The middle cerebral artery blood velocity response to acute normobaric hypoxia occurs independently of changes in ventilation in humans.

NEW FINDINGS: What is the central question of this study? Does the ventilatory response to moderate acute hypoxia increase cerebral perfusion independently of changes in arterial oxygen tension in humans? What is the main finding and its importance? The ventilatory response does not increase middle cerebral artery mean blood velocity during moderate isocapnic acute hypoxia beyond that elicited by reduced oxygen saturation. ABSTRACT: Hypoxia induces ventilatory, cardiovascular and cerebrovascular adjustments to defend against reductions in systemic oxygen delivery. We aimed to determine whether the ventilatory response to moderate acute hypoxia increases cerebral perfusion independently of changes in arterial oxygenation. Eleven young healthy individuals were exposed to four 15 min experimental conditions: (1) normoxia (partial pressure of end-tidal oxygen, PETO2  = 100 mmHg), (2) hypoxia ( PETO2  = 50 mmHg), (3) normoxia with breathing volitionally matched to levels observed during hypoxia (hyperpnoea; PETO2  = 100 mmHg) and (4) hypoxia ( PETO2  = 50 mmHg) with respiratory frequency and tidal volume volitionally matched to levels observed during normoxia (i.e., restricted breathing (RB)). Isocapnia was maintained in all conditions. Middle cerebral artery mean blood velocity (MCA Vmean ), assessed by transcranial Doppler ultrasound, was increased during hypoxia (58 ± 12 cm/s, P = 0.04) and hypoxia + RB (61 ± 14 cm/s, P < 0.001) compared to normoxia (55 ± 11 cm/s), while it was unchanged during hyperpnoea (52 ± 13 cm/s, P = 0.08). MCA Vmean was not different between hypoxia and hypoxia + RB (P > 0.05). These findings suggest that the hypoxic ventilatory response does not increase cerebral perfusion, indexed using MCA Vmean , during moderate isocapnic acute hypoxia beyond that elicited by reduced oxygen saturation.

Regional anaesthesia for labour, operative vaginal delivery and caesarean delivery: a narrative review.

This narrative review discusses recent evidence surrounding the use of regional anaesthesia in the obstetric setting, including intrapartum techniques for labour and operative vaginal delivery, and caesarean delivery. Pudendal nerve blockade, ideally administered by an obstetrician, should be considered for operative vaginal delivery if neuraxial analgesia is contraindicated. Regional techniques are increasingly utilised in clinical practice for caesarean delivery to minimise opioid consumption, reduce pain, improve postpartum recovery and facilitate earlier discharge as part of enhanced recovery protocols. The evidence surrounding transversus abdominis plane and quadratus lumborum blockade supports their use when: long-acting neuraxial opioids cannot be administered due to contraindications; if emergency delivery necessitates general anaesthesia; or as a postoperative rescue technique. Current data suggest quadratus lumborum blockade is no more effective than transversus abdominis plane blockade after caesarean delivery. Transversus abdominis plane blockade, wound catheter insertion and single shot wound infiltration are all effective techniques for reducing postoperative opioid consumption, with transversus abdominis plane blockade favoured, followed by wound catheters and then wound infiltration. Ilio-inguinal and iliohypogastric, erector spinae plane and rectus sheath blockade all require further studies to determine their efficacy for caesarean delivery in the presence or absence of long-acting neuraxial opioids. Future studies are needed to: compare approaches for individual techniques; determine which combinations of techniques and dosing regimens result in optimal analgesic and recovery outcomes following delivery; and elucidate the populations that benefit most from regional anaesthesia in the obstetric setting.

Human cerebrovascular responses to diving are not related to facial cooling.

