Anaphylaxis to clindamycin following cutaneous exposure.

BACKGROUND: The role and importance of skin barrier as an immunologic organ and as a potent way of sensitization is well known. However, antibiotics anaphylaxis following skin sensitization has not been reported. CASE PRESENTATION: We describe the first case of intravenous clindamycin anaphylaxis, with likely sensitization due to previous topical exposure to clindamycin gel for acne in a 14-year-old boy with history of atopy and mild atopic dermatitis. CONCLUSION: This case highlights the potential sensitization to drug allergens, including antibiotics, via the skin.

Improvements in the method of radiation anomaly detection by spectral comparison ratios.

We present a new procedure for configuring the Nuisance-rejection Spectral Comparison Ratio Anomaly Detection (N-SCRAD) method. The procedure minimizes detectable count rates of source spectra at a specified false positive rate using simulated annealing. We also present a new method for correcting the estimates of background variability used in N-SCRAD to current conditions of the total count rate. The correction lowers detection thresholds for a specified false positive rate, enabling greater sensitivity to targets.

[Antenatal perineal rehabilitation in patients with stress urinary incontinence during pregnancy: preliminary study]. / Intérêt de la rééducation périnéale prénatale chez les patientes présentant une incontinence urinaire d'effort pendant la grossesse: étude préliminaire.

OBJECTIVE: To evaluate the results of antenatal perineal rehabilitation (APR) in patients complaining of stress urinary incontinence (SUI) during pregnancy. MATERIAL AND METHODS: Ten patients complaining of SUI during pregnancy participated in a standardizedAPR program. A phone investigation was carried late after delivery to evaluate patient satisfaction, improvement of SUI and effect of this therapeutic approach on sexual function and pelvic floor stability. The patients were invited to respond to two quality of life and symptom questionnaires (ISP, QIP). Results obtained were compared with those of a control group of 10 patients who did not present SUI during pregnancy, and who did not participate in APR, but took part in a conventional program of postnatal perineal rehabilitation (PPR). The groups were matched for age, BMI, parity and obstetrical history. Delivery modalities (instrumental deliveries and episiotomy rate) were analyzed in both groups. RESULTS: The rate of satisfaction with perineal rehabilitation were 10/10 and 7/10 for the APR and the PPR respectively. Delivery modalities were not different in the APR group. Four of the 10 patients who presented SUI during pregnancy had persistent SUI 14 months after childbirth. One of the 10 patients who did not present SUI during pregnancy presented SUI 22 months after the childbirth. CONCLUSION: This study provides incentive to conduct a prospective study to demonstrate that antenatal perinealrehabilitation is an effective way to reduce the risk of persistent SUI after childbirth. Although these preliminary results have to be confirmed by larger series, this management scheme can be proposed.

Electrical induction of ventricular fibrillation for resuscitation from postcountershock pulseless and asystolic cardiac arrests.

BACKGROUND: There is increasing evidence that defibrillation from prolonged ventricular fibrillation (VF) before CPR decreases survival. It remains unclear, however, whether harmful effects are due primarily to initial countershock of ischemic myocardium or to resultant postdefibrillation rhythms (ie, pulseless electrical activity [PEA] or asystole). METHODS AND RESULTS: We induced 15 dogs into 12 minutes of VF and randomized them to 3 groups. Group 1 was defibrillated at 12 minutes and then administered advanced cardiac life support (ACLS); group 2 was allowed to remain in VF and was subsequently defibrillated after 4 minutes of ACLS; group 3 was defibrillated at 12 minutes, electrically refibrillated, and then defibrillated after 4 minutes of ACLS. All group 1 and 3 animals were defibrillated into PEA/asystole at 12 minutes. After 4 minutes of ACLS, group 2 and 3 animals were effectively defibrillated into sinus rhythm. The extension of VF in group 2 and 3 subjects paradoxically resulted in shorter mean resuscitation times (251+/-15 and 245+/-7 seconds, respectively, versus 459+/-66 seconds for group 1; P<0.05) and improved 1-hour survival (10 of 10 group 2 and 3 dogs versus 1 of 5 group 1 dogs; Fisher's exact, P<0.005) compared with more conservatively managed group 1 subjects. CONCLUSIONS: Precountershock CPR during VF appears more conducive to resuscitation than CPR during postcountershock PEA or asystole. The intentional induction of VF may prove useful in the management of PEA and asystolic arrests.

