[Acute severe pain in emergencies. The key for efficient analgesia]. / Douleur aiguë intense en médecine d'urgence. Les clefs d'une analgésie efficace.

OBJECTIVE: To measure severe acute pain (SAP) frequency, to describe SAP management and to bring to view the conditions of analgesia success in emergency medicine. DESIGN: Multicentre prospective survey: 7 days in Emergency Departments (ED), 30 days in Mobile Intensive Care Units (MICU). Multivariate analysis to measure the independent effect on pain relief of factors identified by Chi squared test. SETTING: All of 6 ED and 8 MICU of a French region. PATIENTS: Over 15 years of age. MAIN OUTCOME MEASURES: Pain intensity was assessed with Visual Analog Scale (VAS) before and after ED or MICU management. SAP group (defined by initial VAS score > 40 mm) was analyzed for pain relief (defined by final VAS score < or = 40 mm). Influence on pain relief through pain aetiology, initial pain intensity, treatment delay and opioid use was analyzed. RESULTS: 1,082 fulfilled medical forms for 3,419 eligible patients. SAP frequency was estimated 36% (CI95 = 34-38%) in ED and 29% (CI95 = 25-33%) in MICU. SAP (n = 368) was often persistent: 45% (CI95 = 43-47%) after discharge from ED and 26% (CI95 = 22-30%) after MICU intervention. The prognostic factors of pain control success revealed by Chi squared test were: MICU (vs ED), treatment delay < or = 3 hours (vs > 3 hours), opioid use (vs non opioid use) and VAS pain level < or = 70 mm (vs > 70 mm). The last 3 factors were confirmed by multivariate analysis. Treatment delay, opioid use, and pain level were found to be determinants of efficient analgesia for SAP. CONCLUSION: Despite the high frequency of SAP in ED and MICU, pain control is not satisfying. Opioid use and early treatment are determinant in analgesia efficiency for SAP and should be therefore encouraged to improve pain relief in emergency medicine.

[Toward a medical approach to the evaluation of activity in a physician-staffed mobile intensive care unit]. / Vers une médicalisation de l'évaluation de l'activité en Smur.

OBJECTIVE: To test the ability of various medical criteria for classifying the patients in a physician-staffed mobile intensive care unit (MICU) by referring to intervention times. STUDY DESIGN: Prospective, open study. PATIENTS AND METHODS: For all the on-scene interventions of the MICUs over a 10-month period, the following data were prospectively collected: pre-hospital diagnosis, initial severity score, medical care score, immediate outcome and three intervention times: on-scene time (OS), time spent with the patient by the MICU team (MT), total duration of intervention (TD). RESULTS: A total of 3,672 MICU interventions were included. Median times were 45 min (32-59) for OS, 66 min (41-91) for MT and 85 min (61-116) for TD. The amount of interventions in a city was correlated with the population (R = 0.95; P < 0.001). The medical care score was greater than one in more than half of the patients. It defined five groups of patients which were different for the three intervention times (P < or = 0.001). A third of the patients were directly transported by the MICU to an ICU. For the median test, immediate outcome groups were different for the three intervention times (P < 0.001). After exclusion of patients with initial cardiac arrest, initial severity score defined five groups of patients which were different for the three intervention times (P < 0.002). Initial severity score and medical care score were correlated (R = 0.37; P < 0.001). CONCLUSION: A classification of the patients based on immediate outcome would be a more accurate indicator of the variability in medical care and consumption of resources in a physician-staffed MICU. In addition, a medical intervention score should be developed to better characterise this medical activity.

Benefit of active compression-decompression cardiopulmonary resuscitation as a prehospital advanced cardiac life support. A randomized multicenter study.

BACKGROUND: We compared short-term prognosis of active compression-decompression (ACD) and standard (STD) cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrests. METHODS AND RESULTS: We randomized advanced cardiac life support (ACLS) with ACD ACLS CPR on odd days and STD ACLS CPR on even days. We measured the rates of return of spontaneous circulation (ROSC), survival at 1 hour (H1), at 24 hours (H24), and at 1 month (D30): hospital discharge (HD); neurological outcome; and complications. Mean times from collapse to basic cardiac life support CPR was 9 minutes and from collapse to ACLS CPR was 21 minutes. Compared with the STD ACLS patients (n = 258), ACD ACLS patients (n = 254) had higher survival rates (ROSC, 44.9% versus 29.8%, P = .0004; H1, 36.6% versus 24.8%, P = .003; H24, 26% versus 13.6%, P = .002; HD without neurological impairment, 5.5% versus 1.9%, P = .03) and a trend for improvement in neurological outcome at D30 (Glasgow-Pittsburgh Outcome Categories = 1.6 +/- 0.8 versus 2.3 +/- 1.1. P = .09). Sternal dislodgements (2.9% versus 0.4%, P = .03) and hemoptysis (5.4% versus 1.3%, P = .01) were more frequent in the ACD ACLS group. CONCLUSIONS: Despite long time intervals, ACD significantly improved short-term survival rates in out-of-hospital cardiac arrests compared with STD CPR.