NEW FINDINGS: What is the central question of this study? Does facial cooling-mediated stimulation of cutaneous trigeminal afferents associated with the diving response increase cerebral blood flow or are factors associated with breath-holding (e.g. arterial carbon dioxide accumulation, pressor response) more important in humans? What is the main finding and its importance? Physiological factors associated with breath-holding such as arterial carbon dioxide accumulation and the pressor response, but not facial cooling (trigeminal nerve stimulation), make the predominant contribution to diving response-mediated increases in cerebral blood flow in humans. ABSTRACT: Diving evokes a pattern of physiological responses purported to preserve oxygenated blood delivery to vital organs such as the brain. We sought to uncouple the effects of trigeminal nerve stimulation on cerebral blood flow (CBF) from other modifiers associated with the diving response, such as apnoea and changes in arterial carbon dioxide tension. Thirty-seven young healthy individuals participated in separate trials of facial cooling (FC, 3 min) and cold pressor test (CPT, 3 min) under poikilocapnic (Protocol 1) and isocapnic conditions (Protocol 2), facial cooling while either performing a breath-hold (FC +BH) or breathing spontaneously for a matched duration (FC -BH) (Protocol 3), and BH during facial cooling (BH +FC) or without facial cooling (BH -FC) (Protocol 4). Under poikilocapnic conditions neither facial cooling nor CPT evoked a change in middle cerebral artery blood flow velocity (MCA vmean ; transcranial Doppler) (P > 0.05 vs. baseline). Under isocapnic conditions, facial cooling did not change MCA vmean (P > 0.05), whereas CPT increased MCA vmean by 13% (P < 0.05). Facial cooling with a concurrent BH markedly increased MCA vmean (Δ23%) and internal carotid artery blood flow (ICAQ ; duplex Doppler ultrasound) (Δ26%) (P < 0.001), but no change in MCA vmean and ICAQ was observed when facial cooling was accompanied by spontaneous breathing (P > 0.05). Finally, MCA vmean and ICAQ were similarly increased by BH either with or without facial cooling. These findings suggest that physiological factors associated with BH, and not facial cooling (i.e. trigeminal nerve stimulation) per se, make the predominant contribution to increases in CBF during diving in humans.

High spatial resolution identification of hematoma in inhomogeneous head phantom using broadband fNIR system.

This paper presents a novel method for early detection of hematomas using highly sensitive optical fNIR imaging methods based on broadband photon migration. The NIR experimental measurements of inhomogeneous multi-layer phantoms representing human head are compared to 3D numerical modeling over broadband frequencies of 30-1000 MHz. A finite element method (FEM) simulation of the head phantom are compared to measurements of insertion loss and phase using custom-designed broadband free space optical transmitter (Tx) and receiver (Rx) modules that are developed for photon migration at wavelengths of 670 nm, 795 nm, 850 nm, though results of 670 nm are discussed here. Standard error is used to compute error between 3D FEM modeling and experimental measurements by fitting experimental data to the [Formula: see text]. Error results are shown at narrowband and broadband frequency modulation in order to have confidence in 3D numerical modeling. A novel method is established here to identify presence of hematoma based on first and second derivatives of changes in insertion loss and phase (∆IL and ∆IP), where frequency modulated photons sensitive to different sizes of hematoma is identified for wavelength of 670 nm. The high accuracy of this comparison provides confidence in optical bio-imaging and its eventual application to TBI detection.

Endovascular Intervention for a Carotid-Cavernous Fistula: A Case Report.

A carotid-cavernous fistula is a rare vascular anomaly involving abnormal communication between the carotid artery and the cavernous sinus. This condition leads to the shunting of arterial blood directly into the venous system, causing diverse clinical manifestations. The classification includes direct and indirect fistulas, with endovascular techniques emerging as a preferred treatment option. In this report, we present the case of a 58-year-old male who presented with progressive right-sided proptosis, headache, and visual disturbances. He exhibited right abducens nerve palsy, reduced visual acuity, and a dilated superior ophthalmic vein on imaging. A multidisciplinary team confirmed the diagnosis of a carotid-cavernous fistula and chose to pursue endovascular embolization. Catheter angiography revealed the fistula and balloon-assisted occlusion restored normal arterial flow. The patient's symptoms improved, and follow-up showed complete resolution of proptosis and enhanced visual acuity. Successful endovascular embolization underscores the significance of a multidisciplinary approach and showcases the positive outcomes achievable when diverse specialties converge for patient well-being.

A systematic review of patient-reported outcome measures used to assess sleep in postpartum women using Consensus Based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines.

