Sequential compression device with thigh-high sleeves supports mean arterial pressure during Caesarean section under spinal anaesthesia.

BACKGROUND: This study investigated the use of a Sequential Compression Device (SCD) with thigh-high sleeves and a preset pressure of 50 mm Hg that recruits blood from the lower limbs intermittently, as a method to prevent spinal hypotension during elective Caesarean section. Possible association of arterial pressure changes with maternal, fetal, haemodynamic, and anaesthetic factors were studied. METHODS: Fifty healthy parturients undergoing elective Caesarean section under spinal anaesthesia were randomly assigned to either SCD (n=25) or control (n=25) groups. A standardized protocol for pre-hydration and anaesthetic technique was followed. Hypotension was defined as a decrease in any mean arterial pressure (MAP) measurement by more than 20% of the baseline MAP. Systolic (SAP), MAP and diastolic (DAP) arterial pressure, pulse pressure (PP), and heart rate (HR) were noted at baseline and every minute after the spinal block until delivery. RESULTS: A greater than 20% decrease in MAP occurred in 52% of patients in the SCD group vs 92% in the control group (P=0.004, odds ratio 0.094, 95% CI 0.018-0.488). There were no significant differences in SAP, DAP, HR, and PP between the groups. CONCLUSION: SCD use in conjunction with vasopressor significantly reduced the incidence of a 20% reduction of MAP.

Complex regional pain syndrome (CRPS) with resistance to local anesthetic block: a case report.

We present a case of complex regional pain syndrome (CRPS) Type 1 in a 12-year-old girl. The patient did not respond to the usual therapeutic modalities used to treat CRPS, including physical therapy, lumbar sympathetic block, epidural local anesthetic block, intravenous lidocaine infusion, or other oral medications. Of note is the fact that, during epidural block, the patient demonstrated a resistance to local anesthetic neural blockade in the area of the body involved with the pain problem. The mechanism of this resistance could be related to the changes in the dorsal horn cells of the spinal cord, secondary to activation of N-methyl-D-aspartate receptors, which may play a role in the pathophysiology of this pain syndrome.

The ethics of cost containment from the anesthesiologist's perspective.

Cost containment, as an essential part of current effort to manage health care, has been examined thoroughly from the perspectives of finance and patient care. In this article, the ethics of cost containment are discussed from the vantage point of the health care provider. Cost-cutting initiatives, however necessary and sound, nevertheless may place anesthesiologists in situations of ethical conflict and ultimately interfere with their rights as workers and professionals. The anesthesiology community is encouraged to investigate the effect of cost-cutting measures on patients and physicians alike.

The effect of halothane on the amplitude and frequency characteristics of heart sounds in children.

UNLABELLED: Although continuous auscultation has been used during surgery as a monitor of cardiac function for many years, the effect of anesthetics on heart sounds has never been quantified. We determined the root mean squared amplitude and frequency characteristics (peak frequency, spectral edge, and power ratios) of the first (S1) and second (S2) heart sounds in 19 healthy children during induction of anesthesia with halothane. In all patients, halothane decreased the amplitude of S1 (R2 = 0.87 +/- 0.12) and S2 (R2 = 0.66 +/- 0.33) and the high-frequency components (>80 Hz) of these sounds. These changes were clearly audible and preceded decreases in heart rate and blood pressure. The spectral edge decreased for S1 in 18 patients (R2 = 0.73 +/- 0.24) and for S2 in 13 patients (R2 = 0.58 +/- 0.25). Peak frequency did not change. The rapidity with which myocardial depression and its associated changes in heart sound characteristics occurred confirms that continuous auscultation of heart sounds is a useful clinical tool for hemodynamic monitoring of anesthetized infants and children. IMPLICATIONS: Heart sound characteristics can be used to monitor cardiac function during halothane anesthesia in children. The changes occur rapidly and precede noticeable changes in heart rate and blood pressure.

Patient's perceptions of an anesthesia preoperative computerized patient interview.

Our desire to elicit a more complete medical history from our patients led to the implementation of a preoperative computerized interview. We previously demonstrated the effectiveness of the interview by computing its mean completion time for the overall patient population (n = 120), and further examined the effects of age, gender, and educational level. In this study, we investigated patient perception of the interview itself. Before and after taking the computer interview, we asked the patients to complete a paper and pencil questionnaire comprised of sixteen questions, expressing their feelings toward the computer interview. Responses elicited prior to taking the computer interview were compared with those obtained afterward. The Stuart-Maxwell test was used to determine statistically significant differences in answers before and after the interview. Initial questionnaire responses reflected a positive attitude toward computer usage which became even stronger after the interview. The only negative responses elicited were really more "doctor positive" than "computer negative." We conclude that patients looked favorably upon participating in a computerized medical interview provided that physician-patient contact is maintained.

Intraoperative management of a patient with a chronic, previously undiagnosed traumatic diaphragmatic hernia.

Traumatic diaphragmatic hernia (TDH) occurs in approximately 5% of hospitalized motor vehicle accident victims and 10% of victims of penetrating chest injury. Although most such injuries are diagnosed at the time of initial trauma, approximately 10% become apparent only months or years later. The TDH patient is at risk for surgical complications, including pulmonary aspiration, hypoxemia, and hemodynamic instability. Diagnosis and proper management of TDH is essential in order to minimize such complications. The anesthetic management of a patient with a preexisting TDH presenting for lumbar laminectomy is discussed.

Esophageal stethoscope placement depth: its effect on heart and lung sound monitoring during general anesthesia.