[Tracheal intubation in prehospital resuscitation: importance of rapid-sequence induction anesthesia]. / Intubation [correction of Induction] trachéale en réanimation préhospitalière: intérêt de l'induction anesthésique à séquence rapide.

OBJECTIVE: To investigate complications of emergency endotracheal intubation (EEI), possibly facilitated by rapid-sequence induction, in the prehospital critical care setting: 1) the difficulty of intubation; 2) the cardiorespiratory consequences of intubation; 3) the relationship between the occurrence of complications and prognosis. STUDY DESIGN: Prospective non randomized, open study. PATIENTS: All patients treated over a 5-month period by a physician-manned ambulance service and requiring EEI. METHODS: Patients were allocated either in with cardiac arrest (CA) group or a group with maintained spontaneous circulation (SC). Difficulty of intubation was assessed by the number of attempts. RESULTS: Two hundred and twenty-four consecutive EEI were carried out by physicians (46%) and residents (38%) not trained in anaesthesia, anaesthetists (8%), or nurse anaesthetists (7%). Trachea was intubated after a maximum of three attempts in all patients. Success rate at the first attempt was 91%. It was 92% in CA patients (n = 76) and 90% in SC patients (P = 0.59). Anaesthetic induction, with (n = 112) or without (n = 12) succinylcholine, was used to facilitate 84% of intubations in SC patients. Complications occurred in 30 patients (20%). There was no relationship between the latter and hospital mortality, duration of ventilatory support, duration of stay in the intensive care unit. CONCLUSION: In this study, EEI in SC patients was frequently facilitated by rapid sequence induction and was associated with a high success rate at the first attempt, as in CA patients. Morbidity was low. All physicians involved in emergency airway management should be skilled in this technique.

End-tidal carbon dioxide during cardiopulmonary resuscitation in humans presenting mostly with asystole: a predictor of outcome.

OBJECTIVE: To determine whether continuous semiquantitative assessment of end-tidal CO2 could provide a highly sensitive predictor of return of spontaneous circulation during cardiopulmonary resuscitation (CPR). DESIGN: Prospective, clinical study. SETTING: Prehospital CPR. PATIENTS: One hundred twenty patients, during nontraumatic cardiac arrest. INTERVENTIONS: End-tidal CO2 values were measured continuously after tracheal intubation, and were categorized as the initial value, and as minimal and maximal values during the first 20 mins. MEASUREMENTS AND MAIN RESULTS: Presenting rhythm was asystole in 22 of the first 24 patients. Return of spontaneous circulation occurred in eight patients. Initial, minimal, and maximal end-tidal CO2 values were significantly (p < .01) higher in these patients than in the patients without return of spontaneous circulation. Cutoff values providing a 100% sensitivity and the highest specificity in predicting return of spontaneous circulation were found to be 10 torr for initial and maximal end-tidal CO2 values, and 2 torr for the minimal end-tidal CO2 value. The number of patients required to reject (with a risk error of <.05) the hypothesis of an actual sensitivity of < or = 90% for an observed sensitivity of 100% was found to be 95. In the second part of the study, this hypothesis was prospectively tested for initial and maximal end-tidal CO2 values in the subsequent 96 patients. Presenting cardiac rhythm was asystole in 87 patients. Return of spontaneous circulation was obtained in 30 patients. The cutoff value of 10 torr for maximal end-tidal CO2 during the first 20 mins after tracheal intubation provided an observed sensitivity of 100% in predicting return of spontaneous circulation with a specificity of 67%. This result allows rejection of the hypothesis of an actual sensitivity of < or = 90% (p = .042). By contrast, the observed sensitivity of initial end-tidal CO2 was only 87%. CONCLUSIONS: End-tidal CO2 represents a valuable tool for monitoring patients presenting with asystole during prehospital CPR. Fluctuations in end-tidal CO2 during CPR and the utility of end-tidal CO2 in detecting return of spontaneous circulation justify its continuous measurement. In addition, a high sensitivity (>90%) in predicting return of spontaneous circulation is prospectively demonstrated using the maximal end-tidal CO2 during the first 20 mins after tracheal intubation, with a cutoff value of 10 torr. Such a prognostic indicator could be used for a more rational approach to prolonged CPR.

