The introduction of chloroform anesthesia in Madrid. Notes for studying its history]

Until present, the introduction of chloroform anesthesia in Madrid has not been specifically studied by any author. Therefore, knowledge of the events related to this happening is lacking. We have studied this chapter of our history by analyzing primary documents and articles published at the daily press, political press, and scientific journals of Madrid during 1847 to 1848. This investigation allowed us to follow the most relevant news dealing with the discovery of the drug and with its first experimental and clinical applications in Madrid. Based on the present bibliographic material we could establish a chronologic report of all surgical interventions using chloroform that were performed in Madrid. We conclude that albeit surgeons in Madrid were not the first to use chloroform in Spain, they were, however, the ones who most extensively used it. Their contribution was of relevance in the settlement of the new anesthetic agent in Spain.     

Two cases of hearing disorder following general anesthesia]

Hearing impairment is not often considered as a potential complication of general anesthesia, despite several reports of post-operative sensorineural hearing loss. These disorders have occurred after otological as well as cardiobypass surgery. We experienced two patients both of whom had undergone orthopedic surgery. In both cases the patients experienced bilateral reversible hearing impairment after general anesthesia with nitrous oxide. It is likely that a change in the middle ear pressure as a result of Eustachian tube dysfunction may have caused transient conductive hearing loss added to sensorineural hearing disorder. After these cases we interviewed a series of 115 patients who had undergone general anesthesia to assess the extent of this problem. Contrary to our expectation, 7 patients complained of ear fullness or autophony after inhalation of nitrous oxide, although these symptons diminished within 24 hours. It is important to be aware of the possibility of hearing impairment when nitrous oxide is used especially if the patient has a history of a previous middle ear disease.     

The auditory steady-state response is not a suitable monitor of anesthesia

Previous studies show that the human 40-Hz auditory steady-state response (ASSR) disappears on induction of general anesthesia, suggesting that it may be a good candidate for a monitor of anesthesia. In this study, we aimed to learn whether all normal alert adults display ASSRs with adequate signal-to-noise ratio. Clicks were presented at a series of frequencies between 35 and 70 Hz and electroencephalographic records taken at the vertex were Fourier transformed. ASSRs were observable as sharp peaks in the electroencephalograph spectrum at the frequency of the clicks. Initial results showed that a discernible ASSR could not be obtained from about half the subjects studied at any click frequency used. Further investigation revealed that in subjects whose ASSR was undetectable in the alert state, induction of a drowsy mental state resulted in appearance of an observable ASSR. This was attributable to an increase in signal in the drowsy state, not to a decrease in noise. We conclude that, because a significant proportion of subjects do not display easily recordable ASSRs when alert, it is not practical to use disappearance of the ASSR as a routine test for adequacy of anesthesia. IMPLICATIONS: Auditory steady-state responses (ASSRs) are brain waves evoked by auditory stimuli. Because they reportedly disappear under general anesthesia, they have been suggested as potential indicators of anesthetic depth. However, in this study, we show that about half our normal adult subjects did not produce measurable ASSRs when awake. This suggests that ASSRs are not good candidates for use in monitoring anesthetic depth during surgery.     

History of the introduction of ether anesthesia in Spain. A new contribution to its study

Ether anesthesia was introduced in Spain on January 13, 1847. Dr. Diego de Argumosa y Obregón, from Madrid, was the first Spanish surgeon who operated with the help of sulphuric ether. Almost at the same time, by the end of January, the dentist Oliverio Machechan administered ether to 2 patients in whom he performed dental operations. Subsequently, ether was used in several parts of Spain: Barcelona, Pamplona, Motril, and by several Madrid surgeons through February and March. In Santiago de Compostela ether was also introduced very soon, and, on the basis of the data from the studies of Dr. José González Olivares (the surgeons who first tried it in that town), most authors dealing with this issue state that it was probably in Santiago de Compostela where these experiments were carried out simultaneously with those by Argumosa in Madrid or even before. We have in some occasions defended that thesis; however, we were not satisfied with it and we decided to reinvestigate the facts. We had access to other sources and we concluded that anesthetics were really used a very early phase in Santiago de Compostela, but in the case of ether it was later than Argumosa and Oliverio Machechan used it in Madrid and Mendoza in Barcelona. In the present article we analyze these facts in detail, with emphasis on those that we consider historically relevant and that had not been previously dealt with by any other author addressing these issues.     

