The performance of spinal anesthesia is marginally more difficult in the elderly

BACKGROUND AND OBJECTIVES

We sought to determine if spinal anesthesia is more difficult to perform in the elderly.

METHODS

All spinal anesthetics administered over 18 months by 18 anesthesiologists were eligible. We excluded anesthetics for hip fractures and cesarean deliveries. We recorded time to completion, number of spinal needles used, and number of approaches. The patients were prospectively divided into three age categories: patients <50 years of age (group 1); 50-70 years of age (group 2); and >70 years of age (group 3). Descriptive statistics and chi-square test were performed.

RESULTS

Nine hundred and ninety-nine anesthetics were analyzed. There were 368, 336, and 295 entries in groups 1, 2, and 3, respectively. Although the mean +/- SD (in min) times to accomplish the spinal technique were not significantly different (4.3 +/- 4.1, 4.4 +/- 3.2, and 4.6 +/- 3.4 for groups 1, 2, and 3), there was a statistically greater frequency of more than one spinal needle used and more than one approach needed in the elderly.

CONCLUSIONS

We conclude that patient age is a minor independent predictor of increased technical difficulty with spinal anesthesia.

A "zero tolerance for overtime" increases surgical per case costs

PURPOSE

One technique which some hospitals have used in an attempt to control Operating Room costs is a "zero tolerance for overtime" policy. We used a case cost analysis to determine if this policy was always cost effective.

METHOD

A case cost analysis was designed based on a "test case" which would start late in the day. The case would last for three hours of which 1 1/2 hr would be during regular hours, and 1 1/2 hr would incur overtime. Costs were analysed using a "patient pays," "society pays," and "hospital pays" analysis. Costs were based on figures determined from the SMBD-Jewish General Hospital budget, Québec Health Insurance fees, and Government of Canada statistics.

RESULTS

Regardless of who pays, in this case scenario it was more cost effective to proceed than to postpone surgery. Costs of proceeding with the surgery in the "patient pays," "society pays," and "hospital pays" models were $1,832.00, $1,227.40, and $1,215.00 respectively. The costs of postponing the surgery in the same three models were $1,937.00, $1,336.80, and $1,436.00.

CONCLUSION

A "zero tolerance for overtime" policy may be too rigid to be consistently cost effective.

Late operating room starts: experience with an education trial

PURPOSE

This study was undertaken to determine if late starts of first cases in the Operating theatres at the SMBD-Jewish General Hospital remained a problem after identification of the causes of late starts and remedial actions being taken.

METHODS

Hospital approval was obtained. A retrospective chart audit analyzed a two week period (10 days with 90 elective surgical cases) in October 1993. The time of entry by the first patient into each Operating Room (OR) was transcribed from the nursing records from each OR. A late start was defined as patient entry into the OR after 0745 hr. This audit revealed 77.8% of patients scheduled' for surgery at 0745 entered the OR late with a cumulative time lost of 1101 min. The reasons for this inefficiency were identified by a follow-up assessment in April 1995 as a result of this audit. Corrective measures included presentation of inpatients for the first case, reorganization of transport personnel schedules to facilitate arrival of patients to the OR, alteration of patient verification procedures prior to entry to the OR, and education of nursing, anaesthesia, and surgical personnel of the scope of the problem of late OR starts. All attending surgeons were notified either by letter or by discussion at departmental rounds. These measures were in effect by July 1995. A second audit, using the same methodology as the first, evaluated a two week period (10 days with 87 elective surgical cases) in October 1995.

RESULTS

The second audit showed 65.5% of patients (average of 9 operating rooms daily) scheduled for surgery at 0745 entered the OR late with 601 min lost. The average delay for late starting cases decreased from 15.73 +/- 4.56 to 10.54 +/- 3.92 min (P < 0.05).

CONCLUSION

Late OR starts are common and only modest improvements can be achieved without cooperation from anaesthetists and surgeons to arrive on time.