Cardiopulmonary resuscitation with a hydraulic-pneumatic band.

Improved blood flow during cardiopulmonary resuscitation (CPR) has been shown to enhance survival from cardiac arrest. Chest compression with a circumferential pneumatic vest enhances blood flow, but the size, weight, and energy consumption of the inflation system limit its portability and, thereby, have made clinical studies difficult. The purpose of this investigation was to study an improved circumferential chest compression device that uses a constricting band that is pneumatically actuated. The constricting band applies its force to a hydraulic cushion that contacts the anterior and lateral aspects of the chest. The hydraulic cushion transfers the circumferential constriction to inward force. CPR was performed on subjects 5 mins after induction of ventricular fibrillation, with the hydraulic-pneumatic band system (HB-CPR), with a pneumatic vest system (PV-CPR), and with standard manual CPR (S-CPR), each done for 2 mins in randomized order. Aortic and right atrial pressures were measured with micromanometers. Coronary perfusion pressure was calculated as the mean difference between the aortic and right atrial pressures during the release phase of chest compression. Aortic pressure and coronary perfusion pressure with HB-CPR and PV-CPR were improved over S-CPR, and HB-CPR produced comparable pressures to those of PV-CPR. The system for performing HB-CPR, however, was substantially lighter (10 vs. 50 kg) and consumed less energy (300 vs. 1000 watts) than that for PV-CPR. Thus, HB-CPR appears to produce a similar improvement in hemodynamics over S-CPR as PV-CPR but may be more portable than PV-CPR. Therefore, HB-CPR may allow larger scale testing of circumferential chest compression approaches.

Resuscitation after prolonged ventricular fibrillation with use of monophasic and biphasic waveform pulses for external defibrillation.

BACKGROUND: Survival after prolonged ventricular fibrillation (VF) appears severely limited by 2 major factors: (1) low defibrillation success rates and (2) persistent post-countershock myocardial dysfunction. Biphasic (BP) waveforms may prove capable of favorably modifying these limitations. However, they have not been rigorously tested against monophasic (MP) waveforms in clinical models of external defibrillation, particularly where rescue from prolonged VF is the general rule. METHODS AND RESULTS: We randomized 26 dogs to external countershocks with either MP or BP waveforms. Hemodynamics were assessed after shocks applied during sinus rhythm, after brief VF (>10 seconds), and after resuscitation from prolonged VF (>10 minutes). Short-term differences in percent change in left ventricular +dP/dt(max) (MP -16+/-28%, BP +9.1+/-24%; P=0.03) and left ventricular -dP/dt(max) (MP -37+/-26%, BP -18+/-20%; P=0.05) were present after rescue from brief VF, with BP animals exhibiting less countershock-induced dysfunction. After prolonged VF, the BP group had lower mean defibrillation thresholds (107+/-57 versus 172+/-88 J for MP, P=0.04) and significantly shorter resuscitation times (397+/-73.7 versus 488+/-74.3 seconds for MP, P=0.03). CONCLUSIONS: External defibrillation is more efficacious with BP countershocks than with MP countershocks. The lower defibrillation thresholds and shorter resuscitation times associated with BP waveform defibrillation may improve survival after prolonged VF arrest.

Is a pressor necessary during aortic perfusion and oxygenation therapy of cardiac arrest?