Distress during the induction of anesthesia and postoperative behavioral outcomes.

We determined whether children who are extremely anxious during the induction of anesthesia are more at risk of developing postoperative negative behavioral changes compared with children who appear calm during the induction process. Children (n = 91) aged 1-7 yr scheduled for general anesthesia and elective outpatient surgery were recruited. Using validated measures of preoperative anxiety and postoperative behaviors, children were evaluated during the induction of general anesthesia and on Postoperative Days 1, 2, 3, 7, and 14. Using a multivariate logistic regression model, in which the dependent variable was the presence or absence of postoperative negative behavioral changes and the independent variables included several potential predictors, we demonstrated that anxiety of the child, time after surgery, and type of surgical procedure were predictors for postoperative maladaptive behavior. The frequency of negative postoperative behavioral changes decreased with time after surgery, and the frequency of negative postoperative behavioral changes increased when the child exhibited increased anxiety during the induction of anesthesia. Finally, we found a significant correlation (r) of 0.42 (P = 0.004) between the anxiety of the child during induction and the excitement score on arrival to the postanesthesia care unit. We conclude that children who are anxious during the induction of anesthesia have an increased likelihood of developing postoperative negative behavioral changes. We recommend that anesthesiologists advise parents of children who are anxious during the induction of anesthesia of the increased likelihood that their children will develop postoperative negative behavioral changes such as nightmares, separation anxiety, and aggression toward authority. IMPLICATIONS: Anesthesiologists who care for children who are anxious during the induction of anesthesia should inform parents that these children have an increased likelihood of developing postoperative negative behavioral changes.     

Reduction of anesthesia process times after the introduction of an internal transfer pricing system for anesthesia services

To improve operating room workflow, an internal transfer pricing system (ITPS) for anesthesia services was introduced in our hospital in 2001. The basic principle of the ITPS is that the department of anesthesia receives reimbursement only for the surgically controlled time, not for anesthesia-controlled time (ACT). A reduction in anesthesia process times is therefore beneficial for the anesthesia department. In this study, we analyzed the ACT (with its parts: preparation before induction, induction, extubation, and recovery room transfer) for 3 yr before and 3 yr after the introduction of the ITPS in 55,776 cases. Furthermore, the anesthesia cases were subsegmented into 10 different anesthesia techniques, and the process times were studied. The average total ACT was reduced from 40.4 +/- 23.5 min in 1998 to 34.3 +/- 21.7 min in 2003. The main effect came from reductions in anesthesia preparation time and recovery room transfer time, whereas induction and extubation time changed little. A significant reduction in average ACT was seen in 7 of 10 analyzed anesthesia techniques, ranging from 4 to 18 min. We conclude that transfer pricing of anesthesia services based on the surgically controlled time can be a successful approach to reduce anesthesia process times.     

Predicting which child-parent pair will benefit from parental presence during induction of anesthesia: a decision-making approach

Using a multiply matched, concurrent cohort analysis, with 568 subjects matched from data obtained by our laboratory over the past 7 yr, we examined whether parental presence during induction of anesthesia (PPIA) reduces children's anxiety depending on the interaction between child and parent's baseline anxiety. Children's and parents' baseline anxiety was assessed preoperatively; children's anxiety was again assessed during induction of anesthesia. We found that anxious children who received PPIA from a calm parent were significantly less anxious during induction of anesthesia as compared with anxious children who did not receive PPIA (P = 0.03). In contrast, calm children who received PPIA from an overly anxious parent were significantly more anxious as compared with calm children who were not accompanied by a parent (P = 0.002). We found no effect of PPIA on children's anxiety during induction of anesthesia when calm parents accompanied calm children into the operating room (P = 0.15) or when overly anxious parents accompanied anxious children (P = 0.49). We conclude that the presence of a calm parent does benefit an anxious child during induction of anesthesia and the presence of an overly anxious parent has no benefit.     

