David R. Danielson

Angiotensin system inhibitors in a general surgical population.

We studied the relationship between the timing of discontinuing chronic angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor subtype 1 antagonists (ARA) and hypotension after the induction of general anesthesia in a general surgical population. We retrospectively studied 267 hypertensive patients receiving chronic ACEI/ARA therapy undergoing elective noncardiac surgery under general anesthesia. During preoperative visits, patients were asked to either take their last ACEI/ARA therapy on the morning of surgery or withhold it up to 24 h before surgery. The number of hours from the last ACEI/ARA dose to surgery was recorded during the preoperative interview. Electronic medical and anesthesia records were reviewed for comorbidities, type and dose of anesthetics used, intraoperative hemodynamics, IV fluids, perioperative vasopressor administration, and rate of severe postoperative complications. Arterial blood pressure (BP) and heart rate were recorded during the 60-min postinduction period, and hypotension was classified as moderate (systolic BP ≤85 mm Hg) and severe (systolic BP ≤65 mm Hg). We analyzed all variables separately for patients who took their last ACEI/ARA therapy <10 h and ≥10 h before surgery. During the first 30 min after anesthetic induction, moderate hypotension was more frequent in patients whose most recent ACEI/ARA therapy was taken <10 h (60%) compared with those who stopped it ≥10 h (46%) before induction (P = 0.02). The adjusted odds ratio for moderate hypotension was 1.74 (95% confidence interval, 1.03–2.93) for those who took their ACEI/ARA therapy <10 h before surgery (P = 0.04). There were no differences between groups in the incidence of severe hypotension, nor was there a difference in the use of vasopressors. During the 31–60 min after induction, the incidence of either moderate (P = 0.43) or severe (P = 0.97) hypotension was similar in the two groups. No differences in postoperative complications were found between groups. In conclusion, discontinuation of ACEI/ARA therapy at least 10 h before anesthesia was associated with a reduced risk of immediate postinduction hypotension.

Requirements for muscle relaxants during radical retropubic prostatectomy.

BackgroundThe need for the routine use of muscle relaxants to provide an adequate surgical field for intraabdominal surgery has not been established. This study tested the hypothesis that vecuronium decreases the frequency of unacceptable operating conditions for patients undergoing radical retropubic prostatectomy who are anesthetized with isoflurane and fentanyl. MethodsAfter obtaining informed consent, patients in this blinded, placebo-controlled study were randomized to receive either an infusion of vecuronium or saline (placebo) beginning 5 min after fascial incision during the maintenance of anesthesia with at least 1 minimum alveolar concentration end-tidal isoflurane and fentanyl infusion. The surgical field was graded from 1 (excellent) to 4 (unacceptable) by the surgeons at 15-min intervals. If a grade 4 rating occurred (defined as a treatment failure), the patient received rescue vecuronium. ResultsA total of 120 patients are included in this report (59 in the vecuronium group and 61 in the placebo group). The frequency of treatment failure in the placebo group was 17 of 61 (27.9%) versus 1 of 59 (1.7%) in the control group who received vecuronium (P < 0.001). Thirty-eight patients (62.3%) in the placebo group and 52 patients (88.1%) in the vecuronium group had surgical field ratings of ≤ 2 (good to excellent) at each time assessed throughout the procedure. ConclusionThe study hypothesis was confirmed. However, an isoflurane–fentanyl anesthetic alone produced a good to excellent surgical field in approximately two thirds of patients undergoing radical retropubic prostatectomy without the use of muscle relaxants. Thus, the routine use of muscle relaxants in adequately anesthetized patients undergoing this procedure may not be indicated.

Comparison of lumbar and thoracic epidural morphine for relief of postthoracotomy pain

The use of epidural narcotics has revolutionized postoperative analgesia. Narcotics injected in this fashion provide excellent analgesia with a relatively low incidence of side effects. In addition a significant improvement in postoperative pulmonary function has been demonstrated with epidural narcotics as compared to narcotics given intravenously (1). Patients having operations that are known to cause significant impairment in postoperative pulmonary function stand to benefit a great deal from improved postoperative analgesia, especially those with preexisting pulmonary disease. Early reports stress the segmental nature of analgesia with epidural morphine and suggest placement of the epidural catheter at the dermatome level corresponding to the origin of the pain. We, therefore, adopted the practice of placing thoracic epidural catheters in patients undergoing thoracotomy. Unfortunately, this requires placement of epidural catheters at the T5-6 level for patients undergoing standard thoracotomy incisions, a level at which interspaces are most narrow and spinous processes are most angulated. In addition, the potential for spinal cord trauma always exists whenever needles are inserted above L2. Therefore, in patients in whom insertion of a thoracic epidural catheter was not possible technically, we began to place lumbar epidural catheters. Because of earlier reports of segmental distribution of analgesia with epidural narcotics, our initial expectations were that patients with lumbar epidural catheters might not achieve adequate analgesia or would only achieve adequate analgesia with higher doses. Surprisingly, we noted that with similar doses, the analgesic effect of lumbar epidural morphine was similar to that of patients receiving thoracic epidural morphine. We, therefore, decided to study retrospectively a