Changes in PCO2 with acute changes in cardiac index

PURPOSE

A direct relationship between cardiac index (CI) and end-tidal PCO2 (PETCO2) shortly after decreased CI was reported, but arterial PCO2 was not measured. Our purpose was to supply the missing information on the immediate effects of alterations in CI on PaCO2, PETCO2 and thus on Pa-PETCO2.

METHODS

We measured CI, Pa and PETCO2 and calculated the difference in 20 patients scheduled for elective heart surgery just before and immediately after the sternotomy. The measurements were made using standard methods: thermodilution for CI, infra-red and blood gas analysis for PET and PaCO2 respectively. The results were analyzed by linear regression.

RESULTS

Very significant, direct and immediate changes in PET and PaCO2 with changes in CI were noted. The ratios were 3.8 and 4.2 mmHg L-1 respectively. The calculated values of r were 0.75 (P < 0.001) for PETCO2 and 0.64 (P < 0.005) for PaCO2. The magnitude of individual change in PCO2 varied considerably such that the alterations in Pa-PETCO2 were also variable, without any correlation with the direction or magnitude of change in CI.

CONCLUSION

Our results explain the reported wide variations in Pa-PETCO2 that accompany perturbations of cardiac output. Our observations pertain to the unsteady state only. The results suggest that PETCO2 can be used to estimate changes in CI with a reasonable degree of confidence.

Acute ventilatory complications during laparoscopic upper abdominal surgery

PURPOSE

This article examines and summarizes the published reports dealing with subcutaneous emphysema, pneumothorax and carbon dioxide (CO2) embolism during laparoscopic upper abdominal surgery. The purpose is to describe the expected clinical picture, the differential diagnosis and the management of these complications.

SOURCE

The information was obtained from a Medline literature search and the annual meeting supplements of Anesthesiology, Anesth Analg, Br J Anaesth and Can J Anaesth.

PRINCIPAL FINDINGS

An abrupt increase in PETCO2 is the first sign of subcutaneous emphysema and of pneumothorax. Desaturation and increased airway pressure occur with pneumothorax, but not with subcutaneous emphysema alone. Desaturation and increased airway pressure also occur with bronchial intubation. The preliminary diagnosis is made by verifying the position of the tube, examination of the patient for swelling and crepitus and auscultation for air entry. Chest radiography and paracentesis confirm the diagnosis of pneumothorax, which frequently occurs with subcutaneous emphysema but is rarely of the tension type. Pulmonary embolism due to CO2 during LUAS has not been reported, but the available data suggest that small, haemodynamically inconsequential CO2 embolism occurs without change in PETCO2. Massive embolism is possible and will markedly decrease PETCO2, arterial O2 saturation (SpO2) and blood pressure.

CONCLUSION

The immediate recognition of the three complications requires continuous monitoring of PETCO2, arterial saturation, airway pressure, and an index of pulmonary compliance.

Cardiopulmonary function and laparoscopic cholecystectomy

This review analyzes the literature dealing with cardiopulmonary function during and pulmonary function following laparoscopic cholecystectomy in order to describe the patterns of changes in these functions and the mechanisms involved as well as to identify areas of concern and lacunae in our knowledge. Information was obtained from a Medline literature search and the annual meeting supplements of Anesthesiology, Anesth Analg, Br J Anaesth, and Can J Anaesth. The principal findings were that changes in cardiovascular function due to the insufflation are characterized by an immediate decrease in cardiac index and an increase in mean arterial blood pressure and systemic vascular resistance. In the next few minutes there is partial restoration of cardiac index and resistance but blood pressure and heart rate do not change. The pattern is the result of the interaction between increased abdominal pressure, neurohumoral responses and absorbed CO2. Pulmonary function changes are characterized by reduced compliance without large alterations in PaO2, but tissue oxygenation can be adversely affected due to reduced O2 delivery. A major difficulty in maintaining normocarbia is due to the abdominal distention reducing pulmonary compliance and to CO2 absorption. End tidal CO2 tension is not a reliable index of PaCO2, particularly in ASA III-IV patients. The pattern of lung function following LC is characterized by a transient reduction in lung volumes and capacities with a restrictive breathing pattern and the loss of the abdominal contribution to breathing. Atelectasis also occurs. These changes are qualitatively similar to but of a lesser magnitude than those following "open" abdominal operations. It is concluded that the changes in cardiopulmonary function during laparoscopic upper abdominal surgery lead us to suggest judicious invasive monitoring and careful interpretation in ASA III-IV patients. Lung function following extensive procedures in sick patients has not been reported.

