Respiratory effects of spinal anaesthesia for caesarean section.

We report the changes observed in a number of pulmonary function tests performed on 36 patients undergoing Caesarean section under spinal anaesthesia. The tests comprised peak expiratory flow, forced expiratory volume in one second, forced vital capacity, forced expiratory volume in one second to forced vital capacity ratio and the maximal mid-expiratory flow. Significant changes occurred that are consistent with a restrictive ventilatory defect. These changes persisted for four hours after the induction of spinal anaesthesia. Administration of 35% oxygen by facemask failed to change significantly fetal umbilical vein pH or partial pressure of oxygen.

Time course of neuromuscular effects and pharmacokinetics of rocuronium bromide (Org 9426) during isoflurane anaesthesia in patients with and without renal failure.

We have studied the onset and duration of action and pharmacokinetics of rocuronium bromide (Org 9426) during anaesthesia with nitrous oxide, fentanyl and isoflurane after a single bolus dose of rocuronium 0.6 mg kg-1 in nine patients with chronic renal failure requiring regular haemodialysis, and in nine healthy control patients. Blood samples were collected over 390 min and concentrations of rocuronium and its putative metabolites measured using HPLC. Onset time for maximum block, duration of clinical relaxation (T1(25)) and recovery index, were 61 (SD 25.0) s and 65 (16.4) s, 55 (26.9) min and 42 (9.3) min and 28 (12.3) min and 19 (8.8) min, respectively, for patients with and without renal failure. The time for TOF ratio to return spontaneously to 0.7 was 99 (41.1) min and 73 (24.2) min, respectively, in the two groups. None of these differences was significant. The pharmacokinetic data were best described by a three-exponential equation. There were significant differences between patients with and without renal failure in the rates of clearance (2.5 (1.1) ml kg-1 min-1 and 3.7 (1.4) ml kg-1 min-1, respectively) and the mean residence times (97.1 (48.7) min and 58.3 (9.6) min) P < 0.05). The differences in other kinetic parameters were not significant. We conclude that the effects of rocuronium may be prolonged in patients with renal disease, because of a decreased clearance of the drug.

New models for PA advancement. Forum discussion.

Many PAs are grappling with the problem of how to best advance their careers. In this roundtable, the participants discuss traditional methods of advancement and examine the need for new models.

Automating the medical practice--promise and peril.

Pick up any newspaper or news magazine and chances are that an article on health care reform will be prominently featured. While we await the details of the plans for reform, we can divine some major implications. With certainty, one of these will be the need to access and integrate vast amounts of patient and provider data. These medical data, in electronic form, will fuel the interplay between provider, hospital, government organizations, and private health care management. These data will be used: to drive the outcome studies that will examine medical resource consumption; to track prescribing practices; to facilitate patient follow-up; and to monitor wellness programs. In short, data management will be an unseen, but very present, companion to all our practice decisions. The successful medical practitioners in the coming era will be those whose practices have an electronic infrastructure that allows comprehensive medical record keeping, inclusive of patient charting, billing, coding, scheduling, and data reporting to third parties.

Using the Internet Gopher Protocol to link a computerized patient record and distributed electronic resources.

At Duke University Medical Center, we are developing a prototype clinical application for automated patient care plans with integrated links to electronic documents and other electronic resources. These links are implemented using the Internet Gopher Protocol, an emerging standard for distributed document search and retrieval. Use of this protocol permits storage of electronic documents in an open, nonproprietary manner. This paper discusses the architecture of the link mechanism and presents some of the advantages and disadvantages of the proposed method.

Vasopressor therapy for hypotension during epidural anesthesia for cesarean section: effects on maternal and fetal flow velocity ratios.

