Additive Effects of Cointoxicants in Single-Opioid Induced Deaths

A forensic drug database (FDD) was used to capture comprehensive data from all drug-related deaths in West Virginia, with deaths also included from the northern New England states of Maine, Vermont, and New Hampshire. All four states serve predominantly rural populations under two million and all have similar state medical examiner systems that employ statewide uniform death certification policies and practices. This study focused on 1482 single opioid deaths (fentanyl, hydrocodone, methadone, and oxycodone) in the FDD from 2007-2011. We modeled relationships between the opioid concentrations and the presence or absence of the following commonly occurring non-opioid cointoxicants: benzodiazepines (alprazolam and diazepam), alcohol, tricyclic antidepressants, selective serotonin reuptake inhibitors, and diphenhydramine. Additional covariates of state, age, body mass index, and sex were included. Results showed that the presence of alcohol, benzodiazepines, and antidepressants were each associated with statistically significant lower concentrations of some but not all of the opioids studied, which may obscure the interpretation of postmortem toxicology results alone. Fentanyl concentrations appeared to be the least associated with the presence or absence of the variables studied, and cointoxicant alcohol appeared to be associated with lower concentrations in opioid concentrations than were most of the other factors in the model studied. These findings underscore the importance of documenting all potential cointoxicants in opioid-related deaths.

Self-assembled nanofiber hydrogels for mechanoresponsive therapeutic anti-TNFα antibody delivery

Low molecular weight hydrogels, prepared from glycosyl-nucleoside-lipid amphiphiles, exhibit shear-thinning behaviour and reversible thermally- and mechanically-triggered sol-gel transitions. Using mechanical shear stimulation, the release of entrapped anti-TNFα increases and the released anti-TNFα demonstrates efficacy in in vitro neutralization bioassays. Delivery of anti-TNFα is of general interest and broad medicinal utility for treating autoimmune diseases such as rheumatoid arthritis.

Mental illness and psychotropic drug use among prescription drug overdose deaths: a medical examiner chart review

OBJECTIVE

Between 1999 and 2006, there was a 120% increase in the rate of unintentional drug overdose deaths in the United States. This study identifies the prevalence of mental illness, a risk factor for substance abuse, and chronic pain among prescription drug overdose deaths in West Virginia and ascertains whether psychotropic drugs contributing to the deaths were used to treat mental illness or for nonmedical purposes.

METHOD

In 2007, we abstracted data on mental illness, pain, and drugs contributing to death from all unintentional prescription drug overdose deaths in 2006 recorded by the West Virginia Office of the Chief Medical Examiner. Decedent prescription records were obtained from the state prescription drug monitoring program.

RESULTS

Histories of mental illness and pain were documented in 42.7% and 56.6% of 295 decedents, respectively. Psychotropic drugs contributed to 48.8% of the deaths, with benzodiazepines involved in 36.6%. Benzodiazepines contributing to death were not associated with mental illness (adjusted odds ratio [AOR] = 1.1; 95% CI, 0.6-1.8), while all other psychotropic drugs were (AOR = 3.9; 95% CI, 2.0-7.6). Of decedents with contributory benzodiazepines, 46.3% had no prescription for the drug.

CONCLUSIONS

Mental illness may have contributed to substance abuse associated with deaths. Clinicians should screen for mental illness when prescribing opioids and recommend psychotherapy as an adjunct or an alternate to pharmacotherapy. Benzodiazepines may have been used nonmedically rather than as a psychotropic drug, reflecting drug diversion. Restricting benzodiazepine prescriptions to a 30-day supply with no refills might be considered.

A comparison of drug overdose deaths involving methadone and other opioid analgesics in West Virginia

AIMS

To describe all people dying from unintentional overdoses of methadone or other opioid analgesics (OOA) in West Virginia in 2006.

DESIGN

We analyzed medical examiner data supplemented by data from the state prescription drug monitoring program. We compared people whose deaths involved methadone with those whose deaths involved OOA.