STUDY OBJECTIVE: Occlusion of the descending aorta and infusion of oxygenated ultrapurified polymerized bovine hemoglobin may improve the efficacy of advanced cardiac life support (ACLS). Because selective aortic perfusion and oxygenation (SAPO) directly increases coronary perfusion pressure, exogenous epinephrine may not be required. The purpose of this study was to determine whether exogenous epinephrine is necessary during SAPO by comparing the rate of return of spontaneous circulation and aortic and coronary perfusion pressures during ACLS-SAPO in animals treated with either intra-aortic epinephrine or saline solution. METHODS: A prospective, randomized, interventional before-after trial with a canine model of ventricular fibrillation cardiac arrest and ACLS based on external chest compression was performed. The ECG, right atrial, aortic arch, and esophageal pulse pressures were measured continuously. A descending aortic occlusion balloon catheter was placed through the femoral artery. Ventricular fibrillation was induced, and no therapy was given during the 10-minute arrest time. Basic life support was then initiated and normalized by standardization of esophageal pulse pressure and central aortic blood gases. After 3 minutes of basic life support, the aortic occlusion balloon was inflated, and 0.01 mg/kg epinephrine or saline solution was administered through the aortic catheter followed by 450 mL of ultrapurified polymerized bovine hemoglobin over 2 minutes. Defibrillation was then attempted. The outcomes and changes in intravascular pressures were compared. RESULTS: Aortic pressures were higher during infusions in animals treated with epinephrine. During infusion, the mean aortic relaxation pressure increased by 58+/-5 mm Hg in animals that had received epinephrine versus 20+/-11 mm Hg in those that had received saline placebo. The coronary perfusion pressure during infusion increased by 52+/-8 mm Hg in animals that had received epinephrine versus 26+/-10 mm Hg in those that had received saline. Only 2 of 7 animals in the placebo group had return of spontaneous circulation versus 7 of 8 in the epinephrine group. CONCLUSION: The addition of epinephrine to ACLS-SAPO increases vital organ perfusion pressures and improves outcome from cardiac arrest. There appears to be a profound loss of arterial vasomotor tone after prolonged arrest. This loss of vasomotor tone may make exogenous pressors necessary for resuscitation after prolonged cardiac arrest.

Emergency department cardiopulmonary bypass in the treatment of human cardiac arrest.

OBJECTIVE: To study the use of emergency department (ED) femoro-femoral cardiopulmonary bypass (CPB) in the resuscitation of medical cardiac arrest patients. DESIGN: Prospective, uncontrolled trial. SETTING: Urban academic ED staffed with board-certified emergency physicians (EPs). PARTICIPANTS: Ten patients with medical cardiac arrest unresponsive to standard therapy. INTERVENTIONS: Femoro-femoral CPB instituted by EPs. RESULTS: The time of cardiac arrest prior to CPB (mean+/-SD) was 32.0+/-13.6 min. The cardiac output while on CPB was 4.09+/-1.03 L/min with an average of 229+/-111 min on bypass. All 10 patients had resumption of spontaneous cardiac activity while on CPB. Seven of these were weaned from CPB with intrinsic spontaneous circulation. Of these, six patients were transferred from the ED to the operating room for cannula removal and vessel repair while the other patient died in the ED soon after discontinuing CPB. Mean survival was 47.8+/-44.7 h in the six patients leaving the ED. Although these patients had successful hemodynamic resuscitation, there were no long-term survivors. CONCLUSION: CPB instituted by EPs is feasible and effective for the hemodynamic resuscitation of cardiac arrest patients unresponsive to advanced cardiac life support therapy. Future efforts need to focus on improving long-term outcome.

Objective measurements for guiding initiation, sequencing, and discontinuation of life-support intervention.

At present, there are only a limited number of objective measures available to clinicians resuscitating patients from cardiac arrest. The electrocardiogram and end-tidal CO2 are easily applied, but the data they produce are of only limited utility in evaluating the efficacy of chest compression and in choosing the sequence of therapies. In particular, we are in need of an objective test that can tell us when the myocardium will defibrillate into a perfusing rhythm. The ventricular fibrillation waveform holds information that we have not yet begun to utilize. Parameters derived from power spectrum analysis, such as ventricular fibrillation median frequency, appear promising. Combination of both old and new parameters may allow us to more accurately evaluate the efficacy of therapy.