Neuromuscular effects of rocuronium on the diaphragm and adductor pollicis muscles in anesthetized patients.

BACKGROUND: Rocuronium has properties that may make it suitable for rapid-sequence intubation. However, its neuromuscular effects have been studied only on the adductor pollicis. This study compares the neuromuscular effect of rocuronium on the diaphragm and adductor pollicis in humans. METHODS: The forces generated by the diaphragm and the adductor pollicis during supramaximal single-twitch stimulation of the phrenic and ulnar nerves, respectively, were studied during thiopental, fentanyl, and nitrous oxide-oxygen anesthesia. In 6 patients, cumulative doses of 0.15, 0.25, 0.35, 0.45, and 0.60 mg.kg-1 rocuronium were given over a 9-min period. The doses for 50% (ED50) and 95% (ED95) depression of twitch height were calculated. In another 12 patients, the times for maximal effect and 10%, 25%, 50%, 75%, and 90% recovery of the twitch height were calculated after a bolus dose of 0.60 mg.kg-1 rocuronium. RESULTS: ED50 and ED95 were higher for the diaphragm (0.26 +/- 0.07 and 0.50 +/- 0.20 mg.kg-1, respectively) than for the adductor pollicis (0.14 +/- 0.05 and 0.24 +/- 0.04 mg.kg-1). Rocuronium 0.60 mg.kg-1 produced 100% paralysis of the adductor pollicis in all patients and of the diaphragm in 9 of 12 patients. The onset time for muscle relaxation after 0.6 mg.kg-1 rocuronium was shorter for the adductor pollicis than for the diaphragm (80 +/- 20 vs. 120 +/- 62 s). Times for 10%, 25%, 75%, and 90% recovery of twitch height were 34 +/- 10, 40 +/- 13, 56 +/- 20, and 64 +/- 21 min, respectively, for the adductor pollicis, and significantly shorter for the diaphragm: 17 +/- 10, 23 +/- 9, 33 +/- 13, and 35 +/- 10 min, respectively. CONCLUSIONS: The diaphragm is more resistant than the adductor pollicis to rocuronium, as shown by greater ED50 and ED95 and faster recovery of the twitch height. The intubating dose of 0.60 mg.kg-1 is close to the ED95 of 0.50 mg.kg-1 for the diaphragm.

Effect of epinephrine on end-tidal carbon dioxide pressure during prehospital cardiopulmonary resuscitation.

This prospective study was designed to quantify the effect of epinephrine on end-tidal PCO2 (PetCO2) during prehospital cardiopulmonary resuscitation (CPR) in humans. It included 20 patients (age range, 26 to 90 years) who presented in ventricular asystole on arrival of the prehospital medical team. Protocol began 5 minutes after tracheal intubation and during chest compressions. Mechanical ventilation was applied at constant rate and tidal volume. PetCO2 was measured before and 3 minutes after peripheral intravenous (IV) injection of 2 mg epinephrine. No other resuscitative drugs were administered during the study period. Mean PetCO2 decreased from 16.7 +/- 9.3 mm Hg before epinephrine to 12.6 +/- 7.1 mm Hg after epinephrine. The mean change in PetCO2 was 4.15 +/- 3.5 mm Hg (P < .0001). Four patients exhibited return of spontaneous circulation (ROSC). The decrease in PetCO2 was similar between the patients who exhibited ROSC and those who did not. There was a significant relationship between the epinephrine-induced change in PetCO2 and the PetCO2 value before epinephrine injection (r = .760; P < .0001). This study demonstrates a variable decrease in PetCO2 after IV epinephrine injection during CPR. Isolated PetCO2 readings may be misleading in assessing CPR efficacy or predicting outcome, and continuous measurement is recommended.

Accuracy of respiratory inductive plethysmography during wakefulness and sleep in patients with obstructive sleep apnea.