FINDINGS

The methadone group included 87 decedents, and the OOA group included 163 decedents. Most were male. Decedents in the methadone group were significantly younger than those in the OOA group: more than a quarter were 18-24 years of age. For both groups, approximately 50% had a history of pain, and 80% had a history of substance abuse. There was no intergroup difference in the prevalence of benzodiazepines at post-mortem. Methadone was significantly less likely to have ever been prescribed than OOA. Among those with prescriptions, the proportion prescribed within 30 days of death was significantly greater for methadone than for hydrocodone, but not for oxycodone. Ten (11.5%) of the methadone decedents were enrolled in an opiate treatment program (OTP) at the time of death.

CONCLUSIONS

The high prevalence of a substance abuse history and lack of prescriptions suggest that most of the deaths in both groups are related to substance abuse. There was no indication of a harmful effect from methadone's metabolic interaction with benzodiazepines, but provider or patient unfamiliarity with methadone may have been a risk factor. Prescribing methadone, especially to young males, requires extra care. Providers, OTPs and coroners/medical examiners should use state prescription drug monitoring programs to monitor the use of controlled substances by their patients.

Fatal all-terrain vehicle crashes: injury types and alcohol use

BACKGROUND

Since the 1990s, West Virginia has led the U.S. in the per-capita death rate from all-terrain vehicle (ATV) crashes, with rates eight times the national average and continually increasing. A comprehensive assessment was conducted of ATV fatalities to provide critical guidance for community interventions and public health policy to prevent further deaths.

METHODS

In 2007, death certificates for 2004 to 2006 with ICD-10 codes correlating to ATV crashes were used to identify decedents involved in crashes occurring in West Virginia. Data were abstracted from medical examiner records regarding crash circumstances, sustained injuries, and toxicology.

RESULTS

During 2004-2006, a total of 112 fatal ATV crashes were identified. Nearly all (92%) decedents were the ATV operator, and only 15% were known to have worn helmets. Among 54 traffic crashes, collisions (56%) and head injuries (65%) predominated, whereas the majority of 58 nontraffic crashes were rollovers (55%) and were most commonly associated with compression injuries of the thorax and abdomen (36%). Regardless of crash class (i.e., traffic versus nontraffic), alcohol was detected in the blood of 50% of decedents; of those, 88% had blood alcohol concentrations >OR=0.08% (mean=0.17%), West Virginia's legal limit. Drugs of abuse were identified in 21% of decedents, including marijuana (11%); opioid analgesics (7%); diazepam (6%); cocaine (2%); and methamphetamine (1%).

CONCLUSIONS

Fatal crash and injury types differ significantly depending on the location of ATV use, although alcohol and drug abuse are frequent risk factors in all types of ATV crashes. In addition to promoting helmet use, interventions are needed to address alcohol use among ATV users.

Patterns of abuse among unintentional pharmaceutical overdose fatalities

CONTEXT

Use and abuse of prescription narcotic analgesics have increased dramatically in the United States since 1990. The effect of this pharmacoepidemic has been most pronounced in rural states, including West Virginia, which experienced the nation's largest increase in drug overdose mortality rates during 1999-2004.

OBJECTIVE

To evaluate the risk characteristics of persons dying of unintentional pharmaceutical overdose in West Virginia, the types of drugs involved, and the role of drug abuse in the deaths.

DESIGN, SETTING, AND PARTICIPANTS

Population-based, observational study using data from medical examiner, prescription drug monitoring program, and opiate treatment program records. The study population was all state residents who died of unintentional pharmaceutical overdoses in West Virginia in 2006.

MAIN OUTCOME MEASURES

Rates and rate ratios for selected demographic variables. Prevalence of specific drugs among decedents and proportion that had been prescribed to decedents. Associations between demographics and substance abuse indicators and evidence of pharmaceutical diversion, defined as a death involving a prescription drug without a documented prescription and having received prescriptions for controlled substances from 5 or more clinicians during the year prior to death (ie, doctor shopping).