Leakage in anesthesia circuits--a comparison between 1998 and 2005 investigations

BACKGROUND: We checked for the occurrence of any leakage in an anesthesia circuit to estimate the present situation of airtightness of an anesthesia circuit in 55 anesthesia machines at various medical institutions in Okinawa. METHODS: Leakage was detected and measured by a leak checker. RESULTS: A certain degree of leakage was found in 28 of the anesthesia machines (51%). The average and maximal amounts of leakage in the anesthesia machines were 0.26, and 1.29 l x min(-1), respectively. Thirty-eight of anesthesia machines met the standards of a low flow leak test (69%). The average and maximal amounts of leakage in the inside circuit were 0.02, and 0.20 l x min(-1), respectively. The leak points of the inside circuit were present in a unidirectional valve for an oxygen sensor (14%) and for unknown reason (7%). The average and maximal amounts of leakage in the outside circuit were 0.24, and 1.29 l x min(-1), respectively. Leak points in the inside circuit were found in the corrugated breathing tube (82%) and canister (32%). CONCLUSIONS: Most instances of leakage of the above described anesthesia circuits were identified in the corrugated breathing tube and canister. As a result of our findings, we strongly recommend that these parts be checked very carefully during pre-anesthetic leak tests.     

Application of the mixed venous blood concentration equation in desflurane anesthesia

BACKGROUND: We have previously proposed an equation derived from Fick's law and Lin's concept of effective blood concentration (EBC) to calculate the mixed venous blood concentration (MVBC) of isoflurane. Desflurane has a lower blood/air partition coefficient than isoflurane and, as such, promotes a faster induction and recovery from anesthesia. In this study, we investigated the application of the MVBC equation to predict the MVBC of desflurane. METHODS: We maintained anesthesia with a fixed inspired concentration (CI) of desflurane (10%) during cardiac anesthesia in 11 patients. In order to measure the real concentrations of desflurane in mixed venous blood, pulmonary arterial blood samples were collected at different time points via a Swan-Ganz catheter for gas chromatographic-mass spectrometric determination. The relationship between the calculated concentrations and the actual blood sample concentrations of desflurane in mixed venous blood was investigated. Lin's EBC method was also used and the results were compared with those of MVBC. RESULTS: The calculations from our derived MVBC equation and the actual blood concentrations showed a similar kinetic pattern; the concentration levels were approximately the same and correlated well (r = 0.89) during anesthesia. However, the EBC method failed to accurately estimate the actual blood concentrations. CONCLUSIONS: The results demonstrate that our equation, but not the EBC method, may be useful for estimating pulmonary blood concentrations of desflurane. The clinical significance and the importance of the method merit further investigation.     

Some Spanish contributions to anesthesiology at the end of the XIXth century]

At the end of the XIXth century some original, although poorly known, Spanish contributions were made on the field of inhalational general anesthesia that are important for the history of our specialty in Spain. The purpose of this work is to report the Spanish contributions to inhalational general anesthesia made during the chronological period that coincides with the locus-regional anesthetic techniques grown after the appearance of cocaine in 1884.     