Free and Conjugated Amines in Human Lumbar Cerebrospinal Fluid

Significant amounts of acid‐hydrolyzable conjugates of 3,4‐dihydroxyphenylethylamine, norepinephrine, and 5‐hydroxytryptamine were detected in lumbar CSF from 22 awake unpremedicated healthy individuals. In the CSF samples, the amounts of conjugated amines almost always exceeded the amounts of free amines, but were less than the amounts of the acid metabolites 3,4‐dihydroxyphenylacetic acid, homovanillic acid, and 5‐hydroxyindoleacetic acid.

Preoperative evaluation of patients with history of allergy to penicillin: Comparison of 2 models of practice

OBJECTIVE To study whether allergy consultation and penicillin allergy skin testing affects the selection of antibacterial prophylaxis perioperatively in surgical patients with history of allergy to penicillin (HOAP). PATIENTS AND METHODS From January 1 through June 30, 2004, we compared 2 different models of practice at our institution. At the Preoperative Evaluation Clinic (POEC), all patients with HOAP are evaluated by an allergist and undergo skin testing for allergy to penicillin. At other (non-POEC) preoperative evaluation settings (OPES), patients with HOAP do not undergo allergy consultation and penicillin skin testing before surgery. Of the 4889 patients screened at the POEC during the study period, 412 consecutive patients with HOAP were included in the study. Of the 416 patients screened at OPES, 69 consecutive patients with HOAP were studied. Logistic regression was used to assess whether allergy consultation was associated with the choice of antibiotic for antibacterial prophylaxis perioperatively, after adjusting for age, sex, and type of surgery. RESULTS Perioperative cephalosporin use was greater among patients screened at POEC vs those screened at OPES (70% vs 39%, P<.001 unadjusted; P=.04 adjusted for age, sex, and type of surgery). Vancomycin use was lower for patients screened at POEC vs those screened at OPES (10% vs 28%, P<.001 unadjusted; P=.03 adjusted). CONCLUSION For patients with HOAP, evaluation at the POEC was associated with increased use of cephalosporin and decreased use of vancomycin.

Perioperative Ingestion of Caffeine and Postoperative Headache

The interruption of daily consumption of caffeine-containing beverages can cause headache and other symptoms within 8 hours. Resumption of caffeine alleviates these symptoms. Surgical patients routinely fast preoperatively and may have postoperative symptoms from caffeine withdrawal. In the current study, we determined whether perioperative caffeine consumption altered the incidence of postoperative headache. After institutional approval of the study design, 233 surgical outpatients were surveyed about history of headaches, caffeine consumption, and the presence and severity of headaches postoperatively. Of the 233 patients, 190 (82%) drank caffeinated beverages daily (mean daily consumption, 290 mg of caffeine). Postoperative headaches occurred in 22% of patients who routinely drank caffeinated beverages but in only 7% of those who did not (P < 0.03). Other factors associated with postoperative headaches included a history of frequent headaches (P < 0.0001), age of 50 years or younger (P < 0.002), and amount of daily caffeine ingested (P < 0.01). Among daily caffeine drinkers, those who drank caffeinated beverages on the day of the surgical procedure had a lower incidence of postoperative headaches than did those who abstained (17% versus 28%; P < 0.04). Postoperative headaches may be related to several factors. Perioperative intake of caffeine altered postoperative well-being. Caffeine given preoperatively may limit postoperative withdrawal headaches among the millions of daily drinkers of caffeinated beverages. A randomized, prospective, and blinded trial to test this hypothesis is warranted.