RESULTS

Of 295 decedents, 198 (67.1%) were men and 271 (91.9%) were aged 18 through 54 years. Pharmaceutical diversion was associated with 186 (63.1%) deaths, while 63 (21.4%) were accompanied by evidence of doctor shopping. Prevalence of diversion was greatest among decedents aged 18 through 24 years and decreased across each successive age group. Having prescriptions for a controlled substance from 5 or more clinicians in the year prior to death was more common among women (30 [30.9%]) and decedents aged 35 through 44 years (23 [30.7%]) compared with men (33 [16.7%]) and other age groups (40 [18.2%]). Substance abuse indicators were identified in 279 decedents (94.6%), with nonmedical routes of exposure and illicit contributory drugs particularly prevalent among drug diverters. Multiple contributory substances were implicated in 234 deaths (79.3%). Opioid analgesics were taken by 275 decedents (93.2%), of whom only 122 (44.4%) had ever been prescribed these drugs.

CONCLUSION

The majority of overdose deaths in West Virginia in 2006 were associated with nonmedical use and diversion of pharmaceuticals, primarily opioid analgesics.

Identification of N,N-dimethylamphetamine formed by methylation of methamphetamine in formalin-fixed liver tissue by multistage mass spectrometry

Methamphetamine is methylated in the presence of unbuffered formalin solutions within hours at room temperature. The product, N,N-dimethylamphetamine, is also found in human liver exposed to methamphetamine followed by incubation with formalin. In the present study, a direct mass spectrometric method was developed to identify N,N-dimethylamphetamine in human liver before and after treatment with formalin. Human liver samples were obtained from four deaths that were investigated by the West Virginia Office of Chief Medical Examiner. Full toxicological analysis was conducted on samples from the decedents and methamphetamine was among the positive findings in each case. The method used to expose liver tissue to formaldehyde involved treating a small piece of liver from each case with formalin solution (20% v/v) for 24 h at room temperature. The formalin treated tissues were homogenized and the resulting suspension was sonicated for 5 min, and then centrifuged. Supernatant aliquots were directly analyzed by electrospray ionization (ESI) mass spectrometry without chromatographic isolation. Positive ion multistage mass spectra recorded in MS, MS/MS and MS/MS/MS (MS3) modes were used to confirm the presence of N,N-dimethylamphetamine and methamphetamine in the mixture. Liver tissue not treated with formalin did not contain a detectable level of N,N-dimethylamphetamine. Decreases in methamphetamine concentrations in liver tissue resulting from treatment with formalin were measured using deuterium-labeled methamphetamine as internal standard. The method can be completed in less than 2 h on thawed tissue. The results suggest that the process of fixing tissues with formalin may lead to false negative findings for methamphetamine.

Methylation of 3,4-Methylenedioxymethamphetamine in Formalin-Fixed Human Liver Tissue

3,4-Methylenedioxymethamphetamine (MDMA or ecstasy) is a commonly consumed recreational drug. As is the case with most secondary amines, MDMA reacts with formaldehyde under acidic conditions to form tertiary amines. This reaction is likely to occur in formalin-fixed tissue. In formalin solutions, MDMA is methylated producing 3,4-methylenedioxy-N,N-dimethylamphetamine (MDDA). MDDA standard was synthesized by treating methylenedioxyamphetamine HCl in formaldehyde solution. Structure confirmation was by electrospray ionization-mass spectrometry (MS) and MS-MS. Randomly chosen human liver pieces (100-200 mg) were injected with 2 microg of MDMA HCl. The liver pieces in centrifuge tubes were covered with 200 microL of formalin solution (20% v/v), held at room temperature for 24 h, and then homogenized. The resulting suspension was sonicated for 5 min and then centrifuged. Controls consisted of substitution of 200 microL of water in place of formalin solution. Supernatant aliquots (10 mciroL) were added to 500 microL of 0.1% formic acid in acetonitrile for MS analysis. Positive ion electrospray spectra recorded in MS, MS2, and MS3 modes were used to confirm the presence of methylated MDMA. Liver tissue containing added MDMA HCl but not treated with formalin did not show a detectable level of methylated MDMA.

