J. A. Freeman

Postoperative pain-related morbidity: Video-assisted thoracic surgery versus thoracotomy☆

One hundred thirty-eight consecutive, nonrandomized patients, with equivalent demographic and preoperative physiologic parameters, underwent either a video-assisted thoracic surgical (VATS) approach (n = 81) or a limited lateral thoracotomy (LLT) approach (n = 57) to accomplish pulmonary resection for peripheral lung lesions (< or = 3 cm in diameter). Wedge resection was done in 74 VATS patients and 19 LLT patients. Seven patients underwent VATS lobectomy and 38 patients had lobectomy performed through an LLT. Pain was quantitated by postoperative narcotic requirements, the need for intercostal/epidural analgesia, and patient perception of pain index scoring. Shoulder and pulmonary function (forced expiratory volume in 1 second) were measured preoperatively, 3 days postoperatively, and at 3 weeks of follow-up. Patients undergoing VATS experienced significantly less postoperative pain. No patients undergoing VATS required intercostal block/epidural analgesia; 31 LLT patients (54%) required this treatment for breakthrough pain (p = 0.001). Narcotic requirements were less (p = 0.05) among VATS patients, which correlated with lower perception of pain index after operation for VATS patients. Shoulder girdle strength was equally impaired at day 3, but function was more improved in VATS patients at 3 weeks (p = 0.01). Patients undergoing wedge resection alone by LLT had greater impairment in early (day 3) pulmonary function (forced expiratory volume in 1 second) (p = 0.002); this difference from VATS was not sustained at 3 weeks. Video-assisted thoracic surgery is associated with reduced pain, shoulder dysfunction, and early pulmonary impairment compared with LLT for select patients requiring pulmonary resection.

Postreperfusion syndrome: Hypotension after reperfusion of the transplanted liver

Sixty-nine patients undergoing liver transplantation were evaluated to elucidate the relationship between hypotension and physiological changes seen on reperfusion of the grafted liver. Measured variables included hemodynamic profiles, core temperature, serum potassium, ionized calcium levels, arterial blood-gas tensions, and acid-base state. Measurements were taken 60 minutes after skin incision (baseline), 5 minutes before reperfusion, and 30 seconds and 5 minutes after reperfusion. On the basis of changes in mean arterial pressure (MAP) patients were divided in two groups. Group 1 (n = 49) maintained MAP greater than 70% and group 2 (n = 20) had MAP less than 70% of the baseline value for at least 1 minute within 5 minutes after reperfusion. On reperfusion, changes common to both groups were 27% increase in cardiac filling pressures, 23% base deficit, and 30% serum potassium level and a decrease of 16% in cardiac output and 9% in temperature. Compared with group 1, group 2 had greater decrease in systemic vascular resistance (SVR) (1097 +/- 868 and 741 +/- 399 dyn.s-1. cm-5, respectively, P < .05) and higher potassium level (4.5 +/- 0.8 and 5.3 +/- 0.8 mmol/L, P < .05). Collectively in both groups, there was no correlation between MAP and physiological variables; however, there was a poor correlation with SVR (r = .32, P < .01). Reperfusion hypotension seen in group 2 patients correlated only with a decrease in systemic vascular resistance (r = .5, P < .05). Acute hyperkalemia, hypothermia, and acidosis do not appear to be major causes of reperfusion hypotension.

Pharmacokinetics and pharmacodynamics of doxacurium in normal patients and in those with hepatic or renal failure.

&NA; We determined the pharmacokinetics and duration of action of a bolus dose of doxacurium (15 μg/kg) in 27 patients anesthetized with isoflurane and nitrous oxide. Nine patients had normal renal and liver functions and were undergoing a variety of surgical procedures, nine were undergoing cadaveric kidney transplantation because of end‐stage renal disease, and nine were undergoing cadaveric liver transplantation because of end‐stage hepatocellular disease. Plasma concentrations of doxacurium were measured for 6 h after administration using a sensitive and specific capillary gas chromatographic assay. Plasma concentration versus time data were analyzed by a noncompartmental method based on statistical moments. Neuromuscular blockade was assessed by measuring the electromyographic evoked response of the adductor pollicis muscle to train‐of‐four stimulation of the ulnar nerve. The degree of neuromuscular blockade after doxacurium administration was described as the percent of control of the first train‐of‐four response. The pharmacokinetic variables were (normal vs hepatic failure vs renal failure, respectively): volume of distribution at steady state (220 ± 110 vs 290 ± 60 vs 270 ± 130 mL/kg [mean ± SD]), plasma clearance (2.7 ± 1.6 vs 2.3 ± 0.4 vs 1.2 ± 0.7 mL·kg−1·min−1), mean residence time (95.2 ± 57 vs 129.4 ± 30 vs 270 ± 210 min), and elimination half‐life (99 ± 54 vs 115 ± 31 vs 221 ± 156 min). Plasma clearance and mean residence time differed significantly between patients with renal failure and control patients. There was no significant difference in the onset times or in clinical effective duration, although the clinical duration tended to be longer and more variable in the patients with renal failure. This unpredictable response and the possibility of prolonged blockade should be borne in mind if doxacurium is to be used in patients with renal failure.