Office-based wire-guided open breast biopsy under local anesthesia is accurate and cost effective

BACKGROUND: Mammographic abnormalities found to be malignant by stereotactic biopsy still require a wire-guided biopsy (WGB) in most cases. We have previously described a simplified method of WGB that allows the procedure to be done with a minimum of dissection and under local anesthesia in the office setting. We hypothesized that this procedure can be used to produce cost-effective, office-based breast preservation therapy (BPT). METHODS: We reviewed our recent experience with this WGB method to determine applicability and accuracy in the office setting. A cost-effectiveness analysis was also performed to determine potential charge reductions when this method is used to avoid operating room (OR) usage for either lumpectomy or lumpectomy plus sentinel lymph node biopsy (SLNB). RESULTS: Of the 164 biopsies reviewed, 114 (70%) were performed in the office setting under local anesthesia and 50 (30%) were performed in the OR. The most common reasons for choosing the OR setting included performance of biopsy during an unrelated procedure requiring the OR (16 cases), patient preference (12), deep lesions (6), and the inability of the patient to cooperate with local anesthesia (5). The complication rates were similar between the two settings (7% for office-based and 4% for OR; P = 0.697), and in neither setting were any lesions missed. A cost-effectiveness analysis using our Current Procedure Terminology (CPT)-based charges revealed a potential per-case charge reduction of $4,632 for office-based lumpectomy and $4306 for office-based lumpectomy/SLNB, using our method of WGB and local anesthesia, compared with the OR setting. CONCLUSIONS: Office-based WGB using our previously described method is accurate and can be applied to at least 70% of patients. Based on the favorable results of our cost analysis and rising support for SLNB, we anticipate increased utilization of the clinic setting and local anesthesia for BPT in the future.     

Preperitoneal mesh repair of spigelian hernias under local anesthesia: description and clinical evaluation of a new technique

We report on a new method for the repair of spigelian hernia, in which we combined the step-by-step local anesthesia and open preperitoneal mesh repair techniques. After initial infiltration of local anesthetics, we incised the attenuated fascia and slightly enlarged the fascial defect to facilitate easy return of hernial content into the abdominal cavity. We injected preperitoneally, in a radial fashion around the peritoneal sac, more saline solution, consisting of 1:200,000 epinephrine (g:g) and 1/3 bupivacain (v:v). We dissected the peritoneum away from the anterior abdominal wall to create a preperitoneal pocket of sufficient size. We spread open a 9 x 9-cm polypropylene mesh in the area, as if we were doing a GPRVS of Stoppa. We followed up our four patients for an average of 32 months. All four cases had an uneventful recovery and were discharged in an average of 3.5 days. They returned to normal daily activity on the 9th day after surgery. We suggest that the preperitoneal mesh repair of a spigelian hernia under local anesthesia is a simple and feasible technique with favorable early and late postoperative results and deserves further investigation in larger series.     

The absence of dominant alpha-oscillatory EEG activity during emergence from delta-dominant anesthesia predicts neurocognitive impairment- results from a prospective observational trial

Study objectivePostoperative neurocognitive disorders (PND) are common complications after surgery under general anesthesia. In our aging society the incidence of PND will increase. Hence, interdisciplinary efforts should be taken to minimize the occurrence of PND. Electroencephalographic (EEG) monitoring of brain activity during anesthesia or emergence from anesthesia is a promising tool to identify patients at risk. We therefore investigated whether we could identify specific EEG signatures during emergence of anesthesia that are associated with the occurrence of PND.Design and patientsWe performed a prospective observational investigation on 116 patients to evaluate the EEG features during emergence from general anesthesia dominated by slow delta waves in patients with and without delirium in the postoperative care unit (PACU-D) as assessed by the CAM-ICU and the RASS.Main resultsDuring emergence both the frontal and global EEG of patients with PACU-D were significantly different from patients without PACU-D. PACU-D patients had lower relative alpha power and reduced fronto-parietal alpha coherence.ConclusionsWith our analysis we show differences in EEG features associated with anesthesia emergence in patients with and without PACU-D. Frontal and global EEG alpha-band features could help to identify patients with PACU-D.Clinical trial number: NCT03287401     

Spinal cord compression caused by hematoma related to neuroaxial anesthesia in Spain