Asphyxial deaths caused by automobile exhaust inhalation not attributable to carbon monoxide toxicity: study of 2 cases

The authors report two suicides that resulted from the intentional inhalation of automobile exhaust gases in which death occurred without the formation of physiologically significant amounts of carboxyhemoglobin. These circumstances are correlated with measurements of the involved vehicles' exhaust gases, which showed reduced concentrations of carbon monoxide present, reflecting improvements in automobile engine technology. In the absence of carbon monoxide toxicity, the authors attribute death in these cases to asphyxia caused by carbon dioxide intoxication and diminished atmospheric oxygen concentrations.

Shaken infant syndrome: developmental neuropathology, progressive cortical dysplasia, and epilepsy

This study describes the developmental neuropathology of two infants who survived 7 and 9 years, respectively, an episode of violent shaking (shaken infant syndrome) early in their lives. The shaking injuries include cortical and subcortical contusions, hemorrhages, hypoxic/ischemic and axonal damage, and severe edema. The types, distribution, and resolution of these shaking injuries are detailed by sequential radiographic studies and by pathologic examination at postmortem. Despite their severity and extent, these injuries resolved in a relatively short period of time. By 6 months, the original injuries are repaired and the resultant encephaloclastic encephalopathies (e.g., multicystic encephalomalacia, porencephaly, generalized white matter attenuation, diffuse cortical atrophy, microgyria, ulegyria, and hydrocephalus ex vacuo) are well established. No appreciable pathologic differences are detected when radiographic findings at 6 months of age are compared to postmortem observations. On the other hand, undamaged and/or partially damaged cortical regions survive the original insult and undergo post-injury reorganization that transforms the residual cortex structural and presumably functional organization. Prominent features of this post-injury reorganization include progressive cortical dysplasia with cytoarchitectural disorganization, laminar obliteration, morphologic and functional (synaptic reorganization) transformation of some neurons, preservation of layer 1 intrinsic fibers and Cajal-Retzius cells, and the presence of large (hypertrophic) intrinsic neurons with intense neurofilament immunoreactivity. We propose that this progressive dysplastic process modifies the residual cortex structural and functional organization, influences the child's neurological and psychological maturation, and may play a significant role in the pathogenesis of ensuing neurological and/or psychological sequelae.

Evidence of active nerve cell degeneration in the substantia nigra of humans years after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine exposure

This report provides the first detailed neuropathological study of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism in humans. All 3 subjects self-administered the drug under the impression it was "synthetic heroin" and subsequently developed severe and unremitting parkinsonism, which was L-dopa responsive, at least in the earlier stages of illness. Survival times ranged from 3 to 16 years. Neuropathological examination revealed moderate to severe depletion of pigmented nerve cells in the substantia nigra in each case. Lewy bodies were not present. In Patients 1 and 2, there was gliosis and clustering of microglia around nerve cells. Patient 3 had a similar picture and also showed large amounts of extraneuronal melanin. These findings are indicative of active, ongoing nerve cell loss, suggesting that a time-limited insult to the nigrostriatal system can set in motion a self-perpetuating process of neurodegeneration. Although the mechanism by which this occurs is far from clear, the precedent set by the cases could have broad implications for human neurodegenerative disease.

Fatal hypernatremic dehydration in exclusively breast-fed newborn infants due to maternal lactation failure

Infants who die of hypernatremic dehydration usually demonstrate at autopsy an underlying condition or disease process that predisposes to increased water loss. In the absence of such findings, forensic concerns may focus sharply on parental or caretaker neglect as an underlying cause of death. In this case report, we describe unrecognized fatal hypernatremic dehydration in two exclusively breast-fed neonates due solely to failure of maternal lactation. We further describe epidemiologic and etiologic features of such deaths and discuss forensic difficulties encountered in their certification.

Quinolones for the treatment and prophylaxis of tuberculosis

Quinolones possess enormous potential as antimycobacterial agents, and have been proven to have excellent in vitro activity against M. tuberculosis, as well as limited in vivo efficacy. These drugs appear to be safe and well tolerated even when taken for an extended period. This is important considering that one of the most significant factors contributing to resistance is compliance. Quinolones exhibit great promise for initial treatment and retreatment of MDRTB, a rapidly growing problem, as well as for prevention. They have shown to be as effective as some of the first-line agents currently used in treating TB. There appears to be overwhelming need to further study these agents and determine their role in the treatment of TB. In the future, quinolones may emerge as first-line therapy for TB.