Hematocrit as a predictor of significant injury after penetrating trauma.

A study was undertaken to determine if there are differences in hematocrit (HCT) during the initial evaluation of patients with and without significant visceral intrathoracic or intraabdominal injury after penetrating trauma and, if so, the predictive value of this parameter. Sixty consecutive adults with potentially significant penetrating trauma who presented to an urban municipal trauma center during a 10-week period were studied. Diagnostic variables were recorded for all patients at risk for significant injury, defined as intrathoracic or intraabdominal injury requiring surgical intervention. Patients were ultimately grouped on the basis of operative findings or observation to discharge. Acquired variables included vital signs, initial HCT (HCT-0), HCT at 15 minutes (HCT-15), HCT at 30 minutes (HCT-30), and fluid administered. Twenty-one patients had significant injuries (INJ), and 39 did not (NO-INJ). INJ patients had lower HCT values than NO-INJ on presentation (35% +/- 6% and 41% +/- 5%, respectively). At presentation, a low HCT was predictive of significant injury, but a normal HCT did not preclude injury. The changes in HCT from arrival to 15 minutes, between INJ and NO-INJ patients, were similar (-1.5% +/- 3% and -0.6% +/- 3% respectively). Only when the decrease in HCT was > or =6.5% from presentation measurements was it predictive of injury. During the first 15 minutes a decrease in HCT of > or =6.5% had a positive predictive value and specificity of 1.0. The change in HCT between 15 and 30 minutes was less useful. There was a large difference between the amounts of fluid given to injured and uninjured patients, which may have been responsible for some of the differences in HCT between the two groups. These results show that HCT may have some diagnostic utility during the early management of penetrating trauma. Presentation with an HCT below normal, or an early decrease in HCT, is an indicator of potential injury. Although many patients with serious internal injuries do not manifest large decreases early after presentation, those who do have a high probability of internal injury. The lower the HCT, or the greater the decrease, the greater the probability that a significant injury exists.

Dose-response relationship between aortic infusions of polymerized bovine hemoglobin and return of circulation in a canine model of ventricular fibrillation and advanced cardiac life support.

OBJECTIVES: Return of spontaneous circulation after cardiac arrest may be a function of vital organ perfusion. Selective aortic perfusion and oxygenation with oxygenated ultrapurified polymerized bovine hemoglobin improves vital organ perfusion and is an effective adjunct in the treatment of cardiac arrest. This study determined the dose-response relationship between intra-aortic oxygenated ultrapurified polymerized bovine hemoglobin and return of spontaneous circulation. DESIGN: Randomized, interventional study, using a clinically relevant model of ventricular fibrillation with a prolonged arrest time and cardiopulmonary resuscitation based on external chest compression and aortic occlusion with oxygenated ultrapurified polymerized bovine hemoglobin infusion. SETTING: University, resuscitation research laboratory. SUBJECTS: Fasted, mongrel dogs (> 20 kg). INTERVENTIONS: After alpha-chloralose anesthesia, blood gases and vital signs were normalized. Electrocardiogram, aortic arch, and intraesophageal pressures were measured continuously. A descending aortic occlusion-infusion balloon catheter was placed through the femoral artery. Ventricular fibrillation was induced and basic life support was begun after 10 mins. Interanimal differences in basic life support were minimized by standardization of the esophageal pulse pressure and aortic blood gases. At 13 mins, the aortic occlusion balloon was inflated and a dose of 10, 20, or 30 mL/kg of ultrapurified polymerized bovine hemoglobin was infused at 300 mL/min. Defibrillation was attempted at the end of the infusion. MEASUREMENTS AND MAIN RESULTS: Only two of five animals given 10 mL/kg of ultrapurified polymerized bovine hemoglobin had return of spontaneous circulation, vs. four of five animals given 20 mL/kg, and all seven animals given 30 mL/kg. All resuscitated animals were alive at 1 hr after return of spontaneous circulation. CONCLUSIONS: There is a dose-response relationship between the volume of oxygenated ultrapurified polymerized bovine hemoglobin administered by selective aortic perfusion and oxygenation and return of spontaneous circulation after prolonged cardiac arrest. This result supports the hypothesis that vital organ flow is causally related to improved outcome.