Success rates of blind orotracheal intubation using a transillumination technique with a lighted stylet

The technique of guided orotracheal intubation using a lighted stylet depends on the transillumination of the soft tissues of the neck to direct the tube through the glottis and into the trachea. We conducted an operating room study of this technique, recording success rates and intubation times of 50 patients undergoing elective surgery. All patients were intubated successfully, 35 of 50 (70%) on the first attempt, 12 of 15 (80%) on the second attempt, and three of three (100%) on the third attempt. The average time for intubation was 37 seconds. A new design of the lighted stylet method resulted from the experience gained. Intubator training and experience influenced initial success rates, and the cadaver laboratory was of particular value in teaching the technique.

A comparison of techniques for placement of double-lumen endobronchial tubes

STUDY OBJECTIVE To compare two methods of double-lumen endobronchial tube placement for thoracic surgery and to identify factors that provide a rational basis for placement method selection. DESIGN Prospective, randomized study. SETTING Teaching hospital. PATIENTS 58 ASA physical status II, III, and IV patients scheduled for surgical procedures requiring elective left-sided endobronchial intubation. INTERVENTIONS Patients were assigned randomly to either a group in which the initial placement method was the traditional approach of placing the endobronchial tube through the larynx and then advanced blindly into the left mainstem bronchus, or to a second group in which the left mainstem bronchus was intubated under direct vision using the fiberoptic bronchoscope. MEASUREMENTS AND MAIN RESULTS Of the 32 patients who underwent the traditional approach, primary success occurred in 27 patients and eventual success in 30. In 27 patients undergoing the directed approach, primary success occurred in 21 patients and eventual success in 25. Two patients in each group required the alternative method. The blind approach took 88 (+/- 91) seconds and the directed approach took 181 (+/- 193) seconds (p = 0.029). Timing data were analyzed using analysis of variance with respect to method and secretions and then t-tests as appropriate. Categorical data were analyzed using the Kruskal-Wallis and Fishers exact tests as appropriate. All values are reported as means +/- SD. CONCLUSION Both the blind and directed approaches resulted in successful left mainstem placement of the endobronchial tube in the majority of patients but either method may fail when used alone. More time was required using the directed approach. Operator experience with both methods will increase the likelihood of success. The choice of the initial approach may be influenced by patient factors as well as available equipment and personnel.

Impairment of anesthesia task performance by laser protection goggles

This study was designed to determine whether the wearing of colored goggles, commonly used during laser surgery, increased the time needed to perform simple tasks or the likelihood of medication errors. The Stromberg Dexterity Test and the Medication Sorting Task (MST), a test of our own design, were used to measure the speed and accuracy of identifying medications. Thirty anesthesia care providers performed the tests twice, once with colored goggles and once without. Ambient light during the test was controlled to approximate that in the operating room during laser surgery. Times required to complete the tests improved with repetition of the test. When colored goggles were worn, more time was needed to complete the tests. More errors, especially serious errors in medication sorting, occurred when goggles were worn than when they were not. The wearing of colored goggles in combination with low levels of illumination and stress due to time constraints, may increase the potential for medication errors.

Pharmacokinetics and Pharmacodynamics of Cisatracurium in Patients with End-Stage Liver Disease Undergoing Liver Transplantation

We determined the pharmacokinetics and pharmacodynamics of cisatracurium, one of the 10 isomers of atracurium, in 14 patients with end-stage liver disease undergoing liver transplantation and in 11 control patients with normal hepatic and renal function undergoing elective surgery. Blood samples were collected for 8 h after i.v. bolus administration of cisatracurium 0.1 mg kg-1 (2 x ED95). Plasma concentrations of cisatracurium and its metabolites were determined using an HPLC method with fluorescence detection. Pharmacokinetic variables were determined using non-compartmental methods. Neuromuscular block was assessed by measuring the electromyographic evoked response of the adductor pollicis muscle to train-of-four stimulation of the ulnar nerve using a Puritan-Bennett Datex (Helsinki, Finland) monitor. Pharmacodynamic modelling was completed using semi-parametric effect-compartment analysis. Volume of distribution at steady state was 195 (SD 38) ml kg-1 in liver transplant patients and 161 (23) ml kg-1 in control patients (P < 0.05), plasma clearance was 6.6 (1.1) ml kg-1 min-1 in liver transplant patients and 5.7 (0.8) ml kg-1 min-1 in control patients (P < 0.05), but elimination half-lives were similar: 24.4 (2.9) min in liver transplant patients vs 23.5 (3.5) min in control patients (ns). The time to maximum block was 2.4 (0.8) min in liver transplant patients compared with 3.3 (1.0) min in control patients (P < 0.05), but the clinical effective duration of action (time to 25% recovery) was similar: 53.5 (11.9) min in liver transplant patients compared with 46.9 (6.9) min in control patients (ns). The recovery index (25-75% recovery) was also similar in both groups: 15.4 (4.2) min in liver transplant patients and 12.8 (1.9) min in control patients (ns). After cisatracurium, peak laudanosine concentrations were 16 (5) and 21 (5) ng ml-1 in liver transplant and control patients, respectively. In summary, minor differences in the pharmacokinetics and pharmacodynamics of cisatracurium in liver transplant and control patients were not associated with any clinically significant differences in recovery profiles after a single dose of cisatracurium.