UNLABELLED: Although the esophageal stethoscope has been used for many years, the effect of the depth of placement on the quality of the sounds obtained has never been investigated. The amplitude and frequency characteristics of the first and second heart sound and of inspiratory and expiratory breath sounds were determined at various stethoscope depths (from the distal tip) in 17 healthy anesthetized adults. The amplitude for each type of sound varied markedly with depth. Maximal amplitude for S1 was at 34 +/- 3 cm, for S2 at 27 +/- 2 cm, for inspiratory breath sound at 28 +/- 2 cm, and for expiratory breath sound at 26 +/- 2 cm. There was a positive linear correlation between the depth of maximal amplitude of these sounds and patient height. Peak frequency, in general, did not change with depth. We conclude that investigators should measure and document depth when performing studies involving the esophageal stethoscope. IMPLICATIONS: Analysis of sound from the esophageal stethoscope at various depths reveals that placement depth greatly affects the sounds. A depth of 28-32 cm is recommended for clinical use; S1, S2, and inspiratory and expiratory sounds have a high amplitude in that range.

An evolutionary solution to anesthesia automated record keeping.

In the course of five years the development of an automated anesthesia record keeper has evolved through nearly a dozen stages, each marked by new features and sophistication. Commodity PC hardware and software minimized development costs. Object oriented analysis, programming and design supported the process of change. In addition, we developed an evolutionary strategy that optimized motivation, risk management, and maximized return on investment. Besides providing record keeping services, the system supports educational and research activities and through a flexible plotting paradigm, supports each anesthesiologist's focus on physiological data during and after anesthesia.

Lumbar epidural analgesia for labor and vaginal delivery.

Lumbar epidural analgesia has become the preferred method of pain relief for labor and delivery. Proper administration of epidural analgesia offers many advantages for both mother and fetus. With the availability of various local anesthetics, opioids, and infusion techniques, the analgesia can be tailored to the specific needs of the mother, fetus, and labor. Its effect on the progress of labor remains a controversial topic subject to ongoing investigation.

Auscultation revisited: the waveform and spectral characteristics of breath sounds during general anesthesia.

Although auscultation is commonly used as a continuous monitoring tool during anesthesia, the breath sounds of anesthetized patients have never been systematically studied. In this investigation we used digital audio technology to record and analyze the breath sounds of 14 healthy adult patients receiving general anesthesia with positive pressure ventilation. Sounds recorded from inside the esophagus were compared to those recorded from the surface of the chest, and corresponding airflow was measured with a pneumotachograph. The sound samples associated with inspiratory and expiratory phases were analyzed in the time domain (RMS amplitude) and frequency domain (peak frequency, spectral edge, and power ratios). There was a positive linear correlation (R2 > 0.9) between inspiratory flow and sound amplitude in the precordial and esophageal samples of all patients. The RMS amplitude of the inspiratory and expiratory sounds was approximately 13 times greater when recorded from inside the esophagus than from the surface of the chest in all patients at all flows (p < 0.001). The peak frequency (Hz) was significantly higher in the esophageal recordings than the precordial samples (298 +/- 9 vs 181 +/- 10, P < 0.0001), as was the 97% spectral edge (Hz) (740 +/- 7 vs 348 +/- 16, P < 0.0001). In the adult population esophageal stethoscopes yield higher frequencies and greater amplitude than precordial stethoscopes. Quantification of lung sounds may provide for improved monitoring and diagnostic capability during anesthesia and surgery.

Use of EMLA cream in the treatment of post-herpetic neuralgia.

EMLA cream is an acronym for eutectic mixture of local anesthetics. It contains lidocaine and prilocaine creams. A eutectic preparation, applied topically, penetrates into the dermis after an application period of 1 to 2 hours. This case report describes the successful treatment with EMLA cream of post-herpetic neuralgia, which was resistant to other modes of therapy, and briefly discusses the pharmacology of EMLA cream.

False aneurysm of the axillary artery following brachial plexus block.

Brachial plexus blockade is a commonly used technique for providing surgical anesthesia for the upper extremity. Although various approaches have been described, the axillary approach is the safest and most frequently used. Most complications associated with axillary nerve block are related to local or systemic anesthetic toxicity, bleeding, infection, and nerve damage. A case of false aneurysm of the axillary artery following axillary nerve block is reported. The possible occurrence of this complication should be kept in mind to avoid permanent neurologic sequelae.

Respiratory distress associated with stereotactic irrigation of a brain cyst.

Stereotactic neurosurgery is a procedure that usually requires monitored sedation or general anesthesia. The authors report a case in which stereotactic irrigation of a brain cyst was temporally associated with respiratory distress. Additionally, the stereotactic apparatus limits the anesthesiologist's access to the airway.

Prolonged neuromuscular blockade following vecuronium infusion.

Administration of vecuronium by infusion is an increasingly common technique, both in the operating room and in the intensive care unit (ICU), for patients requiring prolonged neuromuscular blockade and mechanical ventilation. The major advantage of vecuronium over older neuromuscular blocking agents is its rapid excretion and intermediate duration of action. Prior to the current case report, the longest reported continuous paralysis after the cessation of a vecuronium infusion was 90 hours. A case of an 81-year-old patient with renal failure and subclinical chronic cirrhosis of the liver, who remained paralyzed for 13 days following a vecuronium infusion, is described. Intensive monitoring of neuromuscular function is recommended whenever muscle relaxants are administered by continuous infusion.