The purpose of this study was to identify the influence of hypotension as a result of epidural anesthesia and of its treatment with either ephedrine or methoxamine on uteroplacental and umbilical flow velocity ratios and fetal acid-base status. Fifty healthy women with an uncomplicated full-term pregnancy were studied during elective cesarean section under epidural anesthesia. A method of continuously recording flow velocity waveforms was used that allowed the identification of simultaneous values of maternal and fetal Doppler indices related to events during the induction of anesthesia. In 15 patients in whom arterial blood pressure did not decrease, the uteroplacental pulsatility index (UtPI) did not change, but the umbilical pulsatility index (UmPI) decreased from a mean (95% confidence interval) of 0.98 (0.88-1.09) to 0.91 (0.82-0.99) (P less than 0.05). In 32 patients who experienced hypotension of at least 15%, the UtPI increased from 0.82 (0.76-0.89) to 1.04 (0.92-1.17) (P less than 0.01). Treatment with ephedrine had no influence on either the UtPI or UmPI, but treatment with methoxamine resulted in brief increases in the UtPI of 0.47 (0.24-0.69) during the first 5 min after its administration; the increases were brief and resolved within 2 min. The choice of vasopressor drug had no influence on the UtPI recorded just before surgery commenced (final UtPI), but those patients who experienced hypotension had significantly larger final UtPIs (1.02 (0.91-1.10)) than those who never became hypotensive (0.86 (0.72-0.99)), and this was associated with significantly increased placental hydrogen ion gradients. The choice of vasopressor drug appears to be of minor importance compared with the avoidance of hypotension.

Transmural surgical gown pressure measurements in the operating theater.

Transmural gown pressures encountered when the surgeon comes into contact with a patient were measured in the operating theater. The surgical gown industry has assumed these pressures to be less than 5 psi in testing the efficacy of the gown and drape barrier material to impede bacterial transmission through its pores. In this study, pressure-sensitive contact film and resistive strain gauge recordings made from the surgeon's abdominal region and forearms indicated peak contact pressures in excess of 60 psi. This report indicates a need to reassess the basis of test utilization in evaluating barrier materials used in gowns and drapes.

Continuous vecuronium infusion for prolonged muscle relaxation in children.

Facilitation of mechanical ventilation of the lungs using an infusion of vecuronium in 11 infants and children and four neonates in an intensive care unit is described. A loading dose of vecuronium of 0.1 mg.kg-1 was followed by an infusion at an initial rate of 0.1 mg.kg-1.hr-1. The infusion rate was adjusted to maintain a neuromuscular block of approximately 90% as assessed by the presence of one response to a train-of-four stimulation. The duration of the infusions varied from 9.5 to 179 hr. The mean dose of vecuronium administered was 0.14 mg.kg-1.hr-1 (+/- 0.05, SD) in the children and 0.11 mg.kg-1.hr-1 (+/- 0.05) in the neonates. Mean recovery times from the time of stopping the infusion until absence of apparent fade in response to tetanic stimulation were 51.7 (+/- 17.6) and 46.8 (+/- 16.5) min for the children and neonates respectively. No adverse cardiovascular or toxic effects were noted. This technique of vecuronium infusion to facilitate mechanical ventilation of the lungs is feasible and satisfactory in clinical use.

Effect of stimulation of the P6 antiemetic point on postoperative nausea and vomiting.

The antiemetic action of stimulation of the P6 (Neiguan) acupuncture (ACP) point has been studied in women, premedicated with nalbuphine 10 mg, undergoing minor gynaecological operations under methohexitone-nitrous oxide-oxygen anaesthesia. Invasive ACP--manual or electrical at 10 Hz--applied for 5 min at the time of administration of the premedication markedly reduced the incidence of vomiting and nausea in the first 6 h after operation, compared with untreated controls. This did not occur with stimulation of a "dummy" ACP point outside the recognized ACP meridians. Non-invasive methods (stimulation via a conducting stud or by pressure) were equally as effective as invasive ACP during the early postoperative period. However, both these non-invasive approaches were less effective than invasive ACP in the 1-6 h postoperative period, although each was as effective as two standard antiemetics (cyclizine 50 mg, metoclopramide 10 mg). In view of the total absence of any side effects in more than 500 ACP procedures, the clinical applications of this finding are worthy of further study.