STUDY OBJECTIVES: We performed a systematic review to identify the best patient-reported outcome measure (PROM) of postpartum sleep in women. METHODS: We searched four databases for validated PROMs used to assess postpartum sleep. Studies were considered if they evaluated at least one psychometric measurement property of a PROM. An overall performance rating was assigned for each psychometric measurement property of each PROM based upon COSMIN criteria. A modified GRADE approach was used to assess the level of evidence and recommendations were then made for each PROM. RESULTS: We identified 15 validation studies of eight PROMs, in 9,070 postpartum women. An adequate number of sleep domains was assessed by five PROMs: Bergen Insomnia Scale (BIS), Pittsburgh Sleep Quality Index (PSQI), General Sleep Disturbance Scale (GSDS), Athens Insomnia Scale (AIS), and the Sleep Symptom Checklist (SSC). BIS and GSDS were the only PROMs to demonstrate adequate content validity and at least a low level of evidence of sufficient internal consistency, resulting in Class A recommendations. The BIS was the only PROM, which is easily accessible and free to use for noncommercial research, that achieved a Class A recommendation. CONCLUSION: The BIS is the best currently available PROM of postpartum sleep. However, this PROM fails to assess several important domains such as sleep duration (and efficiency), chronotype, sleep-disordered breathing and medication usage. Future studies should focus on evaluating the psychometric measurement properties of BIS in the North American setting and in different cultural groups, or to develop a more specific PROM of postpartum sleep.

Drying of colloidal suspensions and polymer solutions near the contact line: deposit thickness at low capillary number.

Drying experiments with a receding contact line have been performed with silica colloidal suspensions and polyacrylamide (PAAm) polymer solutions. The experimental setup allows to control the receding movement of the contact line and the evaporation flux separately. Deposit thickness as a function of these two control parameters has been investigated. The different systems exhibit a similar behavior: in the regime of very low capillary numbers the deposit thickness scaled by the solute volume concentration and the evaporation rate is proportional to the inverse of the contact line velocity. Both the scaling exponent and the constant (which has the dimension of a length) do not depend on the system under study. The observation of this evaporative regime confirms some recent results obtained by Le Berre et al. on a very different system (phospholipidic molecules) and fully supports their interpretation. Following their approach, a simple model based on mass balance accounts for these results. This implies that this regime is dominated by the evaporation and that the deformation of the meniscus induced by viscous forces does not play any significant role. When increasing the velocity, another regime is observed where the thickness does not depend significantly on the velocity.

Predictive factors for nutritional behavior among pregnant women attending antenatal care clinic in 6th of October City.

BACKGROUND: Good maternal nutrition during pregnancy is important to ensure health for both the mother and the foetus. This study aimed to assess nutritional knowledge and behavior among a group of Egyptian pregnant women in addition to identify the factors influencing both their nutritional knowledge and behavior. METHODS: This comparative cross sectional study included 300 pregnant women attending the antenatal care clinics in 6th of October University private hospital and El-Hussary primary health care (PHC) unit. The data was collected through a modified nutritional survey that was translated from Spanish to Arabic and revised by language experts for clarity. RESULTS: Almost all of the women attending the private hospital were university educated while about half of the women attending the PHC unit were graduated from technical education. In general, the level of knowledge about food requirements of both groups was satisfactory good; however, neither of them fulfilled the WHO recommendations of food intake during pregnancy or the optimum number of meals per day. The mean of random blood glucose was higher among the women attending the PHC unit; the BMI, mid arm circumference and subcutaneous fat were higher among the same group as well. In regard to fulfilling the WHO recommended servings per day, only starch and fat items were fulfilled by both groups, whereas the other three items (vegetables, fruits and dairy products) were merely included in the diets of both groups. CONCLUSIONS: Healthy behavior among pregnant women in both group were influenced by their educational level, occupation as well as their pre-gestational BMI. Those were the only three significant predictive factors, where women with higher education showed an active lifestyle. In addition, women starting with normal BMI before pregnancy had better healthy behaviours including the choice of healthy diets.

Effect of silver diamine fluoride on the prevention of erosive tooth wear in vitro.

OBJECTIVES: To investigate the ability of silver diamine fluoride (SDF) to prevent erosive tooth wear in enamel and dentin. METHODS: SDF (38 %) was compared to deionized water (DIW, negative control), potassium fluoride (KF, fluoride control), silver nitrate (AgNO3, silver control), and fluoride varnish (FV, clinical reference) using erosion and erosion-abrasion cycling models. Bovine enamel and dentin slabs were embedded in resin blocks. Two resin blocks were glued to form study blocks (n=8, per treatment), one for erosion and the other for the erosion-abrasion model. The blocks were treated once and then subjected to a five-day cycling model, with five daily citric acid erosive challenges (0.3 % citric acid/pH 2.6). Abrasion was performed using a toothbrushing machine with a medium-abrasive silica as abrasive (erosion-abrasion model only). Artificial saliva was used to remineralize the specimens after erosion/abrasion and as storage media between cycles. Surface loss (SL) was determined by non-contact profilometry. Data were analyzed using ANOVA (α=0.05). RESULTS: Both eroded-abraded enamel and dentin specimens exhibited significantly more SL in all treatment groups than the only eroded ones (p<0.001). For dentin, both AgNO3 and DIW groups had significantly more SL than SDF, KF, and FV groups (p<0.001), for both models. For enamel, specimens had more SL in both AgNO3 and DIW groups compared to SDF, KF, and FV groups, in the erosion model. When enamel specimens were subjected to erosion-abrasion, FV resulted in the least SL (p<0.001). CONCLUSION: SDF was effective in reducing dental erosion on both substrates, but dental erosion-abrasion only on dentin. CLINICAL SIGNIFICANCE: SDF may become a viable intervention for ETW prevention in dentin (e.g. exposed roots) once its efficacy has been confirmed under clinical conditions.