"Hyperacute" subdural hematoma: CT mimic of recurrent episodes of bleeding in the setting of child abuse

Mixed density extraaxial hematomae on computed tomography (CT) scanning generally represent recurrent episodes of bleeding (chronic subdural hematoma with rebleeding). Hyperacute hemorrhages in which the patient is actively bleeding or has a coagulopathy have also been described as mixed density. We report a case of child abuse in a fourteen month old child who presented with a CT scan showing a mixed density subdural hematoma which was originally interpreted as recurrent episodes of hemorrhage, but who had evidence of only acute, active bleeding at surgery and by histologic examination. There is a proportionally high incidence of subdural hematoma in cases of child abuse, due in part to the increased susceptibility of the immature brain to trauma. Because the mechanism of injury is different for hemorrhage due to hyperacute subdural hematoma (SDH) and that of acute bleeding within a chronic SDH, the distinction between these entities has potentially important legal implications in cases of suspected child abuse. This potential pitfall in interpretation of the CT scan has not to our knowledge been reported in the forensic literature.

Blunt impact to the chest leading to sudden death from cardiac arrest during sports activities

BACKGROUND

Sudden death from cardiac arrest in a young person may occur during sports play after a blunt blow to the chest in the absence of structural cardiovascular disease or traumatic injury (cardiac concussion or commotio cordis). We studied the clinical features of this apparently uncommon but important phenomenon.

METHODS

We identified cases from the registries of relevant agencies and organizations, as well as newsmedia accounts, and developed a clinical profile of 25 children and young adults, 3 to 19 years of age.

RESULTS

Each victim collapsed with cardiac arrest immediately after an unexpected blow to the chest, which was usually inflicted by a projectile (such as a baseball or hockey puck). Incidents took place during organized competitive sports in 16 cases and in recreational settings at home, at school, or on the playground in 9. In each instance, the impact to the chest was not judged to be extraordinary for the sport involved and did not appear to have sufficient force to cause death. Twelve victims collapsed virtually instantaneously on impact, whereas 13 remained conscious and physically active for a brief time before cardiac arrest. Cardiopulmonary resuscitation was administered within about three minutes to 19 victims, but normal cardiac rhythm could be restored in only 2 (both incurred irreversible brain damage and died shortly thereafter). Seven victims (28 percent) were wearing some form of protective chest padding.

CONCLUSIONS

We speculate that most sudden deaths related to impact to the chest (not associated with traumatic injury) are due to ventricular dysrhythmia induced by an abrupt, blunt precordial blow, presumably delivered at an electrically vulnerable phase of ventricular excitability. This profile of blunt chest impact leading to cardiac arrest adds to our understanding of the range of causes of sudden death on the athletic field and may help in the development of preventive measures.

Patterns of facial resuscitation injury in infancy

Cardiopulmonary resuscitation (CPR)-related artifacts in pediatric rescue that have the potential for serious complications in surviving patients have been well described in the medical literature. Medically trivial soft-tissue injuries, especially of the face and neck, carry predominantly forensic significance and have received less attention. We describe such injuries in nine of 25 consecutive cases of infants who received CPR, and correlate those injuries with specific rescue maneuvers. Techniques for effective investigation and interpretation of such injuries are suggested.

Delayed fatal hemothorax due to traumatic carotid dissection: a case report of a previously unreported cause of death

A unique case of delayed fatal hemothorax in a 12-year-old girl resulting from atypical dissection of a traumatic carotid aneurysm is reported, due to occult neck trauma received in a sledding accident which occurred one week prior to death. Aspects of traumatic carotid dissection and forensic implications of delayed presentation of such findings in the setting of occult trauma are discussed.

Commotio cordis in two amateur ice hockey players despite the use of commercial chest protectors: case reports

We describe two recent deaths in 15-year-old male ice hockey players. Both adolescents died of commotio cordis from chest impacts by ice hockey pucks despite their use of commercially designed and manufactured chest protectors. Commotio cordis is discussed as a preventable sports-related injury in the adolescent age group, and the need for improved chest protective equipment in preventing such injuries is also examined.

