Christopher J. Jankowski

Anesthetic, patient, and surgical risk factors for neurologic complications after prolonged total tourniquet time during total knee arthroplasty

Nerve injury after prolonged tourniquet inflation results from the combined effects of ischemia and mechanical trauma. Tourniquet release, allowing a reperfusion interval of 10–30 min followed by re-inflation, has been recommended to extend the duration of total tourniquet time. However, this practice has not been confirmed clinically. We retrospectively reviewed the medical records of 1001 patients undergoing 1166 primary or revision knee replacements with tourniquet time more than 120 min during a 5-yr interval. Mean total tourniquet time was 145 ± 25 min (range, 120–308 min). In 759 patients, the tourniquet inflation was uninterrupted. Two tourniquet inflations, interrupted by a single deflation, were noted in 371 patients, and 3 tourniquet inflations interrupted by 2 deflation intervals were noted in 23 patients. A total of 129 neurologic complications (peroneal and/or tibial nerve palsies) were noted in 90 patients for an overall incidence of 7.7%. Eighty-five cases involved the peroneal nerve and 44 cases involved the tibial nerve. In 39 cases, both peroneal and tibial deficits were noted. Complete neurologic recovery occurred in 76 (89%) peroneal and 44 (100%) tibial palsies. Postoperative neurologic dysfunction was associated with younger age (P < 0.001; odds ratio = 0.7 per 10-yr increase), longer tourniquet time (P < 0.001; odds ratio = 2.8 per 30-min increase), and preoperative flexion contracture >20° (P = 0.002; odds ratio = 3.9). In a subset of 116 patients with tourniquet times ≥180 min, longer duration of deflation was associated with a decreased frequency of neurologic complications (P = 0.048). We conclude that the likelihood of neurologic dysfunction increases with total tourniquet time and that a reperfusion interval only modestly decreases the risk of nerve injury.

Enhanced recovery in gynecologic surgery.

OBJECTIVE: To investigate the effects of enhanced recovery (a multimodal perioperative care enhancement protocol) in patients undergoing gynecologic surgery. METHODS: Consecutive patients managed under an enhanced recovery pathway and undergoing cytoreduction, surgical staging, or pelvic organ prolapse surgery between June 20, 2011, and December 20, 2011, were compared with consecutive historical controls (March to December 2010) matched by procedure. Wilcoxon rank-sum, &khgr;2, and Fisher’s exact tests were used for comparisons. Direct medical costs incurred in the first 30 days were obtained from the Olmsted County Healthcare Expenditure and Utilization Database and standardized to 2011 Medicare dollars. RESULTS: A total of 241 enhanced recovery women in the case group (81 cytoreduction, 84 staging, and 76 vaginal surgery) were compared with women in the control groups. In the cytoreductive group, patient-controlled anesthesia use decreased from 98.7% to 33.3% and overall opioid use decreased by 80% in the first 48 hours with no change in pain scores. Enhanced recovery resulted in a 4-day reduction in hospital stay with stable readmission rates (25.9% of women in the case group compared with 17.9% of women in the control group) and 30-day cost savings of more than

Cognitive and functional predictors and sequelae of postoperative delirium in elderly patients undergoing elective joint arthroplasty.

7,600 per patient (18.8% reduction). No differences were observed in rate (63% compared with 71.8%) or severity of postoperative complications (grade 3 or more: 21% compared with 20.5%). Similar, albeit less dramatic, improvements were observed in the other two cohorts. Ninety-five percent of patients rated satisfaction with perioperative care as excellent or very good. CONCLUSIONS: Implementation of enhanced recovery was associated with acceptable pain management with reduced opioids, reduced length of stay with stable readmission and morbidity rates, good patient satisfaction, and substantial cost reductions. LEVEL OF EVIDENCE: II

Anesthesia and Incident Dementia: A Population-Based Nested Case-Control Study

BACKGROUND: Postoperative delirium (POD) is common in the elderly and associated with adverse outcomes. The cognitive and functional sequelae of POD in elective surgical patients are not known. We sought to determine whether (1) lower scores on sensitive neurocognitive tests are an independent risk factor for POD in elderly surgical patients, and (2) POD predicts cognitive and functional decline 3 months postoperatively. METHODS: We conducted a prospective, cohort study on patients ≥65 years old undergoing total hip or knee arthroplasty. Participants underwent preoperative neurocognitive and functional testing. POD was diagnosed using the Confusion Assessment Method. Patients who developed POD and matched controls underwent repeat neurocognitive and functional testing 3 months after surgery. RESULTS: Four hundred eighteen patients met entry criteria, and 42 (10%) developed POD. There were no differences in baseline Mini-Mental State Examination scores, alcohol abuse, depression, and verbal intelligence between groups. Independent predictors of POD included age, history of psychiatric illness, decreased functional status, and decreased verbal memory. For all tests, changes from before to 3 months after surgery were similar between those patients with POD and matched controls. CONCLUSIONS: Subtly reduced preoperative neurocognitive and functional status predict POD. However, in the small group that developed POD, there was no evidence of cognitive and functional decline 3 months after surgery. POD is associated with decreased preoperative cognitive reserve but, in elderly elective surgical patients, may be without adverse cognitive or functional sequelae 3 months postoperatively.