Clinician-delivered Intervention to Facilitate Tobacco Quitline Use by Surgical Patients

Background:Telephone quitlines that provide counseling support are efficacious in helping cigarette smokers quit and have been widely disseminated; currently, they are underused. Surgery represents a teachable moment for smoking cessation, which can benefit surgical outcomes; however, few surgical patients receive smoking cessation interventions. This study developed and tested a clinician-delivered intervention to facilitate quitline use by adult patients scheduled for elective surgery. Methods:After formative work involving patients and clinicians, a brief intervention was designed to facilitate telephone quitline use. It was then evaluated in a randomized trial of 300 adults scheduled for elective surgery. A control standard brief stop-smoking intervention served as a comparator, with both interventions delivered by clinicians. The primary outcome was the use rate of a quitline accessed through a dedicated toll-free telephone number, with use defined as completing at least one full counseling session. Secondary outcomes included self-reported abstinence from cigarettes at 30 and 90 days postoperatively. Results:Subject characteristics were similar between the two groups. Records from the designated quitline documented that 29 of 149 subjects (19.5%) in the quitline intervention group and 0 of 151 subjects in the control group completed the first full counseling session (P < 0.0001). There were no significant differences in the self-reported point-prevalent and continuous abstinence rates between groups at either 30 or 90 days postoperatively, although rates tended to be higher in the quitline intervention group. Conclusions:Clinicians can effectively facilitate quitline use by surgical patients. Further work is necessary to evaluate the efficacy of this approach in terms of long-term abstinence from cigarette smoking.

Randomised trial of intranasal nicotine and postoperative pain, nausea and vomiting in non-smoking women

Background The primary aim of this study is to test the hypothesis that intranasal nicotine reduces postoperative opioid use among non-smoking women. The second aim is to determine the effects of intranasal nicotine on the incidence of postoperative nausea and vomiting (PONV). Methods In this double-blind, randomised placebo-controlled trial, non-smoking women undergoing gynaecological procedures received either 3 mg intranasal nicotine (N = 90) or placebo spray (N = 89) at the conclusion of surgery. Postoperative opioid use (intravenous morphine equivalents) and PONV rates were recorded during the recovery room (postanaesthesia care unit, PACU) stay and first 24 postoperative hours. Results From an overall analysis, opioid dose administered within the first 24 h was lower in patients receiving nicotine [median (25th, 75th) 38 (17, 62) mg for placebo vs. 25 (13, 46) mg for nicotine; P = 0.012]. Inpatients who received intranasal nicotine used less opioid. From an overall analysis, patients in the nicotine group were more likely to experience nausea (71.1 vs. 56.2% P = 0.044), receive rescue antiemetics (57.8 vs. 38.2% P = 0.011), and report higher Nausea Verbal Descriptive Scores [2 (0, 2; vs. 1 (0, 2), P = 0.006] in PACU. Inpatients who received nicotine were more likely to receive antiemetics (P = 0.009) and report higher Nausea Verbal Descriptive Scores (P = 0.025) in the PACU. Conclusion Intraoperative use of intranasal nicotine has a sustained opioid-sparing effect in non-smoking women undergoing gynaecological procedures and is associated with a higher frequency of PONV.

Drug-Eluting Stents: Patient Understanding of the Risks of Premature Cessation of Antiplatelet Drugs

OBJECTIVE Drug-eluting coronary stent use is common. Antiplatelet drug use after stent placement is necessary to prevent stent thrombosis. It has been recommended that at the time of stent placement, patients be given instructions regarding stopping antiplatelet drugs before elective surgery. Unfortunately, patients may be given inappropriate preoperative instructions by health care providers or may stop the drugs on their own. This can lead to perioperative myocardial infarctions and death. DESIGN Survey. SETTING Preoperative evaluation clinic of 2 teaching hospitals. PARTICIPANTS One hundred sixteen patients with coronary stents completed a 13-question survey. The questionnaire assessed patient understanding of stent type and the risks of stopping antiplatelet drugs, in addition to communication among the patient, their surgeon, and their treating cardiologist before elective surgery. INTERVENTION None. MEASUREMENTS AND MAIN RESULTS The majority of patients stated either they had received no instructions from their implanting cardiologist regarding future surgery and antiplatelet drugs or they were unsure if any instructions had been given. Most patients (57%) received antiplatelet instructions regarding their planned surgery from their surgeon, whereas only 14% received instructions with (known) cardiology input. The majority of patients were unaware or unsure of any risk in prematurely stopping their antiplatelet drugs. CONCLUSION Many patients are unaware of their stent type and the risks of inappropriately stopping antiplatelet drugs. Furthermore, they may have received either inappropriate preoperative instructions or no instructions at all. The opportunity exists to improve preoperative communication with patients in order to minimize perioperative thrombotic risks of coronary stents.

The epidural blood patch: are more than two ever necessary?

Headache is a protean disorder with both extraand intracranial etiologies possible. Postlumbar puncture headache (PLPH) has been described extensively and may be complicated by headache of other etiologies. Since introduced by Gormley in 1960, the epidural blood patch (EBP) has become an accepted means of therapy for PLPH (1). The rare need for more than two properly performed epidural blood patches attests to its effectiveness (2). We present a report of a patient with headache of more than one etiology who required a total of four epidural blood patches for resolution of her PLPH.