An unusual entrance wound associated with rimfire rifles

In many cases of self-inflicted contact wounds of the head with rimfire rifles, we have noted that the entrance wound appears unusual: in 50% of cases studied, a pencil-like extension or zone of blackened and seared skin extends downward from the entrance. The most probable cause for the appearance of this wound is a momentary break in contact between the muzzle and skin as the victim reaches for the trigger with resultant escape of a jet of hot sooty gas. Whereas not unique for rimfire rifles, such a wound from a handgun is uncommon.

Clinical considerations for the use of intravenous nicardipine in the treatment of postoperative hypertension

The incidence of postoperative hypertension after both cardiac and noncardiac surgery is a major concern. alpha-Adrenergic-blocking drugs, such as phentolamine, and direct-acting vasodilators, such as nitroglycerin and nitroprusside, are commonly used to treat hypertension. Nifedipine, a calcium channel blocker, may also be used, but because no intravenous preparation is available, its effects are not titratable. A new short-acting calcium channel blocker, nicardipine, is a potent vasodilator and produces more selective responses in the coronary versus the systemic vascular circulation. It is an effective cerebral vasodilator, increasing cerebral blood flow and oxygen delivery. Nicardipine can be administered as an intravenous loading infusion of 10 to 15 mg/hr for 25 minutes, followed by a maintenance infusion of 3 to 5 mg/hr. Nicardipine has a short duration factor, is easily titratable and is as effective as nitroglycerin or nitroprusside in the control of hypertension. In summary, nicardipine has many properties of an ideal drug for the treatment of postoperative hypertension.

Effects of doxacurium chloride on biventricular cardiac function in patients with cardiac disease

The effects of doxacurium chloride, a new long-acting non-depolarizing neuromuscular blocking drug, on cardiac performance were studied in 45 patients undergoing high-dose fentanyl-diazepam-oxygen anaesthesia for cardiac surgery. Data were collected at baseline (10 min after tracheal intubation), and at 2, 5 and 10 min after an i.v. bolus of doxacurium with a rapid-response thermistor pulmonary arterial catheter, using two-dimensional transoesophageal echocardiography, and direct arterial pressure measurement. The patients were allocated to four groups based on the type of surgery and dose of doxacurium (0.05 or 0.08 mg kg-1). No changes in left or right ventricular dimensions or contractility were detected in any group. Although significant changes (P less than 0.05) occurred in several groups, all these changes were clinically insignificant (less than 10% change from baseline values), and were similar to those seen in unstimulated anaesthetized patients. Doxacurium appears to be a safe drug for use in patients undergoing cardiac surgery, and is devoid of significant cardiovascular side effects in the doses tested.

Hemodynamic effects of verapamil during fentanyl-nitrous oxide anesthesia

The hemodynamic effects of a verapamil infusion were investigated in six dogs given fentanyl-nitrous oxide anesthesia. Verapamil, 0.2 mg/kg, was given followed by an infusion of 3, 6, and 9 micrograms/kg per minute, which produced plasma verapamil concentrations ranging from 98 to 204 ng/ml. Verapamil significantly reduced the systemic vascular resistance index and mean arterial pressure. The decrease in afterload led to an increase in cardiac index, since there was little change in myocardial contractility (LV dP/dt). Administration of calcium chloride, 20 mg/kg, did not reverse the hemodynamic effects of verapamil. The data indicate that in dogs verapamil can be given, even in high concentrations, during fentanyl-nitrous oxide anesthesia without serious adverse electrophysiologic or hemodynamic consequences.