Sugammadex: A Novel Agent for the Reversal of Neuromuscular Blockade

OBJECTIVE To test the hypothesis that exposure to procedures requiring general anesthesia during adulthood is not significantly associated with incident dementia using a retrospective, population-based, nested, case-control study design. PARTICIPANTS AND METHODS Using the Rochester Epidemiology Project and the Mayo Clinic Alzheimers Disease Patient Registry, residents of Olmsted County, Minnesota, diagnosed as having dementia between January 1, 1985, and December 31, 1994, were identified. For each incident case, a sex- and age-matched control was randomly selected from the general pool of Olmsted County residents who were dementia free in the index year of dementia diagnosis. Medical records were reviewed to determine exposures to procedures requiring anesthesia after age 45 years and before the index year. Data were analyzed using logistic regression. RESULTS We analyzed 877 cases of dementia, each with a corresponding control. Of the dementia cases, 615 (70%) underwent 1681 procedures requiring general anesthesia; of the controls, 636 (73%) underwent 1638 procedures. When assessed as a dichotomous variable, anesthetic exposure was not significantly associated with dementia (odds ratio, 0.89; 95% CI, 0.73-1.10; P=.27). In addition, no significant association was found when exposure was quantified as number of procedures (odds ratios, 0.87, 0.86, and 1.0 for 1, 2-3, and ≥4 exposures, respectively, compared with none; P=.51). CONCLUSION This study found no significant association between exposure to procedures requiring general anesthesia after age 45 years and incident dementia.

Prolonged High-Dose Isoflurane for Refractory Status Epilepticus: Is It Safe?

To achieve spontaneous ventilation after completion of surgery, the nondepolarizing effects on skeletal muscle relaxation are often reversed by administration of an acetylcholinesterase inhibitor. However, these agents increase acetylcholine at both the neuromuscular junction and the muscarinic receptors. Therefore, coadministration of an anticholinergic agent is required to prevent parasympathetic adverse effects. In addition, a relative pharmacologic ceiling effect is seen with inhibition of acetylcholinesterase, necessitating some recovery of neuromuscular function before an acetylcholinesterase inhibitor is administered. Sugammadex is a new modified γ‐cyclodextrin compound under clinical investigation in the United States. It does not interact with cholinergic mechanisms to elicit reversal. Instead, it is a selective relaxant binding agent and acts by forming a 1:1 complex with steroidal nondepolarizing neuromuscular blockers in the plasma, lowering the effective concentration available at the receptor. Due to its selectivity, sugammadex does not inhibit the effects of nondepolarizing agents of the benzylisoquinolinium class. In contrast to acetylcholinesterase inhibition, sugammadex is effective even when administered during profound blockade, and it does not require coadministration of an anticholinergic agent. It provides a novel mechanism of action for reversal of the neuromuscular block induced by nondepolarizing aminosteroidal agents.

Living donor liver transplantation using a right lobe graft in an adult with situs inversus

Isoflurane is an alternative treatment for refractory status epilepticus. Little is known regarding human toxicities caused by isoflurane. We present 2 patients with prolonged refractory status epilepticus treated with high concentrations of isoflurane who developed signal abnormalities on magnetic resonance imaging. Patient 1 was treated with isoflurane for 85 days with 1975.2% concentration-hours. Patient 2 was treated with isoflurane for 34 days with 1382.4% concentration-hours. Serial brain magnetic resonance images in both showed progressive T2 signal hyperintensity involving thalamus and cerebellum, which improved after discontinuation of isoflurane. These cases suggest that isoflurane may be neurotoxic when used in high doses for long time periods.

Pain relief and functional status after vaginal hysterectomy: intrathecalversus general anesthesia

Situs inversus totalis is a rare anatomic variant in which there is a complete mirror image of the thoracic and abdominal viscera. The common association of situs inversus and biliary atresia has led to a variety of modifications of surgical techniques utilizing both living donor and deceased donor liver grafts, with mixed results in the pediatric liver transplant population. The use of a living donor liver graft in an adult with situs inversus has not yet been described. However, living donor liver transplantation (LDLT) has produced excellent results in the adult population, particularly in the cholestatic population, which may be disadvantaged by the model for end‐stage liver disease system. This is the first report of a successful living donor right liver graft in an adult with end‐stage liver disease secondary to primary sclerosing cholangitis and situs inversus totalis. (Liver Transpl 2005;11:111–113.)