OBJECTIVES: Spinal cord compression from a hematoma is a rare serious complication of neuroaxial anesthesia. Our objective was to investigate cases reported and published by Spanish authors. MATERIAL AND METHODS: Cases of spinal cord compression related to neuroaxial hematomas (epidural, subarachnoid, or both) reported at congreses and meetings in Spain or published in Medline-indexed journals from 1989 through December 2002 were reviewed. The clinical characteristics, risk factors, treatments, and outcomes were described for each case. RESULTS: Since 1996, when the first cases were reported, 20 cases in all have appeared: 8 related to sub-arachnoid anesthesia, 8 to epidural anesthesia, 1 to a combination, and 1 to diagnostic lumbar puncture. In 2 cases, the neuroaxial technique used was poorly defined. Factors that might have caused the complication could be identified in 11 cases, among which there were 7 cases of anesthetic puncture or manipulation of an epidural catheter during a period of hemorrhagic risk because of antithrombotic therapy. The hematoma was evacuated surgically in 11 cases, and medical treatment was provided in 9 cases. The neurologic outcome was satisfactory in 14 cases. CONCLUSIONS: The number of compressive spinal hematomas reported or published by Spanish authors is fairly high, and there are cases related to both sub-arachnoid and epidural anesthesia. Nonsurgical treatment was provided in 45% of the cases and the outcome was satisfactory in 70%. Risk factors were identified in over half of the reported cases.     

Predictors of hypotension after induction of general anesthesia

Hypotension after induction of general anesthesia is a common event. In the current investigation, we sought to identify the predictors of clinically significant hypotension after the induction of general anesthesia. Computerized anesthesia records of 4096 patients undergoing general anesthesia were queried for arterial blood pressure (BP), demographic information, preoperative drug history, and anesthetic induction regimen. The median BP was determined preinduction and for 0-5 and 5-10 min postinduction of anesthesia. Hypotension was defined as either: mean arterial blood pressure (MAP) decrease of >40% and MAP <70 mm Hg or MAP <60 mm Hg. Overall, 9% of patients experienced severe hypotension 0-10 min postinduction of general anesthesia. Hypotension was more prevalent in the second half of the 0-10 min interval after anesthetic induction (P < 0.001). In 2406 patients with retrievable outcome data, prolonged postoperative stay and/or death was more common in patients with versus those without postinduction hypotension (13.3% and 8.6%, respectively, multivariate P < 0.02). Statistically significant multivariate predictors of hypotension 0-10 min after anesthetic induction included: ASA III-V, baseline MAP <70 mm Hg, age > or =50 yr, the use of propofol for induction of anesthesia, and increasing induction dosage of fentanyl. Smaller doses of propofol, etomidate, and thiopental were not associated with less hypotension. To avoid severe hypotension, alternatives to propofol anesthetic induction (e.g., etomidate) should be considered in patients older than 50 yr of age with ASA physical status > or =3. We conclude that it is advisable to avoid propofol induction in patients who present with baseline MAP <70 mm Hg.     

Comparison of sequential combined spinal-epidural anesthesia and spinal anesthesia for cesarean section

AIM: The aim of our study was to prove that by using sequential combined spinal-epidural (CSE) anesthesia it is possible to overcome the limits connected to the use of spinal anesthesia (SA) alone for elective cesarean section. METHODS: We examined 100 women submitted to cesarean section; SA was administered to 50 patients and sequential CSE technique to the other 50. In every woman before execution of the anesthesia we infused 500 mL of a plasma expander and a previous administration of 5 mg of ephedrine. The CSE was executed at the L1-L2 intervertebral space, administering in spinal anesthesia 5 mg of levobupivacaine with 5 _g of sufentanil, and in peridural anesthesia 10-12 mL of levobupivacaine 0.25% according to the patient's height. The peridural catheter for postoperative analgesia was then positioned. In the group of women submitted only to SA, 7.5-8 mg of levobupivacaine was injected, according to the patient's height, in the L1-L2 intervertebral space, with 5 _g of sufentanil. We considered the following adverse effects: hypotension; bradycardia; vomiting; intraoperative discomfort and motor block. RESULTS: The results obtained showed that, with a P < or = 0.05, the incidence of motor block (P < 0.001), discomfort (P < 0.001) and hypotension (P = 0.021) in the SA group is greater than in the CSE group. The difference in the incidence of vomiting (P = 0.147) and bradycardia (P = 0.067) between the 2 groups is not statistically significant. CONCLUSIONS: In our opinion sequential CSE can be considered an important step forward in the regional anesthesia used for elective cesarean section.     

