45 degrees to the left, d) head rotated to the right, or e) head rotated the left. For ethical reasons, only patients with ICP < or = 20 mm Hg were included. Intracranial pressure increased every time the head was in a nonneutral position. The most important and statistically significant increases in ICP were recorded when the table was in a 30 degree Trendelenburg position with the head straight or rotated to the right or left, or every time the head was flexed and rotated to the right or left-whatever the position of the table was. These observations suggest that patients with known compromised cerebral compliance would benefit from monitoring ICP during positioning, if the use of a lumbar drainage is planed to improve venous return, cerebral blood volume, ICP, and overall operating conditions.

Adult↗

Plasma and cerebrospinal fluid concentration of neuropeptide Y, serotonin, and catecholamines in patients under propofol or isoflurane anesthesia.

Propofol is a widely used anesthetic for both induction and maintenance of anesthesia during surgery. A strong feeling of hunger has been reported during the early recovery period after propofol anesthesia. We have investigated the effect of propofol on appetite in 10 patients undergoing a craniotomy and in parallel measured neuropeptide Y (NPY), catecholamines, and serotonin levels in the cerebrospinal fluid and plasma during anesthesia. Ten patients anesthetized with a volatile agent (isoflurane) served as a control group. Plasma NPY and catecholamines levels were not affected by surgery at any time. We observed a strong increase in NPY concentrations in the cerebrospinal fluid independently of the anesthetic technique agent used, whereas catecholamines were unchanged. We found that serotonin concentrations decreased significantly in the plasma (but not in the cerebrospinal fluid) of patients treated by propofol when compared with the control group; this decrease was associated with an increase of hunger early postoperatively. We concluded that the proappetite effect of propofol is mediated through a decrease of serotonin at the peripheral level.

Adult↗

Neuroleptanesthesia: current status.

PURPOSE: To review the current status and possible future of neuroleptanalgesia/anesthesia, techniques that may be nearly extinct. SOURCE: Articles from 1966 to present were obtained from the Current Science and Medline databases. Search terms include neurolepananalgesia/anesthesia, conscious sedation, droperidol, benzodiazepines, propofol, ketamine, and opioids. Information and abstracts obtained from meetings on this topic helped complete the collection of information. PRINCIPAL FINDINGS: Droperidol/fentanyl may still be clinically indicated in the management of surgical seizure therapy for electrocorticography. However, the high incidence of post-operative sedation and restlessness discourage its use for other surgical or diagnostic procedures. Many surgical interventions, once thought ideally suited for neuroleptic agents, now meet better success with newer medications. The use of midazolam and/or propofol, in association with newer opioids, provides ideal anesthetic combinations. CONCLUSION: The advantages of newer anesthetic agents have redefined the clinical indications for neuroleptanesthesia. In routine modern anesthesia, anxiolysis, sedation, and/or analgesia is better provided, with quicker recovery, by the new pharmacokinetic and pharmacodynamic characteristics of recent medications than by the neuroleptic component of neuroleptanesthesia.

Adjuvants, Anesthesia↗