Future directions for resuscitation research. IV. Innovative advanced life support pharmacology.

The topics discussed in this session include a partial review of laboratory and clinical studies examining the effects of adrenergic agonists on restoration of spontaneous circulation after cardiac arrest, the effects of varying doses of epinephrine, and the effects of novel vasopressors, buffer agents (NaHCO3, THAM, 'Carbicarb') and anti-arrhythmics (lidocaine, bretylium, amiodarone) in refractory ventricular fibrillation. Novel therapeutic approaches include titrating electric countershocks against electrocardiographic power spectra and of preceding the first countershocks with single or multiple drug treatments. These approaches need to be investigated further in controlled animal and patient studies. Epidemiologic data from randomized clinical outcome studies can give clues, but cannot document pharmacologic mechanisms in the dynamically changing events during attempts to achieve restoration of spontaneous circulation from prolonged cardiac arrest. Also, rapid drug administration by the intraosseous route was compared with intratracheal and intravenous (i.v.) drug administration. Many studies on the above treatments have yielded conflicting results because of differences between healthy hearts of animals and sick hearts of patients, differences in arrest (no-flow) times and cardiopulmonary resuscitation (CPR) (low-flow) times, different pharmacokinetics, different dose/response requirements, and different timing of drug administration during low-flow CPR versus during spontaneous circulation. The need to stabilize normotension and prevent rearrest by titrated novel drug administration, once spontaneous circulation has been restored, requires research. Most of the above topics require some re-evaluation in clinically realistic animal models and in cardiac arrest patients, especially by titration of old and new drug treatments against variables that can be monitored continuously during resuscitation.

Future directions for resuscitation research. III. External cardiopulmonary resuscitation advanced life support.

This discussion about advanced cardiac life support (ACLS) reflects disappointment with the over 50% of out-of-hospital cardiopulmonary resuscitation (CPR) attempts that fail to achieve restoration of spontaneous circulation (ROSC). Hospital discharge rates are equally poor for in-hospital CPR attempts outside special care units. Early bystander CPR and early defibrillation (manual, semi-automatic or automatic) are the most effective methods for achieving ROSC from ventricular fibrillation (VF). Automated external defibrillation (AED), which is effective in the hands of first responders in the out-of-hospital setting, should also be used and evaluated in hospitals, inside and outside of special care units. The first countershock is most important. Biphasic waveforms seem to have advantages over monophasic ones. Tracheal intubation has obvious efficacy when the airway is threatened. Scientific documentation of specific types, doses, and timing of drug treatments (epinephrine, bicarbonate, lidocaine, bretylium) are weak. Clinical trials have failed so far to document anything statistically but a breakthrough effect. Interactions between catecholamines and buffers need further exploration. A major cause of unsuccessful attempts at ROSC is the underlying disease, which present ACLS guidelines do not consider adequately. Early thrombolysis and early coronary revascularization procedures should also be considered for selected victims of sudden cardiac death. Emergency cardiopulmonary bypass (CPB) could be a breakthrough measure, but cannot be initiated rapidly enough in the field due to technical limitations. Open-chest CPR by ambulance physicians deserves further trials. In searches for causes of VF, neurocardiology gives clues for new directions. Fibrillation and defibrillation thresholds are influenced by the peripheral sympathetic and parasympathetic nervous systems and impulses from the frontal cerebral cortex. CPR for cardiac arrest of the mother in advanced pregnancy requires modifications and outcome data. Until more recognizable critical factors for ROSC are identified, titrated sequencing of ACLS measures, based on physiologic rationale and sound judgement, rather than rigid standards, gives the best chance for achieving survival with good cerebral function.

Aortic-based therapy for cardiac arrest.