Surgical peri- and postoperative plexus anesthesia in subacromial decompression of the shoulder

AIM: The aim of the present investigation was to check the peri- and postoperative plexus anesthesia on early functional outcome and postoperative analgetic consumption during subacromialen decompression until the date of discharge. METHODS: 50 patients in the period 01.01.1997 to 01.10.1998 treated by an arthroscopic or open subacromial decompression of the shoulder were registered. Pre- and postoperative functional movement and postoperative analgetic consumption within the first 12 days after the operation were compared according to the procedure used. RESULTS: The peri- and postoperative plexus anesthesia had a positive influence to early functional outcome as well as on the analgetic consumption. The results are shown in the group of arthroscopic (18) surgery and in the group of the patients operated in an open (32) technique. The patients with plexus anesthesia showed a better functional movement of the shoulder directly postoperatively and a lower consumption analgetic drags. At the time of discharge we found no significant differences between the subjects in both groups. CONCLUSION: The investigation shows that peri- and postoperative plexus anesthesia has no positive influence on the early functional outcome after subacromial decompression of the shoulder.     

Awareness during anesthesia in children: a prospective cohort study

During routine adult anesthesia, the risk of awareness is 0.1%-0.2%. No recent studies have reported the incidence in children. Altered pharmacology and differing anesthesia techniques suggest that the incidence may differ in children. In this prospective cohort study, we determined the incidence of awareness during anesthesia in children. Eight-hundred-sixty-four children aged 5-12 yr who had undergone general anesthesia at The Royal Children's Hospital were interviewed on 3 occasions to determine the incidence of awareness. The awareness assessment was nested within a larger study of behavior change after anesthesia. Reports of suspected awareness were sent to four independent adjudicators. If they all agreed, a case was classified as true awareness. Twenty-eight reports were generated. There were 7 cases of true awareness, for an incidence of 0.8% (95% confidence interval, 0.3%-1.7%). Only one aware child received neuromuscular blockers, compared with 12% in the nonaware group. No aware child reported distress, and no substantial difference was detected in behavior disturbance between aware (20%) and nonaware (16%) children. The data provide some evidence that, like adults, children are also at risk of intraoperative awareness. Although the cause remains unclear, anesthesiologists should be alerted to the possibility of awareness in children.     

Spinal anesthesia with bupivacaine for a patient with a history of severe leg pain after intrathecal dibucaine

An 87-year-old man was scheduled for the 11th transurethral bladder tumor resection (TURBT). He had a history of non-active syphilis for 21 years, diabetes mellitus for 7 years, and severe emphysema. Preoperative physical examination of the lower extremities, revealed loss of knee-jerk reflex, and loss of vibratory and proprioceptive perception. Four years previously, he underwent TURBT twice under spinal anesthesia with dibucaine, which caused severe leg pain during anesthesia. Therefore, subsequent TURBTs (eight times) were performed under general anesthesia with tracheal intubation, which frequently caused postoperative respiratory distress. Recently, bupivacaine, less neurotoxic than dibucaine, was on the market in Japan for use in spinal anesthesia. Therefore we planned spinal anesthesia using 0.5% bupivacaine, 2.0 ml. This time, he did not complain of leg pain during anesthesia, and postoperative conditions were satisfactory. We can conclude that bupivacaine is very useful for spinal anesthesia especially in patients with a history of leg pain by spinal anesthesia with dibucaine.