To assess the accuracy of the respiratory inductive plethysmograph (RIP) during sleep in obese patients with obstructive sleep apnea (OSA), we monitored 13 patients with OSA during wakefulness and nocturnal sleep with simultaneous measurements of tidal volume from RIP and integrated airflow. Patients wore a tightly fitting face mask with pneumotachograph during wakefulness and sleep. Calibrations were performed during wakefulness prior to sleep and compared with subsequent wakeful calibrations at the end of the study. Patients maintained the same posture during sleep (supine, 11; lateral, two) as during calibrations. There were no significant differences in calibrations before sleep and after awakening. The mean error in 13 patients undergoing RIP measurements of tidal volume during wakefulness was -0.7 +/- 3.4 percent while that during sleep was 2.1 +/- 14.9 percent (p < 0.001). The standard deviation (SD) of the differences between individual breaths measured by RIP and integrated airflow was 9.8 +/- 5.5 percent during wakefulness and 25.5 +/- 18.6 percent during sleep (p < 0.001). During both wakefulness and sleep, errors in RIP tidal volume were not significantly correlated with body mass index. In 12 patients with at least 10 percent time in each of stages 1 and 2 sleep, SD was greater in stage 2 sleep compared with wakefulness and stage 1 (p < 0.001). In three patients who manifested all stages of sleep, SD was greater in REM sleep than in wakefulness and all stages of non-REM sleep (p < 0.001). In three patients who manifested all stages of sleep, SD was greater in REM sleep than in wakefulness and all stages of non REM sleep (p < 0.001). This was associated with paradoxic motion of the rib cage in two patients during REM. We conclude that, despite increased errors in individual breath measurements during sleep, more marked during stages 2 and REM sleep, RIP is clinically useful to measure ventilation quantitatively in obese patients with sleep apnea. The criterion of a decrease of 50 percent in tidal volume assessed by RIP is appropriate to define hypopneas in such patients.

[Ambulatory urologic surgery]. / La chirurgie urologique ambulatoire.

Outpatient urinary tract surgery has been possible in our department since November 1988. In this programme, surgical procedures are performed in patients who do not remain in hospital overnight. Stringent surgical, medical and social criteria are prerequisites to this kind of surgery. Between November 1988 and October 1990, 260 outpatients have been admitted in our department to undergo endoscopic surgery (110 cases), conventional surgery (110 cases), extracorporeal lithotripsy (44 cases) or various types of exploration, local drug perfusions and change or removal of stents (37 cases). Thirty six patients stayed in the inpatient department for the first night. One patient was readmitted the day after his discharge because of clotting after bladder biopsies. At the end of this first experience, ambulatory surgery of the urinary tract has proved to be safe for the patients and to offer many advantages on economical, psychological and medical grounds. It can be predicted that in the future the number of outpatient procedures will increase dramatically.

[Measurement of respiratory effects of propofol by indirect spirometry]. / Effets respiratoires du propofol mesurés par la spirométrie indirecte.

The effects of a continuous steady rate infusion of propofol on spontaneous ventilation were studied in eight unpremedicated ASA 1 male patients. All were non smokers, aged 29 +/- 8 years, and weighed 67 +/- 9 kg. After an initial 1 mg.kg-1 bolus, they received 10 mg.kg-1.h-1 propofol for 10 min, followed by 8 mg.kg-1.h-1 for a further 10 min, and then 6 mg.kg-1.h-1 during the whole study period. Endotracheal intubation was carried out using lidocaine for local anaesthesia. Spontaneous ventilation was assessed during three periods of five minutes: in the awake subject, using indirect spirometry (measurement of variations in chest circumference) and direct spirometry separately, and then, in the anaesthetized subject, using both methods simultaneously. This study aimed: a) to compare the results obtained with the two methods, b) to characterize the effects of propofol anaesthesia on chest wall mechanics using the partitioning of ventilation between rib cage and abdomen provided by the non-invasive method, and c) to assess abdominal compliance by means of a gastric balloon catheter. There was an increase in rib cage ventilation in the awake state, induced by the apparatus for direct spirometry (mouth piece, nose clip). This explained that the ventilatory depression induced by propofol anaesthesia was more pronounced when measured by the direct method. The major determinant of this depression was a shortened inspiratory time, and, to a lesser extent, a decreased mean inspiratory flow rate. By contrast to inhalational anaesthesia, rib cage ventilation was preserved during propofol anaesthesia. The decrease in abdominal ventilation was partly related to a lowered abdominal compliance, suggesting recruitment of the abdominal muscles.

[Ambulatory urologic surgery]. / La chirurgie urologique ambulatoire.