Disposition of fleroxacin, a new trifluoroquinolone, and its metabolites. Pharmacokinetics in renal failure and influence of haemodialysis.

The pharmacokinetics of fleroxacin and its metabolites following a single oral dose of fleroxacin 400mg were examined in 6 healthy subjects and 24 patients with various degrees of renal insufficiency. Plasma and urine samples, collected at various times after administration, were assayed by high performance liquid chromatography (HPLC). In healthy subjects, Cmax was 6.8 +/- 0.7 mg/L; tmax = about 1h, t1/2 = 14 +/- 2h, total clearance = 4.86 +/- 0.72 L/h and the percentage of unchanged fleroxacin excreted in urine in 48 hours was 48 +/- 4% (HPLC). Plasma concentrations of metabolites were very low and accounted for no more than 5% of the levels of unchanged fleroxacin. In uraemic patients Cmax did not change, whatever the degree of renal failure; tmax was increased in patients with a glomerular filtration rate below 0.6 L/h, and Vd/f was independent of the severity of renal failure. These data suggest that bioavailability of the drug is unchanged. In uraemic patients t1/2 was prolonged and AUC multiplied by a factor of 2 to 3. A linear relationship was found between total and renal clearances of fleroxacin and creatinine clearance. Accumulation of N-demethyl-fleroxacin and N-oxide-fleroxacin was very high in uraemic patients, due to slow formation of these metabolites and decreased urinary elimination. Dialysance of fleroxacin and of its metabolites was approximately 3.6 to 4.8 L/h. These findings suggest that fleroxacin dosage may need to be reduced in patients with severe renal disease; in haemodialysed patients, treated every 2 days, a single dose of fleroxacin 400mg is recommended at the end of each dialysis session.

Telithromycin (HMR 3647) achieves high and sustained concentrations in tonsils of patients undergoing tonsillectomy.

Telithromycin, the first ketolide antimicrobial to be developed for clinical use, has potent activity against group A beta-haemolytic streptococci (GABHS), including macrolide-resistant strains. The penetration of telithromycin into tonsils was assessed in 22 adults undergoing tonsillectomy at 3, 12 or 24 h after the fourth dose of oral telithromycin 800 mg once daily. Telithromycin rapidly penetrated tonsillar tissues, achieving a mean concentration of 3.95 mg/kg at 3 h post dose, 3.4 times greater than the corresponding plasma concentration (1.22 mg/l. The mean tonsil:plasma concentration ratio increased to 13.1 at 24 h post dose, indicating slower elimination from tonsils than plasma. Tonsillar and plasma concentrations exceeded the MIC(50) for GABHS throughout the 24-h dosing period. These findings suggest that telithromycin may be an effective new alternative treatment for GABHS tonsillopharyngitis.

Pharmacokinetics of the ketolide telithromycin after single and repeated doses in patients with hepatic impairment.