cGMP modulation of Ca2+sensitivity in airway smooth muscle

PurposeWe tested the hypothesis that the use of subarachnoid block (SAB) for vaginal hysterectomy produces superior postoperative analgesia and improves functional status at 12 weeks postoperatively.MethodsIn this randomized controlled trial 89 patients received either standardized general anesthesia vs SAB with bupivacaine, clonidine, and morphine. Postoperatively, patients in both groups received multimodal pain management. Primary outcomes included evaluation of pain and functional status (SF-36 Health Survey) over the 12 postoperative weeks.ResultsPain was well controlled throughout the study, as judged from the average pain numerical scale scores of ≤ 3 in both groups, at all times studied. Intrathecal analgesia lessened pain and decreased the use of morphine both in the postanesthesia care unit (PACU) and over the first 12 hr after discharge from the PACU (P < 0.001). Although patients who received SAB had a lower frequency of postoperative nausea in the PACU than the patients in the general anesthesia group (P = 0.021), this effect was not extended beyond the PACU stay. Subarachnoid block did not affect the length of hospitalization. At the two-week follow-up 69% of patients in the SAB group and 48% patients in the general anesthesia group were pain free (P = 0.044). At all evaluation intervals patients’ functional status was comparable between the SAB and general anesthesia group.ConclusionsA significantly better immediate postoperative analgesia was present in the SAB group, and the duration was consistent with the expected action of intrathecally administered drugs. Tw o weeks after surgery a higher percentage of the patients in the SAB group reported no pain. However, SAB had no effect on either length of hospitalization or patients’ postoperative functional status.RésuméObjectifNous avons vérifié l’hypothèse voulant que l’usage d’un block sous-arachnoïdien (BSA) pour l’hystérectomie vaginale produise une analgésie postopératoire supérieure et améliore l’état fonctionnel jusqu’à 12 semaines après l’opération.MéthodeĽétude randomisée et contrôlée a porté sur 89 patientes qui ont reçu une anesthésie générale normalisée ou un BSA avec de la bupivacaïne, de la clonidine et de la morphine. Après l’opération, toutes les patientes ont reçu un traitement de la douleur multimodal. La douleur et l’état fonctionnel (SF-36 Health Survey) ont été notés pendant 12 semaines postopératoires.RésultatsLa douleur a été bien contrôlée tout au long de l’étude, si l’on en juge par les scores moyens à l’échelle de douleur numérique ≤ 3 dans les deux groupes pour toutes les mesures prises. Ľanalgésie intrathécale a réduit la douleur et diminué l’usage de morphine à la salle de réveil (SDR) et pendant les 12 premières heures après le départ de la SDR (P < 0,001). Les patientes du groupe BSA ont eu moins de nausées postopératoires en SDR que les patientes sous anesthésie générale (AG), (P = 0,021), mais cet effet ne s’est pas prolongé au delà du séjour en SDR. Le BSA n’a pas permis d’écourter l’hospitalisation. Lors de l’examen de contrôle à la deuxième semaine, 69% des patientes du groupe BSA et 48% du groupe d’AG n’avaient plus de douleur (P= 0,044). Pendant toute l’étude, l’état fonctionnel a été comparable entre les groupes.ConclusionUne analgésie postopératoire immédiate significativement meilleure a été notée avec le BSA et de durée conforme à l’action attendue des médicaments intrathécaux administrés. Deux semaines après l’opération, un plus fort pourcentage de patientes du groupe BSA était sans douleur. Le BSA n’a cependant pas modifié la durée de l’hospitalisation ou l’état fonctionnel postopératoire des patientes.

Abdominal Incision Injection of Liposomal Bupivacaine and Opioid Use After Laparotomy for Gynecologic Malignancies.

A β-escin-permeabilized canine tracheal smooth muscle preparation was used to test the hypothesis that cGMP decreases Ca2+ sensitivity in airway smooth muscle primarily by inhibiting the membrane receptor-coupled mechanisms that regulate Ca2+ sensitivity and not by inhibiting Ca2+/calmodulin activation of the contractile proteins. 8-Bromo-cGMP (100 μM) had no effect on the free Ca2+concentration-response curves generated in the absence of muscarinic receptor stimulation. In the presence of 100 μM ACh plus 10 μM GTP, 8-bromo-cGMP (100 μM) caused a rightward shift of the free Ca2+ concentration-response curve, significantly increasing the EC50for free Ca2+ from 0.35 ± 0.03 to 0.75 ± 0.06 μM; this effect of 8-bromo-cGMP was concentration dependent from 1 to 100 μM. 8-Bromo-cGMP (100 μM) decreased the level of regulatory myosin light chain (rMLC) phosphorylation for a given cytosolic Ca2+ concentration but had no effect on the amount of isometric force produced for a given level of rMLC phosphorylation. These findings suggest that cGMP decreases Ca2+ sensitivity in canine tracheal smooth muscle primarily by inhibiting the membrane receptor-coupled mechanisms that modulate the relationship between cytosolic Ca2+ concentration and rMLC phosphorylation.