Cardiovascular effects of a nifedipine infusion during fentanyl-nitrous oxide anesthesia in dogs

The hemodynamic effects of a nifedipine infusion were investigated in eight dogs given fentanyl/pancuronium/nitrous oxide/oxygen anesthesia. Nifedipine (20 micrograms/kg) was given intravenously over two minutes immediately prior to each 30-minute infusion at 2 micrograms/kg/min, 4 micrograms/kg/min, and 6 micrograms/kg/min. The range of plasma nifedipine levels obtained was 52.1 to 113.7 ng/mL. The predominant hemodynamic effects were significant reductions in systemic vascular resistance (SVR) and mean aortic pressure (MAP), accompanied by a rise in cardiac index and heart rate (HR). Administration of calcium chloride (20 mg/kg) after the nifedipine infusion had no effect on SVR or MAP, but HR was significantly reduced. Serum epinephrine and norepinephrine levels increased after the infusion of nifedipine and suggested that fentanyl did not completely overcome the sympathetic response to the profound vasodilatation. The resulting tachycardia in combination with diastolic hypotension from nifedipine could have a detrimental effect on the myocardial oxygen balance.

Comparative hemodynamic effects of labetalol and hydralazine in the treatment of postoperative hypertension

The antihypertensive efficacy and safety of IV labetalol were evaluated and compared with the efficacy and safety of IV hydralazine in the treatment of postoperative hypertension. Twenty patients undergoing major noncardiac surgery were entered into the study. Patients were randomized and treated for postoperative hypertension with either labetalol (n = 10) or hydralazine (n = 10). Labetalol and hydralazine both produced significant reductions in arterial blood pressure (p less than 0.001) within 10 minutes, which lasted at least 2 hours. In addition, labetalol produced a significant reduction in the heart rate and rate-pressure product without creating any adverse effects. In contrast, hydralazine produced significant sinus tachycardia requiring IV propranolol in three patients, two of whom developed transient ST segment depression. These results indicate that labetalol is safe and effective for the control of postoperative hypertension, especially in those patients who are least able to tolerate tachycardia.

Comparison of propofol and thiamylal for induction and maintenance of anaesthesia for outpatient surgery

In an open, randomized study we have compared the safety and efficacy of propofol with thiamylal for induction and maintenance of anaesthesia supplemented by nitrous oxide in elective termination of pregnancy. Induction of anaesthesia was achieved with either propofol 2.5 mg kg-1 or thiamylal 4.0 mg kg-1 followed by maintenance with 70% nitrous oxide in oxygen and repeat boluses of 25% of the induction dose i.v. as indicated clinically. Both drugs induced and maintained anaesthesia reliably, with some minor differences. Recovery from propofol was significantly more rapid. The patients in the propofol group were alert and orientated early in the postoperative period, with less nausea or vomiting. Propofol has properties that are of particular benefit in anaesthesia for ambulatory surgery.

Open heart surgery in patients in the eighth and ninth decades of life

One hundred fifty-one patients aged 70-89 years underwent a variety of open heart surgical procedures during a period of 1 year. We divided these patients into two groups: Group A was comprised of 127 patients between 70 and 79 years of age. In group B, 24 patients were between 80 and 89 years of age. These patients underwent elective open heart surgery. Information was retrieved retrospectively from the computerized data pool of the cardiothoracic registry in our institution. Statistical analysis in these two groups revealed no significant differences in any of the evaluated factors. We concluded that age should not be a contraindication for cardiac operations.

Response of lower esophageal contractility to changing concentrations of halothane or isoflurane: a multicenter study

A multiple-center study was performed to determine the relationship between lower esophageal contractility, clinical signs, and anesthetic concentration as expressed by minimum alveolar concentration (MAC). One hundred four American Society of Anesthesiologists Class I through III patients were exposed to isoflurane (with and without nitrous oxide) or halothane in concentrations of 0.5, 1.0, and 1.5 MAC. Heart rate and systolic blood pressure were continuously monitored. Both the amplitude and frequency of spontaneous and provoked lower esophageal contractions were measured in situ by using a 24-F probe equipped with provoking and measuring balloons. Combined results demonstrated statistically significant correlations (P less than 0.001) between lower esophageal contractility and MAC. Spontaneous lower esophageal contractions decreased from 1.10 +/- 0.12 (SEM) contractions per minute (0.5 MAC) to 0.42 +/- 0.05 (1 MAC) to 0.18 +/- 0.05 (1.5 MAC). Provoked lower esophageal contractility values decreased from 45 +/- 4 mm Hg (0.5 MAC) to 29 +/- 3 (1 MAC) to 19 +/- 2 (1.5 MAC). Heart rate changes did not correlate with MAC, and systolic blood pressure correlated in only one of three centers. Intracenter and intercenter analyses failed to demonstrate a significant relationship between lower esophageal contractility and heart rate or systolic blood pressure. No intracenter differences in either amplitude or frequency of lower esophageal contractions were observed, despite differences in volatile agents, induction techniques and agents, patient populations, and durations of anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Dupont critical care lecture: Role of ultrashort-acting β-blockers in the perioperative period