Spinal anaesthesia for patients with previous lower limb amputations

Phantom limb pain has been reported as a transient phenomenon in patients with lower limb amputations during subsequent spinal anaesthesia. In order to determine its incidence and to define any predisposing factors we prospectively studied 23 spinal anaesthetics in 17 patients with previous lower limb amputation. Only one patient developed clinically significant phantom limb pain and we were unable to define any predisposing factors. Given the low incidence of recurrent phantom limb with spinal anaesthesia, its transient nature, and the fact that it can be treated if it occurs, we conclude that spinal anaesthesia is not contraindicated in patients with previous lower limb amputation.

Adult epiglottitis and postobstructive pulmonary edema in a patient with severe coronary artery disease

Epiglottitis is a rare cause of upper airway obstruction that may lead to death in the adult. We report the case of a patient with severe coronary artery disease with adult epiglottitis who required emergency endotracheal intubation. Relief of the airway obstruction was followed by the development of postobstructive pulmonary edema. The literature is reviewed and the following recommendations are made: Patients with adult epiglottitis should be intubated in the presence of any respiratory signs or symptoms. All others should be observed in an intensive care unit with a skilled anesthesiologist available to carry out emergency endotracheal intubation. Inhalation induction with halothane in oxygen should be considered initially; failing that, rigid bronchoscopy, tracheostomy, or transtracheal ventilation should be available. Postobstructive pulmonary edema should be anticipated after relief of airway obstruction has occurred; it can be treated with fluid restriction, diuretics, and continuous positive airway pressure.

Functional stridor diagnosed by the anaesthetist

While stridor is an ominous sign implying severe airway stenosis, not all stridor has an organic aetiology. We present two cases of functional stridor in which the diagnosis was made by the anaesthetist. As experts in the management of difficult airways, anaesthetists should be aware of this clinical entity. Recurrent episodes present as aphonia, dysphonia, dyspnoea, apnoea or unconsciousness. Stridor is usually inspiratory. Flow volume loops show a pattern of variable extrathoracic obstruction with diminished peak inspiratory flow. Awake fibreoptic laryngobronchoscopy reveals normal airway anatomy, intense adduction of false and true vocal cords during inspiration and normal vocal cord motion on expiration. Treatment of functional stridor is supportive. The diagnosis of functional stridor demands exclusion of life-threatening airway stenosis of organic aetiology. A high index of suspicion for this clinical entity will reduce the incidence of unnecessary interventions such as tracheal intubation and tracheostomy.

Patient-controlled analgesia (PCA) using fentanyl in a parturient with a platelet function abnormality

A term parturient with documented platelet dysfunction presented to the case room for induction of labour. Since this bleeding abnormality contraindicated the use of lumbar epidural analgesia (LEA), we elected to use an iv fentanyl patient-controlled analgesia (PCA) technique for pain relief during labour. The patient received a 50 micrograms fentanyl loading dose after which 20 micrograms boluses of fentanyl were self-administered every three minutes as required. The patient received a total of 400 micrograms of fentanyl over the 3 1/2 hr of active labour. Mother and neonate tolerated the fentanyl without sequelae. If facilities to monitor the neonate and mother are present, this method of analgesia is useful in those patients where LEA is contraindicated.