Acupuncture prophylaxis of cancer chemotherapy-induced sickness.

In a multi-facet study we evaluated the efficacy of P6 electroacupuncture (10 Hz applied for 5 min) as an antiemetic in patients receiving a variety of cancer chemotherapy drugs. The study involved 130 (15 in an open pilot study, 10 in a randomized placebo controlled crossover study and 105 in a definitive study) patients who had a history of distressing sickness after previous treatment, and who, on the basis of a previous survey, would be expected to have a 96% chance of this with subsequent therapy. Sickness was either completely absent or reduced considerably in 97% of patients and no side effects were encountered. The limited crossover study, using a 'dummy' acupuncture (ACP) point showed that the beneficial effects were limited to the P6 point. Logistic and ethical considerations excluded the possibility of carrying out a larger placebo-controlled study. While in our hands P6 ACP was an effective antiemetic in patients having cancer chemotherapy, because of the time involved and the brevity of the action (8 h) an alternative approach to electro-ACP is required before this technique is adopted clinically.

Factors improving survival in multisystem trauma patients.

This report analyzes the effect of air versus ground interhospital transport on survival following multisystem injury. There were 136 air-transported patients versus 194 ground-transported patients. The groups were similar in trauma scores, ages, mechanism of injury, and organ systems injured. There was a statistically significant survival advantage for air-transported patients with trauma scores between 10 and 5 (82.8% survival vs. 53.5%, p = less than 0.001). The time interval between accident and admission to the authors' institution was similar for both groups. Important therapeutic interventions contributing to better survival by the air-transported group included higher incidences of endotracheal intubation (50% vs. 25%), blood transfusions (32% vs. 10%), larger volumes of electrolyte fluid (3.3 L per patient vs. 2.1 L per patient) as well as the use of MAST trousers (60.3% vs. 34.9%). Transport charges for both ground and air services were similar. However, helicopter charges met only 15% of the operational budget of the aeromedical service. The remainder of the costs were generated from hospital patient revenues. Overall, total hospital charges were similar for both groups and were influenced by the variability of length of stay, particularly for orthopedic patients.

Antiemetic studies with traditional Chinese acupuncture. A comparison of manual needling with electrical stimulation and commonly used antiemetics.

The application of low frequency (10 Hz) electrical current for 5 minutes to an acupuncture needle placed at the P6 (Neiguan) point is as effective as manual needling in the reduction of emetic sequelae in women premedicated with nalbuphine 10 mg for a minor gynaecological operation carried out under a standard anaesthetic. Both were slightly, but not significantly, better than the antiemetic properties of cyclizine 50 mg.

Reducing wound infections. Improved gown and drape barrier performance.

A 21-month study involving 2181 clean and clean-contaminated general surgical procedures was performed to evaluate the effectiveness of a commercially available disposable gown and drape system vs a cotton system in reducing wound infection. The series in which the disposable spun-laced fiber system was used had a significantly lower overall infection rate (2.83% vs 6.5%) as well as better rates in clean (1.8% vs 3.8%) and clean-contaminated (4.8% vs 11.4%) procedures. This effect was independent of all other factors. The odds of developing a wound infection was 2 1/2 times higher with a cotton system than with a disposable system. Actual cost analysis from three types of hospitals showed lower costs with utilization of disposable gown and drape systems. Hospital charges were significantly higher for those patients developing wound infections. The results of the study demonstrated not only significant reduction in wound infection rates but also major cost savings when a disposable gown and drape system was used in the operating room.

Emergency care of chemical burns.

Because of the large number of potentially injurious chemicals present in the home and workplace, chemical burns pose a unique challenge to the health care professional. For the majority of injuries, prompt and prolonged hydrotherapy is the cornerstone of therapy. The clinician needs to remember that the extent and depth of chemical injuries are difficult to assess in the acute phase; therefore, careful monitoring of blood values, urine output, and other parameters is necessary to gauge the volume of fluid required with major injury.