The pharmacokinetic profiles of single and repeated oral doses of telithromycin 800 mg/day were compared in patients with hepatic impairment and healthy subjects in two open-label, non-randomized, parallel-group, multicentre studies. The maximal plasma concentrations (Cmax) and the area under the plasma concentration-time (AUC) curves for telithromycin were similar in hepatically impaired patients and healthy subjects in the single- and repeated-dose studies. The extent of formation of RU 76363, the major circulating metabolite of telithromycin, was decreased following single and repeated doses in patients with hepatic impairment compared with healthy subjects. In the single-dose study, the Cmax of RU 76363 was 2-fold lower (P<0.01) and the initial elimination half-life (t(1/2lambda1)) was 44% higher (P<0.01). The Cmax and AUC from 0 to 24 h post-dose were approximately 50% lower on Day 1 (P< or =0.01) and Day 7 (P< or =0.001) in the repeated-dose study. The terminal elimination half-life (t(1/2lambdaz)) of telithromycin was 1.4-fold higher (P<0.001) in the hepatically impaired patients compared with the healthy subjects in the single-dose study. However, t(1/2lambda1) and t(1/2lambdaz) were similar after repeated doses in both populations, suggesting that the decrease in formation of RU 76363 is compensated by an increase in clearance via other pathways. Telithromycin 800 mg was well tolerated in both populations. In conclusion, a once-daily dose of telithromycin is well tolerated in patients with hepatic impairment. Exposure to telithromycin was comparable in patients with hepatic impairment and healthy subjects and thus, no dosage adjustment is required in this patient group providing renal function is not severely impaired.

3D Numerical modeling and its experimental verifications for an inhomogeneous head phantom using broadband fNIR system.

Modeling behavior of broadband (30-1000 MHz) frequency modulated near infrared photons through a multilayer phantom is of interest to optical bio-imaging research. Photon dynamics in phantom are predicted using three-dimension (3D) finite element numerical simulation and are related to the measured insertion loss and phase for a given human head geometry in this paper based on three layers of phantom each with distinct optical parameter properties. Simulation and experimental results are achieved for single, two, and three layers solid phantoms using COMSOL (COMSOL AB, Tegnérgatan 23, SE-111 40, Stockholm, Sweden) (for FEM) simulation and custom-designed broadband free space optical transmitter (Tx) and receiver (Rx) modules that are developed for photon migration at wavelengths of 680, 795, and 850 nm. Standard error is used to compute error between two-dimension and 3D FE modeling along with experimental results by fitting experimental data to the functional form of afrequency+b. Error results are shown at narrowband and broadband frequency modulation. Confidence in numerical modeling of the photonic behavior using 3D FEM for human head has been established here by comparing the reflection mode's experimental results with the predictions made by COMSOL for known commercial solid brain phantoms.

Penetration of telithromycin (HMR 3647), a new ketolide antimicrobial, into inflammatory blister fluid following oral administration.

The penetration of telithromycin (HMR 3647), a novel ketolide antimicrobial, has been assessed in an open, single-dose study in eight healthy male subjects. Following a single, oral, 600 mg dose the mean ratio of the concentration of telithromycin in blister fluid over plasma was 1.38. Significant blister fluid concentrations were maintained up to 24 h post-dose. These results indicate that telithromycin penetrates well into inflammatory extracellular fluid, achieving high and sustained concentrations in this medium.

Pharmacokinetics of the new ketolide telithromycin (HMR 3647) administered in ascending single and multiple doses.

Telithromycin (HMR 3647) is a novel ketolide antimicrobial with good activity against both common and atypical respiratory pathogens, including many resistant strains. This randomized, three-period crossover study determined the dose proportionality of telithromycin pharmacokinetics after single and multiple dosing in healthy subjects. In each treatment period, subjects received a single oral dose of 400, 800 or 1,600 mg of telithromycin followed 4 days later by the same dose once daily for 7 days. Blood and urine samples were taken throughout the study for determination of pharmacokinetic parameters for telithromycin and RU 76363, its main metabolite. Telithromycin and RU 76363 achieved steady state within 2 to 3 days of once-daily dosing. A slight accumulation of telithromycin was observed after 7 days of therapy, with values of the area under the concentration-time curve from 0 to 24 h approximately 1.5 times higher than those achieved with the single dose. The pharmacokinetics of telithromycin and RU 76363 deviated moderately from dose proportionality. At a dose of 800 mg/day, telithromycin attained mean maximal and trough plasma concentrations of 2.27 and 0. 070 mg/liter respectively. Elimination was biphasic; initial and terminal half-lives were 2.87 and 9.81 h for the 800-mg dose. Study medication was well tolerated, although adverse events tended to be more frequent at the 1,600-mg dose. This study showed that telithromycin was generally well tolerated and suggests that a once-daily 800-mg oral dose of telithromycin maintains an effective concentration in plasma for the treatment of respiratory tract infections involving the key respiratory pathogens.

[Pharmacokinetics of aspirin in African children with normal nutrition and malnutrition]. / Pharmacocinétique de l'aspirine chez l'enfant africain normonutri et malnutri.