After the failure of electrical countershock, the successful treatment of cardiac arrest is a function of raising aortic pressure so as to improve vital organ perfusion. Pharmacologic pressor agents have until recently been the most direct means of increasing aortic pressure. We have now begun to reevaluate direct aortic techniques including occlusion, infusion, counter-pulsation, and combinations of these. Clinical studies have demonstrated that the aorta can be accessed quickly and reliably even under emergency conditions. Initial laboratory studies indicate that some nonpharmacologic aortic therapies hold promise as adjuncts to external chest compression, or even as stand-alone therapies. Considerable research will be needed to identify the most effective approach before clinical trials can be considered.

Cardiac arrest research in humans--insights into failure.

Cardiac arrest research in humans has failed to fulfil expectations generated by laboratory studies. This reflects a number of factors. It is difficult to perform clinical research in the setting of emergency cardiac resuscitation. Both the epidemiology and pathophysiology of sudden death present special problems to the clinical researcher. Laboratory studies and clinical trials have failed to faithfully mimic each other. Estimation of sample size and application of inclusion/exclusion criteria present special problems in methodology. Our focus on improving long term survival by changing one component of therapy may have been premature and obscured the utility of extant data. Many of these problems can be addressed through refinements in: laboratory models, our understanding of the underlying pathophysiology, estimation of sample size, the application of inclusion/exclusion criteria, the identification of the primary dependent variables and subgroups of interest, the overall quality of therapy. Clinical studies will not generate useful data until these issues, among others, have been addressed.

High atrial natriuretic peptide concentrations blunt the pressor response during cardiopulmonary resuscitation in humans.

OBJECTIVE: To determine the relationship of circulating atrial natriuretic peptide concentrations to the pressor response to high-dose epinephrine in patients undergoing cardiopulmonary resuscitation (CPR) for cardiac arrest. DESIGN: Prospective study. PATIENTS: Fourteen normothermic, adult, prehospital and emergency department patients suffering unexpected cardiac arrest. INTERVENTION: Patients received high-dose epinephrine (0.2 mg/kg) i.v. when standard advanced cardiac life support (including multiple 1-mg dosages of epinephrine) failed to result in return of spontaneous circulation. MEASUREMENTS AND MAIN RESULTS: Cardiac arrest patients were separated into those patients with and without detectable serum atrial natriuretic peptide concentrations, and were termed the "low atrial natriuretic peptide" and "high atrial natriuretic peptide" groups, respectively. Their aortic pressure response to high-dose (0.02 mg/kg) epinephrine was compared. The proportion with positive assays was compared with a group of healthy control subjects. Fourteen patients were studied. Eight patients had low serum atrial natriuretic peptide concentrations and six patients had high circulating atrial natriuretic peptide concentrations. The mean concentration in the high atrial natriuretic peptide group was 151 +/- 82 pg/mL. The proportion with positive assays (six of 14 patients) was greater than in the group in spontaneous circulation (three of 29 patients) (p = .002). The maximal increase in the aortic relaxation-phase pressures after high-dose epinephrine was 9 +/- 7 torr (1.2 +/- 0.9 kPa) in the low atrial natriuretic peptide group and 0 +/- 5 torr (0 +/- 0.7 kPa) in the high atrial natriuretic peptide group (p = .03). The maximal increase in the aortic compression pressures after high-dose epinephrine was 17 +/- 13 torr (2.3 +/- 1.7 kPa) in the low atrial natriuretic peptide group and 2 +/- 10 torr (0.3 +/- 1.3 kPa) in the high atrial natriuretic peptide group (p = .03). Thus, pressor responses after high-dose epinephrine administration were observed in patients in the low atrial natriuretic peptide group, but this response was absent in patients in the high atrial natriuretic peptide group. CONCLUSIONS: Cardiac arrest patients receiving CPR have higher circulating atrial natriuretic peptide concentrations than healthy subjects. High serum atrial natriuretic peptide concentrations may antagonize the vasopressor response to epinephrine. Blocking this effect of atrial natriuretic peptide may improve outcomes in patients suffering cardiac arrest.