beta-blockade can result in extreme bradycardia, significant conduction problems, bronchospasm, or left ventricular dysfunction. For this reason, the use of long-acting beta-blockers is of limited value in the perioperative period. Esmolol, due to its ultrashort action and cardioselective properties, has been shown to be safe and effective for use in treatment of tachycardia and hypertension. Doses of up to 300 microg/kg/min for up to seven hours have been used with a return to baseline parameters within 30 minutes of discontinuation of the infusion. It can also be safely used in treatment of the asthmatic patient with tachycardia or hypertension with no clinically significant increases in airway resistance. Studies using esmolol during general anesthesia have also demonstrated that it appears to have no significant interaction with various anesthetic agents.

Reversal of the adverse cardiovascular effects of intravenous diltiazem in anesthetized dogs

Intravenous diltiazem can be used to treat myocardial ischemia, hypertension, and supraventricular dysrhythmias, but significant adverse effects including atrioventricular block and hypotension have been reported. At the present time, there is controversy as to which drug is most effective in reversing these sequelae. This study was designed to assess the effectiveness of calcium chloride v epinephrine in reversing these side effects. The hemodynamic and electrophysiologic effects of diltiazem infusion were investigated in eight dogs anesthetized with fentanyl and nitrous oxide/oxygen. This study confirmed that diltiazem infusions in high concentrations produced predominantly atrioventricular conduction depression followed by profound hypotension. Epinephrine infusion proved to be most effective in attenuating and eliminating each of these deleterious side effects. In contrast, calcium chloride did not significantly increase heart rate or blood pressure or reverse atrioventricular block. In two instances calcium chloride produced further depression of atrioventricular conduction, leading to severe bradycardia and sinus arrest. Although calcium chloride increased left ventricular contractile force (LV dP/ dt) and cardiac index (CI), mean arterial pressure was not affected and SVR was further decreased. This study indicates that calcium chloride should not be given to reverse the side effects of diltiazem in the presence of atrioventricular conduction block or profound hypotension. Calcium chloride is indicated only when isolated myocardial depression is present and after the calcium channels have been reopened by epinephrine.

The effects of metabolic acidosis and alkalosis on the response to sympathomimetic drugs in dogs

Sympathomimetic drugs are commonly used in many circumstances to increase cardiac output, blood pressure, and myocardial contractility. However, factors such as acidosis or alkalosis are known to influence the action of these drugs. This study looked at the response to the administration of epinephrine, norepinephrine, dopamine, dobutamine, isoproterenol, and glucagon at normal pH and under acidotic (pH 7.2 +/- 0.01) and alkalotic (pH 7.59 +/- 0.01) conditions in 17 dogs. Acidosis was produced with an infusion of hydrochloric acid and alkalosis by infusion of sodium bicarbonate. The infusions were given over one hour followed by a 15- to 30-minute stabilization period. With the administration of each sympathomimetic drug at each pH level, hemodynamic parameters and measurements of myocardia; contractility were recorded. Epinephrine increased cardiac output at normal pH, but decreased cardiac output under conditions of both acidosis and alkalosis; the net change from values at pH 7.40 was nearly 3 L/min. The only other drug to demonstrate this reversal of cardiac output, though to a lesser degree, was dopamine, 10 microg/kg/min, and only in the alkalotic state. Dobutamine was the only drug that decreased contractility under acidotic conditions, while all other drugs caused an increase. In sum, epinephrine was the only drug markedly affected by metabolic acidosis and alkalosis. Isoproterenol's hemodynamic effects were altered the least by changes in acid-base balance. Alkalosis had an equally adverse effect on the cardiovascular system as compared with acidosis.