Pharmacokinetics of aspirin given orally at antipyretic dose (12 mg/kg) were studied in 11 African children aged 4-48 months. In order to examine the influence of nutritional status on aspirin kinetics, children were classified according to Waterlow criteria. Blood samples were collected during the 8 hours following the initial dose. Albumin, prealbumin and transferrin plasma levels were measured and plasma salicylic acid (SA) concentrations determined by a fluorometric method. Nutritional status seemed to have no prominent effect on plasma concentrations of SA. The volume of distribution found in our study was lower than those obtained in other studies. This could be explained by lower plasma aspirin esterase activities in black children. There were large individual variations in plasma salicylate concentrations. For example, even at antipyretic doses, saturation phenomena appeared in two children.

Pharmacokinetics of pefloxacin and amikacin administered simultaneously to intensive care patients.

Ten adult patients with severe infections in an intensive care unit were treated simultaneously with 6 mg/kg pefloxacin and 7.5 mg/kg amikacin, infused i.v. over 1 h every 12 h for 5 days. Twelve h after the last infusion, pefloxacin alone was administered orally (400 mg tablet) every 12 h for 10 days. The pharmacokinetics of pefloxacin and its main metabolites, norfloxacin and pefloxacin N-oxide, were determined after the first (Day 1) and last (Day 5) infusions and after the last oral dose (Day 15). The kinetics of amikacin was determined after the first and the last infusion. The maximal and minimal steady-state plasma concentrations of amikacin were 27.3 and 3.3 mg/l. The total plasma clearance was 83.1 and 67.0 ml/min after the first and the last infusions, respectively, and the half-life was 3.9 and 5.0 h. The maximal and minimal steady-state plasma concentrations of pefloxacin were 13.1 and 7.9 mg/l after i.v. infusion and 13.4 and 9.0 mg/l after oral administration. Pefloxacin elimination (t1/2) increased from 11.3 h after the first infusion to 19.4 h after the last infusion and 21.1 h after the last oral dose. Total body clearance decreased from 90.8 (Day 1) to 51.9 (Day 5) and 56.4 ml/min (Day 15). The volume of distribution did not change significantly over the course of pefloxacin. Mean steady-state plasma concentrations of norfloxacin and pefloxacin N-oxide were respectively 0.5-0.6 mg/l and 0.9-1.3 mg/l after intravenous and oral administration of pefloxacin. There were no pharmacokinetic interaction between the drugs. The dosage regimen led to plasma concentrations of pefloxacin and amikacin within their therapeutic range.

Concentrations of cefpirome in cerebrospinal fluid of children with bacterial meningitis after a single intravenous dose.

A single intravenous dose of cefpirome, 50 mg/kg, was administered to 15 children with bacterial meningitis 24 to 48 h after initiation of standard antibiotic and steroid therapy. Cefpirome concentrations in serum and cerebrospinal fluid were determined at selected time intervals. The mean (standard deviation) peak concentration in cerebrospinal fluid (n = 5) was 10.8 (7.8) microg/ml. Drug concentrations in cerebrospinal fluid above the MIC for Streptococcus pneumoniae at which 90% of the isolates were inhibited were found 2, 4, and 8 h after the dose of cefpirome was given. The penetration of cefpirome into cerebrospinal fluid compares favorably with that of other extended-spectrum cephalosporins and suggests that this agent would be useful in the therapy of childhood meningitis, including cases caused by drug-resistant S. pneumoniae.

Concentrations of cefpodoxime in plasma and lung tissue after a single oral dose of cefpodoxime proxetil.

Eighteen patients undergoing thoracotomy for suspected pulmonary neoplasia were given 200 mg cefpodoxime equivalent by mouth, before operation. Plasma samples were obtained before dose administration, and plasma and lung tissue samples were obtained at the time of operation which was 3, 6 or 12 h after the dose. All samples were assayed for cefpodoxime. The mean ratios for lung tissue/plasma concentrations were similar between 3 and 12 h after dose, suggesting that equilibrium between plasma and lung tissue concentrations was reached within 3 h of medication. The mean concentrations of cefpodoxime in lung tissue were 0.63 +/- 0.16, 0.52 +/- 0.09 and 0.19 +/- 0.02 mg/kg at 3, 6 and 12 h after administration, respectively. These observations indicate good, rapid and sustained penetration into lung tissue in concentrations greater than or equal to the MIC90 for most common micro-organisms found in community-acquired pneumonia.