Since November 1st, 1988, an outpatient clinic has been set up in our department of Urology. Patients come to the clinic on the morning of the procedure and leave in the evening after a few hours of monitoring. Eligibility for outpatient surgery is determined using strict social, surgical and medical criteria. A visit with the anesthesiologist is scheduled one week before the operation. On the day of the procedure, the patient arrives at 7 a.m., is shaved, prepared and operated on by a senior surgeon before impatient operations begin. Postoperative monitoring is carried out as usual and around 6 p.m. the surgeon and the anesthesiologist decide whether the patient can be discharged. Most patients are interviewed by telephone within one week of the procedure. From November 1988 through December 1989, 172 adults were admitted to the outpatient clinic for endoscopic surgery (85 cases), open surgery (42 cases) or other procedures including diagnostic investigations, instillations, and removal or replacement of stents (44 cases). Twenty-three patients were discharged only on the day following the procedure. One patient was readmitted for clotting in the bladder. These preliminary results show that, as compared to inpatient surgery, outpatient surgery is cost-saving, easier to cope with psychologically and less apt to be followed by nosocomial infection, without greater risk to the patient provided inclusion criteria are stringently applied.

Improvement of diaphragmatic function by a thoracic extradural block after upper abdominal surgery.

The effects on diaphragmatic function of a thoracic epidural block were assessed in 13 patients after upper abdominal surgery (UAS). Lung volumes and tidal changes in chest wall circumferences and gastric (delta Pgas) and esophageal (delta Pes) pressures were measured pre- and postoperatively. Volume displacement of the abdomen divided by tidal volume (delta VAB/VT) and delta Pgas/delta Pes were taken as indices of the diaphragmatic contribution to tidal breathing. These respiratory variables were obtained in the postoperative period, before and after epidural injection of 0.5% plain bupivacaine to achieve a block up to the T4 segment. UAS was constantly associated with a decrease in VT, delta VAB/VT, delta Pgas/delta Pes, and forced vital capacity (FVC). Epidural block was associated with an increase in VT, delta VAB/VT, and FVC. delta Pgas and delta Pgas/delta Pes returned to their preoperative values. It is concluded that: 1) diaphragmatic dysfunction observed after UAS is partially reversed by thoracic epidural block; and 2) that inhibitory reflexes of phrenic activity arising from the abdominal compartment (abdominal wall and/or viscera) could be involved in this diaphragmatic dysfunction.

Effects of upper or lower abdominal surgery on diaphragmatic function.

Changes in abdominal (delta AB) and rib cage (delta RC) movements, and in vital capacity, were compared between 23 patients undergoing upper or lower abdominal surgery at 1, 3 and 7 days after surgery. Diaphragmatic index was obtained by measuring the relative abdominal motion (delta AB/delta AB + delta RC) using magnetometers. Electrical activity of abdominal muscles was assessed using needle electrodes after upper abdominal surgery in four additional patients. After upper abdominal surgery, the vital capacity and the diaphragmatic index were markedly reduced for 1 week. No abdominal muscle activity was observed at day 1. After lower abdominal surgery, the vital capacity returned to the normal range within 3 days of operation, without any diaphragmatic impairment. These findings substantiate the role of diaphragmatic dysfunction in postoperative reduction in vital capacity observed after upper abdominal surgery.

Diaphragmatic contractility after upper abdominal surgery.

Postoperative dysfunction of the diaphragm has been reported after upper abdominal surgery. This study was designed to determine whether an impairment in diaphragmatic contractility was involved in the genesis of the diaphragmatic dysfunction observed after upper abdominal surgery. Five patients undergoing upper abdominal surgery were studied. The following measurements were performed before and 4 h after surgery: vital capacity (VC), functional residual capacity (FRC), and forced expiratory volume in 1 s. Diaphragmatic function was also assessed using the ratio of changes in gastric pressure (delta Pga) over changes in transdiaphragmatic pressure (delta Pdi). Finally contractility of the diaphragm was determined by measuring the change in delta Pdi generated during bilateral electrical stimulation of the phrenic nerves (Pdi stim). Diaphragmatic dysfunction occurred in all the patients after upper abdominal surgery as assessed by a marked decrease in delta Pga/delta Pdi from 0.480 +/- 0.040 to -0.097 +/- 0.152 (P less than 0.01) 4 h after surgery compared with preoperative values. VC also markedly decreased after upper abdominal surgery from 3,900 +/- 630 to 2,060 +/- 520 ml (P less than 0.01) 4 h after surgery. In contrast, no change in FRC and Pdi stim was observed 4 h after surgery. In contrast, no change in FRC and Pdi stim was observed 4 h after upper abdominal surgery compared with the preoperative values. We conclude that contractility of the diaphragm is not altered after upper abdominal surgery, and diaphragmatic dysfunction is secondary to other mechanisms such as possible reflexes arising from the periphery (chest wall and/or peritoneum), which could inhibit the phrenic nerve output.